Enable Media Preview to respond to media changes.

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

@@ -20,10 +20,12 @@ import android.Manifest;
 import android.annotation.SuppressLint;
 import android.content.Context;
 import android.content.Intent;
+import android.database.ContentObserver;
 import android.database.Cursor;
 import android.net.Uri;
 import android.os.AsyncTask;
 import android.os.Bundle;
+import android.os.Handler;
 import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
@@ -73,6 +75,7 @@ import org.thoughtcrime.securesms.util.SaveAttachmentTask.Attachment;
 import java.util.HashMap;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Objects;
 
 /**
  * Activity for displaying media attachments in-app
@@ -117,17 +120,20 @@ public final class MediaPreviewActivity extends PassphraseRequiredActivity
   private boolean               showThread;
   private MediaDatabase.Sorting sorting;
 
+  private @Nullable Cursor cursor = null;
+
   public static @NonNull Intent intentFromMediaRecord(@NonNull Context context,
                                                       @NonNull MediaRecord mediaRecord,
                                                       boolean leftIsRecent)
   {
+    DatabaseAttachment attachment = Objects.requireNonNull(mediaRecord.getAttachment());
     Intent intent = new Intent(context, MediaPreviewActivity.class);
     intent.putExtra(MediaPreviewActivity.THREAD_ID_EXTRA, mediaRecord.getThreadId());
     intent.putExtra(MediaPreviewActivity.DATE_EXTRA, mediaRecord.getDate());
-    intent.putExtra(MediaPreviewActivity.SIZE_EXTRA, mediaRecord.getAttachment().getSize());
+    intent.putExtra(MediaPreviewActivity.SIZE_EXTRA, attachment.getSize());
-    intent.putExtra(MediaPreviewActivity.CAPTION_EXTRA, mediaRecord.getAttachment().getCaption());
+    intent.putExtra(MediaPreviewActivity.CAPTION_EXTRA, attachment.getCaption());
     intent.putExtra(MediaPreviewActivity.LEFT_IS_RECENT_EXTRA, leftIsRecent);
-    intent.setDataAndType(mediaRecord.getAttachment().getDataUri(), mediaRecord.getContentType());
+    intent.setDataAndType(attachment.getDataUri(), mediaRecord.getContentType());
     return intent;
   }
 
@@ -228,6 +234,15 @@ public final class MediaPreviewActivity extends PassphraseRequiredActivity
     restartItem = cleanupMedia();
   }
 
+  @Override
+  protected void onDestroy() {
+    if (cursor != null) {
+      cursor.close();
+      cursor = null;
+    }
+    super.onDestroy();
+  }
+
   @Override
   protected void onNewIntent(Intent intent) {
     super.onNewIntent(intent);
@@ -344,6 +359,7 @@ public final class MediaPreviewActivity extends PassphraseRequiredActivity
 
     mediaPager.removeAllViews();
     mediaPager.setAdapter(null);
+    viewModel.setCursor(this, null, leftIsRecent);
 
     return restartItem;
   }
@@ -475,19 +491,46 @@ public final class MediaPreviewActivity extends PassphraseRequiredActivity
   @Override
   public void onLoadFinished(@NonNull Loader<Pair<Cursor, Integer>> loader, @Nullable Pair<Cursor, Integer> data) {
     if (data != null) {
-      @SuppressWarnings("ConstantConditions")
+      if (data.first == cursor) {
-      CursorPagerAdapter adapter = new CursorPagerAdapter(getSupportFragmentManager(),this, data.first, data.second, leftIsRecent);
+        return;
+      }
+
+      if (cursor != null) {
+        cursor.close();
+      }
+      cursor = Objects.requireNonNull(data.first);
+
+      int mediaPosition = Objects.requireNonNull(data.second);
+
+      CursorPagerAdapter adapter = new CursorPagerAdapter(getSupportFragmentManager(),this, cursor, mediaPosition, leftIsRecent);
       mediaPager.setAdapter(adapter);
       adapter.setActive(true);
 
