Merge pull request #335 from metaphore/store-permission-refactoring

File Storage Refactoring

res/drawable/ic_baseline_folder_24.xml

@@ -0,0 +1,10 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24"
+    android:tint="?attr/colorControlNormal">
+  <path
+      android:fillColor="@android:color/white"
+      android:pathData="M10,4H4c-1.1,0 -1.99,0.9 -1.99,2L2,18c0,1.1 0.9,2 2,2h16c1.1,0 2,-0.9 2,-2V8c0,-1.1 -0.9,-2 -2,-2h-8l-2,-2z"/>
+</vector>

res/layout/mediapicker_folder_item.xml

@@ -33,7 +33,8 @@
             android:layout_width="20dp"
             android:layout_height="20dp"
             android:layout_marginEnd="6dp"
-            android:src="@drawable/ic_folder_white_48dp"/>
+            android:tint="@android:color/white"
+            android:src="@drawable/ic_baseline_folder_24"/>
 
         <TextView
             android:id="@+id/mediapicker_folder_item_title"

src/org/thoughtcrime/securesms/CreateProfileActivity.java

@@ -215,7 +215,6 @@ public class CreateProfileActivity extends BaseActionBarActivity implements Inje
 
     this.avatar.setOnClickListener(view -> Permissions.with(this)
                                                       .request(Manifest.permission.CAMERA, Manifest.permission.WRITE_EXTERNAL_STORAGE)
-                                                      .ifNecessary()
                                                       .onAnyResult(this::startAvatarSelection)
                                                       .execute());
 

src/org/thoughtcrime/securesms/DeviceActivity.java

@@ -98,7 +98,6 @@ public class DeviceActivity extends PassphraseRequiredActionBarActivity
   public void onClick(View v) {
     Permissions.with(this)
                .request(Manifest.permission.CAMERA)
-               .ifNecessary()
                .withPermanentDenialDialog(getString(R.string.DeviceActivity_signal_needs_the_camera_permission_in_order_to_scan_a_qr_code))
                .onAllGranted(() -> {
                  getSupportFragmentManager().beginTransaction()

src/org/thoughtcrime/securesms/MediaOverviewActivity.java

@@ -16,7 +16,6 @@
  */
 package org.thoughtcrime.securesms;
 
-import android.Manifest;
 import android.annotation.SuppressLint;
 import android.content.Context;
 import android.content.Intent;
@@ -324,17 +323,19 @@ public class MediaOverviewActivity extends PassphraseRequiredActionBarActivity {
     }
 
     @SuppressWarnings("CodeBlock2Expr")
-    @SuppressLint({"InlinedApi","StaticFieldLeak"})
+    @SuppressLint({"InlinedApi", "StaticFieldLeak"})
     private void handleSaveMedia(@NonNull Collection<MediaDatabase.MediaRecord> mediaRecords) {
       final Context context = getContext();
+
       SaveAttachmentTask.showWarningDialog(context, (dialogInterface, which) -> {
         Permissions.with(this)
-                   .request(android.Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.READ_EXTERNAL_STORAGE)
+                .request(android.Manifest.permission.WRITE_EXTERNAL_STORAGE)
-                   .ifNecessary()
+                .maxSdkVersion(Build.VERSION_CODES.P)
                 .withPermanentDenialDialog(getString(R.string.MediaPreviewActivity_signal_needs_the_storage_permission_in_order_to_write_to_external_storage_but_it_has_been_permanently_denied))
                 .onAnyDenied(() -> Toast.makeText(getContext(), R.string.MediaPreviewActivity_unable_to_write_to_external_storage_without_permission, Toast.LENGTH_LONG).show())
                 .onAllGranted(() -> {
-                     new ProgressDialogAsyncTask<Void, Void, List<SaveAttachmentTask.Attachment>>(context,
+                  new ProgressDialogAsyncTask<Void, Void, List<SaveAttachmentTask.Attachment>>(
+                          context,
                           R.string.MediaOverviewActivity_collecting_attachments,
                           R.string.please_wait) {
                     @Override
@@ -356,8 +357,7 @@ public class MediaOverviewActivity extends PassphraseRequiredActionBarActivity {
                     @Override
                     protected void onPostExecute(List<SaveAttachmentTask.Attachment> attachments) {
                       super.onPostExecute(attachments);
-                         SaveAttachmentTask saveTask = new SaveAttachmentTask(context,
+                      SaveAttachmentTask saveTask = new SaveAttachmentTask(context, attachments.size());
-                                                                              attachments.size());
                       saveTask.executeOnExecutor(THREAD_POOL_EXECUTOR,
                               attachments.toArray(new SaveAttachmentTask.Attachment[attachments.size()]));
                       actionMode.finish();

src/org/thoughtcrime/securesms/MediaPreviewActivity.java

@@ -16,17 +16,16 @@
  */
 package org.thoughtcrime.securesms;
 
-import android.Manifest;
 import android.annotation.SuppressLint;
 import android.annotation.TargetApi;
 
-import androidx.appcompat.widget.Toolbar;
 import androidx.lifecycle.ViewModelProviders;
 import android.content.Context;
 import android.content.Intent;
 import android.database.Cursor;
 import android.net.Uri;
 import android.os.AsyncTask;
+import android.os.Build;
 import android.os.Build.VERSION;
 import android.os.Build.VERSION_CODES;
 import android.os.Bundle;
@@ -341,23 +340,24 @@ public class MediaPreviewActivity extends PassphraseRequiredActionBarActivity im
   @SuppressLint("InlinedApi")
   private void saveToDisk() {
     MediaItem mediaItem = getCurrentMediaItem();
+    if (mediaItem == null) return;
 
-    if (mediaItem != null) {
     SaveAttachmentTask.showWarningDialog(this, (dialogInterface, i) -> {
       Permissions.with(this)
-                   .request(Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.READ_EXTERNAL_STORAGE)
+              .request(android.Manifest.permission.WRITE_EXTERNAL_STORAGE)
-                   .ifNecessary()
+              .maxSdkVersion(Build.VERSION_CODES.P)
               .withPermanentDenialDialog(getString(R.string.MediaPreviewActivity_signal_needs_the_storage_permission_in_order_to_write_to_external_storage_but_it_has_been_permanently_denied))
               .onAnyDenied(() -> Toast.makeText(this, R.string.MediaPreviewActivity_unable_to_write_to_external_storage_without_permission, Toast.LENGTH_LONG).show())
               .onAllGranted(() -> {
                 SaveAttachmentTask saveTask = new SaveAttachmentTask(MediaPreviewActivity.this);
                 long saveDate = (mediaItem.date > 0) ? mediaItem.date : System.currentTimeMillis();
-                     saveTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, new Attachment(mediaItem.uri, mediaItem.type, saveDate, null));
+                saveTask.executeOnExecutor(
+                        AsyncTask.THREAD_POOL_EXECUTOR,
+                        new Attachment(mediaItem.uri, mediaItem.type, saveDate, null));
               })
               .execute();
     });
   }
-  }
 
