Upgrade CameraX to Beta01.

app/build.gradle

@@ -269,8 +269,10 @@ dependencies {
     implementation 'androidx.lifecycle:lifecycle-extensions:2.1.0'
     implementation 'androidx.lifecycle:lifecycle-viewmodel-savedstate:1.0.0-alpha05'
     implementation 'androidx.lifecycle:lifecycle-common-java8:2.1.0'
-    implementation "androidx.camera:camera-core:1.0.0-alpha06"
+    implementation "androidx.camera:camera-core:1.0.0-beta01"
-    implementation "androidx.camera:camera-camera2:1.0.0-alpha06"
+    implementation "androidx.camera:camera-camera2:1.0.0-beta01"
+    implementation "androidx.camera:camera-lifecycle:1.0.0-beta01"
+    implementation "androidx.concurrent:concurrent-futures:1.0.0"
 
     implementation('com.google.firebase:firebase-messaging:17.3.4') {
         exclude group: 'com.google.firebase', module: 'firebase-core'

app/src/main/AndroidManifest.xml

@@ -3,7 +3,7 @@
           xmlns:tools="http://schemas.android.com/tools"
           package="org.thoughtcrime.securesms">
 
-    <uses-sdk tools:overrideLibrary="androidx.camera.core,androidx.camera.camera2"/>
+    <uses-sdk tools:overrideLibrary="androidx.camera.core,androidx.camera.camera2,androidx.camera.lifecycle" />
 
     <permission android:name="org.thoughtcrime.securesms.ACCESS_SECRETS"
                 android:label="Access to TextSecure Secrets"

app/src/main/java/org/thoughtcrime/securesms/ApplicationContext.java

@@ -19,7 +19,7 @@ package org.thoughtcrime.securesms;
 import android.annotation.SuppressLint;
 
 import androidx.appcompat.app.AppCompatDelegate;
-import androidx.camera.camera2.Camera2AppConfig;
+import androidx.camera.camera2.Camera2Config;
 import androidx.camera.core.CameraX;
 import androidx.lifecycle.DefaultLifecycleObserver;
 import androidx.lifecycle.LifecycleOwner;
@@ -386,7 +386,7 @@ public class ApplicationContext extends MultiDexApplication implements DefaultLi
     if (CameraXUtil.isSupported()) {
       new Thread(() -> {
         try {
-          CameraX.init(this, Camera2AppConfig.create(this));
+          CameraX.initialize(this, Camera2Config.defaultConfig());
         } catch (Throwable t) {
           Log.w(TAG, "Failed to initialize CameraX.");
         }

app/src/main/java/org/thoughtcrime/securesms/mediasend/CameraButtonView.java

@@ -44,7 +44,6 @@ public class CameraButtonView extends View {
 
   private boolean isRecordingVideo;
   private float   progressPercent = 0f;
-  private float   latestIncrement = 0f;
 
   private @NonNull  CameraButtonMode     cameraButtonMode = CameraButtonMode.IMAGE;
   private @Nullable VideoCaptureListener videoCaptureListener;
@@ -247,7 +246,6 @@ public class CameraButtonView extends View {
     int action = event.getAction();
     switch (action) {
       case MotionEvent.ACTION_DOWN:
-        latestIncrement = 0f;
         if (isEnabled()) {
           startAnimation(shrinkAnimation);
         }
@@ -258,11 +256,6 @@ public class CameraButtonView extends View {
           float deltaY    = Math.abs(event.getY() - deadzoneRect.top);
           float increment = Math.min(1f, deltaY / maxRange);
 
-          if (Math.abs(increment - latestIncrement) < MINIMUM_ALLOWED_ZOOM_STEP) {
-            break;
-          }
-
-          latestIncrement = increment;
           notifyZoomPercent(ZOOM_INTERPOLATOR.getInterpolation(increment));
           invalidate();
         }

app/src/main/java/org/thoughtcrime/securesms/mediasend/CameraXFragment.java

@@ -22,8 +22,9 @@ import android.widget.TextView;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.annotation.RequiresApi;
-import androidx.camera.core.CameraX;
+import androidx.camera.core.CameraSelector;
 import androidx.camera.core.ImageCapture;
+import androidx.camera.core.ImageCaptureException;
 import androidx.camera.core.ImageProxy;
 import androidx.core.content.ContextCompat;
 import androidx.fragment.app.Fragment;
@@ -204,7 +205,9 @@ public class CameraXFragment extends Fragment implements CameraFragment {
       onCaptureClicked();
     });
 
-    if (camera.hasCameraWithLensFacing(CameraX.LensFacing.FRONT) && camera.hasCameraWithLensFacing(CameraX.LensFacing.BACK)) {
+    camera.setScaleType(CameraXView.ScaleType.CENTER_INSIDE);
+
+    if (camera.hasCameraWithLensFacing(CameraSelector.LENS_FACING_FRONT) && camera.hasCameraWithLensFacing(CameraSelector.LENS_FACING_BACK)) {
       flipButton.setVisibility(View.VISIBLE);
       flipButton.setOnClickListener(v ->  {
         camera.toggleCamera();
@@ -361,15 +364,15 @@ public class CameraXFragment extends Fragment implements CameraFragment {
         selfieFlash
     );
 
-    camera.takePicture(Executors.mainThreadExecutor(), new ImageCapture.OnImageCapturedListener() {
+    camera.takePicture(Executors.mainThreadExecutor(), new ImageCapture.OnImageCapturedCallback() {
       @Override
-      public void onCaptureSuccess(ImageProxy image, int rotationDegrees) {
+      public void onCaptureSuccess(ImageProxy image) {
         flashHelper.endFlash();
 
         SimpleTask.run(CameraXFragment.this.getViewLifecycleOwner().getLifecycle(), () -> {
           stopwatch.split("captured");
           try {
-            return CameraXUtil.toJpeg(image, rotationDegrees, camera.getCameraLensFacing() == CameraX.LensFacing.FRONT);
+            return CameraXUtil.toJpeg(image, camera.getCameraLensFacing() == CameraSelector.LENS_FACING_FRONT);
           } catch (IOException e) {
             return null;
           } finally {
@@ -388,7 +391,7 @@ public class CameraXFragment extends Fragment implements CameraFragment {
       }
 
       @Override
-      public void onError(ImageCapture.ImageCaptureError useCaseError, String message, @Nullable Throwable cause) {
+      public void onError(ImageCaptureException exception) {
         flashHelper.endFlash();
         controller.onCameraError();
       }

app/src/main/java/org/thoughtcrime/securesms/mediasend/CameraXSelfieFlashHelper.java

@@ -6,8 +6,9 @@ import android.view.WindowManager;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.RequiresApi;
+import androidx.camera.core.CameraSelector;
 import androidx.camera.core.CameraX;
-import androidx.camera.core.FlashMode;
+import androidx.camera.core.ImageCapture;
 
 import org.thoughtcrime.securesms.mediasend.camerax.CameraXView;
 
@@ -65,8 +66,10 @@ final class CameraXSelfieFlashHelper {
   }
 
   private boolean shouldUseViewBasedFlash() {
-    return camera.getFlash() == FlashMode.ON &&
+    Integer cameraLensFacing = camera.getCameraLensFacing();
+
+    return camera.getFlash() == ImageCapture.FLASH_MODE_ON &&
            !camera.hasFlash()                &&
-           camera.getCameraLensFacing() == CameraX.LensFacing.FRONT;
+           cameraLensFacing != null && cameraLensFacing == CameraSelector.LENS_FACING_BACK;
   }
 }

app/src/main/java/org/thoughtcrime/securesms/mediasend/CameraXVideoCaptureHelper.java

@@ -23,7 +23,6 @@ import org.thoughtcrime.securesms.mediasend.camerax.CameraXView;
 import org.thoughtcrime.securesms.mediasend.camerax.VideoCapture;
 import org.thoughtcrime.securesms.permissions.Permissions;
 import org.thoughtcrime.securesms.util.MemoryFileDescriptor;
-import org.thoughtcrime.securesms.util.Util;
 import org.thoughtcrime.securesms.video.VideoUtil;
 
 import java.io.FileDescriptor;
@@ -45,12 +44,12 @@ class CameraXVideoCaptureHelper implements CameraButtonView.VideoCaptureListener
   private       boolean       isRecording;
   private       ValueAnimator cameraMetricsAnimator;
 
-  private final VideoCapture.OnVideoSavedListener videoSavedListener = new VideoCapture.OnVideoSavedListener() {
+  private final VideoCapture.OnVideoSavedCallback videoSavedListener = new VideoCapture.OnVideoSavedCallback() {
     @Override
     public void onVideoSaved(@NonNull FileDescriptor fileDescriptor) {
       try {
         isRecording = false;
-        camera.setZoomLevel(0f);
+        camera.setZoomRatio(camera.getMinZoomRatio());
         memoryFileDescriptor.seek(0);
         callback.onVideoSaved(fileDescriptor);
       } catch (IOException e) {
@@ -59,13 +58,9 @@ class CameraXVideoCaptureHelper implements CameraButtonView.VideoCaptureListener
     }
 
     @Override
-    public void onError(@NonNull VideoCapture.VideoCaptureError videoCaptureError,
+    public void onError(int videoCaptureError, @NonNull String message, @Nullable Throwable cause) {
-                        @NonNull String message,
-                        @Nullable Throwable cause)
-    {
       isRecording = false;
       callback.onVideoError(cause);
-      Util.runOnMain(() -> resetCameraSizing());
     }
   };
 
@@ -119,7 +114,7 @@ class CameraXVideoCaptureHelper implements CameraButtonView.VideoCaptureListener
   }
 
   private void beginCameraRecording() {
-    this.camera.setZoomLevel(0f);
+    this.camera.setZoomRatio(this.camera.getMinZoomRatio());
     callback.onVideoRecordStarted();
     shrinkCaptureArea();
     camera.startRecording(memoryFileDescriptor.getFileDescriptor(), Executors.mainThreadExecutor(), videoSavedListener);
@@ -135,22 +130,24 @@ class CameraXVideoCaptureHelper implements CameraButtonView.VideoCaptureListener
 
     if (scaleX == 1f) {
       float targetHeightForAnimation = videoRecordingSize.getHeight() * scale;
+
+      if (screenSize.getHeight() == targetHeightForAnimation) {
+        return;
+      }
+
       cameraMetricsAnimator = ValueAnimator.ofFloat(screenSize.getHeight(), targetHeightForAnimation);
     } else {
+
+      if (screenSize.getWidth() == targetWidthForAnimation) {
+        return;
+      }
+
       cameraMetricsAnimator = ValueAnimator.ofFloat(screenSize.getWidth(), targetWidthForAnimation);
     }
 
     ViewGroup.LayoutParams params = camera.getLayoutParams();
     cameraMetricsAnimator.setInterpolator(new LinearInterpolator());
     cameraMetricsAnimator.setDuration(200);
-    cameraMetricsAnimator.addListener(new AnimationEndCallback() {
-      @Override
-      public void onAnimationEnd(Animator animation) {
-        if (!isRecording) return;
-
-        scaleCameraViewToMatchRecordingSizeAndAspectRatio();
-      }
-    });
     cameraMetricsAnimator.addUpdateListener(animation -> {
       if (scaleX == 1f) {
         params.height = Math.round((float) animation.getAnimatedValue());
@@ -162,20 +159,6 @@ class CameraXVideoCaptureHelper implements CameraButtonView.VideoCaptureListener
     cameraMetricsAnimator.start();
   }
 
-  private void scaleCameraViewToMatchRecordingSizeAndAspectRatio() {
-    ViewGroup.LayoutParams layoutParams = camera.getLayoutParams();
-
-    Size  videoRecordingSize = VideoUtil.getVideoRecordingSize();
-    float scale              = getSurfaceScaleForRecording();
-
-    layoutParams.height = videoRecordingSize.getHeight();
-    layoutParams.width  = videoRecordingSize.getWidth();
-
-    camera.setLayoutParams(layoutParams);
-    camera.setScaleX(scale);
-    camera.setScaleY(scale);
-  }
-
   private Size getScreenSize() {
     DisplayMetrics metrics = camera.getResources().getDisplayMetrics();
     return new Size(metrics.widthPixels, metrics.heightPixels);
@@ -187,16 +170,6 @@ class CameraXVideoCaptureHelper implements CameraButtonView.VideoCaptureListener
     return Math.min(screenSize.getHeight(), screenSize.getWidth()) / (float) Math.min(videoRecordingSize.getHeight(), videoRecordingSize.getWidth());
   }
 
-  private void resetCameraSizing() {
-    ViewGroup.LayoutParams layoutParams = camera.getLayoutParams();
-    layoutParams.width  = ViewGroup.LayoutParams.MATCH_PARENT;
-    layoutParams.height = ViewGroup.LayoutParams.MATCH_PARENT;
-
-    camera.setLayoutParams(layoutParams);
-    camera.setScaleX(1);
-    camera.setScaleY(1);
-  }
-
   @Override
   public void onVideoCaptureComplete() {
     isRecording = false;
@@ -214,8 +187,8 @@ class CameraXVideoCaptureHelper implements CameraButtonView.VideoCaptureListener
 
   @Override
   public void onZoomIncremented(float increment) {
-    float range = camera.getMaxZoomLevel() - camera.getMinZoomLevel();
+    float range = camera.getMaxZoomRatio() - camera.getMinZoomRatio();
-    camera.setZoomLevel(range * increment);
+    camera.setZoomRatio((range * increment) + camera.getMinZoomRatio());
   }
 
   static MemoryFileDescriptor createFileDescriptor(@NonNull Context context) throws MemoryFileDescriptor.MemoryFileException {
@@ -226,7 +199,7 @@ class CameraXVideoCaptureHelper implements CameraButtonView.VideoCaptureListener
     );
   }
 
-  private abstract class AnimationEndCallback implements Animator.AnimatorListener {
+  private static abstract class AnimationEndCallback implements Animator.AnimatorListener {
 
     @Override
     public final void onAnimationStart(Animator animation) {

app/src/main/java/org/thoughtcrime/securesms/mediasend/camerax/CameraXFlashToggleView.java

@@ -5,10 +5,9 @@ import android.os.Bundle;
 import android.os.Parcelable;
 import android.util.AttributeSet;
 
-import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.appcompat.widget.AppCompatImageView;
-import androidx.camera.core.FlashMode;
+import androidx.camera.core.ImageCapture;
 
 import org.thoughtcrime.securesms.R;
 
@@ -43,7 +42,7 @@ public final class CameraXFlashToggleView extends AppCompatImageView {
   public CameraXFlashToggleView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
     super(context, attrs, defStyleAttr);
 
-    super.setOnClickListener((v) -> setFlash(FLASH_MODES.get((flashIndex + 1) % FLASH_ENUM.length)));
+    super.setOnClickListener((v) -> setFlash(FLASH_MODES.get((flashIndex + 1) % FLASH_ENUM.length).getFlashMode()));
   }
 
   @Override
@@ -61,10 +60,12 @@ public final class CameraXFlashToggleView extends AppCompatImageView {
 
   public void setAutoFlashEnabled(boolean isAutoEnabled) {
     supportsFlashModeAuto = isAutoEnabled;
-    setFlash(FLASH_MODES.get(flashIndex));
+    setFlash(FLASH_MODES.get(flashIndex).getFlashMode());
   }
 
-  public void setFlash(@NonNull FlashMode flashMode) {
+  public void setFlash(@ImageCapture.FlashMode int mode) {
+    FlashMode flashMode = FlashMode.fromImageCaptureFlashMode(mode);
+
     flashIndex = resolveFlashIndex(FLASH_MODES.indexOf(flashMode), supportsFlashModeAuto);
     refreshDrawableState();
     notifyListener();
@@ -92,7 +93,7 @@ public final class CameraXFlashToggleView extends AppCompatImageView {
 
       supportsFlashModeAuto = savedState.getBoolean(STATE_SUPPORT_AUTO);
       setFlash(FLASH_MODES.get(
-          resolveFlashIndex(savedState.getInt(STATE_FLASH_INDEX), supportsFlashModeAuto))
+          resolveFlashIndex(savedState.getInt(STATE_FLASH_INDEX), supportsFlashModeAuto)).getFlashMode()
       );
 
       super.onRestoreInstanceState(savedState.getParcelable(STATE_PARENT));
@@ -104,7 +105,7 @@ public final class CameraXFlashToggleView extends AppCompatImageView {
   private void notifyListener() {
     if (flashModeChangedListener == null) return;
 
-    flashModeChangedListener.flashModeChanged(FLASH_MODES.get(flashIndex));
+    flashModeChangedListener.flashModeChanged(FLASH_MODES.get(flashIndex).getFlashMode());
   }
 
   private static int resolveFlashIndex(int desiredFlashIndex, boolean supportsFlashModeAuto) {
@@ -126,6 +127,33 @@ public final class CameraXFlashToggleView extends AppCompatImageView {
   }
 
   public interface OnFlashModeChangedListener {
-    void flashModeChanged(FlashMode flashMode);
+    void flashModeChanged(@ImageCapture.CaptureMode int flashMode);
+  }
+
+  private enum FlashMode {
+
+    AUTO(ImageCapture.FLASH_MODE_AUTO),
+    OFF(ImageCapture.FLASH_MODE_OFF),
+    ON(ImageCapture.FLASH_MODE_ON);
+
+    private final @ImageCapture.FlashMode int flashMode;
+
+    FlashMode(@ImageCapture.FlashMode int flashMode) {
+      this.flashMode = flashMode;
+    }
+
+    @ImageCapture.FlashMode int getFlashMode() {
+      return flashMode;
+    }
+
+    private static FlashMode fromImageCaptureFlashMode(@ImageCapture.FlashMode int flashMode) {
+      for (FlashMode mode : values()) {
+        if (mode.getFlashMode() == flashMode) {
+          return mode;
+        }
+      }
+
+      throw new AssertionError();
+    }
   }
 }

app/src/main/java/org/thoughtcrime/securesms/mediasend/camerax/CameraXModule.java

@@ -20,14 +20,6 @@ import android.Manifest.permission;
 import android.annotation.SuppressLint;
 import android.content.Context;
 import android.content.res.Resources;
-import android.graphics.Matrix;
-import android.graphics.Rect;
-import android.graphics.SurfaceTexture;
-import android.hardware.camera2.CameraAccessException;
-import android.hardware.camera2.CameraCharacteristics;
-import android.hardware.camera2.CameraManager;
-import android.os.Build;
-import android.os.Looper;
 import android.util.Log;
 import android.util.Rational;
 import android.util.Size;
@@ -36,41 +28,53 @@ import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.annotation.RequiresApi;
 import androidx.annotation.RequiresPermission;
-import androidx.annotation.UiThread;
 import androidx.camera.core.AspectRatio;
-import androidx.camera.core.CameraInfo;
+import androidx.camera.core.Camera;
-import androidx.camera.core.CameraInfoUnavailableException;
+import androidx.camera.core.CameraSelector;
-import androidx.camera.core.CameraOrientationUtil;
 import androidx.camera.core.CameraX;
-import androidx.camera.core.FlashMode;
 import androidx.camera.core.ImageCapture;
-import androidx.camera.core.ImageCaptureConfig;
+import androidx.camera.core.ImageCapture.OnImageCapturedCallback;
 import androidx.camera.core.Preview;
-import androidx.camera.core.PreviewConfig;
+import androidx.camera.core.TorchState;
-import androidx.camera.core.VideoCaptureConfig;
+import androidx.camera.core.UseCase;
+import androidx.camera.core.impl.CameraInternal;
+import androidx.camera.core.impl.LensFacingConverter;
+import androidx.camera.core.impl.VideoCaptureConfig;
+import androidx.camera.core.impl.utils.CameraOrientationUtil;
+import androidx.camera.core.impl.utils.executor.CameraXExecutors;
+import androidx.camera.core.impl.utils.futures.FutureCallback;
+import androidx.camera.core.impl.utils.futures.Futures;
+import androidx.camera.lifecycle.ProcessCameraProvider;
+import androidx.core.util.Preconditions;
 import androidx.lifecycle.Lifecycle;
 import androidx.lifecycle.LifecycleObserver;
 import androidx.lifecycle.LifecycleOwner;
-import androidx.lifecycle.LiveData;
 import androidx.lifecycle.OnLifecycleEvent;
 
+import com.google.common.util.concurrent.ListenableFuture;
+
 import org.thoughtcrime.securesms.mms.MediaConstraints;
 import org.thoughtcrime.securesms.video.VideoUtil;
 
-import java.io.File;
 import java.io.FileDescriptor;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Objects;
 import java.util.Set;
 import java.util.concurrent.Executor;
 import java.util.concurrent.atomic.AtomicBoolean;
 
