Improve handling of missing camera during calls.

app/src/main/java/org/thoughtcrime/securesms/ringrtc/Camera.java

@@ -39,11 +39,14 @@ public class Camera implements CameraControl, CameraVideoCapturer.CameraSwitchHa
   private static final String TAG = Log.tag(Camera.class);
 
   @NonNull  private final Context                   context;
-  @Nullable private final CameraVideoCapturer       capturer;
+  @Nullable private       CameraVideoCapturer       capturer;
   @Nullable private       CameraEventListener       cameraEventListener;
   @NonNull  private final EglBaseWrapper            eglBase;
             private final int                       cameraCount;
   @NonNull  private       CameraState.Direction     activeDirection;
+            private       CameraState.Direction     oldActiveDirection;
+            private       CapturerObserver          observer;
+
             private       boolean                   enabled;
             private       boolean                   isInitialized;
             private       int                       orientation;
@@ -79,6 +82,7 @@ public class Camera implements CameraControl, CameraVideoCapturer.CameraSwitchHa
   @Override
   public void initCapturer(@NonNull CapturerObserver observer) {
     if (capturer != null) {
+      this.observer = observer;  // save in case we need to disposeAndFlipCamera
       eglBase.performWithValidEglBase(base -> {
         capturer.initialize(SurfaceTextureHelper.create("WebRTC-SurfaceTextureHelper", base.getEglBaseContext()),
                             context,
@@ -99,6 +103,7 @@ public class Camera implements CameraControl, CameraVideoCapturer.CameraSwitchHa
     if (capturer == null || cameraCount < 2) {
       throw new AssertionError("Tried to flip the camera, but we only have " + cameraCount + " of them.");
     }
+    oldActiveDirection = activeDirection;
     activeDirection = PENDING;
     capturer.switchCamera(this);
   }
@@ -146,6 +151,28 @@ public class Camera implements CameraControl, CameraVideoCapturer.CameraSwitchHa
     }
   }
 
+  public void disposeAndFlipCamera() {
+    if (capturer != null) {
+      capturer.dispose();
+      boolean wasInitialized = isInitialized;
+      isInitialized = false;
+      CameraState.Direction candidateDirection = oldActiveDirection.switchDirection();
+      CameraVideoCapturer captureCandidate = createVideoCapturer(getCameraEnumerator(context), candidateDirection);
+      if (captureCandidate != null) {
+        capturer = captureCandidate;
+        activeDirection = candidateDirection;
+        if (wasInitialized) {
+          initCapturer(this.observer);
+        }
+        if (enabled) {
+          setEnabled(true);
+        }
+      } else {
+        activeDirection = NONE;
+      }
+    }
+  }
+
   int getCount() {
     return cameraCount;
   }
@@ -204,7 +231,9 @@ public class Camera implements CameraControl, CameraVideoCapturer.CameraSwitchHa
   @Override
   public void onCameraSwitchError(String errorMessage) {
     Log.e(TAG, "onCameraSwitchError: " + errorMessage);
-    if (cameraEventListener != null) cameraEventListener.onCameraSwitchCompleted(new CameraState(getActiveDirection(), getCount()));
+    if (cameraEventListener != null) {
+      cameraEventListener.onCameraSwitchFailure(new CameraState(getActiveDirection(), getCount()));
+    }
   }
 
   private static class FilteredCamera2Enumerator extends Camera2Enumerator {
@@ -314,7 +343,7 @@ public class Camera implements CameraControl, CameraVideoCapturer.CameraSwitchHa
     public void onCapturerStarted(boolean success) {
       observer.onCapturerStarted(success);
       if (success && cameraEventListener != null) {
-        cameraEventListener.onFullyInitialized();
+        cameraEventListener.onFullyInitialized(getCameraState());
       }
     }
 

app/src/main/java/org/thoughtcrime/securesms/ringrtc/CameraEventListener.java

@@ -8,7 +8,8 @@ import androidx.annotation.NonNull;
  * onCameraSwitchCompleted is triggered by {@link org.webrtc.CameraVideoCapturer.CameraSwitchHandler}
  */
 public interface CameraEventListener {
-  void onFullyInitialized();
+  void onFullyInitialized(@NonNull CameraState newCameraState);
   void onCameraSwitchCompleted(@NonNull CameraState newCameraState);
+  void onCameraSwitchFailure(@NonNull CameraState newCameraState);
   void onCameraStopped();
 }

app/src/main/java/org/thoughtcrime/securesms/service/webrtc/DeviceAwareActionProcessor.java

