1/*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.webview.chromium;
18
19import android.view.HardwareCanvas;
20import android.view.ViewRootImpl;
21import android.util.Log;
22
23import org.chromium.content.common.CleanupReference;
24
25// Simple Java abstraction and wrapper for the native DrawGLFunctor flow.
26// An instance of this class can be constructed, bound to a single view context (i.e. AwContennts)
27// and then drawn and detached from the view tree any number of times (using requestDrawGL and
28// detach respectively). Then when finished with, it can be explicitly released by calling
29// destroy() or will clean itself up as required via finalizer / CleanupReference.
30class DrawGLFunctor {
31
32    private static final String TAG = DrawGLFunctor.class.getSimpleName();
33
34    // Pointer to native side instance
35    private CleanupReference mCleanupReference;
36    private DestroyRunnable mDestroyRunnable;
37
38    public DrawGLFunctor(long viewContext) {
39        mDestroyRunnable = new DestroyRunnable(nativeCreateGLFunctor(viewContext));
40        mCleanupReference = new CleanupReference(this, mDestroyRunnable);
41    }
42
43    public void destroy() {
44        detach();
45        if (mCleanupReference != null) {
46            mCleanupReference.cleanupNow();
47            mCleanupReference = null;
48            mDestroyRunnable = null;
49        }
50    }
51
52    public void detach() {
53        mDestroyRunnable.detachNativeFunctor();
54    }
55
56    public boolean requestDrawGL(HardwareCanvas canvas, ViewRootImpl viewRootImpl,
57            boolean waitForCompletion) {
58        if (mDestroyRunnable.mNativeDrawGLFunctor == 0) {
59            throw new RuntimeException("requested DrawGL on already destroyed DrawGLFunctor");
60        }
61        if (viewRootImpl == null) {
62            // Can happen during teardown when window is leaked.
63            return false;
64        }
65
66        mDestroyRunnable.mViewRootImpl = viewRootImpl;
67        if (canvas == null) {
68            viewRootImpl.invokeFunctor(mDestroyRunnable.mNativeDrawGLFunctor, waitForCompletion);
69            return true;
70        }
71
72        canvas.callDrawGLFunction(mDestroyRunnable.mNativeDrawGLFunctor);
73        if (waitForCompletion) {
74            viewRootImpl.invokeFunctor(mDestroyRunnable.mNativeDrawGLFunctor,
75                    waitForCompletion);
76        }
77        return true;
78    }
79
80    public static void setChromiumAwDrawGLFunction(long functionPointer) {
81        nativeSetChromiumAwDrawGLFunction(functionPointer);
82    }
83
84    // Holds the core resources of the class, everything required to correctly cleanup.
85    // IMPORTANT: this class must not hold any reference back to the outer DrawGLFunctor
86    // instance, as that will defeat GC of that object.
87    private static final class DestroyRunnable implements Runnable {
88        ViewRootImpl mViewRootImpl;
89        long mNativeDrawGLFunctor;
90        DestroyRunnable(long nativeDrawGLFunctor) {
91            mNativeDrawGLFunctor = nativeDrawGLFunctor;
92        }
93
94        // Called when the outer DrawGLFunctor instance has been GC'ed, i.e this is its finalizer.
95        @Override
96        public void run() {
97            detachNativeFunctor();
98            nativeDestroyGLFunctor(mNativeDrawGLFunctor);
99            mNativeDrawGLFunctor = 0;
100        }
101
102        void detachNativeFunctor() {
103            if (mNativeDrawGLFunctor != 0 && mViewRootImpl != null) {
104                mViewRootImpl.detachFunctor(mNativeDrawGLFunctor);
105            }
106            mViewRootImpl = null;
107        }
108    }
109
110    private static native long nativeCreateGLFunctor(long viewContext);
111    private static native void nativeDestroyGLFunctor(long functor);
112    private static native void nativeSetChromiumAwDrawGLFunction(long functionPointer);
113}
114