1 /*
2  * Copyright (C) 2010 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 
17 package android.view;
18 
19 import android.annotation.NonNull;
20 import android.annotation.Nullable;
21 import android.graphics.Bitmap;
22 import android.graphics.CanvasProperty;
23 import android.graphics.Paint;
24 import android.util.Pools.SynchronizedPool;
25 
26 import dalvik.annotation.optimization.CriticalNative;
27 import dalvik.annotation.optimization.FastNative;
28 
29 /**
30  * A Canvas implementation that records view system drawing operations for deferred rendering.
31  * This is intended for use with a DisplayList. This class keeps a list of all the Paint and
32  * Bitmap objects that it draws, preventing the backing memory of Bitmaps from being freed while
33  * the DisplayList is still holding a native reference to the memory.
34  *
35  * @hide
36  */
37 public final class DisplayListCanvas extends RecordingCanvas {
38     // The recording canvas pool should be large enough to handle a deeply nested
39     // view hierarchy because display lists are generated recursively.
40     private static final int POOL_LIMIT = 25;
41 
42     private static final int MAX_BITMAP_SIZE = 100 * 1024 * 1024; // 100 MB
43 
44     private static final SynchronizedPool<DisplayListCanvas> sPool =
45             new SynchronizedPool<>(POOL_LIMIT);
46 
47     RenderNode mNode;
48     private int mWidth;
49     private int mHeight;
50 
obtain(@onNull RenderNode node, int width, int height)51     static DisplayListCanvas obtain(@NonNull RenderNode node, int width, int height) {
52         if (node == null) throw new IllegalArgumentException("node cannot be null");
53         DisplayListCanvas canvas = sPool.acquire();
54         if (canvas == null) {
55             canvas = new DisplayListCanvas(node, width, height);
56         } else {
57             nResetDisplayListCanvas(canvas.mNativeCanvasWrapper, node.mNativeRenderNode,
58                     width, height);
59         }
60         canvas.mNode = node;
61         canvas.mWidth = width;
62         canvas.mHeight = height;
63         return canvas;
64     }
65 
recycle()66     void recycle() {
67         mNode = null;
68         sPool.release(this);
69     }
70 
finishRecording()71     long finishRecording() {
72         return nFinishRecording(mNativeCanvasWrapper);
73     }
74 
75     @Override
isRecordingFor(Object o)76     public boolean isRecordingFor(Object o) {
77         return o == mNode;
78     }
79 
80     ///////////////////////////////////////////////////////////////////////////
81     // Constructors
82     ///////////////////////////////////////////////////////////////////////////
83 
DisplayListCanvas(@onNull RenderNode node, int width, int height)84     private DisplayListCanvas(@NonNull RenderNode node, int width, int height) {
85         super(nCreateDisplayListCanvas(node.mNativeRenderNode, width, height));
86         mDensity = 0; // disable bitmap density scaling
87     }
88 
89     ///////////////////////////////////////////////////////////////////////////
90     // Canvas management
91     ///////////////////////////////////////////////////////////////////////////
92 
93 
94     @Override
setDensity(int density)95     public void setDensity(int density) {
96         // drop silently, since DisplayListCanvas doesn't perform density scaling
97     }
98 
99     @Override
isHardwareAccelerated()100     public boolean isHardwareAccelerated() {
101         return true;
102     }
103 
104     @Override
setBitmap(Bitmap bitmap)105     public void setBitmap(Bitmap bitmap) {
106         throw new UnsupportedOperationException();
107     }
108 
109     @Override
isOpaque()110     public boolean isOpaque() {
111         return false;
112     }
113 
114     @Override
getWidth()115     public int getWidth() {
116         return mWidth;
117     }
118 
119     @Override
getHeight()120     public int getHeight() {
121         return mHeight;
122     }
123 
124     @Override
getMaximumBitmapWidth()125     public int getMaximumBitmapWidth() {
126         return nGetMaximumTextureWidth();
127     }
128 
129     @Override
getMaximumBitmapHeight()130     public int getMaximumBitmapHeight() {
131         return nGetMaximumTextureHeight();
132     }
133 
134     ///////////////////////////////////////////////////////////////////////////
135     // Setup
136     ///////////////////////////////////////////////////////////////////////////
137 
138     @Override
insertReorderBarrier()139     public void insertReorderBarrier() {
140         nInsertReorderBarrier(mNativeCanvasWrapper, true);
141     }
142 
143     @Override
insertInorderBarrier()144     public void insertInorderBarrier() {
145         nInsertReorderBarrier(mNativeCanvasWrapper, false);
146     }
147 
148     ///////////////////////////////////////////////////////////////////////////
149     // Functor
150     ///////////////////////////////////////////////////////////////////////////
151 
152     /**
153      * Records the functor specified with the drawGLFunction function pointer. This is
154      * functionality used by webview for calling into their renderer from our display lists.
155      *
156      * @param drawGLFunction A native function pointer
157      */
callDrawGLFunction2(long drawGLFunction)158     public void callDrawGLFunction2(long drawGLFunction) {
159         nCallDrawGLFunction(mNativeCanvasWrapper, drawGLFunction, null);
160     }
161 
162     /**
163      * Records the functor specified with the drawGLFunction function pointer. This is
164      * functionality used by webview for calling into their renderer from our display lists.
165      *
166      * @param drawGLFunction A native function pointer
167      * @param releasedCallback Called when the display list is destroyed, and thus
168      * the functor is no longer referenced by this canvas's display list.
169      *
170      * NOTE: The callback does *not* necessarily mean that there are no longer
171      * any references to the functor, just that the reference from this specific
172      * canvas's display list has been released.