@@ -80,4 +80,23 @@ public abstract class DeviceAwareActionProcessor extends WebRtcActionProcessor {
                        .cameraState(newCameraState)
                        .build();
   }
+
+  @Override
+  public @NonNull WebRtcServiceState handleCameraSwitchFailure(@NonNull WebRtcServiceState currentState, @NonNull CameraState newCameraState) {
+    Log.i(tag, "handleCameraSwitchFailure():");
+
+    BroadcastVideoSink localSink = currentState.getVideoState().getLocalSink();
+    if (localSink != null) {
+      localSink.setRotateToRightSide(false);
+    }
+    if (currentState.getVideoState().getCamera() != null) {
+      // Retry by recreating with the opposite preferred camera
+      currentState.getVideoState().getCamera().disposeAndFlipCamera();
+    }
+
+    return currentState.builder()
+        .changeLocalDeviceState()
+        .cameraState(newCameraState)
+        .build();
+  }
 }

app/src/main/java/org/thoughtcrime/securesms/service/webrtc/SignalCallManager.java

@@ -68,7 +68,6 @@ import org.thoughtcrime.securesms.service.webrtc.state.WebRtcEphemeralState;
 import org.thoughtcrime.securesms.service.webrtc.state.WebRtcServiceState;
 import org.thoughtcrime.securesms.util.AppForegroundObserver;
 import org.thoughtcrime.securesms.util.RecipientAccessList;
-import org.thoughtcrime.securesms.util.RemoteConfig;
 import org.thoughtcrime.securesms.util.TextSecurePreferences;
 import org.thoughtcrime.securesms.util.Util;
 import org.thoughtcrime.securesms.util.rx.RxStore;
@@ -988,8 +987,11 @@ public final class SignalCallManager implements CallManager.Observer, GroupCall.
   }
 
   @Override
-  public void onFullyInitialized() {
+  public void onFullyInitialized(@NonNull final CameraState newCameraState) {
-    process((s, p) -> p.handleOrientationChanged(s, s.getLocalDeviceState().isLandscapeEnabled(), s.getLocalDeviceState().getDeviceOrientation().getDegrees()));
+    process((s, p) -> {
+      WebRtcServiceState s1 = p.handleSetCameraDirection(s, newCameraState);
+      return p.handleOrientationChanged(s1, s.getLocalDeviceState().isLandscapeEnabled(), s.getLocalDeviceState().getDeviceOrientation().getDegrees());
+    });
   }
 
   @Override
@@ -997,6 +999,11 @@ public final class SignalCallManager implements CallManager.Observer, GroupCall.
     process((s, p) -> p.handleCameraSwitchCompleted(s, newCameraState));
   }
 
+  @Override
+  public void onCameraSwitchFailure(@NonNull final CameraState newCameraState) {
+    process((s, p) -> p.handleCameraSwitchFailure(s, newCameraState));
+  }
+
   @Override
   public void onCameraStopped() {
     Log.i(TAG, "Camera error. Muting video.");

app/src/main/java/org/thoughtcrime/securesms/service/webrtc/WebRtcActionProcessor.java

@@ -569,6 +569,11 @@ public abstract class WebRtcActionProcessor {
     return currentState;
   }
 
+  public @NonNull WebRtcServiceState handleCameraSwitchFailure(@NonNull WebRtcServiceState currentState, @NonNull CameraState newCameraState) {
+    Log.i(tag, "handleCameraSwitchFailure not processed");
+    return currentState;
+  }
+
   public @NonNull WebRtcServiceState handleNetworkChanged(@NonNull WebRtcServiceState currentState, boolean available) {
     Log.i(tag, "handleNetworkChanged not processed");
     return currentState;
@@ -630,6 +635,18 @@ public abstract class WebRtcActionProcessor {
                        .build();
   }
 
+  protected @NonNull WebRtcServiceState handleSetCameraDirection(@NonNull WebRtcServiceState currentState, CameraState state) {
+    BroadcastVideoSink sink = currentState.getVideoState().getLocalSink();
+    if (sink != null) {
+      sink.setRotateToRightSide(state.getActiveDirection() == CameraState.Direction.BACK);
+    }
+
+    return currentState.builder()
+                       .changeLocalDeviceState()
+                       .cameraState(state)
+                       .build();
+  }
+
   //endregion Local device
 
   //region End call