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.DisplayList;
20import android.view.HardwareCanvas;
21import android.view.ViewRootImpl;
22import android.util.Log;
23
24import org.chromium.content.common.CleanupReference;
25
26// Simple Java abstraction and wrapper for the native DrawGLFunctor flow.
27// An instance of this class can be constructed, bound to a single view context (i.e. AwContennts)
28// and then drawn and detached from the view tree any number of times (using requestDrawGL and
29// detach respectively). Then when finished with, it can be explicitly released by calling
30// destroy() or will clean itself up as required via finalizer / CleanupReference.
31class DrawGLFunctor {
32
33    private static final String TAG = DrawGLFunctor.class.getSimpleName();
34
35    // Pointer to native side instance
36    private CleanupReference mCleanupReference;
37    private DestroyRunnable mDestroyRunnable;
38
39    public DrawGLFunctor(int viewContext) {
40        mDestroyRunnable = new DestroyRunnable(nativeCreateGLFunctor(viewContext));
41        mCleanupReference = new CleanupReference(this, mDestroyRunnable);
42    }
43
44    public void destroy() {
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        if (mDestroyRunnable.mNativeDrawGLFunctor == 0) {
58            throw new RuntimeException("requested DrawGL on already destroyed DrawGLFunctor");
59        }
60        mDestroyRunnable.mViewRootImpl = viewRootImpl;
61        if (canvas != null) {
62            int ret = canvas.callDrawGLFunction(mDestroyRunnable.mNativeDrawGLFunctor);
63            if (ret != DisplayList.STATUS_DONE) {
64                Log.e(TAG, "callDrawGLFunction error: " + ret);
65                return false;
66            }
67        } else {
68            viewRootImpl.attachFunctor(mDestroyRunnable.mNativeDrawGLFunctor);
69        }
70        return true;
71    }
72
73    public static void setChromiumAwDrawGLFunction(int functionPointer) {
74        nativeSetChromiumAwDrawGLFunction(functionPointer);
75    }
76
77    // Holds the core resources of the class, everything required to correctly cleanup.
78    // IMPORTANT: this class must not hold any reference back to the outer DrawGLFunctor
79    // instance, as that will defeat GC of that object.
80    private static final class DestroyRunnable implements Runnable {
81        ViewRootImpl mViewRootImpl;
82        int mNativeDrawGLFunctor;
83        DestroyRunnable(int nativeDrawGLFunctor) {
84            mNativeDrawGLFunctor = nativeDrawGLFunctor;
85        }
86
87        // Called when the outer DrawGLFunctor instance has been GC'ed, i.e this is its finalizer.
88        @Override
89        public void run() {
90            detachNativeFunctor();
91            nativeDestroyGLFunctor(mNativeDrawGLFunctor);
92            mNativeDrawGLFunctor = 0;
93        }
94
95        void detachNativeFunctor() {
96            if (mNativeDrawGLFunctor != 0 && mViewRootImpl != null) {
97                mViewRootImpl.detachFunctor(mNativeDrawGLFunctor);
98            }
99            mViewRootImpl = null;
100        }
101    }
102
103    private static native int nativeCreateGLFunctor(int viewContext);
104    private static native void nativeDestroyGLFunctor(int functor);
105    private static native void nativeSetChromiumAwDrawGLFunction(int functionPointer);
106}
107