1 /*
   2  * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.javafx.scene.canvas;
  27 
  28 import com.sun.javafx.geom.BaseBounds;
  29 import com.sun.javafx.geom.transform.BaseTransform;
  30 import com.sun.javafx.jmx.MXNodeAlgorithm;
  31 import com.sun.javafx.jmx.MXNodeAlgorithmContext;
  32 import com.sun.javafx.scene.NodeHelper;
  33 import com.sun.javafx.sg.prism.NGNode;
  34 import com.sun.javafx.util.Utils;
  35 import javafx.scene.Node;
  36 import javafx.scene.canvas.Canvas;
  37 
  38 /**
  39  * Used to access internal methods of Canvas.
  40  */
  41 public class CanvasHelper extends NodeHelper {
  42     private static final CanvasHelper theInstance;
  43     private static CanvasAccessor canvasAccessor;
  44 
  45     static {
  46         theInstance = new CanvasHelper();
  47         Utils.forceInit(Canvas.class);
  48     }
  49 
  50     private static CanvasHelper getInstance() {
  51         return theInstance;
  52     }
  53 
  54     public static void initHelper(Canvas canvas) {
  55         setHelper(canvas, getInstance());
  56     }
  57 
  58     @Override
  59     protected NGNode createPeerImpl(Node node) {
  60         return canvasAccessor.doCreatePeer(node);
  61     }
  62 
  63     @Override
  64     protected void updatePeerImpl(Node node) {
  65         super.updatePeerImpl(node);
  66         canvasAccessor.doUpdatePeer(node);
  67     }
  68 
  69     @Override
  70     protected BaseBounds computeGeomBoundsImpl(Node node, BaseBounds bounds,
  71             BaseTransform tx) {
  72         return canvasAccessor.doComputeGeomBounds(node, bounds, tx);
  73     }
  74 
  75     @Override
  76     protected boolean computeContainsImpl(Node node, double localX, double localY) {
  77         return canvasAccessor.doComputeContains(node, localX, localY);
  78     }
  79 
  80     @Override
  81     protected Object processMXNodeImpl(Node node, MXNodeAlgorithm alg, MXNodeAlgorithmContext ctx) {
  82         return canvasAccessor.doProcessMXNode(node, alg, ctx);
  83     }
  84     public static void setCanvasAccessor(final CanvasAccessor newAccessor) {
  85         if (canvasAccessor != null) {
  86             throw new IllegalStateException();
  87         }
  88 
  89         canvasAccessor = newAccessor;
  90     }
  91 
  92     public interface CanvasAccessor {
  93         NGNode doCreatePeer(Node node);
  94         void doUpdatePeer(Node node);
  95         BaseBounds doComputeGeomBounds(Node node, BaseBounds bounds, BaseTransform tx);
  96         boolean doComputeContains(Node node, double localX, double localY);
  97         Object doProcessMXNode(Node node, MXNodeAlgorithm alg, MXNodeAlgorithmContext ctx);
  98     }
  99 
 100 }