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      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.graphics.Bitmap;
     20 import android.graphics.Canvas;
     21 import android.graphics.CanvasProperty;
     22 import android.graphics.Paint;
     23 import android.graphics.Rect;
     24 
     25 /**
     26  * Hardware accelerated canvas.
     27  *
     28  * @hide
     29  */
     30 public abstract class HardwareCanvas extends Canvas {
     31 
     32     @Override
     33     public boolean isHardwareAccelerated() {
     34         return true;
     35     }
     36 
     37     @Override
     38     public void setBitmap(Bitmap bitmap) {
     39         throw new UnsupportedOperationException();
     40     }
     41 
     42     /**
     43      * Invoked before any drawing operation is performed in this canvas.
     44      *
     45      * @param dirty The dirty rectangle to update, can be null.
     46      * @return {@link RenderNode#STATUS_DREW} if anything was drawn (such as a call to clear
     47      *         the canvas).
     48      *
     49      * @hide
     50      */
     51     public abstract int onPreDraw(Rect dirty);
     52 
     53     /**
     54      * Invoked after all drawing operation have been performed.
     55      *
     56      * @hide
     57      */
     58     public abstract void onPostDraw();
     59 
     60     /**
     61      * Draws the specified display list onto this canvas. The display list can only
     62      * be drawn if {@link android.view.RenderNode#isValid()} returns true.
     63      *
     64      * @param renderNode The RenderNode to replay.
     65      */
     66     public void drawRenderNode(RenderNode renderNode) {
     67         drawRenderNode(renderNode, null, RenderNode.FLAG_CLIP_CHILDREN);
     68     }
     69 
     70     /**
     71      * Draws the specified display list onto this canvas.
     72      *
     73      * @param renderNode The RenderNode to replay.
     74      * @param dirty Ignored, can be null.
     75      * @param flags Optional flags about drawing, see {@link RenderNode} for
     76      *              the possible flags.
     77      *
     78      * @return One of {@link RenderNode#STATUS_DONE} or {@link RenderNode#STATUS_DREW}
     79      *         if anything was drawn.
     80      *
     81      * @hide
     82      */
     83     public abstract int drawRenderNode(RenderNode renderNode, Rect dirty, int flags);
     84 
     85     /**
     86      * Draws the specified layer onto this canvas.
     87      *
     88      * @param layer The layer to composite on this canvas
     89      * @param x The left coordinate of the layer
     90      * @param y The top coordinate of the layer
     91      * @param paint The paint used to draw the layer
     92      *
     93      * @hide
     94      */
     95     abstract void drawHardwareLayer(HardwareLayer layer, float x, float y, Paint paint);
     96 
     97     /**
     98      * Calls the function specified with the drawGLFunction function pointer. This is
     99      * functionality used by webkit for calling into their renderer from our display lists.
    100      * This function may return true if an invalidation is needed after the call.
    101      *
    102      * @param drawGLFunction A native function pointer
    103      *
    104      * @return {@link RenderNode#STATUS_DONE}
    105      *
    106      * @hide
    107      */
    108     public int callDrawGLFunction(long drawGLFunction) {
    109         // Noop - this is done in the display list recorder subclass
    110         return RenderNode.STATUS_DONE;
    111     }
    112 
    113     public abstract void drawCircle(CanvasProperty<Float> cx, CanvasProperty<Float> cy,
    114             CanvasProperty<Float> radius, CanvasProperty<Paint> paint);
    115 
    116     public abstract void drawRoundRect(CanvasProperty<Float> left, CanvasProperty<Float> top,
    117             CanvasProperty<Float> right, CanvasProperty<Float> bottom,
    118             CanvasProperty<Float> rx, CanvasProperty<Float> ry,
    119             CanvasProperty<Paint> paint);
    120 
    121     public static void setProperty(String name, String value) {
    122         GLES20Canvas.setProperty(name, value);
    123     }
    124 }
    125