-      viewModel.setCursor(this, data.first, leftIsRecent);
+      viewModel.setCursor(this, cursor, leftIsRecent);
 
-      int item = restartItem >= 0 ? restartItem : data.second;
+      int item = restartItem >= 0 ? restartItem : mediaPosition;
       mediaPager.setCurrentItem(item);
 
       if (item == 0) {
         viewPagerListener.onPageSelected(0);
       }
+
+      cursor.registerContentObserver(new ContentObserver(new Handler(getMainLooper())) {
+        @Override
+        public void onChange(boolean selfChange) {
+          onMediaChange();
+        }
+      });
+    } else {
+      mediaNotAvailable();
+    }
+  }
+
+  private void onMediaChange() {
+    MediaItemAdapter adapter = (MediaItemAdapter) mediaPager.getAdapter();
+
+    if (adapter != null) {
+      adapter.checkMedia(mediaPager.getCurrentItem());
     }
   }
 
@@ -502,6 +545,12 @@ public final class MediaPreviewActivity extends PassphraseRequiredActivity
     return true;
   }
 
+  @Override
+  public void mediaNotAvailable() {
+    Toast.makeText(this, R.string.MediaPreviewActivity_media_no_longer_available, Toast.LENGTH_LONG).show();
+    finish();
+  }
+
   private void toggleUiVisibility() {
     int systemUiVisibility = getWindow().getDecorView().getSystemUiVisibility();
     if ((systemUiVisibility & View.SYSTEM_UI_FLAG_FULLSCREEN) != 0) {
@@ -621,6 +670,11 @@ public final class MediaPreviewActivity extends PassphraseRequiredActivity
     public boolean hasFragmentFor(int position) {
       return mediaPreviewFragment != null;
     }
+
+    @Override
+    public void checkMedia(int currentItem) {
+
+    }
   }
 
   private static void anchorMarginsToBottomInsets(@NonNull View viewToAnchor) {
@@ -712,7 +766,7 @@ public final class MediaPreviewActivity extends PassphraseRequiredActivity
       cursor.moveToPosition(cursorPosition);
 
       MediaDatabase.MediaRecord mediaRecord = MediaDatabase.MediaRecord.from(context, cursor);
-      DatabaseAttachment        attachment  = mediaRecord.getAttachment();
+      DatabaseAttachment        attachment  = Objects.requireNonNull(mediaRecord.getAttachment());
       MediaPreviewFragment      fragment    = MediaPreviewFragment.newInstance(attachment, autoPlay);
 
       mediaFragments.put(position, fragment);
@@ -735,15 +789,14 @@ public final class MediaPreviewActivity extends PassphraseRequiredActivity
       cursor.moveToPosition(getCursorPosition(position));
 
       MediaRecord        mediaRecord       = MediaRecord.from(context, cursor);
+      DatabaseAttachment attachment        = Objects.requireNonNull(mediaRecord.getAttachment());
       RecipientId        recipientId       = mediaRecord.getRecipientId();
       RecipientId        threadRecipientId = mediaRecord.getThreadRecipientId();
 
-      if (mediaRecord.getAttachment().getDataUri() == null) throw new AssertionError();
-
       return new MediaItem(Recipient.live(recipientId).get(),
                            Recipient.live(threadRecipientId).get(),
-                           mediaRecord.getAttachment(),
+                           attachment,
-                           mediaRecord.getAttachment().getDataUri(),
+                           Objects.requireNonNull(attachment.getDataUri()),
                            mediaRecord.getContentType(),
                            mediaRecord.getDate(),
                            mediaRecord.isOutgoing());
@@ -767,6 +820,14 @@ public final class MediaPreviewActivity extends PassphraseRequiredActivity
       return mediaFragments.containsKey(position);
     }
 