   @SuppressLint("StaticFieldLeak")
   private void deleteMedia() {

src/org/thoughtcrime/securesms/RegistrationActivity.java

@@ -268,7 +268,7 @@ public class RegistrationActivity extends BaseActionBarActivity implements Verif
 
   @SuppressLint("StaticFieldLeak")
   private void initializeBackupDetection() {
-    if (!Permissions.hasAll(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
+    if (!Permissions.hasAll(this, Manifest.permission.READ_EXTERNAL_STORAGE)) {
       Log.i(TAG, "Skipping backup detection. We don't have the permission.");
       return;
     }

src/org/thoughtcrime/securesms/VerifyIdentityActivity.java

@@ -172,7 +172,6 @@ public class VerifyIdentityActivity extends PassphraseRequiredActionBarActivity
   public void onClick(View v) {
     Permissions.with(this)
                .request(Manifest.permission.CAMERA)
-               .ifNecessary()
                .withPermanentDenialDialog(getString(R.string.VerifyIdentityActivity_signal_needs_the_camera_permission_in_order_to_scan_a_qr_code_but_it_has_been_permanently_denied))
                .onAllGranted(() -> {
                  FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();

src/org/thoughtcrime/securesms/WebRtcCallActivity.java

@@ -164,7 +164,6 @@ public class WebRtcCallActivity extends Activity {
     if (event != null) {
       Permissions.with(this)
                  .request(Manifest.permission.RECORD_AUDIO, Manifest.permission.CAMERA)
-                 .ifNecessary()
                  .withRationaleDialog(getString(R.string.WebRtcCallActivity_to_answer_the_call_from_s_give_signal_access_to_your_microphone, event.getRecipient().toShortString()),
                                       R.drawable.ic_mic_white_48dp, R.drawable.ic_videocam_white_48dp)
                  .withPermanentDenialDialog(getString(R.string.WebRtcCallActivity_signal_requires_microphone_and_camera_permissions_in_order_to_make_or_receive_calls))

src/org/thoughtcrime/securesms/components/AttachmentTypeSelector.java

@@ -110,7 +110,7 @@ public class AttachmentTypeSelector extends PopupWindow {
   public void show(@NonNull Activity activity, final @NonNull View anchor) {
     updateHeight();
 
-    if (Permissions.hasAll(activity, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
+    if (Permissions.hasAll(activity, Manifest.permission.READ_EXTERNAL_STORAGE)) {
       recentRail.setVisibility(View.VISIBLE);
       loaderManager.restartLoader(1, null, recentRail);
     } else {

src/org/thoughtcrime/securesms/conversation/ConversationActivity.java

@@ -2564,7 +2564,6 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
   public void onRecorderPermissionRequired() {
     Permissions.with(this)
                .request(Manifest.permission.RECORD_AUDIO)
-               .ifNecessary()
                .withRationaleDialog(getString(R.string.ConversationActivity_to_send_audio_messages_allow_signal_access_to_your_microphone), R.drawable.ic_baseline_mic_48)
                .withPermanentDenialDialog(getString(R.string.ConversationActivity_signal_requires_the_microphone_permission_in_order_to_send_audio_messages))
                .execute();
@@ -2765,7 +2764,6 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
     public void onClick(View v) {
       Permissions.with(ConversationActivity.this)
                  .request(Manifest.permission.CAMERA)
-                 .ifNecessary()
                  .withRationaleDialog(getString(R.string.ConversationActivity_to_capture_photos_and_video_allow_signal_access_to_the_camera), R.drawable.ic_baseline_photo_camera_48)
                  .withPermanentDenialDialog(getString(R.string.ConversationActivity_signal_needs_the_camera_permission_to_take_photos_or_video))
                  .onAllGranted(() -> {

src/org/thoughtcrime/securesms/conversation/ConversationFragment.java

@@ -85,6 +85,7 @@ import org.thoughtcrime.securesms.mms.GlideApp;
 import org.thoughtcrime.securesms.mms.OutgoingMediaMessage;
 import org.thoughtcrime.securesms.mms.PartAuthority;
 import org.thoughtcrime.securesms.mms.Slide;
+import org.thoughtcrime.securesms.permissions.Permissions;
 import org.thoughtcrime.securesms.profiles.UnknownSenderView;
 import org.thoughtcrime.securesms.recipients.Recipient;
 import org.thoughtcrime.securesms.sms.MessageSender;
@@ -658,9 +659,15 @@ public class ConversationFragment extends Fragment
   }
 
   private void handleSaveAttachment(final MediaMmsMessageRecord message) {
-    SaveAttachmentTask.showWarningDialog(getActivity(), new DialogInterface.OnClickListener() {
+    SaveAttachmentTask.showWarningDialog(getActivity(), (dialog, which) -> {
-      public void onClick(DialogInterface dialog, int which) {
+      Permissions.with(this)
-        List<SaveAttachmentTask.Attachment> attachments = Stream.of(message.getSlideDeck().getSlides())
+              .request(android.Manifest.permission.WRITE_EXTERNAL_STORAGE)
+              .maxSdkVersion(Build.VERSION_CODES.P)
+              .withPermanentDenialDialog(getString(R.string.MediaPreviewActivity_signal_needs_the_storage_permission_in_order_to_write_to_external_storage_but_it_has_been_permanently_denied))
+              .onAnyDenied(() -> Toast.makeText(getContext(), R.string.MediaPreviewActivity_unable_to_write_to_external_storage_without_permission, Toast.LENGTH_LONG).show())
+              .onAllGranted(() -> {
+                List<SaveAttachmentTask.Attachment> attachments =
+                        Stream.of(message.getSlideDeck().getSlides())
                                 .filter(s -> s.getUri() != null && (s.hasImage() || s.hasVideo() || s.hasAudio() || s.hasDocument()))
                                 .map(s -> new SaveAttachmentTask.Attachment(s.getUri(), s.getContentType(), message.getDateReceived(), s.getFileName().orNull()))
                                 .toList();
@@ -674,7 +681,8 @@ public class ConversationFragment extends Fragment
                 Toast.makeText(getActivity(),
                         getResources().getQuantityString(R.plurals.ConversationFragment_error_while_saving_attachments_to_sd_card, 1),
                         Toast.LENGTH_LONG).show();
-      }
+              })
+              .execute();
     });
   }
 

src/org/thoughtcrime/securesms/database/loaders/RecentPhotosLoader.java

@@ -35,7 +35,7 @@ public class RecentPhotosLoader extends CursorLoader {
 
   @Override
   public Cursor loadInBackground() {
-    if (Permissions.hasAll(context, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
+    if (Permissions.hasAll(context, Manifest.permission.READ_EXTERNAL_STORAGE)) {
       return context.getContentResolver().query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
                                                 PROJECTION, null, null,
                                                 MediaStore.Images.ImageColumns.DATE_MODIFIED + " DESC");

src/org/thoughtcrime/securesms/jobs/LocalBackupJob.java

@@ -26,6 +26,7 @@ import java.util.Locale;
 
 import network.loki.messenger.R;
 
