Restart Camera1 Frame Processing After Taking a Picture - Fixes Issue 824 (#877)

* resetup frame manager after taking full picture for Camera1 Engine

* Wrap frame processing restart in conditional

* Add unit test

cameraview/src/androidTest/java/com/otaliastudios/cameraview/engine/CameraIntegrationTest.java

@@ -1080,6 +1080,20 @@ public abstract class CameraIntegrationTest<E extends CameraBaseEngine> extends
         assert15Frames(processor);
     }
 
+    @Test
+    @Retry(emulatorOnly = true)
+    @SdkExclude(maxSdkVersion = 22, emulatorOnly = true)
+    public void testFrameProcessing_afterPicture() throws Exception {
+        FrameProcessor processor = mock(FrameProcessor.class);
+        camera.addFrameProcessor(processor);
+        openSync(true);
+
+        camera.takePicture();
+        waitForPictureResult(true);
+
+        assert15Frames(processor);
+    }
+
     @Test
     @Retry(emulatorOnly = true)
     @SdkExclude(maxSdkVersion = 22, emulatorOnly = true)

cameraview/src/main/java/com/otaliastudios/cameraview/picture/Full1PictureRecorder.java

@@ -2,12 +2,15 @@ package com.otaliastudios.cameraview.picture;
 
 import android.hardware.Camera;
 
+import androidx.annotation.NonNull;
+import androidx.exifinterface.media.ExifInterface;
+
 import com.otaliastudios.cameraview.PictureResult;
 import com.otaliastudios.cameraview.engine.Camera1Engine;
+import com.otaliastudios.cameraview.engine.offset.Reference;
+import com.otaliastudios.cameraview.engine.orchestrator.CameraState;
 import com.otaliastudios.cameraview.internal.ExifHelper;
-
+import com.otaliastudios.cameraview.size.Size;
-import androidx.annotation.NonNull;
-import androidx.exifinterface.media.ExifInterface;
 
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
@@ -40,6 +43,7 @@ public class Full1PictureRecorder extends FullPictureRecorder {
         // Stopping the preview callback is important on older APIs / emulators,
         // or takePicture can hang and leave the camera in a bad state.
         mCamera.setPreviewCallbackWithBuffer(null);
+        mEngine.getFrameManager().release();
         mCamera.takePicture(
                 new Camera.ShutterCallback() {
                     @Override
@@ -67,7 +71,23 @@ public class Full1PictureRecorder extends FullPictureRecorder {
                         mResult.data = data;
                         mResult.rotation = exifRotation;
                         LOG.i("take(): starting preview again. ", Thread.currentThread());
-                        camera.setPreviewCallbackWithBuffer(mEngine);
+
+                        if (mEngine.getState().isAtLeast(CameraState.PREVIEW)) {
+                            camera.setPreviewCallbackWithBuffer(mEngine);
+                            Size previewStreamSize = mEngine.getPreviewStreamSize(Reference.SENSOR);
+                            if (previewStreamSize == null) {
+                                throw new IllegalStateException("Preview stream size " +
+                                        "should never be null here.");
+                            }
+                            // Need to re-setup the frame manager, otherwise no frames are processed
+                            // after takePicture() is called
+                            mEngine.getFrameManager().setUp(
+                                    mEngine.getFrameProcessingFormat(),
+                                    previewStreamSize,
+                                    mEngine.getAngles()
+                            );
+                        }
+
                         camera.startPreview(); // This is needed, read somewhere in the docs.
                         dispatchResult();
                     }