Reland: ImageCapture: Queue up requests while device not ready

media/capture/video/android/video_capture_device_android.h

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_CAPTURE_VIDEO_ANDROID_VIDEO_CAPTURE_DEVICE_ANDROID_H_
 #define MEDIA_CAPTURE_VIDEO_ANDROID_VIDEO_CAPTURE_DEVICE_ANDROID_H_
 
 #include <jni.h>
 #include <string>
 
 #include "base/android/scoped_java_ref.h"
 #include "base/macros.h"
+#include "base/memory/weak_ptr.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread.h"
 #include "base/threading/thread_checker.h"
 #include "base/time/time.h"
 #include "media/capture/capture_export.h"
 #include "media/capture/video/video_capture_device.h"
 
+namespace base {
+class SingleThreadTaskRunner;
+}
+
 namespace tracked_objects {
 class Location;
-}  // namespace tracked_
+}  // namespace tracked_objects
 
 namespace media {
 
 // VideoCaptureDevice on Android. The VideoCaptureDevice API's are called
 // by VideoCaptureManager on its own thread, while OnFrameAvailable is called
 // on JAVA thread (i.e., UI thread). Both will access |state_| and |client_|,
 // but only VideoCaptureManager would change their value.
 class CAPTURE_EXPORT VideoCaptureDeviceAndroid : public VideoCaptureDevice {
  public:
   // Automatically generated enum to interface with Java world.
@@ skipping 57 matching lines @@
                const base::android::JavaParamRef<jstring>& message);
 
   // Implement org.chromium.media.VideoCapture.nativeOnPhotoTaken.
   void OnPhotoTaken(JNIEnv* env,
                     const base::android::JavaParamRef<jobject>& obj,
                     jlong callback_id,
                     const base::android::JavaParamRef<jbyteArray>& data);
 
  private:
   enum InternalState {
-    kIdle,       // The device is opened but not in use.
-    kCapturing,  // Video is being captured.
-    kError       // Hit error. User needs to recover by destroying the object.
+    kIdle,        // The device is opened but not in use.
+    kConfigured,  // The device has been AllocateAndStart()ed.
+    kError        // Hit error. User needs to recover by destroying the object.
   };
 
   VideoPixelFormat GetColorspace();
   void SetErrorState(const tracked_objects::Location& from_here,
                      const std::string& reason);
 
-  base::ThreadChecker thread_checker_;
+  void DoGetPhotoCapabilities(GetPhotoCapabilitiesCallback callback);
+  void DoSetPhotoOptions(mojom::PhotoSettingsPtr settings,
+                         SetPhotoOptionsCallback callback);
+  void DoTakePhoto(TakePhotoCallback callback);
 
-  // Prevent racing on accessing |state_| and |client_| since both could be
-  // accessed from different threads.
+  // Thread on which we are created.
+  const scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;
+
+  // |lock_| protects |state_|, |client_|, |got_first_frame_| and
+  // |photo_requests_queue_| from concurrent access.
   base::Lock lock_;
   InternalState state_;
   std::unique_ptr<VideoCaptureDevice::Client> client_;
+  bool got_first_frame_;
+  // Photo-related requests waiting for |got_first_frame_| to be served. Android
+  // APIs need the device capturing or nearly-capturing to be fully oeprational.
+  std::list<base::Closure> photo_requests_queue_;
 
-  bool got_first_frame_;
   base::TimeTicks expected_next_frame_time_;
   base::TimeTicks first_ref_time_;
   base::TimeDelta frame_interval_;
 
   // List of |photo_callbacks_| in flight, being served in Java side.
   base::Lock photo_callbacks_lock_;
   std::list<std::unique_ptr<TakePhotoCallback>> photo_callbacks_;
 
   gfx::Size next_photo_resolution_;
 
   const VideoCaptureDeviceDescriptor device_descriptor_;
   VideoCaptureFormat capture_format_;
 
   // Java VideoCaptureAndroid instance.
   base::android::ScopedJavaLocalRef<jobject> j_capture_;
 
+  base::WeakPtrFactory<VideoCaptureDeviceAndroid> weak_ptr_factory_;
+
   DISALLOW_IMPLICIT_CONSTRUCTORS(VideoCaptureDeviceAndroid);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_CAPTURE_VIDEO_ANDROID_VIDEO_CAPTURE_DEVICE_ANDROID_H_