[camera_android] Support concurrently image capture and image streaming

packages/camera/camera_android/android/src/main/java/io/flutter/plugins/camera/Camera.java

@@ -21,6 +21,7 @@
 import android.hardware.camera2.params.SessionConfiguration;
 import android.media.CamcorderProfile;
 import android.media.EncoderProfiles;
+import android.media.Image;
 import android.media.ImageReader;
 import android.media.MediaRecorder;
 import android.os.Build;
@@ -414,8 +415,13 @@ private void createCaptureSession(
 
     List<Surface> remainingSurfaces = Arrays.asList(surfaces);
     if (templateType != CameraDevice.TEMPLATE_PREVIEW) {
-      // If it is not preview mode, add all surfaces as targets.
+      // If it is not preview mode, add all surfaces as targets
+      // except the surface used for still capture as this should
+      // not be part of a repeating request.
       for (Surface surface : remainingSurfaces) {
+        if (surface == pictureImageReader.getSurface()) {
+          continue;
+        }
         previewRequestBuilder.addTarget(surface);
       }
     }
@@ -539,6 +545,10 @@ private void startCapture(boolean record, boolean stream) throws CameraAccessExc
       surfaces.add(imageStreamReader.getSurface());
     }
 
+    // Add pictureImageReader surface to allow for still capture
+    // during recording/image streaming.
+    surfaces.add(pictureImageReader.getSurface());
+
     createCaptureSession(
         CameraDevice.TEMPLATE_RECORD, successCallback, surfaces.toArray(new Surface[0]));
   }
@@ -659,7 +669,6 @@ public void onCaptureCompleted(
         };
 
     try {
-      captureSession.stopRepeating();
       Log.i(TAG, "sending capture request");
       captureSession.capture(stillBuilder.build(), captureCallback, backgroundHandler);
     } catch (CameraAccessException e) {
@@ -1140,10 +1149,15 @@ public void startPreviewWithImageStream(EventChannel imageStreamChannel)
   public void onImageAvailable(ImageReader reader) {
     Log.i(TAG, "onImageAvailable");
 
+    // Use acquireNextImage since image reader is only for one image.
+    Image image = reader.acquireNextImage();
+    if (image == null) {
+      return;
+    }
+
     backgroundHandler.post(
         new ImageSaver(
-            // Use acquireNextImage since image reader is only for one image.
-            reader.acquireNextImage(),
+            image,
             captureFile,
             new ImageSaver.Callback() {
               @Override