Reorganizes Chromecast code to better reflect functional dependencies.

chromecast/shell/android/apk/src/org/chromium/chromecast/shell/ExternalVideoSurfaceContainer.java

-// Copyright 2014 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.chromecast.shell;
-
-import android.content.Context;
-import android.graphics.Canvas;
-import android.view.Surface;
-import android.view.SurfaceHolder;
-import android.view.SurfaceView;
-import android.view.ViewGroup;
-
-import org.chromium.base.CalledByNative;
-import org.chromium.base.JNINamespace;
-import org.chromium.base.VisibleForTesting;
-import org.chromium.content.browser.ContentViewCore;
-import org.chromium.content.browser.RenderCoordinates;
-
-import java.lang.ref.WeakReference;
-
-/**
- * This is a container for external video surfaces.
- * The object is owned by the native peer and it is owned by WebContents.
- *
- * The expected behavior of the media player on the video hole punching is as follows.
- * 1) If it requests the surface, it will call requestExternalVideoSurface().
- *    When the resolution of the video is changed, it'll call requestExternalVideoSurface().
- * 2) Whenever the size or the position of the video element is changed, it'll notify through
- *    onExternalVideoSurfacePositionChanged().
- * 3) Whenever the page that contains the video element is scrolled or zoomed,
- *    onFrameInfoUpdated() will be called.
- * 4) Usually steps 1) ~ 3) are repeated during the playback.
- * 5) If the player no longer needs the surface any more, it'll call
- *    releaseExternalVideoSurface().
- *
- * Please contact ycheo@chromium.org or wonsik@chromium.org if you have any
- * questions or issues for this class.
- *
- * Note(gunsch): This class was copied wholesale from android_webview/native
- * for the use of chromecast/. Owners of content/ have expressed not wanting
- * this code in content/ to discourage usage, since they don't plan to support
- * hole-punching long term. In the meantime, this copy is a workaround to avoid
- * a dependency on android_webview.
- */
-@JNINamespace("chromecast::shell")
-public class ExternalVideoSurfaceContainer implements SurfaceHolder.Callback {
-    protected static final int INVALID_PLAYER_ID = -1;
-
-    // Because WebView does hole-punching by itself, instead, the hole-punching logic
-    // in SurfaceView can clear out some web elements like media control or subtitle.
-    // So we need to disable its hole-punching logic.
-    private static class NoPunchingSurfaceView extends SurfaceView {
-        public NoPunchingSurfaceView(Context context) {
-            super(context);
-        }
-        // SurfaceView.dispatchDraw implementation punches a hole in the view hierarchy.
-        // Disable this by making this a no-op.
-        @Override
-        protected void dispatchDraw(Canvas canvas) {}
-    }
-
-    // There can be at most 1 external video surface for now.
-    // If there are the multiple requests for the surface, then the second video will
-    // kick the first one off.
-    // To support the mulitple video surfaces seems impractical, because z-order between
-    // the multiple SurfaceViews is non-deterministic.
-    private static WeakReference<ExternalVideoSurfaceContainer> sActiveContainer =
-            new WeakReference<ExternalVideoSurfaceContainer>(null);
-
-    private final long mNativeExternalVideoSurfaceContainer;
-    private final ContentViewCore mContentViewCore;
-    private int mPlayerId = INVALID_PLAYER_ID;
-    private SurfaceView mSurfaceView;
-
-    // The absolute CSS coordinates of the video element.
-    private float mLeft;
-    private float mTop;
-    private float mRight;
-    private float mBottom;
-
-    // The physical location/size of the external video surface in pixels.
-    private int mX;
-    private int mY;
-    private int mWidth;
-    private int mHeight;
-
-    /**
-     * Factory class to facilitate dependency injection.
-     */
-    public static class Factory {
-        public ExternalVideoSurfaceContainer create(
-                long nativeExternalVideoSurfaceContainer, ContentViewCore contentViewCore) {
-            return new ExternalVideoSurfaceContainer(
-                    nativeExternalVideoSurfaceContainer, contentViewCore);
-        }
-    }
-    private static Factory sFactory = new Factory();
-
-    @VisibleForTesting
-    public static void setFactory(Factory factory) {
-        sFactory = factory;
-    }
-
-    @CalledByNative
-    private static ExternalVideoSurfaceContainer create(
-            long nativeExternalVideoSurfaceContainer, ContentViewCore contentViewCore) {
-        return sFactory.create(nativeExternalVideoSurfaceContainer, contentViewCore);
-    }
-
-    protected ExternalVideoSurfaceContainer(
-            long nativeExternalVideoSurfaceContainer, ContentViewCore contentViewCore) {
-        assert contentViewCore != null;
-        mNativeExternalVideoSurfaceContainer = nativeExternalVideoSurfaceContainer;
-        mContentViewCore = contentViewCore;
-        initializeCurrentPositionOfSurfaceView();
-    }
-
-    /**
-     * Called when a media player wants to request an external video surface.
-     * @param playerId The ID of the media player.
-     */
-    @CalledByNative
-    protected void requestExternalVideoSurface(int playerId) {
-        if (mPlayerId == playerId) return;
-
-        if (mPlayerId == INVALID_PLAYER_ID) {
-            setActiveContainer(this);
-        }
-
-        mPlayerId = playerId;
-        initializeCurrentPositionOfSurfaceView();
-
-        createSurfaceView();
-    }
-
-    /**
-     * Called when a media player wants to release an external video surface.
-     * @param playerId The ID of the media player.