+    @Override
+    public void checkMedia(int position) {
+      MediaPreviewFragment fragment = mediaFragments.get(position);
+      if (fragment != null) {
+        fragment.checkMediaStillAvailable();
+      }
+    }
+
     private int getCursorPosition(int position) {
       if (leftIsRecent) return position;
       else              return cursor.getCount() - 1 - position;
@@ -805,5 +866,6 @@ public final class MediaPreviewActivity extends PassphraseRequiredActivity
     void pause(int position);
     @Nullable View getPlaybackControls(int position);
     boolean hasFragmentFor(int position);
+    void checkMedia(int currentItem);
   }
 }

app/src/main/java/org/thoughtcrime/securesms/database/AttachmentDatabase.java

@@ -309,6 +309,23 @@ public class AttachmentDatabase extends Database {
     }
   }
 
+  public boolean hasAttachment(@NonNull AttachmentId id) {
+    SQLiteDatabase database = databaseHelper.getReadableDatabase();
+
+    try (Cursor cursor = database.query(TABLE_NAME,
+                                        new String[]{ROW_ID, UNIQUE_ID},
+                                        PART_ID_WHERE,
+                                        id.toStrings(),
+                                        null,
+                                        null,
+                                        null)) {
+      if (cursor != null && cursor.getCount() > 0) {
+        return true;
+      }
+    }
+    return false;
+  }
+
   public boolean hasAttachmentFilesForMessage(long mmsId) {
     String   selection = MMS_ID + " = ? AND (" + DATA + " NOT NULL OR " + TRANSFER_STATE + " != ?)";
     String[] args      = new String[] { String.valueOf(mmsId), String.valueOf(TRANSFER_PROGRESS_DONE) };

app/src/main/java/org/thoughtcrime/securesms/database/Database.java

@@ -67,6 +67,10 @@ public abstract class Database {
     cursor.setNotificationUri(context.getContentResolver(), DatabaseContentProviders.Conversation.getUriForThread(threadId));
   }
 
+  protected void setNotifyConversationListeners(Cursor cursor) {
+    cursor.setNotificationUri(context.getContentResolver(), DatabaseContentProviders.Conversation.getUriForAllThreads());
+  }
+
   protected void setNotifyVerboseConversationListeners(Cursor cursor, long threadId) {
     cursor.setNotificationUri(context.getContentResolver(), DatabaseContentProviders.Conversation.getVerboseUriForThread(threadId));
   }

app/src/main/java/org/thoughtcrime/securesms/database/DatabaseContentProviders.java

@@ -27,6 +27,10 @@ public class DatabaseContentProviders {
     public static Uri getVerboseUriForThread(long threadId) {
       return Uri.parse(CONTENT_URI_STRING + "verbose/" + threadId);
     }
+
+    public static Uri getUriForAllThreads() {
+      return Uri.parse(CONTENT_URI_STRING);
+    }
   }
 
   public static class Attachment extends NoopContentProvider {

app/src/main/java/org/thoughtcrime/securesms/database/MediaDatabase.java

@@ -89,11 +89,19 @@ public class MediaDatabase extends Database {
   }
 
   public @NonNull Cursor getGalleryMediaForThread(long threadId, @NonNull Sorting sorting) {
+    return getGalleryMediaForThread(threadId, sorting, false);
+  }
+
+  public @NonNull Cursor getGalleryMediaForThread(long threadId, @NonNull Sorting sorting, boolean listenToAllThreads) {
     SQLiteDatabase database = databaseHelper.getReadableDatabase();
     String         query    = sorting.applyToQuery(applyEqualityOperator(threadId, GALLERY_MEDIA_QUERY));
     String[]       args     = {threadId + ""};
     Cursor         cursor   = database.rawQuery(query, args);
+    if (listenToAllThreads) {
+      setNotifyConversationListeners(cursor);
+    } else {
       setNotifyConversationListeners(cursor, threadId);
+    }
     return cursor;
   }
 

app/src/main/java/org/thoughtcrime/securesms/database/loaders/PagingMediaLoader.java