+//TODO AC: Needs to be refactored to use Storage Access Framework or Media Store API.
 public class LocalBackupJob extends BaseJob {
 
   public static final String KEY = "LocalBackupJob";

src/org/thoughtcrime/securesms/loki/activities/SettingsActivity.kt

@@ -251,7 +251,6 @@ class SettingsActivity : PassphraseRequiredActionBarActivity() {
         // Ask for an optional camera permission.
         Permissions.with(this)
                 .request(Manifest.permission.CAMERA)
-                .ifNecessary()
                 .onAnyResult {
                     tempFile = AvatarSelection.startAvatarSelection(this, false, true)
                 }

src/org/thoughtcrime/securesms/mediasend/MediaFolder.java

@@ -12,14 +12,12 @@ public class MediaFolder {
   private final String     title;
   private final int        itemCount;
   private final String     bucketId;
-  private final FolderType folderType;
 
-  MediaFolder(@NonNull Uri thumbnailUri, @NonNull String title, int itemCount, @NonNull String bucketId, @NonNull FolderType folderType) {
+  MediaFolder(@NonNull Uri thumbnailUri, @NonNull String title, int itemCount, @NonNull String bucketId) {
     this.thumbnailUri = thumbnailUri;
     this.title        = title;
     this.itemCount    = itemCount;
     this.bucketId     = bucketId;
-    this.folderType   = folderType;
   }
 
   Uri getThumbnailUri() {
@@ -38,10 +36,6 @@ public class MediaFolder {
     return bucketId;
   }
 
-  FolderType getFolderType() {
-    return folderType;
-  }
-
   enum FolderType {
     NORMAL, CAMERA
   }

src/org/thoughtcrime/securesms/mediasend/MediaPickerFolderAdapter.java

@@ -75,7 +75,6 @@ class MediaPickerFolderAdapter extends RecyclerView.Adapter<MediaPickerFolderAda
     void bind(@NonNull MediaFolder folder, @NonNull GlideRequests glideRequests, @NonNull EventListener eventListener) {
       title.setText(folder.getTitle());
       count.setText(String.valueOf(folder.getItemCount()));
-      icon.setImageResource(folder.getFolderType() == MediaFolder.FolderType.CAMERA ? R.drawable.ic_camera_alt_white_24dp : R.drawable.ic_folder_white_48dp);
 
       glideRequests.load(folder.getThumbnailUri())
                    .diskCacheStrategy(DiskCacheStrategy.NONE)

src/org/thoughtcrime/securesms/mediasend/MediaRepository.java

@@ -5,7 +5,6 @@ import android.content.Context;
 import android.database.Cursor;
 import android.net.Uri;
 import android.os.AsyncTask;
-import android.os.Environment;
 import android.provider.MediaStore.Images;
 import android.provider.MediaStore.Video;
 import android.provider.OpenableColumns;
@@ -33,11 +32,6 @@ import java.util.Map;
 
 /**
  * Handles the retrieval of media present on the user's device.
- * @deprecated Usage of this class is unsafe on Android API 30 and up,
- * the public external directory is no longer exposed to the apps.
- * <p><b>
- * The functionality of this class should be refactored to use
- * <a href="https://developer.android.com/reference/android/provider/MediaStore">MediaStore</a>.
  */
 class MediaRepository {
 
@@ -82,30 +76,17 @@ class MediaRepository {
       }
     }
 
-    String            cameraBucketId = imageFolders.getCameraBucketId() != null ? imageFolders.getCameraBucketId() : videoFolders.getCameraBucketId();
-    FolderData        cameraFolder   = cameraBucketId != null ? folders.remove(cameraBucketId) : null;
     List<MediaFolder> mediaFolders = Stream.of(folders.values()).map(folder -> new MediaFolder(folder.getThumbnail(),
                                                                                                  folder.getTitle(),
                                                                                                  folder.getCount(),
-                                                                                                 folder.getBucketId(),
+                                                                                                 folder.getBucketId()))
-                                                                                                 MediaFolder.FolderType.NORMAL))
                                                                   .sorted((o1, o2) -> o1.getTitle().toLowerCase().compareTo(o2.getTitle().toLowerCase()))
                                                                   .toList();
 
     Uri allMediaThumbnail = imageFolders.getThumbnailTimestamp() > videoFolders.getThumbnailTimestamp() ? imageFolders.getThumbnail() : videoFolders.getThumbnail();
-
     if (allMediaThumbnail != null) {
       int allMediaCount = Stream.of(mediaFolders).reduce(0, (count, folder) -> count + folder.getItemCount());
-
+      mediaFolders.add(0, new MediaFolder(allMediaThumbnail, context.getString(R.string.MediaRepository_all_media), allMediaCount, Media.ALL_MEDIA_BUCKET_ID));
-      if (cameraFolder != null) {
-        allMediaCount += cameraFolder.getCount();
-      }
-
-      mediaFolders.add(0, new MediaFolder(allMediaThumbnail, context.getString(R.string.MediaRepository_all_media), allMediaCount, Media.ALL_MEDIA_BUCKET_ID, MediaFolder.FolderType.NORMAL));
-    }
-
-    if (cameraFolder != null) {
-      mediaFolders.add(0, new MediaFolder(cameraFolder.getThumbnail(), cameraFolder.getTitle(), cameraFolder.getCount(), cameraFolder.getBucketId(), MediaFolder.FolderType.CAMERA));
     }
 
     return mediaFolders;
@@ -113,8 +94,6 @@ class MediaRepository {
 
   @WorkerThread
   private @NonNull FolderResult getFolders(@NonNull Context context, @NonNull Uri contentUri) {
-    String                  cameraPath         = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM).getAbsolutePath() + File.separator + "Camera";
-    String                  cameraBucketId     = null;
     Uri                     globalThumbnail    = null;
     long                    thumbnailTimestamp = 0;
     Map<String, FolderData> folders            = new HashMap<>();
@@ -135,10 +114,6 @@ class MediaRepository {
         folder.incrementCount();
         folders.put(bucketId, folder);
 