+import static androidx.camera.core.ImageCapture.FLASH_MODE_OFF;
+
 /** CameraX use case operation built on @{link androidx.camera.core}. */
+// Begin Signal Custom Code Block
 @RequiresApi(21)
+// End Signal Custom Code Block
 final class CameraXModule {
   public static final String TAG = "CameraXModule";
 
-  private static final int MAX_VIEW_DIMENSION = 2000;
   private static final float UNITY_ZOOM_SCALE = 1f;
   private static final float ZOOM_NOT_SUPPORTED = UNITY_ZOOM_SCALE;
   private static final Rational ASPECT_RATIO_16_9 = new Rational(16, 9);
@@ -78,22 +82,27 @@ final class CameraXModule {
   private static final Rational ASPECT_RATIO_9_16 = new Rational(9, 16);
   private static final Rational ASPECT_RATIO_3_4 = new Rational(3, 4);
 
-  private final CameraManager mCameraManager;
+  private final Preview.Builder mPreviewBuilder;
-  private final PreviewConfig.Builder mPreviewConfigBuilder;
   private final VideoCaptureConfig.Builder mVideoCaptureConfigBuilder;
-  private final ImageCaptureConfig.Builder mImageCaptureConfigBuilder;
+  private final ImageCapture.Builder mImageCaptureBuilder;
-  private final CameraXView mCameraView;
+  private final CameraXView mCameraXView;
   final AtomicBoolean mVideoIsRecording = new AtomicBoolean(false);
   private CameraXView.CaptureMode mCaptureMode = CameraXView.CaptureMode.IMAGE;
   private long mMaxVideoDuration = CameraXView.INDEFINITE_VIDEO_DURATION;
   private long mMaxVideoSize = CameraXView.INDEFINITE_VIDEO_SIZE;
-  private FlashMode mFlash = FlashMode.OFF;
+  @ImageCapture.FlashMode
+  private int mFlash = FLASH_MODE_OFF;
+  @Nullable
+  @SuppressWarnings("WeakerAccess") /* synthetic accessor */
+      Camera mCamera;
   @Nullable
   private ImageCapture mImageCapture;
   @Nullable
   private VideoCapture mVideoCapture;
+  @SuppressWarnings("WeakerAccess") /* synthetic accessor */
   @Nullable
   Preview mPreview;
+  @SuppressWarnings("WeakerAccess") /* synthetic accessor */
   @Nullable
   LifecycleOwner mCurrentLifecycle;
   private final LifecycleObserver mCurrentLifecycleObserver =
@@ -102,27 +111,44 @@ final class CameraXModule {
         public void onDestroy(LifecycleOwner owner) {
           if (owner == mCurrentLifecycle) {
             clearCurrentLifecycle();
-            mPreview.removePreviewOutputListener();
+            mPreview.setSurfaceProvider(null);
           }
         }
       };
   @Nullable
   private LifecycleOwner mNewLifecycle;
-  private float mZoomLevel = UNITY_ZOOM_SCALE;
+  @SuppressWarnings("WeakerAccess") /* synthetic accessor */
   @Nullable
-  private Rect mCropRegion;
+  Integer mCameraLensFacing = CameraSelector.LENS_FACING_BACK;
+  @SuppressWarnings("WeakerAccess") /* synthetic accessor */
   @Nullable
-  private CameraX.LensFacing mCameraLensFacing = CameraX.LensFacing.BACK;
+  ProcessCameraProvider mCameraProvider;
 
   CameraXModule(CameraXView view) {
-    this.mCameraView = view;
+    mCameraXView = view;
 
-    mCameraManager = (CameraManager) view.getContext().getSystemService(Context.CAMERA_SERVICE);
+    Futures.addCallback(ProcessCameraProvider.getInstance(view.getContext()),
+        new FutureCallback<ProcessCameraProvider>() {
+          // TODO(b/124269166): Rethink how we can handle permissions here.
+          @SuppressLint("MissingPermission")
+          @Override
+          public void onSuccess(@Nullable ProcessCameraProvider provider) {
+            Preconditions.checkNotNull(provider);
+            mCameraProvider = provider;
+            if (mCurrentLifecycle != null) {
+              bindToLifecycle(mCurrentLifecycle);
+            }
+          }
 
-    mPreviewConfigBuilder = new PreviewConfig.Builder().setTargetName("Preview");
+          @Override
+          public void onFailure(Throwable t) {
+            throw new RuntimeException("CameraX failed to initialize.", t);
+          }
+        }, CameraXExecutors.mainThreadExecutor());
 
-    mImageCaptureConfigBuilder =
+    mPreviewBuilder = new Preview.Builder().setTargetName("Preview");
-        new ImageCaptureConfig.Builder().setTargetName("ImageCapture");
+
+    mImageCaptureBuilder = new ImageCapture.Builder().setTargetName("ImageCapture");
 
     // Begin Signal Custom Code Block
     mVideoCaptureConfigBuilder =
@@ -132,42 +158,8 @@ final class CameraXModule {
                                         .setBitRate(VideoUtil.VIDEO_BIT_RATE);
     // End Signal Custom Code Block
   }
-
-  /**
-   * Rescales view rectangle with dimensions in [-1000, 1000] to a corresponding rectangle in the
-   * sensor coordinate frame.
-   */
-  private static Rect rescaleViewRectToSensorRect(Rect view, Rect sensor) {
-    // Scale width and height.
-    int newWidth = Math.round(view.width() * sensor.width() / (float) MAX_VIEW_DIMENSION);
-    int newHeight = Math.round(view.height() * sensor.height() / (float) MAX_VIEW_DIMENSION);
-
-    // Scale top/left corner.
-    int halfViewDimension = MAX_VIEW_DIMENSION / 2;
-    int leftOffset =
-        Math.round(
-            (view.left + halfViewDimension)
-                * sensor.width()
-                / (float) MAX_VIEW_DIMENSION)
-            + sensor.left;
-    int topOffset =
-        Math.round(
-            (view.top + halfViewDimension)
-                * sensor.height()
-                / (float) MAX_VIEW_DIMENSION)
-            + sensor.top;
-
-    // Now, produce the scaled rect.
-    Rect scaled = new Rect();
-    scaled.left = leftOffset;
-    scaled.top = topOffset;
-    scaled.right = scaled.left + newWidth;
-    scaled.bottom = scaled.top + newHeight;
-    return scaled;
-  }
-
   @RequiresPermission(permission.CAMERA)
-  public void bindToLifecycle(LifecycleOwner lifecycleOwner) {
+  void bindToLifecycle(LifecycleOwner lifecycleOwner) {
     mNewLifecycle = lifecycleOwner;
 
     if (getMeasuredWidth() > 0 && getMeasuredHeight() > 0) {
@@ -189,9 +181,12 @@ final class CameraXModule {
       throw new IllegalArgumentException("Cannot bind to lifecycle in a destroyed state.");
     }
 
-    final int cameraOrientation;
+    if (mCameraProvider == null) {
-    try {
+      // try again once the camera provider is no longer null
-      Set<CameraX.LensFacing> available = getAvailableCameraLensFacing();
+      return;
+    }
+
+    Set<Integer> available = getAvailableCameraLensFacing();
 
     if (available.isEmpty()) {
       Log.w(TAG, "Unable to bindToLifeCycle since no cameras available");
@@ -209,19 +204,11 @@ final class CameraXModule {
     }
 
     // Do not attempt to create use cases for a null cameraLensFacing. This could occur if
-      // the
+    // the user explicitly sets the LensFacing to null, or if we determined there
-      // user explicitly sets the LensFacing to null, or if we determined there
     // were no available cameras, which should be logged in the logic above.
     if (mCameraLensFacing == null) {
       return;
     }
-      CameraInfo cameraInfo = CameraX.getCameraInfo(getLensFacing());
-      cameraOrientation = cameraInfo.getSensorRotationDegrees();
-    } catch (CameraInfoUnavailableException e) {
-      throw new IllegalStateException("Unable to get Camera Info.", e);
-    } catch (Exception e) {
-      throw new IllegalStateException("Unable to bind to lifecycle.", e);
-    }
 
     // Set the preferred aspect ratio as 4:3 if it is IMAGE only mode. Set the preferred aspect
     // ratio as 16:9 if it is VIDEO or MIXED mode. Then, it will be WYSIWYG when the view finder
@@ -230,23 +217,32 @@ final class CameraXModule {
     boolean isDisplayPortrait = getDisplayRotationDegrees() == 0
         || getDisplayRotationDegrees() == 180;
 
-    // Begin Signal Custom Code Block
     Rational targetAspectRatio;
+
+    // Begin Signal Custom Code Block
     int resolution = CameraXUtil.getIdealResolution(Resources.getSystem().getDisplayMetrics().widthPixels, Resources.getSystem().getDisplayMetrics().heightPixels);
-    Log.i(TAG, "Ideal resolution: " + resolution);
-    if (getCaptureMode() == CameraXView.CaptureMode.IMAGE) {
-      mImageCaptureConfigBuilder.setTargetResolution(CameraXUtil.buildResolutionForRatio(resolution, ASPECT_RATIO_4_3, isDisplayPortrait));
-      targetAspectRatio = isDisplayPortrait ? ASPECT_RATIO_3_4 : ASPECT_RATIO_4_3;
-    } else {
-      mImageCaptureConfigBuilder.setTargetResolution(CameraXUtil.buildResolutionForRatio(resolution, ASPECT_RATIO_16_9, isDisplayPortrait));
-      targetAspectRatio = isDisplayPortrait ? ASPECT_RATIO_9_16 : ASPECT_RATIO_16_9;
-    }
-    mImageCaptureConfigBuilder.setCaptureMode(CameraXUtil.getOptimalCaptureMode());
-    mImageCaptureConfigBuilder.setLensFacing(mCameraLensFacing);
     // End Signal Custom Code Block
 
-    mImageCaptureConfigBuilder.setTargetRotation(getDisplaySurfaceRotation());
+    if (getCaptureMode() == CameraXView.CaptureMode.IMAGE) {
-    mImageCapture = new ImageCapture(mImageCaptureConfigBuilder.build());
+//      mImageCaptureBuilder.setTargetAspectRatio(AspectRatio.RATIO_4_3);
+      // Begin Signal Custom Code Block
+      mImageCaptureBuilder.setTargetResolution(CameraXUtil.buildResolutionForRatio(resolution, ASPECT_RATIO_4_3, isDisplayPortrait));
+      // End Signal Custom Code Block
+      targetAspectRatio = isDisplayPortrait ? ASPECT_RATIO_3_4 : ASPECT_RATIO_4_3;
+    } else {
+      // Begin Signal Custom Code Block
+      mImageCaptureBuilder.setTargetResolution(CameraXUtil.buildResolutionForRatio(resolution, ASPECT_RATIO_16_9, isDisplayPortrait));
+      // End Signal Custom Code Block
+//      mImageCaptureBuilder.setTargetAspectRatio(AspectRatio.RATIO_16_9);
+      targetAspectRatio = isDisplayPortrait ? ASPECT_RATIO_9_16 : ASPECT_RATIO_16_9;
+    }
+
+    // Begin Signal Custom Code Block
+    mImageCaptureBuilder.setCaptureMode(CameraXUtil.getOptimalCaptureMode());
+    // End Signal Custom Code Block
+
+    mImageCaptureBuilder.setTargetRotation(getDisplaySurfaceRotation());
+    mImageCapture = mImageCaptureBuilder.build();
 
     // Begin Signal Custom Code Block
     Size size = VideoUtil.getVideoRecordingSize();
@@ -255,46 +251,37 @@ final class CameraXModule {
     // End Signal Custom Code Block
 
     mVideoCaptureConfigBuilder.setTargetRotation(getDisplaySurfaceRotation());
-    mVideoCaptureConfigBuilder.setLensFacing(mCameraLensFacing);
 
     // Begin Signal Custom Code Block
     if (MediaConstraints.isVideoTranscodeAvailable()) {
-      mVideoCapture = new VideoCapture(mVideoCaptureConfigBuilder.build());
+      mVideoCapture = new VideoCapture(mVideoCaptureConfigBuilder.getUseCaseConfig());
     }
-    mPreviewConfigBuilder.setLensFacing(mCameraLensFacing);
+    // End Signal Custom Code Block
 
     // Adjusts the preview resolution according to the view size and the target aspect ratio.
     int height = (int) (getMeasuredWidth() / targetAspectRatio.floatValue());
-    mPreviewConfigBuilder.setTargetResolution(new Size(getMeasuredWidth(), height));
+    mPreviewBuilder.setTargetResolution(new Size(getMeasuredWidth(), height));
 
-    mPreview = new Preview(mPreviewConfigBuilder.build());
+    mPreview = mPreviewBuilder.build();
-    mPreview.setOnPreviewOutputUpdateListener(
+    mPreview.setSurfaceProvider(mCameraXView.getPreviewView().getPreviewSurfaceProvider());
-        new Preview.OnPreviewOutputUpdateListener() {
-          @Override
-          public void onUpdated(@NonNull Preview.PreviewOutput output) {
-            boolean needReverse = cameraOrientation != 0 && cameraOrientation != 180;
-            int textureWidth =
-                needReverse
-                    ? output.getTextureSize().getHeight()
-                    : output.getTextureSize().getWidth();
-            int textureHeight =
-                needReverse
-                    ? output.getTextureSize().getWidth()
-                    : output.getTextureSize().getHeight();
-            CameraXModule.this.onPreviewSourceDimensUpdated(textureWidth,
-                textureHeight);
-            CameraXModule.this.setSurfaceTexture(output.getSurfaceTexture());
-          }
-        });
 
+    CameraSelector cameraSelector =
+        new CameraSelector.Builder().requireLensFacing(mCameraLensFacing).build();
     if (getCaptureMode() == CameraXView.CaptureMode.IMAGE) {
-      CameraX.bindToLifecycle(mCurrentLifecycle, mImageCapture, mPreview);
+      mCamera = mCameraProvider.bindToLifecycle(mCurrentLifecycle, cameraSelector,
+          mImageCapture,
+          mPreview);
     } else if (getCaptureMode() == CameraXView.CaptureMode.VIDEO) {
-      CameraX.bindToLifecycle(mCurrentLifecycle, mVideoCapture, mPreview);
+      mCamera = mCameraProvider.bindToLifecycle(mCurrentLifecycle, cameraSelector,
+          mVideoCapture,
+          mPreview);
     } else {
-      CameraX.bindToLifecycle(mCurrentLifecycle, mImageCapture, mVideoCapture, mPreview);
+      mCamera = mCameraProvider.bindToLifecycle(mCurrentLifecycle, cameraSelector,
+          mImageCapture,
+          mVideoCapture, mPreview);
     }
-    setZoomLevel(mZoomLevel);
+
+    setZoomRatio(UNITY_ZOOM_SCALE);
     mCurrentLifecycle.getLifecycle().addObserver(mCurrentLifecycleObserver);
     // Enable flash setting in ImageCapture after use cases are created and binded.
     setFlash(getFlash());
@@ -310,7 +297,7 @@ final class CameraXModule {
         "Explicit open/close of camera not yet supported. Use bindtoLifecycle() instead.");
   }
 
-  public void takePicture(Executor executor, ImageCapture.OnImageCapturedListener listener) {
+  public void takePicture(Executor executor, OnImageCapturedCallback callback) {
     if (mImageCapture == null) {
       return;
     }
@@ -319,35 +306,19 @@ final class CameraXModule {
       throw new IllegalStateException("Can not take picture under VIDEO capture mode.");
     }
 
-    if (listener == null) {
+    if (callback == null) {
-      throw new IllegalArgumentException("OnImageCapturedListener should not be empty");
+      throw new IllegalArgumentException("OnImageCapturedCallback should not be empty");
     }
 
-    mImageCapture.takePicture(executor, listener);
+    mImageCapture.takePicture(executor, callback);
-  }
-
-  public void takePicture(File saveLocation, Executor executor, ImageCapture.OnImageSavedListener listener) {
-    if (mImageCapture == null) {
-      return;
-    }
-
-    if (getCaptureMode() == CameraXView.CaptureMode.VIDEO) {
-      throw new IllegalStateException("Can not take picture under VIDEO capture mode.");
-    }
-
-    if (listener == null) {
-      throw new IllegalArgumentException("OnImageSavedListener should not be empty");
-    }
-
-    ImageCapture.Metadata metadata = new ImageCapture.Metadata();
-    metadata.isReversedHorizontal = mCameraLensFacing == CameraX.LensFacing.FRONT;
-    mImageCapture.takePicture(saveLocation, metadata, executor, listener);
   }
 
   // Begin Signal Custom Code Block
   @RequiresApi(26)
-  public void startRecording(FileDescriptor file, Executor executor, final VideoCapture.OnVideoSavedListener listener) {
+  public void startRecording(FileDescriptor file,
                              // End Signal Custom Code Block
+                             Executor executor,
+                             final VideoCapture.OnVideoSavedCallback callback) {
     if (mVideoCapture == null) {
       return;
     }
@@ -356,31 +327,31 @@ final class CameraXModule {
       throw new IllegalStateException("Can not record video under IMAGE capture mode.");
     }
 
-    if (listener == null) {
+    if (callback == null) {
-      throw new IllegalArgumentException("OnVideoSavedListener should not be empty");
+      throw new IllegalArgumentException("OnVideoSavedCallback should not be empty");
     }
 
     mVideoIsRecording.set(true);
     mVideoCapture.startRecording(
         file,
         executor,
-        new VideoCapture.OnVideoSavedListener() {
+        new VideoCapture.OnVideoSavedCallback() {
           @Override
-          // Begin Signal Custom Code block
+          // Begin Signal Custom Code Block
           public void onVideoSaved(@NonNull FileDescriptor savedFile) {
           // End Signal Custom Code Block
             mVideoIsRecording.set(false);
-            listener.onVideoSaved(savedFile);
+            callback.onVideoSaved(savedFile);
           }
 
           @Override
           public void onError(
-              @NonNull VideoCapture.VideoCaptureError videoCaptureError,
+              @VideoCapture.VideoCaptureError int videoCaptureError,
               @NonNull String message,
               @Nullable Throwable cause) {
             mVideoIsRecording.set(false);
             Log.e(TAG, message, cause);
-            listener.onError(videoCaptureError, message, cause);
+            callback.onError(videoCaptureError, message, cause);
           }
         });
   }
@@ -402,9 +373,9 @@ final class CameraXModule {
 
   // TODO(b/124269166): Rethink how we can handle permissions here.
   @SuppressLint("MissingPermission")
-  public void setCameraLensFacing(@Nullable CameraX.LensFacing lensFacing) {
+  public void setCameraLensFacing(@Nullable Integer lensFacing) {
     // Setting same lens facing is a no-op, so check for that first
-    if (mCameraLensFacing != lensFacing) {
+    if (!Objects.equals(mCameraLensFacing, lensFacing)) {
       // If we're not bound to a lifecycle, just update the camera that will be opened when we
       // attach to a lifecycle.
       mCameraLensFacing = lensFacing;
@@ -417,7 +388,7 @@ final class CameraXModule {
   }
 
   @RequiresPermission(permission.CAMERA)
-  public boolean hasCameraWithLensFacing(CameraX.LensFacing lensFacing) {
+  public boolean hasCameraWithLensFacing(@CameraSelector.LensFacing int lensFacing) {
     String cameraId;
     try {
       cameraId = CameraX.getCameraWithLensFacing(lensFacing);
@@ -429,14 +400,14 @@ final class CameraXModule {
   }
 
   @Nullable
-  public CameraX.LensFacing getLensFacing() {
+  public Integer getLensFacing() {
     return mCameraLensFacing;
   }
 
   public void toggleCamera() {
     // TODO(b/124269166): Rethink how we can handle permissions here.
     @SuppressLint("MissingPermission")
-    Set<CameraX.LensFacing> availableCameraLensFacing = getAvailableCameraLensFacing();
+    Set<Integer> availableCameraLensFacing = getAvailableCameraLensFacing();
 
     if (availableCameraLensFacing.isEmpty()) {
       return;
@@ -447,106 +418,65 @@ final class CameraXModule {
       return;
     }
 
-    if (mCameraLensFacing == CameraX.LensFacing.BACK
+    if (mCameraLensFacing == CameraSelector.LENS_FACING_BACK
-        && availableCameraLensFacing.contains(CameraX.LensFacing.FRONT)) {
+        && availableCameraLensFacing.contains(CameraSelector.LENS_FACING_FRONT)) {
-      setCameraLensFacing(CameraX.LensFacing.FRONT);
+      setCameraLensFacing(CameraSelector.LENS_FACING_FRONT);
       return;
     }
 
