Implement out-of-band video compositing on Android: Step 1

content/public/android/java/src/org/chromium/content/browser/ExternalVideoSurfaceViewHolder.java

Index: content/public/android/java/src/org/chromium/content/browser/ExternalVideoSurfaceViewHolder.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/ExternalVideoSurfaceViewHolder.java b/content/public/android/java/src/org/chromium/content/browser/ExternalVideoSurfaceViewHolder.java
new file mode 100644
index 0000000000000000000000000000000000000000..505ef2093716e5ccca0cf2b35acdb456f547437a
--- /dev/null
+++ b/content/public/android/java/src/org/chromium/content/browser/ExternalVideoSurfaceViewHolder.java
@@ -0,0 +1,110 @@
+// 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.
+
+package org.chromium.content.browser;
+
+import android.content.Context;
+import android.util.Log;
+import android.view.Gravity;
+import android.view.Surface;
+import android.view.SurfaceHolder;
+import android.view.SurfaceView;
+import android.widget.FrameLayout;
+
+import org.chromium.base.CalledByNative;
+import org.chromium.base.JNINamespace;
+
+/**
+ * Provides a container that may hold an external video surface.
+ * The surface will be created on-demand.
+ */
+@JNINamespace("content")
+public class ExternalVideoSurfaceViewHolder extends FrameLayout implements SurfaceHolder.Callback {
+    private static final String TAG = ExternalVideoSurfaceViewHolder.class.getSimpleName();
+
+    // SurfaceView object that holding an external surface to render video.
+    private SurfaceView mSurfaceView = null;
+
+    // Native pointer to C++ ExternalVideoSurfaceViewHolder object which will be set by
+    // nativeInit().
+    private int mNativeExternalVideoSurfaceViewHolder = 0;
+
+    /**
+     * Constructs a new ExternalVideoSurfaceViewHolder.
+     *
+     * @param context The context used to create this.
+     */
+    public ExternalVideoSurfaceViewHolder(Context context) {
+        super(context);
+        mNativeExternalVideoSurfaceViewHolder = nativeInit();
+        assert mNativeExternalVideoSurfaceViewHolder != 0;
+    }
+
+    /**
+     * Destroy the internal state of ExternalVideoSurfaceViewHolder.
+     */
+    public void destroy() {
+        if (mSurfaceView != null) {
+            mSurfaceView.getHolder().removeCallback(this);
+            removeView(mSurfaceView);
+        }
+        nativeDestroy(mNativeExternalVideoSurfaceViewHolder);
+        mNativeExternalVideoSurfaceViewHolder = 0;
+    }
+
+    /**
+     * Request external video surface to be created.
+     */
+    @CalledByNative
+    public void requestExternalVideoSurface() {
+        if (mSurfaceView == null) {
+            mSurfaceView = new SurfaceView(getContext());
+            mSurfaceView.getHolder().addCallback(this);
+
+            addView(mSurfaceView, new FrameLayout.LayoutParams(
+                    FrameLayout.LayoutParams.MATCH_PARENT,
+                    FrameLayout.LayoutParams.MATCH_PARENT,
+                    Gravity.NO_GRAVITY));
+        }
+    }
+
+    /**
+     * For ContentViewCore to inject native pointer to ContentViewCoreImpl C++ object.
+     * @return native pointer to C++ object.
+     */
+    int getNativeExternalVideoSurfaceViewHolder() {
+        return mNativeExternalVideoSurfaceViewHolder;
+    }
+
+    // SurfaceHolder.Callback implementations.
+
+    @Override
+    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
+    }
+
+    @Override
+    public void surfaceCreated(SurfaceHolder holder) {
+        if (mNativeExternalVideoSurfaceViewHolder == 0) {
+            Log.e(TAG, "Destroyed native object already.");
+            return;
+        }
+        nativeAttachExternalVideoSurface(mNativeExternalVideoSurfaceViewHolder,
+                holder.getSurface());
+    }
+
+    @Override
+    public void surfaceDestroyed(SurfaceHolder holder) {
+        if (mNativeExternalVideoSurfaceViewHolder == 0) {
+            Log.e(TAG, "Destroyed native object already.");
+            return;
+        }
+        nativeDetachExternalVideoSurface(mNativeExternalVideoSurfaceViewHolder);
+    }
+
+    private native int nativeInit();
+    private native void nativeDestroy(int nativeExternalVideoSurfaceViewHolder);
+    private native void nativeAttachExternalVideoSurface(int nativeExternalVideoSurfaceViewHolder,
+            Surface surface);
+    private native void nativeDetachExternalVideoSurface(int nativeExternalVideoSurfaceViewHolder);
+}