-        if (cameraBucketId == null && path.startsWith(cameraPath)) {
-          cameraBucketId = bucketId;
-        }
-
         if (timestamp > thumbnailTimestamp) {
           globalThumbnail    = thumbnail;
           thumbnailTimestamp = timestamp;
@@ -146,7 +121,7 @@ class MediaRepository {
       }
     }
 
-    return new FolderResult(cameraBucketId, globalThumbnail, thumbnailTimestamp, folders);
+    return new FolderResult(globalThumbnail, thumbnailTimestamp, folders);
   }
 
   @WorkerThread
@@ -163,7 +138,8 @@ class MediaRepository {
   }
 
   @WorkerThread
-  private @NonNull List<Media> getMediaInBucket(@NonNull Context context, @NonNull String bucketId, @NonNull Uri contentUri, boolean hasOrienation) {
+  private @NonNull List<Media> getMediaInBucket(@NonNull Context context, @NonNull String bucketId, @NonNull Uri contentUri, boolean hasOrientation) {
+    //TODO Constrain media file size to match the Loki protocol limit.
     List<Media> media         = new LinkedList<>();
     String      selection     = Images.Media.BUCKET_ID + " = ? AND " + Images.Media.DATA + " NOT NULL";
     String[]    selectionArgs = new String[] { bucketId };
@@ -171,7 +147,7 @@ class MediaRepository {
 
     String[] projection;
 
-    if (hasOrienation) {
+    if (hasOrientation) {
       projection = new String[]{Images.Media._ID, Images.Media.MIME_TYPE, Images.Media.DATE_TAKEN, Images.Media.ORIENTATION, Images.Media.WIDTH, Images.Media.HEIGHT, Images.Media.SIZE};
     } else {
       projection = new String[]{Images.Media._ID, Images.Media.MIME_TYPE, Images.Media.DATE_TAKEN, Images.Media.WIDTH, Images.Media.HEIGHT, Images.Media.SIZE};
@@ -187,7 +163,7 @@ class MediaRepository {
         Uri    uri         = Uri.withAppendedPath(contentUri, cursor.getString(cursor.getColumnIndexOrThrow(Images.Media._ID)));
         String mimetype    = cursor.getString(cursor.getColumnIndexOrThrow(Images.Media.MIME_TYPE));
         long   dateTaken   = cursor.getLong(cursor.getColumnIndexOrThrow(Images.Media.DATE_TAKEN));
-        int    orientation = hasOrienation ? cursor.getInt(cursor.getColumnIndexOrThrow(Images.Media.ORIENTATION)) : 0;
+        int    orientation = hasOrientation ? cursor.getInt(cursor.getColumnIndexOrThrow(Images.Media.ORIENTATION)) : 0;
         int    width       = cursor.getInt(cursor.getColumnIndexOrThrow(getWidthColumn(orientation)));
         int    height      = cursor.getInt(cursor.getColumnIndexOrThrow(getHeightColumn(orientation)));
         long   size        = cursor.getLong(cursor.getColumnIndexOrThrow(Images.Media.SIZE));
@@ -284,26 +260,19 @@ class MediaRepository {
   }
 
   private static class FolderResult {
-    private final String                  cameraBucketId;
     private final Uri                     thumbnail;
     private final long                    thumbnailTimestamp;
     private final Map<String, FolderData> folderData;
 
-    private FolderResult(@Nullable String cameraBucketId,
+    private FolderResult(@Nullable Uri thumbnail,
-                         @Nullable Uri thumbnail,
                          long thumbnailTimestamp,
                          @NonNull Map<String, FolderData> folderData)
     {
-      this.cameraBucketId     = cameraBucketId;
       this.thumbnail          = thumbnail;
       this.thumbnailTimestamp = thumbnailTimestamp;
       this.folderData         = folderData;
     }
 
-    @Nullable String getCameraBucketId() {
-      return cameraBucketId;
-    }
-
     @Nullable Uri getThumbnail() {
       return thumbnail;
     }

src/org/thoughtcrime/securesms/mediasend/MediaSendActivity.java

@@ -1,6 +1,8 @@
 package org.thoughtcrime.securesms.mediasend;
 
 import android.Manifest;
+
+import androidx.lifecycle.ViewModelProvider;
 import androidx.lifecycle.ViewModelProviders;
 import android.content.Context;
 import android.content.Intent;
@@ -133,7 +135,7 @@ public class MediaSendActivity extends PassphraseRequiredActionBarActivity imple
     countButtonText = findViewById(R.id.mediasend_count_button_text);
     cameraButton    = findViewById(R.id.mediasend_camera_button);
 
-    viewModel = ViewModelProviders.of(this, new MediaSendViewModel.Factory(getApplication(), new MediaRepository())).get(MediaSendViewModel.class);
+    viewModel = new ViewModelProvider(this, new MediaSendViewModel.Factory(getApplication(), new MediaRepository())).get(MediaSendViewModel.class);
     recipient = Recipient.from(this, Address.fromSerialized(getIntent().getStringExtra(KEY_ADDRESS)), true);
     transport = getIntent().getParcelableExtra(KEY_TRANSPORT);
 
@@ -375,7 +377,6 @@ public class MediaSendActivity extends PassphraseRequiredActionBarActivity imple
   private void navigateToCamera() {
     Permissions.with(this)
                .request(Manifest.permission.CAMERA)
-               .ifNecessary()
                .withRationaleDialog(getString(R.string.ConversationActivity_to_capture_photos_and_video_allow_signal_access_to_the_camera), R.drawable.ic_baseline_photo_camera_48)
                .withPermanentDenialDialog(getString(R.string.ConversationActivity_signal_needs_the_camera_permission_to_take_photos_or_video))
                .onAllGranted(() -> {

src/org/thoughtcrime/securesms/mms/AttachmentManager.java

@@ -371,37 +371,25 @@ public class AttachmentManager {
   }
 
   public static void selectDocument(Activity activity, int requestCode) {
-    Permissions.with(activity)
+    selectMediaType(activity, "*/*", null, requestCode);
-               .request(Manifest.permission.WRITE_EXTERNAL_STORAGE)
-               .ifNecessary()
-               .withPermanentDenialDialog(activity.getString(R.string.AttachmentManager_signal_requires_the_external_storage_permission_in_order_to_attach_photos_videos_or_audio))
-               .onAllGranted(() -> selectMediaType(activity, "*/*", null, requestCode))
-               .execute();
   }
 