@@ -11,6 +11,7 @@ import androidx.core.util.Pair;
 import org.thoughtcrime.securesms.attachments.AttachmentId;
 import org.thoughtcrime.securesms.database.AttachmentDatabase;
 import org.thoughtcrime.securesms.database.DatabaseFactory;
+import org.thoughtcrime.securesms.database.MediaDatabase;
 import org.thoughtcrime.securesms.database.MediaDatabase.Sorting;
 import org.thoughtcrime.securesms.mms.PartAuthority;
 import org.thoughtcrime.securesms.util.AsyncLoader;
@@ -35,7 +36,7 @@ public final class PagingMediaLoader extends AsyncLoader<Pair<Cursor, Integer>>
 
   @Override
   public @Nullable Pair<Cursor, Integer> loadInBackground() {
-    Cursor cursor = DatabaseFactory.getMediaDatabase(getContext()).getGalleryMediaForThread(threadId, sorting);
+    Cursor cursor = DatabaseFactory.getMediaDatabase(getContext()).getGalleryMediaForThread(threadId, sorting, threadId == MediaDatabase.ALL_THREADS);
 
     while (cursor.moveToNext()) {
       AttachmentId attachmentId  = new AttachmentId(cursor.getLong(cursor.getColumnIndexOrThrow(AttachmentDatabase.ROW_ID)), cursor.getLong(cursor.getColumnIndexOrThrow(AttachmentDatabase.UNIQUE_ID)));

app/src/main/java/org/thoughtcrime/securesms/mediapreview/MediaPreviewFragment.java

@@ -10,7 +10,13 @@ import androidx.annotation.Nullable;
 import androidx.fragment.app.Fragment;
 
 import org.thoughtcrime.securesms.attachments.Attachment;
+import org.thoughtcrime.securesms.attachments.AttachmentId;
+import org.thoughtcrime.securesms.database.DatabaseFactory;
+import org.thoughtcrime.securesms.mms.PartUriParser;
 import org.thoughtcrime.securesms.util.MediaUtil;
+import org.thoughtcrime.securesms.util.concurrent.SimpleTask;
+
+import java.util.Objects;
 
 public abstract class MediaPreviewFragment extends Fragment {
 
@@ -19,6 +25,7 @@ public abstract class MediaPreviewFragment extends Fragment {
   static final String DATA_CONTENT_TYPE = "DATA_CONTENT_TYPE";
   static final String AUTO_PLAY         = "AUTO_PLAY";
 
+  private   AttachmentId attachmentId;
   protected Events       events;
 
   public static MediaPreviewFragment newInstance(@NonNull Attachment attachment, boolean autoPlay) {
@@ -60,6 +67,12 @@ public abstract class MediaPreviewFragment extends Fragment {
     events = (Events) context;
   }
 
+  @Override
+  public void onResume() {
+    super.onResume();
+    checkMediaStillAvailable();
+  }
+
   public void cleanUp() {
   }
 
@@ -70,8 +83,18 @@ public abstract class MediaPreviewFragment extends Fragment {
     return null;
   }
 
-  public interface Events {
+  public void checkMediaStillAvailable() {
+    if (attachmentId == null) {
+      attachmentId = new PartUriParser(Objects.requireNonNull(requireArguments().getParcelable(DATA_URI))).getPartId();
+    }
 
+    SimpleTask.run(getViewLifecycleOwner().getLifecycle(),
+                   () -> DatabaseFactory.getAttachmentDatabase(requireContext()).hasAttachment(attachmentId),
+                   hasAttachment -> { if (!hasAttachment) events.mediaNotAvailable(); });
+  }
+
+  public interface Events {
     boolean singleTapOnMedia();
+    void mediaNotAvailable();
   }
 }

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

@@ -1271,6 +1271,7 @@
     <string name="MediaPreviewActivity_media_delete_confirmation_title">Delete message?</string>
     <string name="MediaPreviewActivity_media_delete_confirmation_message">This will permanently delete this message.</string>
     <string name="MediaPreviewActivity_s_to_s">%1$s to %2$s</string>
+    <string name="MediaPreviewActivity_media_no_longer_available">Media no longer available.</string>
 
     <!-- MessageNotifier -->
     <string name="MessageNotifier_d_new_messages_in_d_conversations">%1$d new messages in %2$d conversations</string>