src/android_webview/java/src/org/chromium/android_webview/AwPicture.java

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 package org.chromium.android_webview;
   6
   7 import android.graphics.Canvas;
   8 import android.graphics.Picture;
   9 import android.graphics.Rect;
  10
  11 import org.chromium.base.CalledByNative;
  12 import org.chromium.base.JNINamespace;
  13 import org.chromium.content.common.CleanupReference;
  14
  15 import java.io.OutputStream;
  16
  17 // A simple wrapper around a SkPicture, that allows final rendering to be performed using the
  18 // chromium skia library.
  19 @JNINamespace("android_webview")
  20 class AwPicture extends Picture {
  21
  22     private int mNativeAwPicture;
  23
  24     // There is no explicit destroy method on Picture base-class, so cleanup is always
  25     // handled via the CleanupReference.
  26     private static final class DestroyRunnable implements Runnable {
  27         private int mNativeAwPicture;
  28         private DestroyRunnable(int nativeAwPicture) {
  29             mNativeAwPicture = nativeAwPicture;
  30         }
  31         @Override
  32         public void run() {
  33             nativeDestroy(mNativeAwPicture);
  34         }
  35     }
  36
  37     private CleanupReference mCleanupReference;
  38
  39     /**
  40      * @param nativeAwPicture is an instance of the AwPicture native class. Ownership is
  41      *                        taken by this java instance.
  42      */
  43     AwPicture(int nativeAwPicture) {
  44         mNativeAwPicture = nativeAwPicture;
  45         mCleanupReference = new CleanupReference(this, new DestroyRunnable(nativeAwPicture));
  46     }
  47
  48     @Override
  49     public Canvas beginRecording(int width, int height) {
  50         unsupportedOperation();
  51         return null;
  52     }
  53
  54     @Override
  55     public void endRecording() {
  56         // Intentional no-op. The native picture ended recording prior to java c'tor call.
  57     }
  58
  59     @Override
  60     public int getWidth() {
  61         return nativeGetWidth(mNativeAwPicture);
  62     }
  63
  64     @Override
  65     public int getHeight() {
  66         return nativeGetHeight(mNativeAwPicture);
  67     }
  68
  69     // Effectively a local variable of draw(), but held as a member to avoid GC churn.
  70     private Rect mClipBoundsTemporary = new Rect();
  71
  72     @Override
  73     public void draw(Canvas canvas) {
  74         canvas.getClipBounds(mClipBoundsTemporary);
  75         nativeDraw(mNativeAwPicture, canvas,
  76                 mClipBoundsTemporary.left, mClipBoundsTemporary.top,
  77                 mClipBoundsTemporary.right, mClipBoundsTemporary.bottom);
  78     }
  79
  80     @Override
  81     public void writeToStream(OutputStream stream) {
  82         unsupportedOperation();
  83     }
  84
  85     private void unsupportedOperation() {
  86         throw new IllegalStateException("Unsupported in AwPicture");
  87     }
  88
  89     private static native void nativeDestroy(int nativeAwPicture);
  90     private native int nativeGetWidth(int nativeAwPicture);
  91     private native int nativeGetHeight(int nativeAwPicture);
  92     private native void nativeDraw(int nativeAwPicture, Canvas canvas,
  93             int left, int top, int right, int bottom);
  94 }
  95