   public static void selectGallery(Activity activity, int requestCode, @NonNull Recipient recipient, @NonNull String body, @NonNull TransportOption transport) {
     Permissions.with(activity)
-               .request(Manifest.permission.WRITE_EXTERNAL_STORAGE)
+               .request(Manifest.permission.READ_EXTERNAL_STORAGE)
-               .ifNecessary()
                .withPermanentDenialDialog(activity.getString(R.string.AttachmentManager_signal_requires_the_external_storage_permission_in_order_to_attach_photos_videos_or_audio))
-               .onAllGranted(() -> selectMediaType(activity, "image/*", new String[] {"image/*", "video/*"}, requestCode))
+//               .onAllGranted(() -> selectMediaType(activity, "image/*", new String[] {"image/*", "video/*"}, requestCode))
                .onAllGranted(() -> activity.startActivityForResult(MediaSendActivity.buildGalleryIntent(activity, recipient, body, transport), requestCode))
                .execute();
   }
 
   public static void selectAudio(Activity activity, int requestCode) {
-    Permissions.with(activity)
+    selectMediaType(activity, "audio/*", null, requestCode);
-               .request(Manifest.permission.WRITE_EXTERNAL_STORAGE)
-               .ifNecessary()
-               .withPermanentDenialDialog(activity.getString(R.string.AttachmentManager_signal_requires_the_external_storage_permission_in_order_to_attach_photos_videos_or_audio))
-               .onAllGranted(() -> selectMediaType(activity, "audio/*", null, requestCode))
-               .execute();
   }
 
   public static void selectContactInfo(Activity activity, int requestCode) {
     Permissions.with(activity)
                .request(Manifest.permission.WRITE_CONTACTS)
-               .ifNecessary()
                .withPermanentDenialDialog(activity.getString(R.string.AttachmentManager_signal_requires_contacts_permission_in_order_to_attach_contact_information))
                .onAllGranted(() -> {
                  Intent intent = new Intent(Intent.ACTION_PICK, ContactsContract.Contacts.CONTENT_URI);
@@ -414,7 +402,6 @@ public class AttachmentManager {
     /* Loki - Enable again once we have location sharing
     Permissions.with(activity)
                .request(Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION)
-               .ifNecessary()
                .withPermanentDenialDialog(activity.getString(R.string.AttachmentManager_signal_requires_location_information_in_order_to_attach_a_location))
                .onAllGranted(() -> {
                  try {
@@ -444,7 +431,6 @@ public class AttachmentManager {
   public void capturePhoto(Activity activity, int requestCode) {
     Permissions.with(activity)
             .request(Manifest.permission.CAMERA)
-            .ifNecessary()
             .withPermanentDenialDialog(activity.getString(R.string.AttachmentManager_signal_requires_the_camera_permission_in_order_to_take_photos_but_it_has_been_permanently_denied))
             .onAllGranted(() -> {
               try {
@@ -469,6 +455,7 @@ public class AttachmentManager {
   }
 
   private static void selectMediaType(Activity activity, @NonNull String type, @Nullable String[] extraMimeType, int requestCode) {
+    //TODO Constrain media file size to match the Loki protocol limit.
     final Intent intent = new Intent();
     intent.setType(type);
 

src/org/thoughtcrime/securesms/permissions/Permissions.java

@@ -1,6 +1,5 @@
 package org.thoughtcrime.securesms.permissions;
 
-
 import android.app.Activity;
 import android.app.AlertDialog;
 import android.content.Context;
@@ -63,9 +62,8 @@ public class Permissions {
     private @DrawableRes int[]  rationalDialogHeader;
     private              String rationaleDialogMessage;
 
-    private boolean ifNecesary;
+    private int minSdkVersion = 0;
-
+    private int maxSdkVersion = Integer.MAX_VALUE;
-    private boolean condition = true;
 
     PermissionsBuilder(PermissionObject permissionObject) {
       this.permissionObject = permissionObject;
@@ -76,17 +74,6 @@ public class Permissions {
       return this;
     }
 
-    public PermissionsBuilder ifNecessary() {
-      this.ifNecesary = true;
-      return this;
-    }
-
-    public PermissionsBuilder ifNecessary(boolean condition) {
-      this.ifNecesary = true;
-      this.condition  = condition;
-      return this;
-    }
-
     public PermissionsBuilder withRationaleDialog(@NonNull String message, @NonNull @DrawableRes int... headers) {
       this.rationalDialogHeader   = headers;
       this.rationaleDialogMessage = message;
@@ -133,11 +120,29 @@ public class Permissions {
       return this;
     }
 
+    /**
+     * Min Android SDK version to request the permissions for (inclusive).
+     */
+    public PermissionsBuilder minSdkVersion(int minSdkVersion) {
+      this.minSdkVersion = minSdkVersion;
+      return this;
+    }
+
+    /**
+     * Max Android SDK version to request the permissions for (inclusive).
+     */
+    public PermissionsBuilder maxSdkVersion(int maxSdkVersion) {
+      this.maxSdkVersion = maxSdkVersion;
+      return this;
+    }
+
     public void execute() {
       PermissionsRequest request = new PermissionsRequest(allGrantedListener, anyDeniedListener, anyPermanentlyDeniedListener, anyResultListener,
                                                           someGrantedListener, someDeniedListener, somePermanentlyDeniedListener);
 
-      if (ifNecesary && (permissionObject.hasAll(requestedPermissions) || !condition)) {
+      boolean targetSdk = Build.VERSION.SDK_INT >= minSdkVersion && Build.VERSION.SDK_INT <= maxSdkVersion;
+
+      if (!targetSdk || permissionObject.hasAll(requestedPermissions)) {
         executePreGrantedPermissionsRequest(request);
       } else if (rationaleDialogMessage != null && rationalDialogHeader != null) {
         executePermissionsRequestWithRationale(request);

src/org/thoughtcrime/securesms/preferences/ChatsPreferenceFragment.java

@@ -139,7 +139,6 @@ public class ChatsPreferenceFragment extends ListSummaryPreferenceFragment {
     public boolean onPreferenceClick(Preference preference) {
       Permissions.with(ChatsPreferenceFragment.this)
                  .request(Manifest.permission.WRITE_EXTERNAL_STORAGE)
-                 .ifNecessary()
                  .onAllGranted(() -> {
                    if (!((SwitchPreferenceCompat)preference).isChecked()) {
                      BackupDialog.showEnableBackupDialog(getActivity(), (SwitchPreferenceCompat)preference);
@@ -160,7 +159,6 @@ public class ChatsPreferenceFragment extends ListSummaryPreferenceFragment {
     public boolean onPreferenceClick(Preference preference) {
       Permissions.with(ChatsPreferenceFragment.this)
                  .request(Manifest.permission.WRITE_EXTERNAL_STORAGE)
-                 .ifNecessary()
                  .onAllGranted(() -> {
                    Log.i(TAG, "Queing backup...");
                    ApplicationContext.getInstance(getContext())

src/org/thoughtcrime/securesms/registration/WelcomeActivity.java

@@ -55,7 +55,6 @@ public class WelcomeActivity extends BaseActionBarActivity {
   private void onContinueClicked() {
     Permissions.with(this)
         .request(Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.READ_EXTERNAL_STORAGE)
-        .ifNecessary()
         .withRationaleDialog(getString(R.string.activity_landing_permission_dialog_message), R.drawable.ic_baseline_folder_48)
         .onAnyResult(() -> {
           Intent nextIntent = getIntent().getParcelableExtra("next_intent");

src/org/thoughtcrime/securesms/util/BackupUtil.java

@@ -16,6 +16,7 @@ import java.util.Arrays;
 import java.util.Calendar;
 import java.util.Locale;
 
