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.JNINamespace;
  12 import org.chromium.content.common.CleanupReference;
  13
  14 import java.io.OutputStream;
  15
  16 // A simple wrapper around a SkPicture, that allows final rendering to be performed using the
  17 // chromium skia library.
  18 @JNINamespace("android_webview")
  19 class AwPicture extends Picture {
  20
  21     private long mNativeAwPicture;
  22
  23     // There is no explicit destroy method on Picture base-class, so cleanup is always
  24     // handled via the CleanupReference.
  25     private static final class DestroyRunnable implements Runnable {
  26         private long mNativeAwPicture;
  27         private DestroyRunnable(long nativeAwPicture) {
  28             mNativeAwPicture = nativeAwPicture;
  29         }
  30         @Override
  31         public void run() {
  32             nativeDestroy(mNativeAwPicture);
  33         }
  34     }
  35
  36     private CleanupReference mCleanupReference;
  37
  38     /**
  39      * @param nativeAwPicture is an instance of the AwPicture native class. Ownership is
  40      *                        taken by this java instance.
  41      */
  42     AwPicture(long nativeAwPicture) {
  43         mNativeAwPicture = nativeAwPicture;
  44         mCleanupReference = new CleanupReference(this, new DestroyRunnable(nativeAwPicture));
  45     }
  46
  47     @Override
  48     public Canvas beginRecording(int width, int height) {
  49         unsupportedOperation();
  50         return null;
  51     }
  52
  53     @Override
  54     public void endRecording() {
  55         // Intentional no-op. The native picture ended recording prior to java c'tor call.
  56     }
  57
  58     @Override
  59     public int getWidth() {
  60         return nativeGetWidth(mNativeAwPicture);
  61     }
  62
  63     @Override
  64     public int getHeight() {
  65         return nativeGetHeight(mNativeAwPicture);
  66     }
  67
  68     // Effectively a local variable of draw(), but held as a member to avoid GC churn.
  69     private Rect mClipBoundsTemporary = new Rect();
  70
  71     @Override
  72     public void draw(Canvas canvas) {
  73         canvas.getClipBounds(mClipBoundsTemporary);
  74         nativeDraw(mNativeAwPicture, canvas,
  75                 mClipBoundsTemporary.left, mClipBoundsTemporary.top,
  76                 mClipBoundsTemporary.right, mClipBoundsTemporary.bottom);
  77     }
  78
  79     @Override
  80     @SuppressWarnings("deprecation")
  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(long nativeAwPicture);
  90     private native int nativeGetWidth(long nativeAwPicture);
  91     private native int nativeGetHeight(long nativeAwPicture);
  92     private native void nativeDraw(long nativeAwPicture, Canvas canvas,
  93             int left, int top, int right, int bottom);
  94 }
  95