-     */
-    @CalledByNative
-    protected void releaseExternalVideoSurface(int playerId) {
-        if (mPlayerId != playerId) return;
-
-        releaseIfActiveContainer(this);
-
-        mPlayerId = INVALID_PLAYER_ID;
-    }
-
-    @CalledByNative
-    protected void destroy() {
-        releaseExternalVideoSurface(mPlayerId);
-    }
-
-    private void initializeCurrentPositionOfSurfaceView() {
-        mX = Integer.MIN_VALUE;
-        mY = Integer.MIN_VALUE;
-        mWidth = 0;
-        mHeight = 0;
-    }
-
-    private static void setActiveContainer(ExternalVideoSurfaceContainer container) {
-        ExternalVideoSurfaceContainer activeContainer = sActiveContainer.get();
-        if (activeContainer != null) {
-            activeContainer.removeSurfaceView();
-        }
-        sActiveContainer = new WeakReference<ExternalVideoSurfaceContainer>(container);
-    }
-
-    private static void releaseIfActiveContainer(ExternalVideoSurfaceContainer container) {
-        ExternalVideoSurfaceContainer activeContainer = sActiveContainer.get();
-        if (activeContainer == container) {
-            setActiveContainer(null);
-        }
-    }
-
-    private void createSurfaceView() {
-        mSurfaceView = new NoPunchingSurfaceView(mContentViewCore.getContext());
-        mSurfaceView.getHolder().addCallback(this);
-        // SurfaceHoder.surfaceCreated() will be called after the SurfaceView is attached to
-        // the Window and becomes visible.
-        mContentViewCore.getContainerView().addView(mSurfaceView);
-    }
-
-    private void removeSurfaceView() {
-        // SurfaceHoder.surfaceDestroyed() will be called in ViewGroup.removeView()
-        // as soon as the SurfaceView is detached from the Window.
-        mContentViewCore.getContainerView().removeView(mSurfaceView);
-        mSurfaceView = null;
-    }
-
-    /**
-     * Called when the position of the video element which uses the external
-     * video surface is changed.
-     * @param playerId The ID of the media player.
-     * @param left The absolute CSS X coordinate of the left side of the video element.
-     * @param top The absolute CSS Y coordinate of the top side of the video element.
-     * @param right The absolute CSS X coordinate of the right side of the video element.
-     * @param bottom The absolute CSS Y coordinate of the bottom side of the video element.
-     */
-    @CalledByNative
-    protected void onExternalVideoSurfacePositionChanged(
-            int playerId, float left, float top, float right, float bottom) {
-        if (mPlayerId != playerId) return;
-
-        mLeft = left;
-        mTop = top;
-        mRight = right;
-        mBottom = bottom;
-
-        layOutSurfaceView();
-    }
-
-    /**
-     * Called when the page that contains the video element is scrolled or zoomed.
-     */
-    @CalledByNative
-    protected void onFrameInfoUpdated() {
-        if (mPlayerId == INVALID_PLAYER_ID) return;
-
-        layOutSurfaceView();
-    }
-
-    private void layOutSurfaceView() {
-        RenderCoordinates renderCoordinates = mContentViewCore.getRenderCoordinates();
-        RenderCoordinates.NormalizedPoint topLeft = renderCoordinates.createNormalizedPoint();
-        RenderCoordinates.NormalizedPoint bottomRight = renderCoordinates.createNormalizedPoint();
-        topLeft.setAbsoluteCss(mLeft, mTop);
-        bottomRight.setAbsoluteCss(mRight, mBottom);
-        float top = topLeft.getYPix();
-        float left = topLeft.getXPix();
-        float bottom = bottomRight.getYPix();
-        float right = bottomRight.getXPix();
-
-        int x = Math.round(left + renderCoordinates.getScrollXPix());
-        int y = Math.round(top + renderCoordinates.getScrollYPix());
-        int width = Math.round(right - left);
-        int height = Math.round(bottom - top);
-        if (mX == x && mY == y && mWidth == width && mHeight == height) return;
-        mX = x;
-        mY = y;
-        mWidth = width;
-        mHeight = height;
-
-        mSurfaceView.setX(x);
-        mSurfaceView.setY(y);
-        ViewGroup.LayoutParams layoutParams = mSurfaceView.getLayoutParams();
-        layoutParams.width = width;
-        layoutParams.height = height;
-        mSurfaceView.requestLayout();
-    }
-
-    // SurfaceHolder.Callback methods.
-    @Override
-    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {}
-
-    @Override
-    // surfaceCreated() callback can be called regardless of requestExternalVideoSurface,
-    // if the activity comes back from the background and becomes visible.
-    public void surfaceCreated(SurfaceHolder holder) {
-        if (mPlayerId != INVALID_PLAYER_ID) {
-            nativeSurfaceCreated(
-                    mNativeExternalVideoSurfaceContainer, mPlayerId, holder.getSurface());
-        }
-    }
-
-    // surfaceDestroyed() callback can be called regardless of releaseExternalVideoSurface,
-    // if the activity moves to the backgound and becomes invisible.
-    @Override
-    public void surfaceDestroyed(SurfaceHolder holder) {
-        if (mPlayerId != INVALID_PLAYER_ID) {
-            nativeSurfaceDestroyed(mNativeExternalVideoSurfaceContainer, mPlayerId);
-        }
-    }
-
-    private native void nativeSurfaceCreated(
-            long nativeExternalVideoSurfaceContainerImpl, int playerId, Surface surface);
-
-    private native void nativeSurfaceDestroyed(
-            long nativeExternalVideoSurfaceContainerImpl, int playerId);
-}