+//TODO AC: Needs to be refactored to use Storage Access Framework or Media Store API.
 public class BackupUtil {
 
   private static final String TAG = BackupUtil.class.getSimpleName();

src/org/thoughtcrime/securesms/util/CommunicationActions.java

@@ -35,8 +35,7 @@ public class CommunicationActions {
 
     Permissions.with(activity)
         .request(Manifest.permission.RECORD_AUDIO, Manifest.permission.CAMERA)
-        .ifNecessary()
+        .withRationaleDialog(activity.getString(R.string.ConversationActivity_to_call_s_signal_needs_access_to_your_microphone_and_camera),
-        .withRationaleDialog(activity.getString(R.string.ConversationActivity_to_call_s_signal_needs_access_to_your_microphone_and_camera, recipient.toShortString()),
                              R.drawable.ic_mic_white_48dp,
                              R.drawable.ic_videocam_white_48dp)
         .withPermanentDenialDialog(activity.getString(R.string.ConversationActivity_signal_needs_the_microphone_and_camera_permissions_in_order_to_call_s, recipient.toShortString()))

src/org/thoughtcrime/securesms/util/SaveAttachmentTask.java

@@ -1,234 +0,0 @@
-package org.thoughtcrime.securesms.util;
-
-import android.content.Context;
-import android.content.DialogInterface.OnClickListener;
-import android.media.MediaScannerConnection;
-import android.net.Uri;
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
-import androidx.appcompat.app.AlertDialog;
-import android.text.TextUtils;
-import android.webkit.MimeTypeMap;
-import android.widget.Toast;
-
-import network.loki.messenger.R;
-import org.thoughtcrime.securesms.database.NoExternalStorageException;
-import org.thoughtcrime.securesms.logging.Log;
-import org.thoughtcrime.securesms.mms.PartAuthority;
-import org.thoughtcrime.securesms.util.task.ProgressDialogAsyncTask;
-import org.whispersystems.libsignal.util.Pair;
-
-import java.io.File;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
-import java.lang.ref.WeakReference;
-import java.text.SimpleDateFormat;
-
-public class SaveAttachmentTask extends ProgressDialogAsyncTask<SaveAttachmentTask.Attachment, Void, Pair<Integer, String>> {
-  private static final String TAG = SaveAttachmentTask.class.getSimpleName();
-
-          static final int SUCCESS              = 0;
-  private static final int FAILURE              = 1;
-  private static final int WRITE_ACCESS_FAILURE = 2;
-
-  private final WeakReference<Context>      contextReference;
-
-  private final int attachmentCount;
-
-  public SaveAttachmentTask(Context context) {
-    this(context, 1);
-  }
-
-  public SaveAttachmentTask(Context context, int count) {
-    super(context,
-          context.getResources().getQuantityString(R.plurals.ConversationFragment_saving_n_attachments, count, count),
-          context.getResources().getQuantityString(R.plurals.ConversationFragment_saving_n_attachments_to_sd_card, count, count));
-    this.contextReference      = new WeakReference<>(context);
-    this.attachmentCount       = count;
-  }
-
-  @Override
-  protected Pair<Integer, String> doInBackground(SaveAttachmentTask.Attachment... attachments) {
-    if (attachments == null || attachments.length == 0) {
-      throw new AssertionError("must pass in at least one attachment");
-    }
-
-    try {
-      Context      context      = contextReference.get();
-      String       directory    = null;
-
-      if (context == null) {
-        return new Pair<>(FAILURE, null);
-      }
-
-      for (Attachment attachment : attachments) {
-        if (attachment != null) {
-          directory = saveAttachment(context, attachment);
-          if (directory == null) return new Pair<>(FAILURE, null);
-        }
-      }
-
-      if (attachments.length > 1) return new Pair<>(SUCCESS, null);
-      else                        return new Pair<>(SUCCESS, directory);
-    } catch (NoExternalStorageException|IOException ioe) {
-      Log.w(TAG, ioe);
-      return new Pair<>(FAILURE, null);
-    }
-  }
-
-  private @Nullable String saveAttachment(Context context, Attachment attachment)
-      throws NoExternalStorageException, IOException
-  {
-    String      contentType = MediaUtil.getCorrectedMimeType(attachment.contentType);
-    String         fileName = attachment.fileName;
-
-    if (fileName == null) fileName = generateOutputFileName(contentType, attachment.date);
-    fileName = sanitizeOutputFileName(fileName);
-
-    File    outputDirectory = createOutputDirectoryFromContentType(contentType);
-    File          mediaFile = createOutputFile(outputDirectory, fileName);
-    InputStream inputStream = PartAuthority.getAttachmentStream(context, attachment.uri);
-
-    if (inputStream == null) {
-      return null;
-    }
-
-    OutputStream outputStream = new FileOutputStream(mediaFile);
-    Util.copy(inputStream, outputStream);
-
-    MediaScannerConnection.scanFile(context, new String[]{mediaFile.getAbsolutePath()},
-                                    new String[]{contentType}, null);