-    if (mCameraLensFacing == CameraX.LensFacing.FRONT
+    if (mCameraLensFacing == CameraSelector.LENS_FACING_FRONT
-        && availableCameraLensFacing.contains(CameraX.LensFacing.BACK)) {
+        && availableCameraLensFacing.contains(CameraSelector.LENS_FACING_BACK)) {
-      setCameraLensFacing(CameraX.LensFacing.BACK);
+      setCameraLensFacing(CameraSelector.LENS_FACING_BACK);
       return;
     }
   }
 
-  public float getZoomLevel() {
+  public float getZoomRatio() {
-    return mZoomLevel;
+    if (mCamera != null) {
-  }
+      return mCamera.getCameraInfo().getZoomState().getValue().getZoomRatio();
-
+    } else {
-  public void setZoomLevel(float zoomLevel) {
-    // Set the zoom level in case it is set before binding to a lifecycle
-    this.mZoomLevel = zoomLevel;
-
-    if (mPreview == null) {
-      // Nothing to zoom on yet since we don't have a preview. Defer calculating crop
-      // region.
-      return;
-    }
-
-    Rect sensorSize;
-    try {
-      sensorSize = getSensorSize(getActiveCamera());
-      if (sensorSize == null) {
-        Log.e(TAG, "Failed to get the sensor size.");
-        return;
-      }
-    } catch (Exception e) {
-      Log.e(TAG, "Failed to get the sensor size.", e);
-      return;
-    }
-
-    float minZoom = getMinZoomLevel();
-    float maxZoom = getMaxZoomLevel();
-
-    if (this.mZoomLevel < minZoom) {
-      Log.e(TAG, "Requested zoom level is less than minimum zoom level.");
-    }
-    if (this.mZoomLevel > maxZoom) {
-      Log.e(TAG, "Requested zoom level is greater than maximum zoom level.");
-    }
-    this.mZoomLevel = Math.max(minZoom, Math.min(maxZoom, this.mZoomLevel));
-
-    float zoomScaleFactor =
-        (maxZoom == minZoom) ? minZoom : (this.mZoomLevel - minZoom) / (maxZoom - minZoom);
-    int minWidth = Math.round(sensorSize.width() / maxZoom);
-    int minHeight = Math.round(sensorSize.height() / maxZoom);
-    int diffWidth = sensorSize.width() - minWidth;
-    int diffHeight = sensorSize.height() - minHeight;
-    float cropWidth = diffWidth * zoomScaleFactor;
-    float cropHeight = diffHeight * zoomScaleFactor;
-
-    Rect cropRegion =
-        new Rect(
-            /*left=*/ (int) Math.ceil(cropWidth / 2 - 0.5f),
-            /*top=*/ (int) Math.ceil(cropHeight / 2 - 0.5f),
-            /*right=*/ (int) Math.floor(sensorSize.width() - cropWidth / 2 + 0.5f),
-            /*bottom=*/ (int) Math.floor(sensorSize.height() - cropHeight / 2 + 0.5f));
-
-    if (cropRegion.width() < 50 || cropRegion.height() < 50) {
-      Log.e(TAG, "Crop region is too small to compute 3A stats, so ignoring further zoom.");
-      return;
-    }
-    this.mCropRegion = cropRegion;
-
-    mPreview.zoom(cropRegion);
-  }
-
-  public float getMinZoomLevel() {
       return UNITY_ZOOM_SCALE;
     }
+  }
 
-  public float getMaxZoomLevel() {
+  public void setZoomRatio(float zoomRatio) {
-    try {
+    if (mCamera != null) {
-      CameraCharacteristics characteristics =
+      ListenableFuture<Void> future = mCamera.getCameraControl().setZoomRatio(
-          mCameraManager.getCameraCharacteristics(getActiveCamera());
+          zoomRatio);
-      Float maxZoom =
+      Futures.addCallback(future, new FutureCallback<Void>() {
-          characteristics.get(CameraCharacteristics.SCALER_AVAILABLE_MAX_DIGITAL_ZOOM);
+        @Override
-      if (maxZoom == null) {
+        public void onSuccess(@Nullable Void result) {
+        }
+
+        @Override
+        public void onFailure(Throwable t) {
+          // Throw the unexpected error.
+          throw new RuntimeException(t);
+        }
+      }, CameraXExecutors.directExecutor());
+    } else {
+      Log.e(TAG, "Failed to set zoom ratio");
+    }
+  }
+
+  public float getMinZoomRatio() {
+    if (mCamera != null) {
+      return mCamera.getCameraInfo().getZoomState().getValue().getMinZoomRatio();
+    } else {
+      return UNITY_ZOOM_SCALE;
+    }
+  }
+
+  public float getMaxZoomRatio() {
+    if (mCamera != null) {
+      return mCamera.getCameraInfo().getZoomState().getValue().getMaxZoomRatio();
+    } else {
       return ZOOM_NOT_SUPPORTED;
     }
-      if (maxZoom == ZOOM_NOT_SUPPORTED) {
-        return ZOOM_NOT_SUPPORTED;
-      }
-      return maxZoom;
-    } catch (Exception e) {
-      Log.e(TAG, "Failed to get SCALER_AVAILABLE_MAX_DIGITAL_ZOOM.", e);
-    }
-    return ZOOM_NOT_SUPPORTED;
   }
 
   public boolean isZoomSupported() {
-    return getMaxZoomLevel() != ZOOM_NOT_SUPPORTED;
+    return getMaxZoomRatio() != ZOOM_NOT_SUPPORTED;
   }
 
   // TODO(b/124269166): Rethink how we can handle permissions here.
@@ -559,80 +489,47 @@ final class CameraXModule {
 
   int getRelativeCameraOrientation(boolean compensateForMirroring) {
     int rotationDegrees = 0;
-    try {
+    if (mCamera != null) {
-      CameraInfo cameraInfo = CameraX.getCameraInfo(getLensFacing());
+      rotationDegrees =
-      rotationDegrees = cameraInfo.getSensorRotationDegrees(getDisplaySurfaceRotation());
+          mCamera.getCameraInfo().getSensorRotationDegrees(getDisplaySurfaceRotation());
       if (compensateForMirroring) {
         rotationDegrees = (360 - rotationDegrees) % 360;
       }
-    } catch (CameraInfoUnavailableException e) {
-      Log.e(TAG, "Failed to get CameraInfo", e);
-    } catch (Exception e) {
-      Log.e(TAG, "Failed to query camera", e);
     }
 
     return rotationDegrees;
   }
 
   public void invalidateView() {
-    transformPreview();
     updateViewInfo();
   }
 
   void clearCurrentLifecycle() {
-    if (mCurrentLifecycle != null) {
+    if (mCurrentLifecycle != null && mCameraProvider != null) {
       // Remove previous use cases
-      // Begin Signal Custom Code Block
+      List<UseCase> toUnbind = new ArrayList<>();
-      CameraX.unbind(mImageCapture, mPreview);
+      if (mImageCapture != null && mCameraProvider.isBound(mImageCapture)) {
-      if (mVideoCapture != null) {
+        toUnbind.add(mImageCapture);
-        CameraX.unbind(mVideoCapture);
       }
-      // End Signal Custom Code Block
+      if (mVideoCapture != null && mCameraProvider.isBound(mVideoCapture)) {
+        toUnbind.add(mVideoCapture);
+      }
+      if (mPreview != null && mCameraProvider.isBound(mPreview)) {
+        toUnbind.add(mPreview);
       }
 
+      if (!toUnbind.isEmpty()) {
+        mCameraProvider.unbind(toUnbind.toArray((new UseCase[0])));
+      }
+    }
+    mCamera = null;
     mCurrentLifecycle = null;
   }
 
-  private Rect getSensorSize(String cameraId) throws CameraAccessException {
-    CameraCharacteristics characteristics = mCameraManager.getCameraCharacteristics(cameraId);
-    return characteristics.get(CameraCharacteristics.SENSOR_INFO_ACTIVE_ARRAY_SIZE);
-  }
-
-  String getActiveCamera() throws CameraInfoUnavailableException {
-    return CameraX.getCameraWithLensFacing(mCameraLensFacing);
-  }
-
-  @UiThread
-  private void transformPreview() {
-    int previewWidth = getPreviewWidth();
-    int previewHeight = getPreviewHeight();
-    int displayOrientation = getDisplayRotationDegrees();
-
-    Matrix matrix = new Matrix();
-
-    // Apply rotation of the display
-    int rotation = -displayOrientation;
-
-    int px = (int) Math.round(previewWidth / 2d);
-    int py = (int) Math.round(previewHeight / 2d);
-
-    matrix.postRotate(rotation, px, py);
-
-    if (displayOrientation == 90 || displayOrientation == 270) {
-      // Swap width and height
-      float xScale = previewWidth / (float) previewHeight;
-      float yScale = previewHeight / (float) previewWidth;
-
-      matrix.postScale(xScale, yScale, px, py);
-    }
-
-    setTransform(matrix);
-  }
-
   // Update view related information used in use cases
   private void updateViewInfo() {
     if (mImageCapture != null) {
-      mImageCapture.setTargetAspectRatioCustom(new Rational(getWidth(), getHeight()));
+      mImageCapture.setCropAspectRatio(new Rational(getWidth(), getHeight()));
       mImageCapture.setTargetRotation(getDisplaySurfaceRotation());
     }
 
@@ -642,29 +539,46 @@ final class CameraXModule {
   }
 
   @RequiresPermission(permission.CAMERA)
-  private Set<CameraX.LensFacing> getAvailableCameraLensFacing() {
+  private Set<Integer> getAvailableCameraLensFacing() {
     // Start with all camera directions
-    Set<CameraX.LensFacing> available = new LinkedHashSet<>(Arrays.asList(CameraX.LensFacing.values()));
+    Set<Integer> available = new LinkedHashSet<>(Arrays.asList(LensFacingConverter.values()));
 
     // If we're bound to a lifecycle, remove unavailable cameras
     if (mCurrentLifecycle != null) {
-      if (!hasCameraWithLensFacing(CameraX.LensFacing.BACK)) {
+      if (!hasCameraWithLensFacing(CameraSelector.LENS_FACING_BACK)) {
-        available.remove(CameraX.LensFacing.BACK);
+        available.remove(CameraSelector.LENS_FACING_BACK);
       }
 
-      if (!hasCameraWithLensFacing(CameraX.LensFacing.FRONT)) {
+      if (!hasCameraWithLensFacing(CameraSelector.LENS_FACING_FRONT)) {
-        available.remove(CameraX.LensFacing.FRONT);
+        available.remove(CameraSelector.LENS_FACING_FRONT);
       }
     }
 
     return available;
   }
 
-  public FlashMode getFlash() {
+  @ImageCapture.FlashMode
+  public int getFlash() {
     return mFlash;
   }
 
-  public void setFlash(FlashMode flash) {
+  // Begin Signal Custom Code Block
+  public boolean hasFlash() {
+    if (mImageCapture == null) {
+      return false;
+    }
+
+    CameraInternal camera = mImageCapture.getBoundCamera();
+
+    if (camera == null) {
+      return false;
+    }
+
+    return camera.getCameraInfoInternal().hasFlashUnit();
+  }
+  // End Signal Custom Code Block
+
+  public void setFlash(@ImageCapture.FlashMode int flash) {
     this.mFlash = flash;
 
     if (mImageCapture == null) {
@@ -676,101 +590,69 @@ final class CameraXModule {
   }
 
   public void enableTorch(boolean torch) {
-    if (mPreview == null) {
+    if (mCamera == null) {
       return;
     }
-    mPreview.enableTorch(torch);
+    ListenableFuture<Void> future = mCamera.getCameraControl().enableTorch(torch);
+    Futures.addCallback(future, new FutureCallback<Void>() {
+      @Override
+      public void onSuccess(@Nullable Void result) {
+      }
+
+      @Override
+      public void onFailure(Throwable t) {
+        // Throw the unexpected error.
+        throw new RuntimeException(t);
+      }
+    }, CameraXExecutors.directExecutor());
   }
 
   public boolean isTorchOn() {
-    if (mPreview == null) {
+    if (mCamera == null) {
       return false;
     }
-    return mPreview.isTorchOn();
+    return mCamera.getCameraInfo().getTorchState().getValue() == TorchState.ON;
   }
 
   public Context getContext() {
-    return mCameraView.getContext();
+    return mCameraXView.getContext();
   }
 
   public int getWidth() {
-    return mCameraView.getWidth();
+    return mCameraXView.getWidth();
   }
 
   public int getHeight() {
-    return mCameraView.getHeight();
+    return mCameraXView.getHeight();
   }
 
   public int getDisplayRotationDegrees() {
     return CameraOrientationUtil.surfaceRotationToDegrees(getDisplaySurfaceRotation());
   }
 
-  // Begin Signal Custom Code Block
-  public boolean hasFlash() {
-    try {
-      LiveData<Boolean> isFlashAvailable = CameraX.getCameraInfo(getLensFacing()).isFlashAvailable();
-      return isFlashAvailable.getValue() == Boolean.TRUE;
-    } catch (CameraInfoUnavailableException e) {
-      return false;
-    }
-  }
-  // End Signal Custom Code Block
-
   protected int getDisplaySurfaceRotation() {
-    return mCameraView.getDisplaySurfaceRotation();
+    return mCameraXView.getDisplaySurfaceRotation();
-  }
-
-  public void setSurfaceTexture(SurfaceTexture st) {
-    mCameraView.setSurfaceTexture(st);
-  }
-
-  private int getPreviewWidth() {
-    return mCameraView.getPreviewWidth();
-  }
-
-  private int getPreviewHeight() {
-    return mCameraView.getPreviewHeight();
   }
 
   private int getMeasuredWidth() {
-    return mCameraView.getMeasuredWidth();
+    return mCameraXView.getMeasuredWidth();
   }
 
   private int getMeasuredHeight() {
-    return mCameraView.getMeasuredHeight();
+    return mCameraXView.getMeasuredHeight();
   }
 
-  void setTransform(final Matrix matrix) {
+  @Nullable
-    if (Looper.myLooper() != Looper.getMainLooper()) {
+  public Camera getCamera() {
-      mCameraView.post(
+    return mCamera;
-          new Runnable() {
-            @Override
-            public void run() {
-              setTransform(matrix);
-            }
-          });
-    } else {
-      mCameraView.setTransform(matrix);
-    }
-  }
-
-  /**
-   * Notify the view that the source dimensions have changed.
-   *
-   * <p>This will allow the view to layout the preview to display the correct aspect ratio.
-   *
-   * @param width  width of camera source buffers.
-   * @param height height of camera source buffers.
-   */
-  void onPreviewSourceDimensUpdated(int width, int height) {
-    mCameraView.onPreviewSourceDimensUpdated(width, height);
   }
 
+  @NonNull
   public CameraXView.CaptureMode getCaptureMode() {
     return mCaptureMode;
   }
 
-  public void setCaptureMode(CameraXView.CaptureMode captureMode) {
+  public void setCaptureMode(@NonNull CameraXView.CaptureMode captureMode) {
     this.mCaptureMode = captureMode;
     rebindToLifecycle();
   }

app/src/main/java/org/thoughtcrime/securesms/mediasend/camerax/CameraXUtil.java

@@ -1,5 +1,6 @@
 package org.thoughtcrime.securesms.mediasend.camerax;
 
+import android.annotation.SuppressLint;
 import android.annotation.TargetApi;
 import android.content.Context;
 import android.graphics.Bitmap;
@@ -19,14 +20,13 @@ import android.util.Size;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.annotation.RequiresApi;
-import androidx.camera.camera2.impl.compat.CameraManagerCompat;
+import androidx.camera.camera2.internal.compat.CameraManagerCompat;
-import androidx.camera.core.CameraX;
+import androidx.camera.core.CameraSelector;
 import androidx.camera.core.ImageCapture;
 import androidx.camera.core.ImageProxy;
 
 import org.thoughtcrime.securesms.logging.Log;
 import org.thoughtcrime.securesms.mediasend.LegacyCameraModels;
-import org.thoughtcrime.securesms.migrations.LegacyMigrationJob;
 import org.thoughtcrime.securesms.util.Stopwatch;
 
 import java.io.ByteArrayOutputStream;
@@ -57,11 +57,12 @@ public class CameraXUtil {
 
   @SuppressWarnings("SuspiciousNameCombination")
   @RequiresApi(21)
-  public static ImageResult toJpeg(@NonNull ImageProxy image, int rotation, boolean flip) throws IOException {
+  public static ImageResult toJpeg(@NonNull ImageProxy image, boolean flip) throws IOException {
     ImageProxy.PlaneProxy[] planes   = image.getPlanes();
     ByteBuffer              buffer   = planes[0].getBuffer();
     Rect                    cropRect = shouldCropImage(image) ? image.getCropRect() : null;
     byte[]                  data     = new byte[buffer.capacity()];
+    int                     rotation = image.getImageInfo().getRotationDegrees();
 
     buffer.get(data);
 
@@ -86,25 +87,25 @@ public class CameraXUtil {
     return Build.VERSION.SDK_INT >= 21 && !LegacyCameraModels.isLegacyCameraModel();
   }
 
-  public static int toCameraDirectionInt(@Nullable CameraX.LensFacing facing) {
+  public static int toCameraDirectionInt(int facing) {
-    if (facing == CameraX.LensFacing.FRONT) {
+    if (facing == CameraSelector.LENS_FACING_FRONT) {
       return Camera.CameraInfo.CAMERA_FACING_FRONT;
     } else {
       return Camera.CameraInfo.CAMERA_FACING_BACK;
     }
   }
 
-  public static @NonNull CameraX.LensFacing toLensFacing(int cameraDirectionInt) {
+  public static int toLensFacing(@CameraSelector.LensFacing int cameraDirectionInt) {
     if (cameraDirectionInt == Camera.CameraInfo.CAMERA_FACING_FRONT) {
-      return CameraX.LensFacing.FRONT;
+      return CameraSelector.LENS_FACING_FRONT;
     } else {
-      return CameraX.LensFacing.BACK;
+      return CameraSelector.LENS_FACING_BACK;
     }
   }
 
-  public static @NonNull ImageCapture.CaptureMode getOptimalCaptureMode() {
+  public static @NonNull @ImageCapture.CaptureMode int getOptimalCaptureMode() {
-    return FastCameraModels.contains(Build.MODEL) ? ImageCapture.CaptureMode.MAX_QUALITY
+    return FastCameraModels.contains(Build.MODEL) ? ImageCapture.CAPTURE_MODE_MAXIMIZE_QUALITY
-                                                  : ImageCapture.CaptureMode.MIN_LATENCY;
+                                                  : ImageCapture.CAPTURE_MODE_MINIMIZE_LATENCY;
   }
 
   public static int getIdealResolution(int displayWidth, int displayHeight) {
@@ -186,7 +187,7 @@ public class CameraXUtil {
 
   @RequiresApi(21)
   public static int getLowestSupportedHardwareLevel(@NonNull Context context) {
-    CameraManager cameraManager = CameraManagerCompat.from(context).unwrap();
+    @SuppressLint("RestrictedApi") CameraManager cameraManager = CameraManagerCompat.from(context).unwrap();
 
     try {
       int supported = maxHardwareLevel();

app/src/main/java/org/thoughtcrime/securesms/mediasend/camerax/CameraXView.java

@@ -20,10 +20,6 @@ import android.Manifest.permission;
 import android.annotation.SuppressLint;
 import android.content.Context;
 import android.content.res.TypedArray;
-import android.graphics.Matrix;
-import android.graphics.Paint;
-import android.graphics.Rect;
-import android.graphics.SurfaceTexture;
 import android.hardware.display.DisplayManager;
 import android.hardware.display.DisplayManager.DisplayListener;
 import android.os.Bundle;
@@ -33,17 +29,14 @@ import android.os.Parcelable;
 import android.text.TextUtils;
 import android.util.AttributeSet;
 import android.util.Log;
-import android.util.Size;
 import android.view.Display;
 import android.view.MotionEvent;
 import android.view.ScaleGestureDetector;
 import android.view.Surface;
-import android.view.TextureView;
 import android.view.View;
 import android.view.ViewConfiguration;
 import android.view.ViewGroup;
-import android.view.animation.BaseInterpolator;
+import android.widget.FrameLayout;
-import android.view.animation.DecelerateInterpolator;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
@@ -51,33 +44,42 @@ import androidx.annotation.RequiresApi;
 import androidx.annotation.RequiresPermission;
 import androidx.annotation.RestrictTo;
 import androidx.annotation.RestrictTo.Scope;
-import androidx.annotation.UiThread;
+import androidx.camera.core.Camera;
-import androidx.camera.core.CameraInfoUnavailableException;
+import androidx.camera.core.CameraSelector;
-import androidx.camera.core.CameraX;
+import androidx.camera.core.DisplayOrientedMeteringPointFactory;
-import androidx.camera.core.FlashMode;
 import androidx.camera.core.FocusMeteringAction;
+import androidx.camera.core.FocusMeteringResult;
 import androidx.camera.core.ImageCapture;
+import androidx.camera.core.ImageCapture.OnImageCapturedCallback;
+import androidx.camera.core.ImageProxy;
 import androidx.camera.core.MeteringPoint;
+import androidx.camera.core.impl.LensFacingConverter;
+import androidx.camera.core.impl.utils.executor.CameraXExecutors;
+import androidx.camera.core.impl.utils.futures.FutureCallback;
+import androidx.camera.core.impl.utils.futures.Futures;
 import androidx.lifecycle.LifecycleOwner;
 