173      */
drawGLFunctor2(long drawGLFunctor, @Nullable Runnable releasedCallback)174     public void drawGLFunctor2(long drawGLFunctor, @Nullable Runnable releasedCallback) {
175         nCallDrawGLFunction(mNativeCanvasWrapper, drawGLFunctor, releasedCallback);
176     }
177 
178     ///////////////////////////////////////////////////////////////////////////
179     // Display list
180     ///////////////////////////////////////////////////////////////////////////
181 
182     /**
183      * Draws the specified display list onto this canvas. The display list can only
184      * be drawn if {@link android.view.RenderNode#isValid()} returns true.
185      *
186      * @param renderNode The RenderNode to draw.
187      */
drawRenderNode(RenderNode renderNode)188     public void drawRenderNode(RenderNode renderNode) {
189         nDrawRenderNode(mNativeCanvasWrapper, renderNode.getNativeDisplayList());
190     }
191 
192     ///////////////////////////////////////////////////////////////////////////
193     // Hardware layer
194     ///////////////////////////////////////////////////////////////////////////
195 
196     /**
197      * Draws the specified layer onto this canvas.
198      *
199      * @param layer The layer to composite on this canvas
200      */
drawTextureLayer(TextureLayer layer)201     void drawTextureLayer(TextureLayer layer) {
202         nDrawTextureLayer(mNativeCanvasWrapper, layer.getLayerHandle());
203     }
204 
205     ///////////////////////////////////////////////////////////////////////////
206     // Drawing
207     ///////////////////////////////////////////////////////////////////////////
208 
drawCircle(CanvasProperty<Float> cx, CanvasProperty<Float> cy, CanvasProperty<Float> radius, CanvasProperty<Paint> paint)209     public void drawCircle(CanvasProperty<Float> cx, CanvasProperty<Float> cy,
210             CanvasProperty<Float> radius, CanvasProperty<Paint> paint) {
211         nDrawCircle(mNativeCanvasWrapper, cx.getNativeContainer(), cy.getNativeContainer(),
212                 radius.getNativeContainer(), paint.getNativeContainer());
213     }
214 
drawRoundRect(CanvasProperty<Float> left, CanvasProperty<Float> top, CanvasProperty<Float> right, CanvasProperty<Float> bottom, CanvasProperty<Float> rx, CanvasProperty<Float> ry, CanvasProperty<Paint> paint)215     public void drawRoundRect(CanvasProperty<Float> left, CanvasProperty<Float> top,
216             CanvasProperty<Float> right, CanvasProperty<Float> bottom, CanvasProperty<Float> rx,
217             CanvasProperty<Float> ry, CanvasProperty<Paint> paint) {
218         nDrawRoundRect(mNativeCanvasWrapper, left.getNativeContainer(), top.getNativeContainer(),
219                 right.getNativeContainer(), bottom.getNativeContainer(),
220                 rx.getNativeContainer(), ry.getNativeContainer(),
221                 paint.getNativeContainer());
222     }
223 
224     @Override
throwIfCannotDraw(Bitmap bitmap)225     protected void throwIfCannotDraw(Bitmap bitmap) {
226         super.throwIfCannotDraw(bitmap);
227         int bitmapSize = bitmap.getByteCount();
228         if (bitmapSize > MAX_BITMAP_SIZE) {
229             throw new RuntimeException(
230                     "Canvas: trying to draw too large(" + bitmapSize + "bytes) bitmap.");
231         }
232     }
233 
234 
235     // ------------------ Fast JNI ------------------------
236 
237     @FastNative
nCallDrawGLFunction(long renderer, long drawGLFunction, Runnable releasedCallback)238     private static native void nCallDrawGLFunction(long renderer,
239             long drawGLFunction, Runnable releasedCallback);
240 
241 
242     // ------------------ Critical JNI ------------------------
243 
244     @CriticalNative
nCreateDisplayListCanvas(long node, int width, int height)245     private static native long nCreateDisplayListCanvas(long node, int width, int height);
246     @CriticalNative
nResetDisplayListCanvas(long canvas, long node, int width, int height)247     private static native void nResetDisplayListCanvas(long canvas, long node,
248             int width, int height);
249     @CriticalNative
nGetMaximumTextureWidth()250     private static native int nGetMaximumTextureWidth();
251     @CriticalNative
nGetMaximumTextureHeight()252     private static native int nGetMaximumTextureHeight();
253     @CriticalNative
nInsertReorderBarrier(long renderer, boolean enableReorder)254     private static native void nInsertReorderBarrier(long renderer, boolean enableReorder);
255     @CriticalNative
nFinishRecording(long renderer)256     private static native long nFinishRecording(long renderer);
257     @CriticalNative
nDrawRenderNode(long renderer, long renderNode)258     private static native void nDrawRenderNode(long renderer, long renderNode);
259     @CriticalNative
nDrawTextureLayer(long renderer, long layer)260     private static native void nDrawTextureLayer(long renderer, long layer);
261     @CriticalNative
nDrawCircle(long renderer, long propCx, long propCy, long propRadius, long propPaint)262     private static native void nDrawCircle(long renderer, long propCx,
263             long propCy, long propRadius, long propPaint);
264     @CriticalNative
nDrawRoundRect(long renderer, long propLeft, long propTop, long propRight, long propBottom, long propRx, long propRy, long propPaint)265     private static native void nDrawRoundRect(long renderer, long propLeft, long propTop,
266             long propRight, long propBottom, long propRx, long propRy, long propPaint);
267 }
268