-
-    return outputDirectory.getName();
-  }
-
-  private File createOutputDirectoryFromContentType(@NonNull String contentType)
-      throws NoExternalStorageException
-  {
-    File outputDirectory;
-
-    if (contentType.startsWith("video/")) {
-      outputDirectory = ExternalStorageUtil.getVideoDir(getContext());
-    } else if (contentType.startsWith("audio/")) {
-      outputDirectory = ExternalStorageUtil.getAudioDir(getContext());
-    } else if (contentType.startsWith("image/")) {
-      outputDirectory = ExternalStorageUtil.getImageDir(getContext());
-    } else {
-      outputDirectory = ExternalStorageUtil.getDownloadDir(getContext());
-    }
-
-    if (!outputDirectory.mkdirs()) Log.w(TAG, "mkdirs() returned false, attempting to continue");
-    return outputDirectory;
-  }
-
-  private String generateOutputFileName(@NonNull String contentType, long timestamp) {
-    MimeTypeMap      mimeTypeMap   = MimeTypeMap.getSingleton();
-    String           extension     = mimeTypeMap.getExtensionFromMimeType(contentType);
-    SimpleDateFormat dateFormatter = new SimpleDateFormat("yyyy-MM-dd-HHmmss");
-    String           base          = "signal-" + dateFormatter.format(timestamp);
-
-    if (extension == null) extension = "attach";
-
-    return base + "." + extension;
-  }
-
-  private String sanitizeOutputFileName(@NonNull String fileName) {
-    return new File(fileName).getName();
-  }
-
-  private File createOutputFile(@NonNull File outputDirectory, @NonNull String fileName)
-      throws IOException
-  {
-    String[] fileParts = getFileNameParts(fileName);
-    String base = fileParts[0];
-    String extension = fileParts[1];
-
-    File outputFile = new File(outputDirectory, base + "." + extension);
-
-    int i = 0;
-    while (outputFile.exists()) {
-      outputFile = new File(outputDirectory, base + "-" + (++i) + "." + extension);
-    }
-
-    if (outputFile.isHidden()) {
-      throw new IOException("Specified name would not be visible");
-    }
-
-    return outputFile;
-  }
-
-  private String[] getFileNameParts(String fileName) {
-    String[] result = new String[2];
-    String[] tokens = fileName.split("\\.(?=[^\\.]+$)");
-
-    result[0] = tokens[0];
-
-    if (tokens.length > 1) result[1] = tokens[1];
-    else                   result[1] = "";
-
-    return result;
-  }
-
-  @Override
-  protected void onPostExecute(final Pair<Integer, String> result) {
-    super.onPostExecute(result);
-    final Context context = contextReference.get();
-    if (context == null) return;
-
-    switch (result.first()) {
-      case FAILURE:
-        Toast.makeText(context,
-                       context.getResources().getQuantityText(R.plurals.ConversationFragment_error_while_saving_attachments_to_sd_card,
-                                                              attachmentCount),
-                       Toast.LENGTH_LONG).show();
-        break;
-      case SUCCESS:
-        String message = !TextUtils.isEmpty(result.second())  ? context.getResources().getString(R.string.SaveAttachmentTask_saved_to, result.second())
-                                                              : context.getResources().getString(R.string.SaveAttachmentTask_saved);
-        Toast.makeText(context, message, Toast.LENGTH_LONG).show();
-        break;
-      case WRITE_ACCESS_FAILURE:
-        Toast.makeText(context, R.string.ConversationFragment_unable_to_write_to_sd_card_exclamation,
-            Toast.LENGTH_LONG).show();
-        break;
-    }
-  }
-
-  public static class Attachment {
-    public Uri    uri;
-    public String fileName;
-    public String contentType;
-    public long   date;
-
-    public Attachment(@NonNull Uri uri, @NonNull String contentType,
-                      long date, @Nullable String fileName)
-    {
-      if (uri == null || contentType == null || date < 0) {
-        throw new AssertionError("uri, content type, and date must all be specified");
-      }
-      this.uri         = uri;
-      this.fileName    = fileName;
-      this.contentType = contentType;
-      this.date        = date;
-    }
-  }
-
-  public static void showWarningDialog(Context context, OnClickListener onAcceptListener) {
-    showWarningDialog(context, onAcceptListener, 1);
-  }
-
-  public static void showWarningDialog(Context context, OnClickListener onAcceptListener, int count) {
-    AlertDialog.Builder builder = new AlertDialog.Builder(context);
-    builder.setTitle(R.string.ConversationFragment_save_to_sd_card);
-    builder.setIconAttribute(R.attr.dialog_alert_icon);
-    builder.setCancelable(true);
-    builder.setMessage(context.getResources().getQuantityString(R.plurals.ConversationFragment_saving_n_media_to_storage_warning,
-                                                                count, count));
-    builder.setPositiveButton(R.string.yes, onAcceptListener);
-    builder.setNegativeButton(R.string.no, null);
-    builder.show();
-  }
-}
-