+import com.google.common.util.concurrent.ListenableFuture;
+
 import org.thoughtcrime.securesms.R;
 
-import java.io.File;
 import java.io.FileDescriptor;
 import java.util.concurrent.Executor;
 
 /**
  * A {@link View} that displays a preview of the camera with methods {@link
- * #takePicture(Executor, OnImageCapturedListener)},
+ * #takePicture(Executor, OnImageCapturedCallback)},
- * {@link #takePicture(File, Executor, OnImageSavedListener)},
+ * {@link #startRecording(FileDescriptor, Executor, VideoCapture.OnVideoSavedCallback)} and {@link #stopRecording()}.
- * {@link #startRecording(File, Executor, OnVideoSavedListener)} and {@link #stopRecording()}.
  *
  * <p>Because the Camera is a limited resource and consumes a high amount of power, CameraView must
  * be opened/closed. CameraView will handle opening/closing automatically through use of a {@link
  * LifecycleOwner}. Use {@link #bindToLifecycle(LifecycleOwner)} to start the camera.
  */
+// Begin Signal Custom Code Block
 @RequiresApi(21)
-public final class CameraXView extends ViewGroup {
+@SuppressLint("RestrictedApi")
+// End Signal Custom Code Block
+public final class CameraXView extends FrameLayout {
   static final String TAG = CameraXView.class.getSimpleName();
   static final boolean DEBUG = false;
 
@@ -85,7 +87,7 @@ public final class CameraXView extends ViewGroup {
   static final int INDEFINITE_VIDEO_SIZE = -1;
 
   private static final String EXTRA_SUPER = "super";
-  private static final String EXTRA_ZOOM_LEVEL = "zoom_level";
+  private static final String EXTRA_ZOOM_RATIO = "zoom_ratio";
   private static final String EXTRA_PINCH_TO_ZOOM_ENABLED = "pinch_to_zoom_enabled";
   private static final String EXTRA_FLASH = "flash";
   private static final String EXTRA_MAX_VIDEO_DURATION = "max_video_duration";
@@ -121,51 +123,31 @@ public final class CameraXView extends ViewGroup {
           mCameraModule.invalidateView();
         }
       };
-  private TextureView mCameraTextureView;
+  private PreviewView mPreviewView;
-  private Size mPreviewSrcSize = new Size(0, 0);
   private ScaleType mScaleType = ScaleType.CENTER_CROP;
   // For accessibility event
   private MotionEvent mUpEvent;
-  private @Nullable Paint mLayerPaint;
 
-  public CameraXView(Context context) {
+  public CameraXView(@NonNull Context context) {
     this(context, null);
   }
 
-  public CameraXView(Context context, AttributeSet attrs) {
+  public CameraXView(@NonNull Context context, @Nullable AttributeSet attrs) {
     this(context, attrs, 0);
   }
 
-  public CameraXView(Context context, AttributeSet attrs, int defStyle) {
+  public CameraXView(@NonNull Context context, @Nullable AttributeSet attrs, int defStyle) {
     super(context, attrs, defStyle);
     init(context, attrs);
   }
 
   @RequiresApi(21)
-  public CameraXView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
+  public CameraXView(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr,
+                    int defStyleRes) {
     super(context, attrs, defStyleAttr, defStyleRes);
     init(context, attrs);
   }
 
-  /** Debug logging that can be enabled. */
-  private static void log(String msg) {
-    if (DEBUG) {
-      Log.i(TAG, msg);
-    }
-  }
-
-  /** Utility method for converting an displayRotation int into a human readable string. */
-  private static String displayRotationToString(int displayRotation) {
-    if (displayRotation == Surface.ROTATION_0 || displayRotation == Surface.ROTATION_180) {
-      return "Portrait-" + (displayRotation * 90);
-    } else if (displayRotation == Surface.ROTATION_90
-        || displayRotation == Surface.ROTATION_270) {
-      return "Landscape-" + (displayRotation * 90);
-    } else {
-      return "Unknown";
-    }
-  }
-
   /**
    * Binds control of the camera used by this view to the given lifecycle.
    *
@@ -184,21 +166,16 @@ public final class CameraXView extends ViewGroup {
    * @throws IllegalStateException    if camera permissions are not granted.
    */
   @RequiresPermission(permission.CAMERA)
-  public void bindToLifecycle(LifecycleOwner lifecycleOwner) {
+  public void bindToLifecycle(@NonNull LifecycleOwner lifecycleOwner) {
     mCameraModule.bindToLifecycle(lifecycleOwner);
   }
 
   private void init(Context context, @Nullable AttributeSet attrs) {
-    addView(mCameraTextureView = new TextureView(getContext()), 0 /* view position */);
+    addView(mPreviewView = new PreviewView(getContext()), 0 /* view position */);
-    mCameraTextureView.setLayerPaint(mLayerPaint);
     mCameraModule = new CameraXModule(this);
 
-    if (isInEditMode()) {
-      onPreviewSourceDimensUpdated(640, 480);
-    }
-
     if (attrs != null) {
-      TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CameraView);
+      TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CameraXView);
       setScaleType(
           ScaleType.fromId(
               a.getInteger(R.styleable.CameraXView_scaleType,
@@ -217,10 +194,10 @@ public final class CameraXView extends ViewGroup {
           setCameraLensFacing(null);
           break;
         case LENS_FACING_FRONT:
-          setCameraLensFacing(CameraX.LensFacing.FRONT);
+          setCameraLensFacing(CameraSelector.LENS_FACING_FRONT);
           break;
         case LENS_FACING_BACK:
-          setCameraLensFacing(CameraX.LensFacing.BACK);
+          setCameraLensFacing(CameraSelector.LENS_FACING_BACK);
           break;
         default:
           // Unhandled event.
@@ -229,13 +206,13 @@ public final class CameraXView extends ViewGroup {
       int flashMode = a.getInt(R.styleable.CameraXView_flash, 0);
       switch (flashMode) {
         case FLASH_MODE_AUTO:
-          setFlash(FlashMode.AUTO);
+          setFlash(ImageCapture.FLASH_MODE_AUTO);
           break;
         case FLASH_MODE_ON:
-          setFlash(FlashMode.ON);
+          setFlash(ImageCapture.FLASH_MODE_ON);
           break;
         case FLASH_MODE_OFF:
-          setFlash(FlashMode.OFF);
+          setFlash(ImageCapture.FLASH_MODE_OFF);
           break;
         default:
           // Unhandled event.
@@ -252,12 +229,14 @@ public final class CameraXView extends ViewGroup {
   }
 
   @Override
+  @NonNull
   protected LayoutParams generateDefaultLayoutParams() {
     return new LayoutParams(
         ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
   }
 
   @Override
+  @NonNull
   protected Parcelable onSaveInstanceState() {
     // TODO(b/113884082): Decide what belongs here or what should be invalidated on
     // configuration
@@ -265,20 +244,21 @@ public final class CameraXView extends ViewGroup {
     Bundle state = new Bundle();
     state.putParcelable(EXTRA_SUPER, super.onSaveInstanceState());
     state.putInt(EXTRA_SCALE_TYPE, getScaleType().getId());
-    state.putFloat(EXTRA_ZOOM_LEVEL, getZoomLevel());
+    state.putFloat(EXTRA_ZOOM_RATIO, getZoomRatio());
     state.putBoolean(EXTRA_PINCH_TO_ZOOM_ENABLED, isPinchToZoomEnabled());
-    state.putString(EXTRA_FLASH, getFlash().name());
+    state.putString(EXTRA_FLASH, FlashModeConverter.nameOf(getFlash()));
     state.putLong(EXTRA_MAX_VIDEO_DURATION, getMaxVideoDuration());
     state.putLong(EXTRA_MAX_VIDEO_SIZE, getMaxVideoSize());
     if (getCameraLensFacing() != null) {
-      state.putString(EXTRA_CAMERA_DIRECTION, getCameraLensFacing().name());
+      state.putString(EXTRA_CAMERA_DIRECTION,
+          LensFacingConverter.nameOf(getCameraLensFacing()));
     }
     state.putInt(EXTRA_CAPTURE_MODE, getCaptureMode().getId());
     return state;
   }
 
   @Override
-  protected void onRestoreInstanceState(Parcelable savedState) {
+  protected void onRestoreInstanceState(@Nullable Parcelable savedState) {
     // TODO(b/113884082): Decide what belongs here or what should be invalidated on
     // configuration
     // change
@@ -286,39 +266,22 @@ public final class CameraXView extends ViewGroup {
       Bundle state = (Bundle) savedState;
       super.onRestoreInstanceState(state.getParcelable(EXTRA_SUPER));
       setScaleType(ScaleType.fromId(state.getInt(EXTRA_SCALE_TYPE)));
-      setZoomLevel(state.getFloat(EXTRA_ZOOM_LEVEL));
+      setZoomRatio(state.getFloat(EXTRA_ZOOM_RATIO));
       setPinchToZoomEnabled(state.getBoolean(EXTRA_PINCH_TO_ZOOM_ENABLED));
-      setFlash(FlashMode.valueOf(state.getString(EXTRA_FLASH)));
+      setFlash(FlashModeConverter.valueOf(state.getString(EXTRA_FLASH)));
       setMaxVideoDuration(state.getLong(EXTRA_MAX_VIDEO_DURATION));
       setMaxVideoSize(state.getLong(EXTRA_MAX_VIDEO_SIZE));
       String lensFacingString = state.getString(EXTRA_CAMERA_DIRECTION);
       setCameraLensFacing(
           TextUtils.isEmpty(lensFacingString)
               ? null
-              : CameraX.LensFacing.valueOf(lensFacingString));
+              : LensFacingConverter.valueOf(lensFacingString));
       setCaptureMode(CaptureMode.fromId(state.getInt(EXTRA_CAPTURE_MODE)));
     } else {
       super.onRestoreInstanceState(savedState);
     }
   }
 
-  /**
-   * Sets the paint on the preview.
-   *
-   * <p>This only affects the preview, and does not affect captured images/video.
-   *
-   * @param paint The paint object to apply to the preview.
-   * @hide This may not work once {@link android.view.SurfaceView} is supported along with {@link
-   * TextureView}.
-   */
-  @Override
-  @RestrictTo(Scope.LIBRARY_GROUP)
-  public void setLayerPaint(@Nullable Paint paint) {
-    super.setLayerPaint(paint);
-    mLayerPaint = paint;
-    mCameraTextureView.setLayerPaint(paint);
-  }
-
   @Override
   protected void onAttachedToWindow() {
     super.onAttachedToWindow();
@@ -335,33 +298,21 @@ public final class CameraXView extends ViewGroup {
     dpyMgr.unregisterDisplayListener(mDisplayListener);
   }
 
+  PreviewView getPreviewView() {
+    return mPreviewView;
+  }
+
   // TODO(b/124269166): Rethink how we can handle permissions here.
   @SuppressLint("MissingPermission")
   @Override
   protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
-    int viewWidth = MeasureSpec.getSize(widthMeasureSpec);
-    int viewHeight = MeasureSpec.getSize(heightMeasureSpec);
-
-    int displayRotation = getDisplay().getRotation();
-
-    if (mPreviewSrcSize.getHeight() == 0 || mPreviewSrcSize.getWidth() == 0) {
-      super.onMeasure(widthMeasureSpec, heightMeasureSpec);
-      mCameraTextureView.measure(viewWidth, viewHeight);
-    } else {
-      Size scaled =
-          calculatePreviewViewDimens(
-              mPreviewSrcSize, viewWidth, viewHeight, displayRotation, mScaleType);
-      super.setMeasuredDimension(
-          Math.min(scaled.getWidth(), viewWidth),
-          Math.min(scaled.getHeight(), viewHeight));
-      mCameraTextureView.measure(scaled.getWidth(), scaled.getHeight());
-    }
-
     // Since bindToLifecycle will depend on the measured dimension, only call it when measured
     // dimension is not 0x0
     if (getMeasuredWidth() > 0 && getMeasuredHeight() > 0) {
       mCameraModule.bindToLifecycleAfterViewMeasured();
     }
+
+    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
   }
 
   // TODO(b/124269166): Rethink how we can handle permissions here.
@@ -372,114 +323,8 @@ public final class CameraXView extends ViewGroup {
     // binding to lifecycle
     mCameraModule.bindToLifecycleAfterViewMeasured();
 
-    // If we don't know the src buffer size yet, set the preview to be the parent size
-    if (mPreviewSrcSize.getWidth() == 0 || mPreviewSrcSize.getHeight() == 0) {
-      mCameraTextureView.layout(left, top, right, bottom);
-      return;
-    }
-
-    // Compute the preview ui size based on the available width, height, and ui orientation.
-    int viewWidth = (right - left);
-    int viewHeight = (bottom - top);
-    int displayRotation = getDisplay().getRotation();
-    Size scaled =
-        calculatePreviewViewDimens(
-            mPreviewSrcSize, viewWidth, viewHeight, displayRotation, mScaleType);
-
-    // Compute the center of the view.
-    int centerX = viewWidth / 2;
-    int centerY = viewHeight / 2;
-
-    // Compute the left / top / right / bottom values such that preview is centered.
-    int layoutL = centerX - (scaled.getWidth() / 2);
-    int layoutT = centerY - (scaled.getHeight() / 2);
-    int layoutR = layoutL + scaled.getWidth();
-    int layoutB = layoutT + scaled.getHeight();
-
-    // Layout debugging
-    log("layout: viewWidth:  " + viewWidth);
-    log("layout: viewHeight: " + viewHeight);
-    log("layout: viewRatio:  " + (viewWidth / (float) viewHeight));
-    log("layout: sizeWidth:  " + mPreviewSrcSize.getWidth());
-    log("layout: sizeHeight: " + mPreviewSrcSize.getHeight());
-    log(
-        "layout: sizeRatio:  "
-            + (mPreviewSrcSize.getWidth() / (float) mPreviewSrcSize.getHeight()));
-    log("layout: scaledWidth:  " + scaled.getWidth());
-    log("layout: scaledHeight: " + scaled.getHeight());
-    log("layout: scaledRatio:  " + (scaled.getWidth() / (float) scaled.getHeight()));
-    log(
-        "layout: size:       "
-            + scaled
-            + " ("
-            + (scaled.getWidth() / (float) scaled.getHeight())
-            + " - "
-            + mScaleType
-            + "-"
-            + displayRotationToString(displayRotation)
-            + ")");
-    log("layout: final       " + layoutL + ", " + layoutT + ", " + layoutR + ", " + layoutB);
-
-    mCameraTextureView.layout(layoutL, layoutT, layoutR, layoutB);
-
     mCameraModule.invalidateView();
-  }
+    super.onLayout(changed, left, top, right, bottom);
-
-  /** Records the size of the preview's buffers. */
-  @UiThread
-  void onPreviewSourceDimensUpdated(int srcWidth, int srcHeight) {
-    if (srcWidth != mPreviewSrcSize.getWidth()
-        || srcHeight != mPreviewSrcSize.getHeight()) {
-      mPreviewSrcSize = new Size(srcWidth, srcHeight);
-      requestLayout();
-    }
-  }
-
-  private Size calculatePreviewViewDimens(
-      Size srcSize,
-      int parentWidth,
-      int parentHeight,
-      int displayRotation,
-      ScaleType scaleType) {
-    int inWidth = srcSize.getWidth();
-    int inHeight = srcSize.getHeight();
-    if (displayRotation == Surface.ROTATION_90 || displayRotation == Surface.ROTATION_270) {
-      // Need to reverse the width and height since we're in landscape orientation.
-      inWidth = srcSize.getHeight();
-      inHeight = srcSize.getWidth();
-    }
-
-    int outWidth = parentWidth;
-    int outHeight = parentHeight;
-    if (inWidth != 0 && inHeight != 0) {
-      float vfRatio = inWidth / (float) inHeight;
-      float parentRatio = parentWidth / (float) parentHeight;
-
-      switch (scaleType) {
-        case CENTER_INSIDE:
-          // Match longest sides together.
-          if (vfRatio > parentRatio) {
-            outWidth = parentWidth;
-            outHeight = Math.round(parentWidth / vfRatio);
-          } else {
-            outWidth = Math.round(parentHeight * vfRatio);
-            outHeight = parentHeight;
-          }
-          break;
-        case CENTER_CROP:
-          // Match shortest sides together.
-          if (vfRatio < parentRatio) {
-            outWidth = parentWidth;
-            outHeight = Math.round(parentWidth / vfRatio);
-          } else {
-            outWidth = Math.round(parentHeight * vfRatio);
-            outHeight = parentHeight;
-          }
-          break;
-      }
-    }
-
-    return new Size(outWidth, outHeight);
   }
 
   /**
@@ -499,58 +344,12 @@ public final class CameraXView extends ViewGroup {
     return display.getRotation();
   }
 
-  @UiThread
-  SurfaceTexture getSurfaceTexture() {
-    if (mCameraTextureView != null) {
-      return mCameraTextureView.getSurfaceTexture();
-    }
-
-    return null;
-  }
-
-  @UiThread
-  void setSurfaceTexture(SurfaceTexture surfaceTexture) {
-    if (mCameraTextureView.getSurfaceTexture() != surfaceTexture) {
-      if (mCameraTextureView.isAvailable()) {
-        // Remove the old TextureView to properly detach the old SurfaceTexture from the GL
-        // Context.
-        removeView(mCameraTextureView);
-        addView(mCameraTextureView = new TextureView(getContext()), 0);
-        mCameraTextureView.setLayerPaint(mLayerPaint);
-        requestLayout();
-      }
-
-      mCameraTextureView.setSurfaceTexture(surfaceTexture);
-    }
-  }
-
-  @UiThread
-  Matrix getTransform(Matrix matrix) {
-    return mCameraTextureView.getTransform(matrix);
-  }
-
-  @UiThread
-  int getPreviewWidth() {
-    return mCameraTextureView.getWidth();
-  }
-
-  @UiThread
-  int getPreviewHeight() {
-    return mCameraTextureView.getHeight();
-  }
-
-  @UiThread
-  void setTransform(final Matrix matrix) {
-    if (mCameraTextureView != null) {
-      mCameraTextureView.setTransform(matrix);
-    }
-  }
-
   /**
    * Returns the scale type used to scale the preview.
    *
    * @return The current {@link ScaleType}.
    */
+  @NonNull
   public ScaleType getScaleType() {
     return mScaleType;
   }
@@ -562,7 +361,7 @@ public final class CameraXView extends ViewGroup {
    *
    * @param scaleType The desired {@link ScaleType}.
    */
-  public void setScaleType(ScaleType scaleType) {
+  public void setScaleType(@NonNull ScaleType scaleType) {
     if (scaleType != mScaleType) {
       mScaleType = scaleType;
       requestLayout();
@@ -574,6 +373,7 @@ public final class CameraXView extends ViewGroup {
    *
    * @return The current {@link CaptureMode}.
    */
+  @NonNull
   public CaptureMode getCaptureMode() {
     return mCameraModule.getCaptureMode();
   }
@@ -585,7 +385,7 @@ public final class CameraXView extends ViewGroup {
    *
    * @param captureMode The desired {@link CaptureMode}.
    */
-  public void setCaptureMode(CaptureMode captureMode) {
+  public void setCaptureMode(@NonNull CaptureMode captureMode) {
     mCameraModule.setCaptureMode(captureMode);
   }
 
