Add support for inline video playback of gifs in Conversation.

app/src/main/java/org/thoughtcrime/securesms/video/exo/AttachmentMediaSourceFactory.java

@@ -0,0 +1,48 @@
+package org.thoughtcrime.securesms.video.exo;
+
+import android.content.Context;
+import android.net.Uri;
+import android.support.v4.media.MediaDescriptionCompat;
+
+import androidx.annotation.NonNull;
+
+import com.google.android.exoplayer2.extractor.DefaultExtractorsFactory;
+import com.google.android.exoplayer2.extractor.ExtractorsFactory;
+import com.google.android.exoplayer2.source.ExtractorMediaSource;
+import com.google.android.exoplayer2.source.MediaSource;
+import com.google.android.exoplayer2.upstream.DefaultDataSourceFactory;
+
+/**
+ * This class is responsible for creating a MediaSource object for a given Uri, using AttachmentDataSourceFactory
+ */
+public final class AttachmentMediaSourceFactory {
+
+  private final ExtractorMediaSource.Factory extractorMediaSourceFactory;
+
+  public AttachmentMediaSourceFactory(@NonNull Context context) {
+    DefaultDataSourceFactory    defaultDataSourceFactory    = new DefaultDataSourceFactory(context, "GenericUserAgent", null);
+    AttachmentDataSourceFactory attachmentDataSourceFactory = new AttachmentDataSourceFactory(context, defaultDataSourceFactory, null);
+    ExtractorsFactory           extractorsFactory           = new DefaultExtractorsFactory().setConstantBitrateSeekingEnabled(true);
+
+    extractorMediaSourceFactory = new ExtractorMediaSource.Factory(attachmentDataSourceFactory)
+                                                          .setExtractorsFactory(extractorsFactory);
+  }
+
+  /**
+   * Creates a MediaSource for a given MediaDescriptionCompat
+   *
+   * @param description The description to build from
+   *
+   * @return A preparable MediaSource
+   */
+  public @NonNull MediaSource createMediaSource(MediaDescriptionCompat description) {
+    return createMediaSource(description.getMediaUri());
+  }
+
+  /**
+   * Creates a MediaSource for a given Uri
+   */
+  public @NonNull MediaSource createMediaSource(Uri uri) {
+    return extractorMediaSourceFactory.createMediaSource(uri);
+  }
+}