src/org/thoughtcrime/securesms/util/SaveAttachmentTask.kt

@@ -0,0 +1,196 @@
+package org.thoughtcrime.securesms.util
+
+import android.content.ContentValues
+import android.content.Context
+import android.content.DialogInterface.OnClickListener
+import android.net.Uri
+import android.os.Build
+import android.provider.MediaStore
+import android.text.TextUtils
+import android.webkit.MimeTypeMap
+import android.widget.Toast
+import androidx.appcompat.app.AlertDialog
+import network.loki.messenger.R
+import org.thoughtcrime.securesms.logging.Log
+import org.thoughtcrime.securesms.mms.PartAuthority
+import org.thoughtcrime.securesms.util.task.ProgressDialogAsyncTask
+import java.io.File
+import java.io.IOException
+import java.lang.ref.WeakReference
+import java.text.SimpleDateFormat
+
+/**
+ * Saves attachment files to an external storage using [MediaStore] API.
+ */
+class SaveAttachmentTask : ProgressDialogAsyncTask<SaveAttachmentTask.Attachment, Void, Pair<Int, String?>> {
+
+    companion object {
+        @JvmStatic
+        private val TAG = SaveAttachmentTask::class.simpleName
+
+        private const val RESULT_SUCCESS = 0
+        private const val RESULT_FAILURE = 1
+
+        @JvmStatic
+        @JvmOverloads
+        fun showWarningDialog(context: Context, onAcceptListener: OnClickListener, count: Int = 1) {
+            val builder = AlertDialog.Builder(context)
+            builder.setTitle(R.string.ConversationFragment_save_to_sd_card)
+            builder.setIconAttribute(R.attr.dialog_alert_icon)
+            builder.setCancelable(true)
+            builder.setMessage(context.resources.getQuantityString(
+                    R.plurals.ConversationFragment_saving_n_media_to_storage_warning,
+                    count,
+                    count))
+            builder.setPositiveButton(R.string.yes, onAcceptListener)
+            builder.setNegativeButton(R.string.no, null)
+            builder.show()
+        }
+    }
+
+    private val contextReference: WeakReference<Context>
+    private val attachmentCount: Int
+
+    @JvmOverloads
+    constructor(context: Context, count: Int = 1): super(context,
+            context.resources.getQuantityString(R.plurals.ConversationFragment_saving_n_attachments, count, count),
+            context.resources.getQuantityString(R.plurals.ConversationFragment_saving_n_attachments_to_sd_card, count, count)) {
+        this.contextReference = WeakReference(context)
+        this.attachmentCount = count
+    }
+
+    override fun doInBackground(vararg attachments: Attachment?): Pair<Int, String?> {
+        if (attachments.isEmpty()) {
+            throw IllegalArgumentException("Must pass in at least one attachment")
+        }
+
+        try {
+            val context = contextReference.get()
+            var directory: String? = null
+
+            if (context == null) {
+                return Pair(RESULT_FAILURE, null)
+            }
+
+            for (attachment in attachments) {
+                if (attachment != null) {
+                    directory = saveAttachment(context, attachment)
+                    if (directory == null) return Pair(RESULT_FAILURE, null)
+                }
+            }
+
+            return if (attachments.size > 1)
+                Pair(RESULT_SUCCESS, null)
+            else
+                Pair(RESULT_SUCCESS, directory)
+        } catch (e: IOException) {
+            Log.w(TAG, e)
+            return Pair(RESULT_FAILURE, null)
+        }
+    }
+
+    @Throws(IOException::class)
+    private fun saveAttachment(context: Context, attachment: Attachment): String? {
+        val resolver = context.contentResolver
+
+        val contentType = MediaUtil.getCorrectedMimeType(attachment.contentType)!!
+        val fileName = attachment.fileName
+                ?: sanitizeOutputFileName(generateOutputFileName(contentType, attachment.date))
+
+        val mediaRecord = ContentValues()
+        val mediaVolume = if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.P) {
+            MediaStore.VOLUME_EXTERNAL
+        } else {
+            MediaStore.VOLUME_EXTERNAL_PRIMARY
+        }
+        val collectionUri: Uri
+
+        when {
+            contentType.startsWith("video/") -> {
+                collectionUri = MediaStore.Video.Media.getContentUri(mediaVolume)
+                mediaRecord.put(MediaStore.Video.Media.DISPLAY_NAME, fileName)
+                mediaRecord.put(MediaStore.Video.Media.MIME_TYPE, contentType)
+                // Add the date meta data to ensure the image is added at the front of the gallery
+                mediaRecord.put(MediaStore.Video.Media.DATE_ADDED, System.currentTimeMillis())
+                mediaRecord.put(MediaStore.Video.Media.DATE_TAKEN, System.currentTimeMillis())
+
+            }
+            contentType.startsWith("audio/") -> {
+                collectionUri = MediaStore.Audio.Media.getContentUri(mediaVolume)
+                mediaRecord.put(MediaStore.Audio.Media.DISPLAY_NAME, fileName)
+                mediaRecord.put(MediaStore.Audio.Media.MIME_TYPE, contentType)
+                mediaRecord.put(MediaStore.Audio.Media.DATE_ADDED, System.currentTimeMillis())
+                mediaRecord.put(MediaStore.Audio.Media.DATE_TAKEN, System.currentTimeMillis())
+
+            }
+            contentType.startsWith("image/") -> {
+                collectionUri = MediaStore.Images.Media.getContentUri(mediaVolume)
+                mediaRecord.put(MediaStore.Images.Media.TITLE, fileName)
+                mediaRecord.put(MediaStore.Images.Media.DISPLAY_NAME, fileName)
+                mediaRecord.put(MediaStore.Images.Media.MIME_TYPE, contentType)
+                mediaRecord.put(MediaStore.Images.Media.DATE_ADDED, System.currentTimeMillis())
+                mediaRecord.put(MediaStore.Images.Media.DATE_TAKEN, System.currentTimeMillis())
+
+            }
+            else -> {
+                mediaRecord.put(MediaStore.Files.FileColumns.DISPLAY_NAME, fileName)
+                collectionUri = MediaStore.Files.getContentUri(mediaVolume)
+            }
+        }
+
+        val mediaFileUri = resolver.insert(collectionUri, mediaRecord)
+        if (mediaFileUri == null) return null
+
+        val inputStream = PartAuthority.getAttachmentStream(context, attachment.uri)
+        if (inputStream == null) return null
+
+        inputStream.use {
+            resolver.openOutputStream(mediaFileUri).use {
+                Util.copy(inputStream, it)
+            }
+        }
+
+        return mediaFileUri.toString()
+    }
+
+    private fun generateOutputFileName(contentType: String, timestamp: Long): String {
+        val mimeTypeMap = MimeTypeMap.getSingleton()
+        val extension = mimeTypeMap.getExtensionFromMimeType(contentType) ?: "attach"
+        val dateFormatter = SimpleDateFormat("yyyy-MM-dd-HHmmss")
+        val base = "signal-${dateFormatter.format(timestamp)}"
+
+        return "${base}.${extension}";
+    }
+
+    private fun sanitizeOutputFileName(fileName: String): String {
+        return File(fileName).name
+    }
+
+    override fun onPostExecute(result: Pair<Int, String?>) {
+        super.onPostExecute(result)
+        val context = contextReference.get()
+        if (context == null) return
+
+        when (result.first) {
+            RESULT_FAILURE -> {
+                val message = context.resources.getQuantityText(
+                        R.plurals.ConversationFragment_error_while_saving_attachments_to_sd_card,
+                        attachmentCount)
+                Toast.makeText(context, message, Toast.LENGTH_LONG).show()
+            }
+
+            RESULT_SUCCESS -> {
+                val message = if (!TextUtils.isEmpty(result.second)) {
+                    context.resources.getString(R.string.SaveAttachmentTask_saved_to, result.second)
+                } else {
+                    context.resources.getString(R.string.SaveAttachmentTask_saved)
+                }
+                Toast.makeText(context, message, Toast.LENGTH_LONG).show()
+            }
+
+            else -> throw IllegalStateException("Unexpected result value: " + result.first)
+        }
+    }
+
+    data class Attachment(val uri: Uri, val contentType: String, val date: Long, val fileName: String?)
+}

src/org/thoughtcrime/securesms/util/task/ProgressDialogAsyncTask.java

@@ -4,6 +4,8 @@ import android.app.ProgressDialog;
 import android.content.Context;
 import android.os.AsyncTask;
 
+import androidx.annotation.NonNull;
+
 import java.lang.ref.WeakReference;
 
 public abstract class ProgressDialogAsyncTask<Params, Progress, Result> extends AsyncTask<Params, Progress, Result> {
@@ -13,14 +15,14 @@ public abstract class ProgressDialogAsyncTask<Params, Progress, Result> extends
   private final String                 title;
   private final String                 message;
 
-  public ProgressDialogAsyncTask(Context context, String title, String message) {
+  public ProgressDialogAsyncTask(@NonNull Context context, @NonNull String title, @NonNull String message) {
     super();
     this.contextReference = new WeakReference<>(context);
     this.title            = title;
     this.message          = message;
   }
 
-  public ProgressDialogAsyncTask(Context context, int title, int message) {
+  public ProgressDialogAsyncTask(@NonNull Context context, int title, int message) {
     this(context, context.getString(title), context.getString(message));
   }
 
@@ -35,7 +37,7 @@ public abstract class ProgressDialogAsyncTask<Params, Progress, Result> extends
     if (progress != null) progress.dismiss();
   }
 
-  protected Context getContext() {
+  protected @NonNull Context getContext() {
     return contextReference.get();
   }
 }