@@ -601,7 +401,7 @@ public final class CameraXView extends ViewGroup {
   }
 
   /**
-   * Sets the maximum video duration before {@link OnVideoSavedListener#onVideoSaved(File)} is
+   * Sets the maximum video duration before {@link VideoCapture.OnVideoSavedCallback#onVideoSaved(FileDescriptor)} is
    * called automatically. Use {@link #INDEFINITE_VIDEO_DURATION} to disable the timeout.
    */
   private void setMaxVideoDuration(long duration) {
@@ -617,7 +417,7 @@ public final class CameraXView extends ViewGroup {
   }
 
   /**
-   * Sets the maximum video size in bytes before {@link OnVideoSavedListener#onVideoSaved(File)}
+   * Sets the maximum video size in bytes before {@link VideoCapture.OnVideoSavedCallback#onVideoSaved(FileDescriptor)}
    * is called automatically. Use {@link #INDEFINITE_VIDEO_SIZE} to disable the size restriction.
    */
   private void setMaxVideoSize(long size) {
@@ -625,44 +425,32 @@ public final class CameraXView extends ViewGroup {
   }
 
   /**
-   * Takes a picture, and calls {@link OnImageCapturedListener#onCaptureSuccess(ImageProxy, int)}
+   * Takes a picture, and calls {@link OnImageCapturedCallback#onCaptureSuccess(ImageProxy)}
    * once when done.
    *
-   * @param executor The executor in which the listener callback methods will be run.
+   * @param executor The executor in which the callback methods will be run.
-   * @param listener Listener which will receive success or failure callbacks.
+   * @param callback Callback which will receive success or failure callbacks.
    */
-  @SuppressLint("LambdaLast") // Maybe remove after https://issuetracker.google.com/135275901
+  public void takePicture(@NonNull Executor executor, @NonNull OnImageCapturedCallback callback) {
-  public void takePicture(@NonNull Executor executor, @NonNull ImageCapture.OnImageCapturedListener listener) {
+    mCameraModule.takePicture(executor, callback);
-    mCameraModule.takePicture(executor, listener);
   }
 
   /**
-   * Takes a picture and calls {@link OnImageSavedListener#onImageSaved(File)} when done.
+   * Takes a video and calls the OnVideoSavedCallback when done.
    *
    * @param file     The destination.
-   * @param executor The executor in which the listener callback methods will be run.
+   * @param executor The executor in which the callback methods will be run.
-   * @param listener Listener which will receive success or failure callbacks.
+   * @param callback Callback which will receive success or failure.
-   */
-  @SuppressLint("LambdaLast") // Maybe remove after https://issuetracker.google.com/135275901
-  public void takePicture(@NonNull File file, @NonNull Executor executor,
-                          @NonNull ImageCapture.OnImageSavedListener listener) {
-    mCameraModule.takePicture(file, executor, listener);
-  }
-
-  /**
-   * Takes a video and calls the OnVideoSavedListener when done.
-   *
-   * @param file The destination.
-   * @param executor The executor in which the listener callback methods will be run.
-   * @param listener Listener which will receive success or failure callbacks.
    */
   // Begin Signal Custom Code Block
   @RequiresApi(26)
-  @SuppressLint("LambdaLast") // Maybe remove after https://issuetracker.google.com/135275901
-  public void startRecording(@NonNull FileDescriptor file, @NonNull Executor executor,
   // End Signal Custom Code Block
-                             @NonNull VideoCapture.OnVideoSavedListener listener) {
+  public void startRecording(// Begin Signal Custom Code Block
-    mCameraModule.startRecording(file, executor, listener);
+                             @NonNull FileDescriptor file,
+                             // End Signal Custom Code Block
+                             @NonNull Executor executor,
+                             @NonNull VideoCapture.OnVideoSavedCallback callback) {
+    mCameraModule.startRecording(file, executor, callback);
   }
 
   /** Stops an in progress video. */
@@ -685,7 +473,7 @@ public final class CameraXView extends ViewGroup {
    * @throws IllegalStateException if the CAMERA permission is not currently granted.
    */
   @RequiresPermission(permission.CAMERA)
-  public boolean hasCameraWithLensFacing(CameraX.LensFacing lensFacing) {
+  public boolean hasCameraWithLensFacing(@CameraSelector.LensFacing int lensFacing) {
     return mCameraModule.hasCameraWithLensFacing(lensFacing);
   }
 
@@ -706,7 +494,7 @@ public final class CameraXView extends ViewGroup {
    *
    * <p>If called before {@link #bindToLifecycle(LifecycleOwner)}, this will set the camera to be
    * used when first bound to the lifecycle. If the specified lensFacing is not supported by the
-   * device, as determined by {@link #hasCameraWithLensFacing(LensFacing)}, the first supported
+   * device, as determined by {@link #hasCameraWithLensFacing(int)}, the first supported
    * lensFacing will be chosen when {@link #bindToLifecycle(LifecycleOwner)} is called.
    *
    * <p>If called with {@code null} AFTER binding to the lifecycle, the behavior would be
@@ -714,36 +502,33 @@ public final class CameraXView extends ViewGroup {
    *
    * @param lensFacing The desired camera lensFacing.
    */
-  public void setCameraLensFacing(@Nullable CameraX.LensFacing lensFacing) {
+  public void setCameraLensFacing(@Nullable Integer lensFacing) {
     mCameraModule.setCameraLensFacing(lensFacing);
   }
 
-  /** Returns the currently selected {@link LensFacing}. */
+  /** Returns the currently selected lensFacing. */
   @Nullable
-  public CameraX.LensFacing getCameraLensFacing() {
+  public Integer getCameraLensFacing() {
     return mCameraModule.getLensFacing();
   }
 
+  /** Gets the active flash strategy. */
+  @ImageCapture.FlashMode
+  public int getFlash() {
+    return mCameraModule.getFlash();
+  }
+
   // Begin Signal Custom Code Block
   public boolean hasFlash() {
     return mCameraModule.hasFlash();
   }
   // End Signal Custom Code Block
 
-  /** Gets the active flash strategy. */
-  public FlashMode getFlash() {
-    return mCameraModule.getFlash();
-  }
-
   /** Sets the active flash strategy. */
-  public void setFlash(@NonNull FlashMode flashMode) {
+  public void setFlash(@ImageCapture.FlashMode int flashMode) {
     mCameraModule.setFlash(flashMode);
   }
 
-  private int getRelativeCameraOrientation(boolean compensateForMirroring) {
-    return mCameraModule.getRelativeCameraOrientation(compensateForMirroring);
-  }
-
   private long delta() {
     return System.currentTimeMillis() - mDownEventTimestamp;
   }
@@ -793,42 +578,47 @@ public final class CameraXView extends ViewGroup {
     final float y = (mUpEvent != null) ? mUpEvent.getY() : getY() + getHeight() / 2f;
     mUpEvent = null;
 
-    TextureViewMeteringPointFactory pointFactory = new TextureViewMeteringPointFactory(
+    CameraSelector cameraSelector =
-        mCameraTextureView);
+        new CameraSelector.Builder().requireLensFacing(
+            mCameraModule.getLensFacing()).build();
+
+    DisplayOrientedMeteringPointFactory pointFactory = new DisplayOrientedMeteringPointFactory(
+        getDisplay(), cameraSelector, mPreviewView.getWidth(), mPreviewView.getHeight());
     float afPointWidth = 1.0f / 6.0f;  // 1/6 total area
     float aePointWidth = afPointWidth * 1.5f;
-    MeteringPoint afPoint = pointFactory.createPoint(x, y, afPointWidth, 1.0f);
+    MeteringPoint afPoint = pointFactory.createPoint(x, y, afPointWidth);
-    MeteringPoint aePoint = pointFactory.createPoint(x, y, aePointWidth, 1.0f);
+    MeteringPoint aePoint = pointFactory.createPoint(x, y, aePointWidth);
 
-    try {
+    Camera camera = mCameraModule.getCamera();
-      CameraX.getCameraControl(getCameraLensFacing()).startFocusAndMetering(
+    if (camera != null) {
-          FocusMeteringAction.Builder.from(afPoint, FocusMeteringAction.MeteringMode.AF_ONLY)
+      ListenableFuture<FocusMeteringResult> future =
-              .addPoint(aePoint, FocusMeteringAction.MeteringMode.AE_ONLY)
+          camera.getCameraControl().startFocusAndMetering(
-              .build());
+              new FocusMeteringAction.Builder(afPoint,
-    } catch (CameraInfoUnavailableException e) {
+                  FocusMeteringAction.FLAG_AF).addPoint(aePoint,
-      Log.d(TAG, "cannot access camera", e);
+                  FocusMeteringAction.FLAG_AE).build());
+      Futures.addCallback(future, new FutureCallback<FocusMeteringResult>() {
+        @Override
+        public void onSuccess(@Nullable FocusMeteringResult result) {
+        }
+
+        @Override
+        public void onFailure(Throwable t) {
+          // Throw the unexpected error.
+          throw new RuntimeException(t);
+        }
+      }, CameraXExecutors.directExecutor());
+
+    } else {
+      Log.d(TAG, "cannot access camera");
     }
 
     return true;
   }
 
-  /** Returns the width * height of the given rect */
-  private int area(Rect rect) {
-    return rect.width() * rect.height();
-  }
-
-  private int rangeLimit(int val, int max, int min) {
-    return Math.min(Math.max(val, min), max);
-  }
-
   float rangeLimit(float val, float max, float min) {
     return Math.min(Math.max(val, min), max);
   }
 
-  private int distance(int a, int b) {
-    return Math.abs(a - b);
-  }
-
   /**
    * Returns whether the view allows pinch-to-zoom.
    *
@@ -851,47 +641,47 @@ public final class CameraXView extends ViewGroup {
   }
 
   /**
-   * Returns the current zoom level.
+   * Returns the current zoom ratio.
    *
-   * @return The current zoom level.
+   * @return The current zoom ratio.
    */
-  public float getZoomLevel() {
+  public float getZoomRatio() {
-    return mCameraModule.getZoomLevel();
+    return mCameraModule.getZoomRatio();
   }
 
   /**
-   * Sets the current zoom level.
+   * Sets the current zoom ratio.
    *
-   * <p>Valid zoom values range from 1 to {@link #getMaxZoomLevel()}.
+   * <p>Valid zoom values range from {@link #getMinZoomRatio()} to {@link #getMaxZoomRatio()}.
    *
-   * @param zoomLevel The requested zoom level.
+   * @param zoomRatio The requested zoom ratio.
    */
-  public void setZoomLevel(float zoomLevel) {
+  public void setZoomRatio(float zoomRatio) {
-    mCameraModule.setZoomLevel(zoomLevel);
+    mCameraModule.setZoomRatio(zoomRatio);
   }
 
   /**
-   * Returns the minimum zoom level.
+   * Returns the minimum zoom ratio.
    *
-   * <p>For most cameras this should return a zoom level of 1. A zoom level of 1 corresponds to a
+   * <p>For most cameras this should return a zoom ratio of 1. A zoom ratio of 1 corresponds to a
    * non-zoomed image.
    *
-   * @return The minimum zoom level.
+   * @return The minimum zoom ratio.
    */
-  public float getMinZoomLevel() {
+  public float getMinZoomRatio() {
-    return mCameraModule.getMinZoomLevel();
+    return mCameraModule.getMinZoomRatio();
   }
 
   /**
-   * Returns the maximum zoom level.
+   * Returns the maximum zoom ratio.
    *
-   * <p>The zoom level corresponds to the ratio between both the widths and heights of a
+   * <p>The zoom ratio corresponds to the ratio between both the widths and heights of a
    * non-zoomed image and a maximally zoomed image for the selected camera.
    *
-   * @return The maximum zoom level.
+   * @return The maximum zoom ratio.
    */
-  public float getMaxZoomLevel() {
+  public float getMaxZoomRatio() {
-    return mCameraModule.getMaxZoomLevel();
+    return mCameraModule.getMaxZoomRatio();
   }
 
   /**
@@ -935,7 +725,7 @@ public final class CameraXView extends ViewGroup {
      */
     CENTER_INSIDE(1);
 
-    private int mId;
+    private final int mId;
 
     int getId() {
       return mId;
@@ -959,7 +749,7 @@ public final class CameraXView extends ViewGroup {
    * The capture mode used by CameraView.
    *
    * <p>This enum can be used to determine which capture mode will be enabled for {@link
-   * CameraView}.
+   * CameraXView}.
    */
   public enum CaptureMode {
     /** A mode where image capture is enabled. */
@@ -972,7 +762,7 @@ public final class CameraXView extends ViewGroup {
      */
     MIXED(2);
 
-    private int mId;
+    private final int mId;
 
     int getId() {
       return mId;
@@ -1007,10 +797,6 @@ public final class CameraXView extends ViewGroup {
 
   private class PinchToZoomGestureDetector extends ScaleGestureDetector
       implements ScaleGestureDetector.OnScaleGestureListener {
-    private static final float SCALE_MULTIPIER = 0.75f;
-    private final BaseInterpolator mInterpolator = new DecelerateInterpolator(2f);
-    private float mNormalizedScaleFactor = 0;
-
     PinchToZoomGestureDetector(Context context) {
       this(context, new S());
     }
@@ -1022,34 +808,23 @@ public final class CameraXView extends ViewGroup {
 
     @Override
     public boolean onScale(ScaleGestureDetector detector) {
-      mNormalizedScaleFactor += (detector.getScaleFactor() - 1f) * SCALE_MULTIPIER;
+      float scale = detector.getScaleFactor();
-      // Since the scale factor is normalized, it should always be in the range [0, 1]
-      mNormalizedScaleFactor = rangeLimit(mNormalizedScaleFactor, 1f, 0);
 
-      // Apply decelerate interpolation. This will cause the differences to seem less
+      // Speeding up the zoom by 2X.
-      // pronounced
+      if (scale > 1f) {
-      // at higher zoom levels.
+        scale = 1.0f + (scale - 1.0f) * 2;
-      float transformedScale = mInterpolator.getInterpolation(mNormalizedScaleFactor);
+      } else {
+        scale = 1.0f - (1.0f - scale) * 2;
+      }
 
-      // Transform back from normalized coordinates to the zoom scale
+      float newRatio = getZoomRatio() * scale;
-      float zoomLevel =
+      newRatio = rangeLimit(newRatio, getMaxZoomRatio(), getMinZoomRatio());
-          (getMaxZoomLevel() == getMinZoomLevel())
+      setZoomRatio(newRatio);
-              ? getMinZoomLevel()
-              : getMinZoomLevel()
-              + transformedScale * (getMaxZoomLevel() - getMinZoomLevel());
-
-      setZoomLevel(rangeLimit(zoomLevel, getMaxZoomLevel(), getMinZoomLevel()));
       return true;
     }
 
     @Override
     public boolean onScaleBegin(ScaleGestureDetector detector) {
-      float initialZoomLevel = getZoomLevel();
-      mNormalizedScaleFactor =
-          (getMaxZoomLevel() == getMinZoomLevel())
-              ? 0
-              : (initialZoomLevel - getMinZoomLevel())
-              / (getMaxZoomLevel() - getMinZoomLevel());
       return true;
     }
 

app/src/main/java/org/thoughtcrime/securesms/mediasend/camerax/FlashModeConverter.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.thoughtcrime.securesms.mediasend.camerax;
+
+import static androidx.camera.core.ImageCapture.FLASH_MODE_AUTO;
+import static androidx.camera.core.ImageCapture.FLASH_MODE_OFF;
+import static androidx.camera.core.ImageCapture.FLASH_MODE_ON;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.camera.core.ImageCapture.FlashMode;
+
+/**
+ * Helper class that defines certain enum-like methods for {@link FlashMode}
+ */
+final class FlashModeConverter {
+
+  private FlashModeConverter() {
+  }
+
+  /**
+   * Returns the {@link FlashMode} constant for the specified name
+   *
+   * @param name The name of the {@link FlashMode} to return
+   * @return The {@link FlashMode} constant for the specified name
+   */
+  @FlashMode
+  public static int valueOf(@Nullable final String name) {
+    if (name == null) {
+      throw new NullPointerException("name cannot be null");
+    }
+
+    switch (name) {
+      case "AUTO":
+        return FLASH_MODE_AUTO;
+      case "ON":
+        return FLASH_MODE_ON;
+      case "OFF":
+        return FLASH_MODE_OFF;
+      default:
+        throw new IllegalArgumentException("Unknown flash mode name " + name);
+    }
+  }
+
+  /**
+   * Returns the name of the {@link FlashMode} constant, exactly as it is declared.
+   *
+   * @param flashMode A {@link FlashMode} constant
+   * @return The name of the {@link FlashMode} constant.
+   */
+  @NonNull
+  public static String nameOf(@FlashMode final int flashMode) {
+    switch (flashMode) {
+      case FLASH_MODE_AUTO:
+        return "AUTO";
+      case FLASH_MODE_ON:
+        return "ON";
+      case FLASH_MODE_OFF:
+        return "OFF";
+      default:
+        throw new IllegalArgumentException("Unknown flash mode " + flashMode);
+    }
+  }
+}

