ScreenCapture for Android phase1, part I

media/capture/content/android/screen_capture_machine_android.h

+// Copyright 2016 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_CONTENT_ANDROID_SCREEN_CAPTURE_MACHINE_ANDROID_H_
+#define MEDIA_CAPTURE_CONTENT_ANDROID_SCREEN_CAPTURE_MACHINE_ANDROID_H_
+
+#include <jni.h>
+#include <memory>
+
+#include "base/android/scoped_java_ref.h"
+#include "base/memory/weak_ptr.h"
+#include "media/capture/content/screen_capture_device_core.h"
+
+namespace media {
+
+// ScreenCaptureMachineAndroid captures 32bit RGB using SurfaceFlinger.

[mcasas, 2016/05/19 19:11:41]

Or YUV420 triplanar? I didn't see SurfaceFlinger
references in the Java file though.

[braveyao, 2016/05/20 22:27:26]

Done.

+class MEDIA_EXPORT ScreenCaptureMachineAndroid
+    : public media::VideoCaptureMachine,
+      public base::SupportsWeakPtr<ScreenCaptureMachineAndroid> {

[mcasas, 2016/05/19 19:11:41]

Hmm considering the notes in [1], I'd say it's best
to not make this class a base::SupportsWeakPtr<>
and instead have a member WeakPtrFactory, with
a public method GetWeakPtr().


[1]
https://code.google.com/p/chromium/codesearch#chromium/src/base/memory/weak_p...

[braveyao, 2016/05/20 22:27:26]

Checked again, maybe we don't need a weakptr here at all. Removed.

+ public:
+  ScreenCaptureMachineAndroid();
+  ~ScreenCaptureMachineAndroid() override;
+
+  static bool RegisterScreenCaptureMachine(JNIEnv* env);
+  static base::android::ScopedJavaLocalRef<jobject>
+  createScreenCaptureMachineAndroid(jlong nativeScreenCaptureMachineAndroid);
+
+  // Implement org.chromium.media.ScreenCapture.nativeOnFrameAvailable.

[mcasas, 2016/05/19 19:11:41]

s/nativeOnFrameAvailable/nativeOnRGBAFrameAvailable/ ?
Also correct l.37.

I'm surprised this worked correctly: I thought the bindings
actually needed to have a callback correctly identified by
name, how you tried this last PS?

[braveyao, 2016/05/20 22:27:26]

Shame on me... forgot to modify the comments accordingly.
And it works well. What's the concern here?

[mcasas, 2016/05/23 18:19:55]

I thought the gyp/gn infra uses this annotations
to know which native method to map to which
Java mNative... member. Maybe not?

[braveyao, 2016/05/24 00:03:26]

Acknowledged.

+  void OnRGBAFrameAvailable(JNIEnv* env,
+                            jobject obj,
+                            jobject buf,
+                            jint width,
+                            jint height,
+                            jint rowStride,
+                            jlong timestamp);
+  // Implement org.chromium.media.ScreenCapture.nativeOnFrameAvailable.
+  void OnI420FrameAvailable(JNIEnv* env,
+                            jobject obj,
+                            jobject y_buffer,
+                            jint y_stride,
+                            jobject u_buffer,
+                            jint u_stride,
+                            jobject v_buffer,
+                            jint v_stride,
+                            jint width,
+                            jint height,
+                            jlong timestamp);
+
+  // Implement org.chromium.media.ScreenCapture.nativeOnActivityResult.
+  void OnActivityResult(JNIEnv* env, jobject obj, jboolean result);
+
+  // VideoCaptureMachine overrides.
+  void Start(const scoped_refptr<media::ThreadSafeCaptureOracle>& oracle_proxy,
+             const media::VideoCaptureParams& params,
+             const base::Callback<void(bool)> callback) override;
+  void Stop(const base::Closure& callback) override;
+  void MaybeCaptureForRefresh() override;
+
+ private:
+  // Makes all the decisions about which frames to copy, and how.
+  scoped_refptr<media::ThreadSafeCaptureOracle> oracle_proxy_;
+
+  // Cache the last frame for possible refreshing.
+  scoped_refptr<VideoFrame> lastFrame_;
+
+  // Java VideoCaptureAndroid instance.
+  base::android::ScopedJavaLocalRef<jobject> j_capture_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScreenCaptureMachineAndroid);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_CAPTURE_CONTENT_ANDROID_SCREEN_CAPTURE_MACHINE_ANDROID_H_