app/src/main/java/org/thoughtcrime/securesms/mediasend/camerax/PreviewView.java

@@ -0,0 +1,273 @@
+/*
+ * Copyright 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.thoughtcrime.securesms.mediasend.camerax;
+
+import android.content.Context;
+import android.content.res.TypedArray;
+import android.hardware.display.DisplayManager;
+import android.os.Build;
+import android.util.AttributeSet;
+import android.widget.FrameLayout;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.annotation.RequiresApi;
+import androidx.camera.core.Preview;
+
+import org.thoughtcrime.securesms.R;
+
+import java.util.concurrent.Executor;
+
+/**
+ * Custom View that displays camera feed for CameraX's Preview use case.
+ *
+ * <p> This class manages the Surface lifecycle, as well as the preview aspect ratio and
+ * orientation. Internally, it uses either a {@link android.view.TextureView} or
+ * {@link android.view.SurfaceView} to display the camera feed.
+ */
+// Begin Signal Custom Code Block
+@RequiresApi(21)
+// End Signal Custom Code Block
+public class PreviewView extends FrameLayout {
+
+    @SuppressWarnings("WeakerAccess") /* synthetic accessor */
+    Implementation mImplementation;
+
+    private ImplementationMode mImplementationMode;
+
+    private final DisplayManager.DisplayListener mDisplayListener =
+            new DisplayManager.DisplayListener() {
+        @Override
+        public void onDisplayAdded(int displayId) {
+        }
+
+        @Override
+        public void onDisplayRemoved(int displayId) {
+        }
+        @Override
+        public void onDisplayChanged(int displayId) {
+            mImplementation.onDisplayChanged();
+        }
+    };
+
+    public PreviewView(@NonNull Context context) {
+        this(context, null);
+    }
+
+    public PreviewView(@NonNull Context context, @Nullable AttributeSet attrs) {
+        this(context, attrs, 0);
+    }
+
+    public PreviewView(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
+        this(context, attrs, defStyleAttr, 0);
+    }
+
+    public PreviewView(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr,
+            int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+
+        final TypedArray attributes = context.getTheme().obtainStyledAttributes(attrs,
+                R.styleable.PreviewView, defStyleAttr, defStyleRes);
+
+        try {
+            final int implementationModeId = attributes.getInteger(
+                    R.styleable.PreviewView_implementationMode,
+                    ImplementationMode.TEXTURE_VIEW.getId());
+            mImplementationMode = ImplementationMode.fromId(implementationModeId);
+        } finally {
+            attributes.recycle();
+        }
+        setUp();
+    }
+
+    @Override
+    protected void onAttachedToWindow() {
+        super.onAttachedToWindow();
+        final DisplayManager displayManager =
+                (DisplayManager) getContext().getSystemService(Context.DISPLAY_SERVICE);
+        if (displayManager != null) {
+            displayManager.registerDisplayListener(mDisplayListener, getHandler());
+        }
+    }
+
+    @Override
+    protected void onDetachedFromWindow() {
+        super.onDetachedFromWindow();
+        final DisplayManager displayManager =
+                (DisplayManager) getContext().getSystemService(Context.DISPLAY_SERVICE);
+        if (displayManager != null) {
+            displayManager.unregisterDisplayListener(mDisplayListener);
+        }
+    }
+
+    private void setUp() {
+        removeAllViews();
+        switch (mImplementationMode) {
+            case SURFACE_VIEW:
+                mImplementation = new SurfaceViewImplementation();
+                break;
+            case TEXTURE_VIEW:
+                mImplementation = new TextureViewImplementation();
+                break;
+            default:
+                throw new IllegalStateException(
+                        "Unsupported implementation mode " + mImplementationMode);
+        }
+        mImplementation.init(this);
+    }
+
+    /**
+     * Specifies the {@link ImplementationMode} to use for the preview.
+     *
+     * @param implementationMode <code>SURFACE_VIEW</code> if a {@link android.view.SurfaceView}
+     *                           should be used to display the camera feed, or
+     *                           <code>TEXTURE_VIEW</code> to use a {@link android.view.TextureView}
+     */
+    public void setImplementationMode(@NonNull final ImplementationMode implementationMode) {
+        mImplementationMode = implementationMode;
+        setUp();
+    }
+
+    /**
+     * Returns the implementation mode of the {@link PreviewView}.
+     *
+     * @return <code>SURFACE_VIEW</code> if the {@link PreviewView} is internally using a
+     * {@link android.view.SurfaceView} to display the camera feed, or <code>TEXTURE_VIEW</code>
+     * if a {@link android.view.TextureView} is being used.
+     */
+    @NonNull
+    public ImplementationMode getImplementationMode() {
+        return mImplementationMode;
+    }
+
+    /**
+     * Gets the {@link Preview.SurfaceProvider} to be used with
+     * {@link Preview#setSurfaceProvider(Executor, Preview.SurfaceProvider)}.
+     */
+    @NonNull
+    public Preview.SurfaceProvider getPreviewSurfaceProvider() {
+        return mImplementation.getSurfaceProvider();
+    }
+
+    /**
+     * Implements this interface to create PreviewView implementation.
+     */
+    interface Implementation {
+
+        /**
+         * Initializes the parent view with sub views.
+         *
+         * @param parent the containing parent {@link FrameLayout}.
+         */
+        void init(@NonNull FrameLayout parent);
+
+        /**
+         * Gets the {@link Preview.SurfaceProvider} to be used with {@link Preview}.
+         */
+        @NonNull
+        Preview.SurfaceProvider getSurfaceProvider();
+
+        /**
+         *  Notifies that the display properties have changed.
+         *
+         *  <p>Implementation might need to adjust transform by latest display properties such as
+         *  display orientation in order to show the preview correctly.
+         */
+        void onDisplayChanged();
+    }
+
+    /**
+     * The implementation mode of a {@link PreviewView}
+     *
+     * <p>Specifies how the Preview surface will be implemented internally: Using a
+     * {@link android.view.SurfaceView} or a {@link android.view.TextureView} (which is the default)
+     * </p>
+     */
+    public enum ImplementationMode {
+        /** Use a {@link android.view.SurfaceView} for the preview */
+        SURFACE_VIEW(0),
+
+        /** Use a {@link android.view.TextureView} for the preview */
+        TEXTURE_VIEW(1);
+
+        private final int mId;
+
+        ImplementationMode(final int id) {
+            mId = id;
+        }
+
+        public int getId() {
+            return mId;
+        }
+
+        static ImplementationMode fromId(final int id) {
+            for (final ImplementationMode mode : values()) {
+                if (mode.mId == id) {
+                    return mode;
+                }
+            }
+            throw new IllegalArgumentException("Unsupported implementation mode " + id);
+        }
+    }
+
+    /** Options for scaling the preview vis-à-vis its container {@link PreviewView}. */
+    public enum ScaleType {
+        /**
+         * Scale the preview, maintaining the source aspect ratio, so it fills the entire
+         * {@link PreviewView}, and align it to the top left corner of the view.
+         * This may cause the preview to be cropped if the camera preview aspect ratio does not
+         * match that of its container {@link PreviewView}.
+         */
+        FILL_START,
+        /**
+         * Scale the preview, maintaining the source aspect ratio, so it fills the entire
+         * {@link PreviewView}, and center it inside the view.
+         * This may cause the preview to be cropped if the camera preview aspect ratio does not
+         * match that of its container {@link PreviewView}.
+         */
+        FILL_CENTER,
+        /**
+         * Scale the preview, maintaining the source aspect ratio, so it fills the entire
+         * {@link PreviewView}, and align it to the bottom right corner of the view.
+         * This may cause the preview to be cropped if the camera preview aspect ratio does not
+         * match that of its container {@link PreviewView}.
+         */
+        FILL_END,
+        /**
+         * Scale the preview, maintaining the source aspect ratio, so it is entirely contained
+         * within the {@link PreviewView}, and align it to the top left corner of the view.
+         * Both dimensions of the preview will be equal or less than the corresponding dimensions
+         * of its container {@link PreviewView}.
+         */
+        FIT_START,
+        /**
+         * Scale the preview, maintaining the source aspect ratio, so it is entirely contained
+         * within the {@link PreviewView}, and center it inside the view.
+         * Both dimensions of the preview will be equal or less than the corresponding dimensions
+         * of its container {@link PreviewView}.
+         */
+        FIT_CENTER,
+        /**
+         * Scale the preview, maintaining the source aspect ratio, so it is entirely contained
+         * within the {@link PreviewView}, and align it to the bottom right corner of the view.
+         * Both dimensions of the preview will be equal or less than the corresponding dimensions
+         * of its container {@link PreviewView}.
+         */
+        FIT_END
+    }
+}
+

app/src/main/java/org/thoughtcrime/securesms/mediasend/camerax/ScaleTypeTransform.java

@@ -0,0 +1,162 @@
+/*
+ * Copyright 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.thoughtcrime.securesms.mediasend.camerax;
+
+import android.content.Context;
+import android.graphics.Point;
+import android.util.Pair;
+import android.util.Size;
+import android.view.Display;
+import android.view.View;
+import android.view.WindowManager;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.RequiresApi;
+
+// Begin Signal Custom Code Block
+@RequiresApi(21)
+// End Signal Custom Code Block
+final class ScaleTypeTransform {
+
+    /**
+     * Computes the scale by which a view has to scale in x and y in order to fill its parent
+     * while maintaining the buffer's aspect ratio.
+     *
+     * @param container  A parent {@link android.view.View} that wraps {@code view}.
+     * @param view       A child {@link android.view.View} of {@code container}.
+     * @param bufferSize A {@link android.util.Size} whose aspect ratio must be maintained when
+     *                   scaling {@code view} inside its parent {@code container}.
+     * @return The scale by which {@code view} has to scale in x and y in order to fill its
+     * parent while maintaining {@code bufferSize}'s aspect ratio.
+     */
+    @SuppressWarnings("SuspiciousNameCombination")
+    static Pair<Float, Float> getFillScaleWithBufferAspectRatio(@NonNull final View container,
+            @NonNull final View view, @NonNull final Size bufferSize) {
+        // Scaling only makes sense when none of the dimensions are equal to zero. In the
+        // opposite case, a default scale of 1 is returned,
+        if (container.getWidth() == 0 || container.getHeight() == 0 || view.getWidth() == 0
+                || view.getHeight() == 0 || bufferSize.getWidth() == 0
+                || bufferSize.getHeight() == 0) {
+            return new Pair<>(1F, 1F);
+        }
+
+        final int viewRotationDegrees = getRotationDegrees(view);
+        final boolean isNaturalPortrait = isNaturalPortrait(view.getContext(), viewRotationDegrees);
+
+        final int bufferWidth;
+        final int bufferHeight;
+        if (isNaturalPortrait) {
+            bufferWidth = bufferSize.getHeight();
+            bufferHeight = bufferSize.getWidth();
+        } else {
+            bufferWidth = bufferSize.getWidth();
+            bufferHeight = bufferSize.getHeight();
+        }
+
+        // Scale the buffers back to the original output size.
+        float scaleX = bufferWidth / (float) view.getWidth();
+        float scaleY = bufferHeight / (float) view.getHeight();
+
+        int bufferRotatedWidth;
+        int bufferRotatedHeight;
+        if (viewRotationDegrees == 0 || viewRotationDegrees == 180) {
+            bufferRotatedWidth = bufferWidth;
+            bufferRotatedHeight = bufferHeight;
+        } else {
+            bufferRotatedWidth = bufferHeight;
+            bufferRotatedHeight = bufferWidth;
+        }
+
+        // Scale the buffer so that it completely fills the container.
+        final float scale = Math.max(container.getWidth() / (float) bufferRotatedWidth,
+                container.getHeight() / (float) bufferRotatedHeight);
+        scaleX *= scale;
+        scaleY *= scale;
+
+        return new Pair<>(scaleX, scaleY);
+    }
+
+    /**
+     * Computes the top left coordinates for the view to be centered inside its parent.
+     *
+     * @param container A parent {@link android.view.View} that wraps {@code view}.
+     * @param view      A child {@link android.view.View} of {@code container}.
+     * @return A {@link android.graphics.Point} whose coordinates represent the top left of
+     * {@code view} when centered inside its parent.
+     */
+    static Point getOriginOfCenteredView(@NonNull final View container,
+            @NonNull final View view) {
+        final int offsetX = (view.getWidth() - container.getWidth()) / 2;
+        final int offsetY = (view.getHeight() - container.getHeight()) / 2;
+        return new Point(-offsetX, -offsetY);
+    }
+
+    /**
+     * Computes the rotation of a {@link android.view.View} in degrees from its natural
+     * orientation.
+     */
+    static int getRotationDegrees(@NonNull final View view) {
+        final WindowManager windowManager = (WindowManager) view.getContext().getSystemService(
+                Context.WINDOW_SERVICE);
+        if (windowManager == null) {
+            return 0;
+        }
+        final int rotation = windowManager.getDefaultDisplay().getRotation();
+        return SurfaceRotation.rotationDegreesFromSurfaceRotation(rotation);
+    }
+
+    /**
+     * Determines whether the current device is a natural portrait-oriented device
+     *
+     * <p>
+     * Using the current app's window to determine whether the device is a natural
+     * portrait-oriented device doesn't work in all scenarios, one example of this is multi-window
+     * mode.
+     * Taking a natural portrait-oriented device in multi-window mode, rotating it 90 degrees (so
+     * that it's in landscape), with the app open, and its window's width being smaller than its
+     * height. Using the app's width and height would determine that the device isn't
+     * naturally portrait-oriented, where in fact it is, which is why it is important to use the
+     * size of the device instead.
+     * </p>
+     *
+     * @param context         Current context. Can be an {@link android.app.Application} context
+     *                        or an {@link android.app.Activity} context.
+     * @param rotationDegrees The device's rotation in degrees from its natural orientation.
+     * @return Whether the device is naturally portrait-oriented.
+     */
+    private static boolean isNaturalPortrait(@NonNull final Context context,
+            final int rotationDegrees) {
+        final WindowManager windowManager = (WindowManager) context.getSystemService(
+                Context.WINDOW_SERVICE);
+        if (windowManager == null) {
+            return true;
+        }
+
+        final Display display = windowManager.getDefaultDisplay();
+        final Point deviceSize = new Point();
+        display.getRealSize(deviceSize);
+
+        final int width = deviceSize.x;
+        final int height = deviceSize.y;
+        return ((rotationDegrees == 0 || rotationDegrees == 180) && width < height) || (
+                (rotationDegrees == 90 || rotationDegrees == 270) && width >= height);
+    }
+
+    // Prevent creating an instance
+    private ScaleTypeTransform() {
+    }
+}

app/src/main/java/org/thoughtcrime/securesms/mediasend/camerax/SurfaceRotation.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.thoughtcrime.securesms.mediasend.camerax;
+
+import android.view.Surface;
+
+final class SurfaceRotation {
+    /**
+     * Get the int value degree of a rotation from the {@link Surface} constants.
+     *
+     * <p>Valid values for the relative rotation are {@link Surface#ROTATION_0}, {@link
+     *      * Surface#ROTATION_90}, {@link Surface#ROTATION_180}, {@link Surface#ROTATION_270}.
+     */
+    static int rotationDegreesFromSurfaceRotation(int rotationConstant) {
+        switch (rotationConstant) {
+            case Surface.ROTATION_0:
+                return 0;
+            case Surface.ROTATION_90:
+                return 90;
+            case Surface.ROTATION_180:
+                return 180;
+            case Surface.ROTATION_270:
+                return 270;
+            default:
+                throw new UnsupportedOperationException(
+                        "Unsupported surface rotation constant: " + rotationConstant);
+        }
+    }
+
+    /** Prevents construction */
+    private SurfaceRotation() {}
+}

app/src/main/java/org/thoughtcrime/securesms/mediasend/camerax/SurfaceViewImplementation.java

@@ -0,0 +1,180 @@
+/*
+ * Copyright 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.thoughtcrime.securesms.mediasend.camerax;
+
+import android.util.Log;
+import android.util.Size;
+import android.view.Surface;
+import android.view.SurfaceHolder;
+import android.widget.FrameLayout;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.annotation.RequiresApi;
+import androidx.annotation.UiThread;
+import androidx.camera.core.Preview;
+import androidx.camera.core.SurfaceRequest;
+import androidx.core.content.ContextCompat;
+
+/**
+ * The SurfaceView implementation for {@link PreviewView}.
+ */
+@RequiresApi(21)
+final class SurfaceViewImplementation implements PreviewView.Implementation {
+
+    private static final String TAG = "SurfaceViewPreviewView";
+
+    // Synthetic Accessor
+    @SuppressWarnings("WeakerAccess")
+    TransformableSurfaceView mSurfaceView;
+
+    // Synthetic Accessor
+    @SuppressWarnings("WeakerAccess")
+    final SurfaceRequestCallback mSurfaceRequestCallback =
+            new SurfaceRequestCallback();
+
+    private Preview.SurfaceProvider mSurfaceProvider =
+            new Preview.SurfaceProvider() {
+                @Override
+                public void onSurfaceRequested(@NonNull SurfaceRequest surfaceRequest) {
+                    mSurfaceView.post(
+                            () -> mSurfaceRequestCallback.setSurfaceRequest(surfaceRequest));
+                }
+            };
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void init(@NonNull FrameLayout parent) {
+        mSurfaceView = new TransformableSurfaceView(parent.getContext());
+        mSurfaceView.setLayoutParams(
+                new FrameLayout.LayoutParams(
+                        FrameLayout.LayoutParams.MATCH_PARENT,
+                        FrameLayout.LayoutParams.MATCH_PARENT));
+        parent.addView(mSurfaceView);
+        mSurfaceView.getHolder().addCallback(mSurfaceRequestCallback);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @NonNull
+    @Override
+    public Preview.SurfaceProvider getSurfaceProvider() {
+        return mSurfaceProvider;
+    }
+
+    @Override
+    public void onDisplayChanged() {
+
+    }
+
+    /**
+     * The {@link SurfaceHolder.Callback} on mSurfaceView.
+     *
+     * <p> SurfaceView creates Surface on its own before we can do anything. This class makes
+     * sure only the Surface with correct size will be returned to Preview.
+     */
+    class SurfaceRequestCallback implements SurfaceHolder.Callback {
+
+        // Target Surface size. Only complete the SurfaceRequest when the size of the Surface
+        // matches this value.
+        // Guarded by UI thread.
+        @Nullable
+        private Size mTargetSize;
+
+        // SurfaceRequest to set when the target size is met.
+        // Guarded by UI thread.
+        @Nullable
+        private SurfaceRequest mSurfaceRequest;
+
+        // The cached size of the current Surface.
+        // Guarded by UI thread.
+        @Nullable
+        private Size mCurrentSurfaceSize;
+
+        /**
+         * Sets the completer and the size. The completer will only be set if the current size of
+         * the Surface matches the target size.
+         */
+        @UiThread
+        void setSurfaceRequest(@NonNull SurfaceRequest surfaceRequest) {
+            cancelPreviousRequest();
+            mSurfaceRequest = surfaceRequest;
+            Size targetSize = surfaceRequest.getResolution();
+            mTargetSize = targetSize;
+            if (!tryToComplete()) {
+                // The current size is incorrect. Wait for it to change.
+                Log.d(TAG, "Wait for new Surface creation.");
+                mSurfaceView.getHolder().setFixedSize(targetSize.getWidth(),
+                        targetSize.getHeight());
+            }
+        }
+
+        /**
+         * Sets the completer if size matches.
+         *
+         * @return true if the completer is set.
+         */
+        @UiThread
+        private boolean tryToComplete() {
+            Surface surface = mSurfaceView.getHolder().getSurface();
+            if (mSurfaceRequest != null && mTargetSize != null && mTargetSize.equals(
+                    mCurrentSurfaceSize)) {
+                Log.d(TAG, "Surface set on Preview.");
+                mSurfaceRequest.provideSurface(surface,
+                        ContextCompat.getMainExecutor(mSurfaceView.getContext()),
+                        (result) -> Log.d(TAG, "Safe to release surface."));
+                mSurfaceRequest = null;
+                mTargetSize = null;
+                return true;
+            }
+            return false;
+        }
+
+        @UiThread
+        private void cancelPreviousRequest() {
+            if (mSurfaceRequest != null) {
+                Log.d(TAG, "Request canceled: " + mSurfaceRequest);
+                mSurfaceRequest.willNotProvideSurface();
+                mSurfaceRequest = null;
+            }
+            mTargetSize = null;
+        }
+
+        @Override
+        public void surfaceCreated(SurfaceHolder surfaceHolder) {
+            Log.d(TAG, "Surface created.");
+            // No-op. Handling surfaceChanged() is enough because it's always called afterwards.
+        }
+
+        @Override
+        public void surfaceChanged(SurfaceHolder surfaceHolder, int format, int width, int height) {
+            Log.d(TAG, "Surface changed. Size: " + width + "x" + height);
+            mCurrentSurfaceSize = new Size(width, height);
+            tryToComplete();
+        }
+
+        @Override
+        public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
+            Log.d(TAG, "Surface destroyed.");
+            mCurrentSurfaceSize = null;
+            cancelPreviousRequest();
+        }
+    }
+}

app/src/main/java/org/thoughtcrime/securesms/mediasend/camerax/TextureViewImplementation.java

@@ -0,0 +1,238 @@
+/*
+ * Copyright 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.thoughtcrime.securesms.mediasend.camerax;
+
+import static androidx.camera.core.SurfaceRequest.Result;
+
+import android.annotation.SuppressLint;
+import android.graphics.Point;
+import android.graphics.SurfaceTexture;
+import android.util.Log;
+import android.util.Pair;
+import android.util.Size;
+import android.view.Surface;
+import android.view.TextureView;
+import android.view.View;
+import android.widget.FrameLayout;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.RequiresApi;
+import androidx.camera.core.Preview;
+import androidx.camera.core.SurfaceRequest;
+import androidx.camera.core.impl.utils.executor.CameraXExecutors;
+import androidx.camera.core.impl.utils.futures.FutureCallback;
+import androidx.camera.core.impl.utils.futures.Futures;
+import androidx.concurrent.futures.CallbackToFutureAdapter;
+import androidx.core.content.ContextCompat;
+import androidx.core.util.Preconditions;
+
+import com.google.common.util.concurrent.ListenableFuture;
+
+/**
+ * The {@link TextureView} implementation for {@link PreviewView}
+ */
+// Begin Signal Custom Code Block
+@RequiresApi(21)
+@SuppressLint("RestrictedApi")
+// End Signal Custom Code Block
+public class TextureViewImplementation implements PreviewView.Implementation {
+
+    private static final String TAG = "TextureViewImpl";
+
+    private FrameLayout mParent;
+    TextureView mTextureView;
+    SurfaceTexture mSurfaceTexture;
+    private Size mResolution;
+    ListenableFuture<Result> mSurfaceReleaseFuture;
+    SurfaceRequest mSurfaceRequest;
+
+    @Override
+    public void init(@NonNull FrameLayout parent) {
+        mParent = parent;
+    }
+
+    @NonNull
+    @Override
+    public Preview.SurfaceProvider getSurfaceProvider() {
+        return (surfaceRequest) -> {
+            mResolution = surfaceRequest.getResolution();
+            initInternal();
+            if (mSurfaceRequest != null) {
+                mSurfaceRequest.willNotProvideSurface();
+            }
+
+            mSurfaceRequest = surfaceRequest;
+            surfaceRequest.addRequestCancellationListener(
+                    ContextCompat.getMainExecutor(mTextureView.getContext()), () -> {
+                        if (mSurfaceRequest != null && mSurfaceRequest == surfaceRequest) {
+                            mSurfaceRequest = null;
+                            mSurfaceReleaseFuture = null;
+                        }
+                    });
+
+            tryToProvidePreviewSurface();
+        };
+    }
+
+    @Override
+    public void onDisplayChanged() {
+        if (mParent == null || mTextureView == null || mResolution == null) {
+            return;
+        }
+
+        correctPreviewForCenterCrop(mParent, mTextureView, mResolution);
+    }
+
+    private void initInternal() {
+        mTextureView = new TextureView(mParent.getContext());
+        mTextureView.setLayoutParams(
+                new FrameLayout.LayoutParams(mResolution.getWidth(), mResolution.getHeight()));
+        mTextureView.setSurfaceTextureListener(new TextureView.SurfaceTextureListener() {
+            @Override
+            public void onSurfaceTextureAvailable(final SurfaceTexture surfaceTexture,
+                    final int width, final int height) {
+                mSurfaceTexture = surfaceTexture;
+                tryToProvidePreviewSurface();
+            }
+
+            @Override
+            public void onSurfaceTextureSizeChanged(final SurfaceTexture surfaceTexture,
+                    final int width, final int height) {
+                Log.d(TAG, "onSurfaceTextureSizeChanged(width:" + width + ", height: " + height
+                        + " )");
+            }
+
+            /**
+             * If a surface has been provided to the camera (meaning
+             * {@link TextureViewImplementation#mSurfaceRequest} is null), but the camera
+             * is still using it (meaning {@link TextureViewImplementation#mSurfaceReleaseFuture} is
+             * not null), a listener must be added to
+             * {@link TextureViewImplementation#mSurfaceReleaseFuture} to ensure the surface
+             * is properly released after the camera is done using it.
+             *
+             * @param surfaceTexture The {@link SurfaceTexture} about to be destroyed.
+             * @return false if the camera is not done with the surface, true otherwise.
+             */
+            @Override
+            public boolean onSurfaceTextureDestroyed(final SurfaceTexture surfaceTexture) {
+                mSurfaceTexture = null;
+                if (mSurfaceRequest == null && mSurfaceReleaseFuture != null) {
+                    Futures.addCallback(mSurfaceReleaseFuture,
+                            new FutureCallback<Result>() {
+                                @Override
+                                public void onSuccess(Result result) {
+                                    Preconditions.checkState(result.getResultCode()
+                                                    != Result.RESULT_SURFACE_ALREADY_PROVIDED,
+                                            "Unexpected result from SurfaceRequest. Surface was "
+                                                    + "provided twice.");
+                                    surfaceTexture.release();
+                                }
+
+                                @Override
+                                public void onFailure(Throwable t) {
+                                    throw new IllegalStateException("SurfaceReleaseFuture did not "
+                                            + "complete nicely.", t);
+                                }
+                            }, ContextCompat.getMainExecutor(mTextureView.getContext()));
+                    return false;
+                } else {
+                    return true;
+                }
+            }
+
+            @Override
+            public void onSurfaceTextureUpdated(final SurfaceTexture surfaceTexture) {
+            }
+        });
+
+        // Even though PreviewView calls `removeAllViews()` before calling init(), it should be
+        // called again here in case `getPreviewSurfaceProvider()` is called more than once on
+        // the same TextureViewImplementation instance.
+        mParent.removeAllViews();
+        mParent.addView(mTextureView);
+    }
+
+    @SuppressWarnings("WeakerAccess")
+    void tryToProvidePreviewSurface() {
+        /*
+          Should only continue if:
+          - The preview size has been specified.
+          - The textureView's surfaceTexture is available (after TextureView
+          .SurfaceTextureListener#onSurfaceTextureAvailable is invoked)
+          - The surfaceCompleter has been set (after CallbackToFutureAdapter
+          .Resolver#attachCompleter is invoked).
+         */
+        if (mResolution == null || mSurfaceTexture == null || mSurfaceRequest == null) {
+            return;
+        }
+
+        mSurfaceTexture.setDefaultBufferSize(mResolution.getWidth(), mResolution.getHeight());
+
+        final Surface surface = new Surface(mSurfaceTexture);
+        final ListenableFuture<Result> surfaceReleaseFuture =
+                CallbackToFutureAdapter.getFuture(completer -> {
+                    mSurfaceRequest.provideSurface(surface,
+                            CameraXExecutors.directExecutor(), completer::set);
+                    return "provideSurface[request=" + mSurfaceRequest + " surface=" + surface
+                            + "]";
+                });
+        mSurfaceReleaseFuture = surfaceReleaseFuture;
+        mSurfaceReleaseFuture.addListener(() -> {
+            surface.release();
+            if (mSurfaceReleaseFuture == surfaceReleaseFuture) {
+                mSurfaceReleaseFuture = null;
+            }
+        }, ContextCompat.getMainExecutor(mTextureView.getContext()));
+
+        mSurfaceRequest = null;
+
+        correctPreviewForCenterCrop(mParent, mTextureView, mResolution);
+    }
+
+    /**
+     * Corrects the preview to match the UI orientation and completely fill the PreviewView.
+     *
+     * <p>
+     * The camera produces a preview that depends on its sensor orientation and that has a
+     * specific resolution. In order to display it correctly, this preview must be rotated to
+     * match the UI orientation, and must be scaled up/down to fit inside the view that's
+     * displaying it. This method takes care of doing so while keeping the preview centered.
+     * </p>
+     *
+     * @param container   The {@link PreviewView}'s root layout, which wraps the preview.
+     * @param textureView The {@link android.view.TextureView} that displays the preview, its size
+     *                    must match the camera sensor output size.
+     * @param bufferSize  The camera sensor output size.
+     */
+    private void correctPreviewForCenterCrop(@NonNull final View container,
+            @NonNull final TextureView textureView, @NonNull final Size bufferSize) {
+        // Scale TextureView to fill PreviewView while respecting sensor output size aspect ratio
+        final Pair<Float, Float> scale = ScaleTypeTransform.getFillScaleWithBufferAspectRatio(container, textureView,
+                bufferSize);
+        textureView.setScaleX(scale.first);
+        textureView.setScaleY(scale.second);
+
+        // Center TextureView inside PreviewView
+        final Point newOrigin = ScaleTypeTransform.getOriginOfCenteredView(container, textureView);
+        textureView.setX(newOrigin.x);
+        textureView.setY(newOrigin.y);
+
+        // Rotate TextureView to correct preview orientation
+        final int rotation = ScaleTypeTransform.getRotationDegrees(textureView);
+        textureView.setRotation(-rotation);
+    }
+}

app/src/main/java/org/thoughtcrime/securesms/mediasend/camerax/TextureViewMeteringPointFactory.java

@@ -22,6 +22,7 @@ import android.graphics.SurfaceTexture;
 import android.view.TextureView;
 
 import androidx.annotation.NonNull;
+import androidx.annotation.RestrictTo;
 import androidx.camera.core.MeteringPoint;
 import androidx.camera.core.MeteringPointFactory;
 
@@ -45,10 +46,13 @@ public class TextureViewMeteringPointFactory extends MeteringPointFactory {
 
     /**
      * Translates a (x,y) from TextureView.
+     *
+     * @hide
      */
     @NonNull
+    @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
     @Override
-  protected PointF translatePoint(float x, float y) {
+    protected PointF convertPoint(float x, float y) {
         Matrix transform = new Matrix();
         mTextureView.getTransform(transform);
 

app/src/main/java/org/thoughtcrime/securesms/mediasend/camerax/TransformableSurfaceView.java

@@ -0,0 +1,130 @@
+/*
+ * Copyright 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.thoughtcrime.securesms.mediasend.camerax;
+
+import android.content.Context;
+import android.graphics.Matrix;
+import android.graphics.RectF;
+import android.util.AttributeSet;
+import android.view.SurfaceView;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.annotation.RequiresApi;
+
+/**
+ * A subclass of {@link SurfaceView} that supports translation and scaling transformations.
+ */
+// Begin Signal Custom Code Block
+@RequiresApi(21)
+// End Signal Custom Code Block
+final class TransformableSurfaceView extends SurfaceView {
+
+    private RectF mOverriddenLayoutRect;
+
+    TransformableSurfaceView(@NonNull Context context) {
+        super(context);
+    }
+
+    TransformableSurfaceView(@NonNull Context context, @Nullable AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    TransformableSurfaceView(@NonNull Context context, @Nullable AttributeSet attrs,
+            int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    TransformableSurfaceView(@NonNull Context context, @Nullable AttributeSet attrs,
+            int defStyleAttr, int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        if (mOverriddenLayoutRect == null) {
+            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+        } else {
+            setMeasuredDimension((int) mOverriddenLayoutRect.width(),
+                    (int) mOverriddenLayoutRect.height());
+        }
+    }
+
+    /**
+     * Sets the transform to associate with this surface view. Only translation and scaling are
+     * supported. If a rotated transformation is passed in, an exception is thrown.
+     *
+     * @param transform The transform to apply to the content of this view.
+     */
+    void setTransform(final Matrix transform) {
+        if (hasRotation(transform)) {
+            throw new IllegalArgumentException("TransformableSurfaceView does not support "
+                    + "rotation transformations.");
+        }
+
+        final RectF rect = new RectF(getLeft(), getTop(), getRight(), getBottom());
+        transform.mapRect(rect);
+        overrideLayout(rect);
+    }
+
+    private boolean hasRotation(final Matrix matrix) {
+        final float[] values = new float[9];
+        matrix.getValues(values);
+
+        /*
+          A translation matrix can be represented as:
+          (1  0  transX)
+          (0  1  transX)
+          (0  0  1)
+
+          A rotation Matrix of ψ degrees can be represented as:
+          (cosψ  -sinψ  0)
+          (sinψ  cosψ   0)
+          (0     0      1)
+
+          A scale matrix can be represented as:
+          (scaleX  0       0)
+          (0       scaleY  0)
+          (0       0       0)
+
+          Meaning a transformed matrix can be represented as:
+          (scaleX * cosψ    -scaleX * sinψ    transX)
+          (scaleY * sinψ    scaleY * cosψ     transY)
+          (0                0                 1)
+
+          Using the following 2 equalities:
+          scaleX * cosψ = matrix[0][0]
+          -scaleX * sinψ = matrix[0][1]
+
+          The following is deduced:
+          -tanψ = matrix[0][1] / matrix[0][0]
+
+          Or:
+          ψ = -arctan(matrix[0][1] / matrix[0][0])
+         */
+        final double angle = -Math.atan2(values[Matrix.MSKEW_X], values[Matrix.MSCALE_X]);
+
+        return Math.round(angle * (180 / Math.PI)) != 0;
+    }
+
+    private void overrideLayout(final RectF overriddenLayoutRect) {
+        mOverriddenLayoutRect = overriddenLayoutRect;
+        setX(overriddenLayoutRect.left);
+        setY(overriddenLayoutRect.top);
+        requestLayout();
+    }
+}

app/src/main/java/org/thoughtcrime/securesms/mediasend/camerax/VideoCapture.java

@@ -16,7 +16,22 @@
 
 package org.thoughtcrime.securesms.mediasend.camerax;
 
-import android.annotation.SuppressLint;
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 import android.location.Location;
 import android.media.AudioFormat;
 import android.media.AudioRecord;
@@ -30,39 +45,42 @@ import android.media.MediaMuxer;
 import android.media.MediaRecorder.AudioSource;
 import android.os.Handler;
 import android.os.HandlerThread;
-import android.os.Looper;
+import android.util.Log;
 import android.util.Size;
 import android.view.Display;
 import android.view.Surface;
 
 import androidx.annotation.GuardedBy;
+import androidx.annotation.IntDef;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.annotation.RequiresApi;
 import androidx.annotation.RestrictTo;
 import androidx.annotation.RestrictTo.Scope;
-import androidx.camera.core.CameraInfoInternal;
+import androidx.camera.core.CameraInfo;
-import androidx.camera.core.CameraInfoUnavailableException;
 import androidx.camera.core.CameraX;
-import androidx.camera.core.CameraX.LensFacing;
 import androidx.camera.core.CameraXThreads;
-import androidx.camera.core.ConfigProvider;
-import androidx.camera.core.DeferrableSurface;
-import androidx.camera.core.ImageOutputConfig;
-import androidx.camera.core.ImageOutputConfig.RotationValue;
-import androidx.camera.core.ImmediateSurface;
-import androidx.camera.core.SessionConfig;
 import androidx.camera.core.UseCase;
-import androidx.camera.core.UseCaseConfig;
+import androidx.camera.core.impl.CameraInfoInternal;
-import androidx.camera.core.VideoCaptureConfig;
+import androidx.camera.core.impl.CameraInternal;
+import androidx.camera.core.impl.ConfigProvider;
+import androidx.camera.core.impl.DeferrableSurface;
+import androidx.camera.core.impl.ImageOutputConfig;
+import androidx.camera.core.impl.ImageOutputConfig.RotationValue;
+import androidx.camera.core.impl.ImmediateSurface;
+import androidx.camera.core.impl.SessionConfig;
+import androidx.camera.core.impl.UseCaseConfig;
+import androidx.camera.core.impl.VideoCaptureConfig;
 import androidx.camera.core.impl.utils.executor.CameraXExecutors;
+import androidx.camera.core.internal.utils.UseCaseConfigUtil;
 
-import org.thoughtcrime.securesms.logging.Log;
 import org.thoughtcrime.securesms.video.VideoUtil;
 
 import java.io.File;
 import java.io.FileDescriptor;
 import java.io.IOException;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
 import java.nio.ByteBuffer;
 import java.util.Map;
 import java.util.concurrent.Executor;
@@ -77,10 +95,31 @@ import java.util.concurrent.atomic.AtomicBoolean;
  *
  * @hide In the earlier stage, the VideoCapture is deprioritized.
  */
+// Begin Signal Custom Code Block
 @RequiresApi(26)
+// End Signal Custom Code Block
 @RestrictTo(Scope.LIBRARY_GROUP)
+@SuppressWarnings("ClassCanBeStatic") // TODO(b/141958189): Suppressed during upgrade to AGP 3.6.
 public class VideoCapture extends UseCase {
 
+    /**
+     * An unknown error occurred.
+     *
+     * <p>See message parameter in onError callback or log for more details.
+     */
+    public static final int ERROR_UNKNOWN = 0;
+    /**
+     * An error occurred with encoder state, either when trying to change state or when an
+     * unexpected state change occurred.
+     */
+    public static final int ERROR_ENCODER = 1;
+    /** An error with muxer state such as during creation or when stopping. */
+    public static final int ERROR_MUXER = 2;
+    /**
+     * An error indicating start recording was called when video recording is still in progress.
+     */
+    public static final int ERROR_RECORDING_IN_PROGRESS = 3;
+
     /**
      * Provides a static configuration with implementation-agnostic options.
      *
@@ -131,7 +170,6 @@ public class VideoCapture extends UseCase {
     /** For record the first sample written time. */
     private final AtomicBoolean mIsFirstVideoSampleWrite = new AtomicBoolean(false);
     private final AtomicBoolean mIsFirstAudioSampleWrite = new AtomicBoolean(false);
-    private final VideoCaptureConfig.Builder mUseCaseConfigBuilder;
 
     @NonNull
     MediaCodec mVideoEncoder;
@@ -147,7 +185,9 @@ public class VideoCapture extends UseCase {
     private int mAudioTrackIndex;
     /** Surface the camera writes to, which the videoEncoder uses as input. */
     Surface mCameraSurface;
+
     /** audio raw data */
+    @NonNull
     private AudioRecord mAudioRecorder;
     private int mAudioBufferSize;
     private boolean mIsRecording = false;
@@ -163,7 +203,6 @@ public class VideoCapture extends UseCase {
      */
     public VideoCapture(VideoCaptureConfig config) {
         super(config);
-        mUseCaseConfigBuilder = VideoCaptureConfig.Builder.fromConfig(config);
 
         // video thread start
         mVideoHandlerThread.start();
@@ -182,9 +221,6 @@ public class VideoCapture extends UseCase {
         format.setInteger(MediaFormat.KEY_COLOR_FORMAT, CodecCapabilities.COLOR_FormatSurface);
         format.setInteger(MediaFormat.KEY_BIT_RATE, config.getBitRate());
         format.setInteger(MediaFormat.KEY_FRAME_RATE, config.getVideoFrameRate());
-        // Begin Signal Custom Code Block
-        format.setInteger(MediaFormat.KEY_CAPTURE_RATE, config.getVideoFrameRate());
-        // End Signal Custom Code Block
         format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, config.getIFrameInterval());
 
         return format;
@@ -199,9 +235,9 @@ public class VideoCapture extends UseCase {
     @Override
     @Nullable
     @RestrictTo(Scope.LIBRARY_GROUP)
-    protected UseCaseConfig.Builder<?, ?, ?> getDefaultBuilder(LensFacing lensFacing) {
+    protected UseCaseConfig.Builder<?, ?, ?> getDefaultBuilder(@Nullable CameraInfo cameraInfo) {
-        VideoCaptureConfig defaults = CameraX.getDefaultUseCaseConfig(
+        VideoCaptureConfig defaults = CameraX.getDefaultUseCaseConfig(VideoCaptureConfig.class,
-            VideoCaptureConfig.class, lensFacing);
+            cameraInfo);
         if (defaults != null) {
             return VideoCaptureConfig.Builder.fromConfig(defaults);
         }
@@ -216,9 +252,9 @@ public class VideoCapture extends UseCase {
      */
     @Override
     @RestrictTo(Scope.LIBRARY_GROUP)
+    @NonNull
     protected Map<String, Size> onSuggestedResolutionUpdated(
-        Map<String, Size> suggestedResolutionMap) {
+        @NonNull Map<String, Size> suggestedResolutionMap) {
-        VideoCaptureConfig config = (VideoCaptureConfig) getUseCaseConfig();
         if (mCameraSurface != null) {
             mVideoEncoder.stop();
             mVideoEncoder.release();
@@ -234,14 +270,14 @@ public class VideoCapture extends UseCase {
             throw new IllegalStateException("Unable to create MediaCodec due to: " + e.getCause());
         }
 
-        String cameraId = getCameraIdUnchecked(config);
+        String cameraId = getBoundCameraId();
         Size resolution = suggestedResolutionMap.get(cameraId);
         if (resolution == null) {
             throw new IllegalArgumentException(
                 "Suggested resolution map missing resolution for camera " + cameraId);
         }
 
-        setupEncoder(resolution);
+        setupEncoder(cameraId, resolution);
         return suggestedResolutionMap;
     }
 
@@ -250,20 +286,19 @@ public class VideoCapture extends UseCase {
      * called.
      *
      * <p>StartRecording() is asynchronous. User needs to check if any error occurs by setting the
-     * {@link OnVideoSavedListener#onError(VideoCaptureError, String, Throwable)}.
+     * {@link OnVideoSavedCallback#onError(int, String, Throwable)}.
      *
      * @param saveLocation Location to save the video capture
-     * @param executor     The executor in which the listener callback methods will be run.
+     * @param executor     The executor in which the callback methods will be run.
-     * @param listener     Listener to call for the recorded video
+     * @param callback     Callback for when the recorded video saving completion or failure.
      */
-    @SuppressLint("LambdaLast") // Maybe remove after https://issuetracker.google.com/135275901
     // Begin Signal Custom Code Block
     public void startRecording(@NonNull FileDescriptor saveLocation,
-                               @NonNull Executor executor, @NonNull OnVideoSavedListener listener) {
     // End Signal Custom Code Block
+                               @NonNull Executor executor, @NonNull OnVideoSavedCallback callback) {
         mIsFirstVideoSampleWrite.set(false);
         mIsFirstAudioSampleWrite.set(false);
-        startRecording(saveLocation, EMPTY_METADATA, executor, listener);
+        startRecording(saveLocation, EMPTY_METADATA, executor, callback);
     }
 
     /**
@@ -271,26 +306,26 @@ public class VideoCapture extends UseCase {
      * called.
      *
      * <p>StartRecording() is asynchronous. User needs to check if any error occurs by setting the
-     * {@link OnVideoSavedListener#onError(VideoCaptureError, String, Throwable)}.
+     * {@link OnVideoSavedCallback#onError(int, String, Throwable)}.
      *
      * @param saveLocation Location to save the video capture
      * @param metadata     Metadata to save with the recorded video
-     * @param executor     The executor in which the listener callback methods will be run.
+     * @param executor     The executor in which the callback methods will be run.
-     * @param listener     Listener to call for the recorded video
+     * @param callback     Callback for when the recorded video saving completion or failure.
      */
-    @SuppressLint("LambdaLast") // Maybe remove after https://issuetracker.google.com/135275901
-    // Begin Signal Custom Code Block
     public void startRecording(
-        @NonNull FileDescriptor saveLocation, @NonNull Metadata metadata,
+        // Begin Signal Custom Code Block
-        @NonNull Executor executor,
+        @NonNull FileDescriptor saveLocation,
-        @NonNull OnVideoSavedListener listener) {
         // End Signal Custom Code Block
+        @NonNull Metadata metadata,
+        @NonNull Executor executor,
+        @NonNull OnVideoSavedCallback callback) {
         Log.i(TAG, "startRecording");
-        OnVideoSavedListener postListener = new VideoSavedListenerWrapper(executor, listener);
+        OnVideoSavedCallback postListener = new VideoSavedListenerWrapper(executor, callback);
 
         if (!mEndOfAudioVideoSignal.get()) {
             postListener.onError(
-                VideoCaptureError.RECORDING_IN_PROGRESS, "It is still in video recording!",
+                ERROR_RECORDING_IN_PROGRESS, "It is still in video recording!",
                 null);
             return;
         }
@@ -305,12 +340,13 @@ public class VideoCapture extends UseCase {
             }
             // End Signal Custom Code Block
         } catch (IllegalStateException e) {
-            postListener.onError(VideoCaptureError.ENCODER_ERROR, "AudioRecorder start fail", e);
+            postListener.onError(ERROR_ENCODER, "AudioRecorder start fail", e);
             return;
         }
 
-        VideoCaptureConfig config = (VideoCaptureConfig) getUseCaseConfig();
+        CameraInternal boundCamera = getBoundCamera();
-        String cameraId = getCameraIdUnchecked(config);
+        String cameraId = getBoundCameraId();
+        Size resolution = getAttachedSurfaceResolution(cameraId);
         try {
             // video encoder start
             Log.i(TAG, "videoEncoder start");
@@ -320,23 +356,15 @@ public class VideoCapture extends UseCase {
             mAudioEncoder.start();
 
         } catch (IllegalStateException e) {
-            setupEncoder(getAttachedSurfaceResolution(cameraId));
+            setupEncoder(cameraId, resolution);
-            postListener.onError(VideoCaptureError.ENCODER_ERROR, "Audio/Video encoder start fail",
+            postListener.onError(ERROR_ENCODER, "Audio/Video encoder start fail",
                 e);
             return;
         }
 
-        // Get the relative rotation or default to 0 if the camera info is unavailable
+        CameraInfoInternal cameraInfoInternal = boundCamera.getCameraInfoInternal();
-        int relativeRotation = 0;
+        int relativeRotation = cameraInfoInternal.getSensorRotationDegrees(
-        try {
+            ((ImageOutputConfig) getUseCaseConfig()).getTargetRotation(Surface.ROTATION_0));
-            CameraInfoInternal cameraInfoInternal = CameraX.getCameraInfo(cameraId);
-            relativeRotation =
-                cameraInfoInternal.getSensorRotationDegrees(
-                    ((ImageOutputConfig) getUseCaseConfig())
-                        .getTargetRotation(Surface.ROTATION_0));
-        } catch (CameraInfoUnavailableException e) {
-            Log.e(TAG, "Unable to retrieve camera sensor orientation.", e);
-        }
 
         try {
             synchronized (mMuxerLock) {
@@ -355,8 +383,8 @@ public class VideoCapture extends UseCase {
                 }
             }
         } catch (IOException e) {
-            setupEncoder(getAttachedSurfaceResolution(cameraId));
+            setupEncoder(cameraId, resolution);
-            postListener.onError(VideoCaptureError.MUXER_ERROR, "MediaMuxer creation failed!", e);
+            postListener.onError(ERROR_MUXER, "MediaMuxer creation failed!", e);
             return;
         }
 
@@ -378,7 +406,8 @@ public class VideoCapture extends UseCase {
             new Runnable() {
                 @Override
                 public void run() {
-                    boolean errorOccurred = VideoCapture.this.videoEncode(postListener);
+                    boolean errorOccurred = VideoCapture.this.videoEncode(postListener,
+                        cameraId, resolution);
                     if (!errorOccurred) {
                         postListener.onVideoSaved(saveLocation);
                     }
@@ -388,11 +417,11 @@ public class VideoCapture extends UseCase {
 
     /**
      * Stops recording video, this must be called after {@link
-     * VideoCapture#startRecording(File, Metadata, Executor, OnVideoSavedListener)} is called.
+     * VideoCapture#startRecording(File, Metadata, Executor, OnVideoSavedCallback)} is called.
      *
      * <p>stopRecording() is asynchronous API. User need to check if {@link
-     * OnVideoSavedListener#onVideoSaved(File)} or
+     * OnVideoSavedCallback#onVideoSaved(File)} or
-     * {@link OnVideoSavedListener#onError(VideoCaptureError, String, Throwable)} be called
+     * {@link OnVideoSavedCallback#onError(int, String, Throwable)} be called
      * before startRecording.
      */
     public void stopRecording() {
@@ -438,23 +467,17 @@ public class VideoCapture extends UseCase {
             return;
         }
 
-        final Surface surface = mCameraSurface;
         final MediaCodec videoEncoder = mVideoEncoder;
 
-        mDeferrableSurface.setOnSurfaceDetachedListener(
+        // Calling close should allow termination future to complete and close the surface with
-            CameraXExecutors.mainThreadExecutor(),
+        // the listener that was added after constructing the DeferrableSurface.
-            new DeferrableSurface.OnSurfaceDetachedListener() {
+        mDeferrableSurface.close();
-                @Override
+        mDeferrableSurface.getTerminationFuture().addListener(
-                public void onSurfaceDetached() {
+            () -> {
                 if (releaseVideoEncoder && videoEncoder != null) {
                     videoEncoder.release();
                 }
-
+            }, CameraXExecutors.mainThreadExecutor());
-                    if (surface != null) {
-                        surface.release();
-                    }
-                }
-            });
 
         if (releaseVideoEncoder) {
             mVideoEncoder = null;
@@ -473,11 +496,12 @@ public class VideoCapture extends UseCase {
      * @param rotation Desired rotation of the output video.
      */
     public void setTargetRotation(@RotationValue int rotation) {
-        ImageOutputConfig oldConfig = (ImageOutputConfig) getUseCaseConfig();
+        VideoCaptureConfig oldConfig = (VideoCaptureConfig) getUseCaseConfig();
+        VideoCaptureConfig.Builder builder = VideoCaptureConfig.Builder.fromConfig(oldConfig);
         int oldRotation = oldConfig.getTargetRotation(ImageOutputConfig.INVALID_ROTATION);
         if (oldRotation == ImageOutputConfig.INVALID_ROTATION || oldRotation != rotation) {
-            mUseCaseConfigBuilder.setTargetRotation(rotation);
+            UseCaseConfigUtil.updateTargetRotationAndRelatedConfigs(builder, rotation);
-            updateUseCaseConfig(mUseCaseConfigBuilder.build());
+            updateUseCaseConfig(builder.getUseCaseConfig());
 
             // TODO(b/122846516): Update session configuration and possibly reconfigure session.
         }
@@ -488,7 +512,7 @@ public class VideoCapture extends UseCase {
      * audio from selected audio source.
      */
     @SuppressWarnings("WeakerAccess") /* synthetic accessor */
-    void setupEncoder(Size resolution) {
+    void setupEncoder(@NonNull String cameraId, @NonNull Size resolution) {
         VideoCaptureConfig config = (VideoCaptureConfig) getUseCaseConfig();
 
         // video encoder setup
@@ -501,21 +525,32 @@ public class VideoCapture extends UseCase {
         if (mCameraSurface != null) {
             releaseCameraSurface(false);
         }
-        mCameraSurface = mVideoEncoder.createInputSurface();
+        Surface cameraSurface = mVideoEncoder.createInputSurface();
+        mCameraSurface = cameraSurface;
 
         SessionConfig.Builder sessionConfigBuilder = SessionConfig.Builder.createFrom(config);
 
+        if (mDeferrableSurface != null) {
+            mDeferrableSurface.close();
+        }
         mDeferrableSurface = new ImmediateSurface(mCameraSurface);
+        mDeferrableSurface.getTerminationFuture().addListener(
+            cameraSurface::release, CameraXExecutors.mainThreadExecutor()
+        );
 
         sessionConfigBuilder.addSurface(mDeferrableSurface);
 
-        String cameraId = getCameraIdUnchecked(config);
-
         sessionConfigBuilder.addErrorListener(new SessionConfig.ErrorListener() {
             @Override
             public void onError(@NonNull SessionConfig sessionConfig,
                                 @NonNull SessionConfig.SessionError error) {
-                setupEncoder(resolution);
+                // Ensure the bound camera has not changed before calling setupEncoder.
+                // TODO(b/143915543): Ensure this never gets called by a camera that is not bound
+                //  to this use case so we don't need to do this check.
+                if (isCurrentlyBoundCamera(cameraId)) {
+                    // Only reset the pipeline when the bound camera is the same.
+                    setupEncoder(cameraId, resolution);
+                }
             }
         });
 
@@ -620,8 +655,8 @@ public class VideoCapture extends UseCase {
      *
      * @return returns {@code true} if an error condition occurred, otherwise returns {@code false}
      */
-    boolean videoEncode(OnVideoSavedListener videoSavedListener) {
+    boolean videoEncode(@NonNull OnVideoSavedCallback videoSavedCallback, @NonNull String cameraId,
-        VideoCaptureConfig config = (VideoCaptureConfig) getUseCaseConfig();
+                        @NonNull Size resolution) {
         // Main encoding loop. Exits on end of stream.
         boolean errorOccurred = false;
         boolean videoEos = false;
@@ -638,8 +673,8 @@ public class VideoCapture extends UseCase {
             switch (outputBufferId) {
                 case MediaCodec.INFO_OUTPUT_FORMAT_CHANGED:
                     if (mMuxerStarted) {
-                        videoSavedListener.onError(
+                        videoSavedCallback.onError(
-                            VideoCaptureError.ENCODER_ERROR,
+                            ERROR_ENCODER,
                             "Unexpected change in video encoding format.",
                             null);
                         errorOccurred = true;
@@ -656,10 +691,6 @@ public class VideoCapture extends UseCase {
                     break;
                 case MediaCodec.INFO_TRY_AGAIN_LATER:
                     // Timed out. Just wait until next attempt to deque.
-                case MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED:
-                    // Ignore output buffers changed since we dequeue a single buffer instead of
-                    // multiple
-                    break;
                 default:
                     videoEos = writeVideoEncodedBuffer(outputBufferId);
             }
@@ -669,7 +700,7 @@ public class VideoCapture extends UseCase {
             Log.i(TAG, "videoEncoder stop");
             mVideoEncoder.stop();
         } catch (IllegalStateException e) {
-            videoSavedListener.onError(VideoCaptureError.ENCODER_ERROR,
+            videoSavedCallback.onError(ERROR_ENCODER,
                 "Video encoder stop failed!", e);
             errorOccurred = true;
         }
@@ -686,16 +717,15 @@ public class VideoCapture extends UseCase {
                 }
             }
         } catch (IllegalStateException e) {
-            videoSavedListener.onError(VideoCaptureError.MUXER_ERROR, "Muxer stop failed!", e);
+            videoSavedCallback.onError(ERROR_MUXER, "Muxer stop failed!", e);
             errorOccurred = true;
         }
 
         mMuxerStarted = false;
         // Do the setup of the videoEncoder at the end of video recording instead of at the start of
         // recording because it requires attaching a new Surface. This causes a glitch so we don't
-        // want
+        // want that to incur latency at the start of capture.
-        // that to incur latency at the start of capture.
+        setupEncoder(cameraId, resolution);
-        setupEncoder(getAttachedSurfaceResolution(getCameraIdUnchecked(config)));
         notifyReset();
 
         // notify the UI thread that the video recording has finished
@@ -705,7 +735,7 @@ public class VideoCapture extends UseCase {
         return errorOccurred;
     }
 
-    boolean audioEncode(OnVideoSavedListener videoSavedListener) {
+    boolean audioEncode(OnVideoSavedCallback videoSavedCallback) {
         // Audio encoding loop. Exits on end of stream.
         boolean audioEos = false;
         int outIndex;
@@ -766,14 +796,14 @@ public class VideoCapture extends UseCase {
             }
             // End Signal Custom Code Block
         } catch (IllegalStateException e) {
-            videoSavedListener.onError(
+            videoSavedCallback.onError(
-                VideoCaptureError.ENCODER_ERROR, "Audio recorder stop failed!", e);
+                ERROR_ENCODER, "Audio recorder stop failed!", e);
         }
 
         try {
             mAudioEncoder.stop();
         } catch (IllegalStateException e) {
-            videoSavedListener.onError(VideoCaptureError.ENCODER_ERROR,
+            videoSavedCallback.onError(ERROR_ENCODER,
                 "Audio encoder stop failed!", e);
         }
 
@@ -889,39 +919,29 @@ public class VideoCapture extends UseCase {
      * Describes the error that occurred during video capture operations.
      *
      * <p>This is a parameter sent to the error callback functions set in listeners such as {@link
-     * VideoCapture.OnVideoSavedListener#onError(VideoCaptureError, String, Throwable)}.
+     * VideoCapture.OnVideoSavedCallback#onError(int, String, Throwable)}.
      *
      * <p>See message parameter in onError callback or log for more details.
-     */
-    public enum VideoCaptureError {
-        /**
-         * An unknown error occurred.
      *
-         * <p>See message parameter in onError callback or log for more details.
+     * @hide
      */
-        UNKNOWN_ERROR,
+    @IntDef({ERROR_UNKNOWN, ERROR_ENCODER, ERROR_MUXER, ERROR_RECORDING_IN_PROGRESS})
-        /**
+    @Retention(RetentionPolicy.SOURCE)
-         * An error occurred with encoder state, either when trying to change state or when an
+    @RestrictTo(Scope.LIBRARY_GROUP)
-         * unexpected state change occurred.
+    public @interface VideoCaptureError {
-         */
-        ENCODER_ERROR,
-        /** An error with muxer state such as during creation or when stopping. */
-        MUXER_ERROR,
-        /**
-         * An error indicating start recording was called when video recording is still in progress.
-         */
-        RECORDING_IN_PROGRESS
     }
 
     /** Listener containing callbacks for video file I/O events. */
-    public interface OnVideoSavedListener {
+    public interface OnVideoSavedCallback {
         /** Called when the video has been successfully saved. */
+        // TODO: Should remove file argument to match ImageCapture.OnImageSavedCallback
+        //  #onImageSaved()
         // Begin Signal Custom Code Block
         void onVideoSaved(@NonNull FileDescriptor file);
         // End Signal Custom Code Block
 
         /** Called when an error occurs while attempting to save the video. */
-        void onError(@NonNull VideoCaptureError videoCaptureError, @NonNull String message,
+        void onError(@VideoCaptureError int videoCaptureError, @NonNull String message,
                      @Nullable Throwable cause);
     }
 
@@ -936,7 +956,6 @@ public class VideoCapture extends UseCase {
     @RestrictTo(Scope.LIBRARY_GROUP)
     public static final class Defaults
         implements ConfigProvider<VideoCaptureConfig> {
-        private static final Handler DEFAULT_HANDLER = new Handler(Looper.getMainLooper());
         private static final int DEFAULT_VIDEO_FRAME_RATE = 30;
         /** 8Mb/s the recommend rate for 30fps 1080p */
         private static final int DEFAULT_BIT_RATE = 8 * 1024 * 1024;
@@ -973,11 +992,12 @@ public class VideoCapture extends UseCase {
                     .setMaxResolution(DEFAULT_MAX_RESOLUTION)
                     .setSurfaceOccupancyPriority(DEFAULT_SURFACE_OCCUPANCY_PRIORITY);
 
-            DEFAULT_CONFIG = builder.build();
+            DEFAULT_CONFIG = builder.getUseCaseConfig();
         }
 
+        @NonNull
         @Override
-        public VideoCaptureConfig getConfig(LensFacing lensFacing) {
+        public VideoCaptureConfig getConfig(@Nullable CameraInfo cameraInfo) {
             return DEFAULT_CONFIG;
         }
     }
@@ -989,15 +1009,17 @@ public class VideoCapture extends UseCase {
         public Location location;
     }
 
-    private final class VideoSavedListenerWrapper implements OnVideoSavedListener {
+    private final class VideoSavedListenerWrapper implements OnVideoSavedCallback {
 
-        @NonNull Executor mExecutor;
+        @NonNull
-        @NonNull OnVideoSavedListener mOnVideoSavedListener;
+        Executor mExecutor;
+        @NonNull
+        OnVideoSavedCallback mOnVideoSavedCallback;
 
         VideoSavedListenerWrapper(@NonNull Executor executor,
-                                  @NonNull OnVideoSavedListener onVideoSavedListener) {
+                                  @NonNull OnVideoSavedCallback onVideoSavedCallback) {
             mExecutor = executor;
-            mOnVideoSavedListener = onVideoSavedListener;
+            mOnVideoSavedCallback = onVideoSavedCallback;
         }
 
         @Override
@@ -1005,18 +1027,18 @@ public class VideoCapture extends UseCase {
         public void onVideoSaved(@NonNull FileDescriptor file) {
         // End Signal Custom Code Block
             try {
-                mExecutor.execute(() -> mOnVideoSavedListener.onVideoSaved(file));
+                mExecutor.execute(() -> mOnVideoSavedCallback.onVideoSaved(file));
             } catch (RejectedExecutionException e) {
                 Log.e(TAG, "Unable to post to the supplied executor.");
             }
         }
 
         @Override
-        public void onError(@NonNull VideoCaptureError videoCaptureError, @NonNull String message,
+        public void onError(@VideoCaptureError int videoCaptureError, @NonNull String message,
                             @Nullable Throwable cause) {
             try {
                 mExecutor.execute(
-                    () -> mOnVideoSavedListener.onError(videoCaptureError, message, cause));
+                    () -> mOnVideoSavedCallback.onError(videoCaptureError, message, cause));
             } catch (RejectedExecutionException e) {
                 Log.e(TAG, "Unable to post to the supplied executor.");
             }

app/src/main/res/values/styles.xml

@@ -401,4 +401,11 @@
     <declare-styleable name="MaxHeightFrameLayout">
         <attr name="mhfl_maxHeight" format="dimension" />
     </declare-styleable>
+
+    <declare-styleable name="PreviewView">
+        <attr format="enum" name="implementationMode">
+            <enum name="surfaceView" value="0"/>
+            <enum name="textureView" value="1"/>
+        </attr>
+    </declare-styleable>
 </resources>

app/witness-verifications.gradle

@@ -6,6 +6,9 @@ dependencyVerification {
         ['androidx.activity:activity:1.0.0',
          'd1bc9842455c2e534415d88c44df4d52413b478db9093a1ba36324f705f44c3d'],
 
+        ['androidx.annotation:annotation-experimental:1.0.0-rc01',
+         '2f113195f61ecd08ea46cef545f0ea338898391d95425cf4c8836ba2b701f5d6'],
+
         ['androidx.annotation:annotation:1.1.0',
          'd38d63edb30f1467818d50aaf05f8a692dea8b31392a049bfa991b159ad5b692'],
 
@@ -24,11 +27,14 @@ dependencyVerification {
         ['androidx.asynclayoutinflater:asynclayoutinflater:1.0.0',
          'f7eab60c57addd94bb06275832fe7600611beaaae1a1ec597c231956faf96c8b'],
 
-        ['androidx.camera:camera-camera2:1.0.0-alpha06',
+        ['androidx.camera:camera-camera2:1.0.0-beta01',
-         'e50f20deb950ffebcd4d1de5408ef7a5404bec80ec77119e05663c890739b903'],
+         '02e15ad76153d09adcd6631627960707a8786333a8276d05dcbefc2bfe4ef5a1'],
 
-        ['androidx.camera:camera-core:1.0.0-alpha06',
+        ['androidx.camera:camera-core:1.0.0-beta01',
-         '0096cabe539d9b4288f406acfb44264b137ebd600e38e33504ff425c979016c9'],
+         'acba5f196b3bd3ecf756067c9f4fae4f15b81228c2bd6b52212d9454e27599f0'],
+
+        ['androidx.camera:camera-lifecycle:1.0.0-beta01',
+         '25c761a863555d5e008e428cf271caca774c867bf269495dc32a0fdc65770fd5'],
 
         ['androidx.cardview:cardview:1.0.0',
          '1193c04c22a3d6b5946dae9f4e8c59d6adde6a71b6bd5d87fb99d82dda1afec7'],
@@ -36,8 +42,8 @@ dependencyVerification {
         ['androidx.collection:collection:1.1.0',
          '632a0e5407461de774409352940e292a291037724207a787820c77daf7d33b72'],
 
-        ['androidx.concurrent:concurrent-futures:1.0.0-alpha03',
+        ['androidx.concurrent:concurrent-futures:1.0.0',
-         '50812a53912255e3e0f2147d13bbbb81937c3726fda2e984e77a27c7207d96a1'],
+         '5595a40e278a7b39fa78a09490e3d7f3faa95c7b01447148bd38b5ade0605c35'],
 
         ['androidx.constraintlayout:constraintlayout-solver:1.1.3',
          '965c177e64fbd81bd1d27b402b66ef9d7bc7b5cb5f718044bf7a453abc542045'],