1 /*
2 * Copyright (c) 2012, 2014, 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 javafx.scene.canvas;
27
28 import javafx.beans.property.DoubleProperty;
29 import javafx.beans.property.DoublePropertyBase;
30 import javafx.geometry.NodeOrientation;
31 import javafx.scene.Node;
32 import com.sun.javafx.geom.BaseBounds;
33 import com.sun.javafx.geom.RectBounds;
34 import com.sun.javafx.geom.transform.BaseTransform;
35 import com.sun.javafx.jmx.MXNodeAlgorithm;
36 import com.sun.javafx.jmx.MXNodeAlgorithmContext;
37 import com.sun.javafx.scene.DirtyBits;
38 import com.sun.javafx.scene.NodeHelper;
39 import com.sun.javafx.scene.canvas.CanvasHelper;
40 import com.sun.javafx.sg.prism.GrowableDataBuffer;
41 import com.sun.javafx.sg.prism.NGCanvas;
42 import com.sun.javafx.sg.prism.NGNode;
43
44 /**
45 * {@code Canvas} is an image that can be drawn on using a set of graphics
46 * commands provided by a {@code GraphicsContext}.
47 *
48 * <p>
49 * A {@code Canvas} node is constructed with a width and height that specifies the size
50 * of the image into which the canvas drawing commands are rendered. All drawing
51 * operations are clipped to the bounds of that image.
52 *
53 * <p>Example:</p>
54 *
55 * <p>
56 * <pre>
57 import javafx.scene.*;
58 import javafx.scene.paint.*;
59 import javafx.scene.canvas.*;
60
61 Group root = new Group();
62 Scene s = new Scene(root, 300, 300, Color.BLACK);
63
64 final Canvas canvas = new Canvas(250,250);
65 GraphicsContext gc = canvas.getGraphicsContext2D();
66
67 gc.setFill(Color.BLUE);
68 gc.fillRect(75,75,100,100);
69
70 root.getChildren().add(canvas);
71 * </pre>
72 * </p>
73 *
74 * @since JavaFX 2.2
75 */
76 public class Canvas extends Node {
77 static {
78 CanvasHelper.setCanvasAccessor(new CanvasHelper.CanvasAccessor() {
79 @Override
80 public NGNode doCreatePeer(Node node) {
81 return ((Canvas) node).doCreatePeer();
82 }
83
84 @Override
85 public void doUpdatePeer(Node node) {
86 ((Canvas) node).doUpdatePeer();
87 }
88
89 @Override
90 public BaseBounds doComputeGeomBounds(Node node,
91 BaseBounds bounds, BaseTransform tx) {
92 return ((Canvas) node).doComputeGeomBounds(bounds, tx);
93 }
94
95 @Override
96 public boolean doComputeContains(Node node, double localX, double localY) {
97 return ((Canvas) node).doComputeContains(localX, localY);
98 }
99
100 @Override
101 public Object doProcessMXNode(Node node, MXNodeAlgorithm alg, MXNodeAlgorithmContext ctx) {
102 return ((Canvas) node).doProcessMXNode(alg, ctx);
103 }
104 });
105 }
106 static final int DEFAULT_VAL_BUF_SIZE = 1024;
107 static final int DEFAULT_OBJ_BUF_SIZE = 32;
108 private static final int SIZE_HISTORY = 5;
109
110 private GrowableDataBuffer current;
111 private boolean rendererBehind;
112 private int recentvalsizes[];
113 private int recentobjsizes[];
114 private int lastsizeindex;
115
116 private GraphicsContext theContext;
117
118 {
119 // To initialize the class helper at the begining each constructor of this class
120 CanvasHelper.initHelper(this);
121 }
122
123 /**
124 * Creates an empty instance of Canvas.
125 */
126 public Canvas() {
127 this(0, 0);
128 }
129
130 /**
131 * Creates a new instance of Canvas with the given size.
132 *
133 * @param width width of the canvas
134 * @param height height of the canvas
135 */
136 public Canvas(double width, double height) {
137 this.recentvalsizes = new int[SIZE_HISTORY];
138 this.recentobjsizes = new int[SIZE_HISTORY];
139 setNodeOrientation(NodeOrientation.LEFT_TO_RIGHT);
140 setWidth(width);
141 setHeight(height);
142 }
143
144 private static int max(int sizes[], int defsize) {
145 for (int s : sizes) {
146 if (defsize < s) defsize = s;
147 }
148 return defsize;
149 }
150
151 GrowableDataBuffer getBuffer() {
152 NodeHelper.markDirty(this, DirtyBits.NODE_CONTENTS);
153 NodeHelper.markDirty(this, DirtyBits.NODE_FORCE_SYNC);
154 if (current == null) {
155 int vsize = max(recentvalsizes, DEFAULT_VAL_BUF_SIZE);
156 int osize = max(recentobjsizes, DEFAULT_OBJ_BUF_SIZE);
157 current = GrowableDataBuffer.getBuffer(vsize, osize);
158 theContext.updateDimensions();
159 }
160 return current;
161 }
162
163 boolean isRendererFallingBehind() {
164 return rendererBehind;
165 }
166
167 /**
168 * returns the {@code GraphicsContext} associated with this {@code Canvas}.
169 */
170 public GraphicsContext getGraphicsContext2D() {
171 if (theContext == null) {
172 theContext = new GraphicsContext(this);
173 }
174 return theContext;
175 }
176
177 /**
178 * Defines the width of the canvas.
179 *
180 * @profile common
181 * @defaultvalue 0.0
182 */
183 private DoubleProperty width;
184
185 public final void setWidth(double value) {
186 widthProperty().set(value);
187 }
188
189 public final double getWidth() {
190 return width == null ? 0.0 : width.get();
191 }
192
193 public final DoubleProperty widthProperty() {
194 if (width == null) {
195 width = new DoublePropertyBase() {
196
197 @Override
198 public void invalidated() {
199 NodeHelper.markDirty(Canvas.this, DirtyBits.NODE_GEOMETRY);
200 NodeHelper.geomChanged(Canvas.this);
201 if (theContext != null) {
202 theContext.updateDimensions();
203 }
204 }
205
206 @Override
207 public Object getBean() {
208 return Canvas.this;
209 }
210
211 @Override
212 public String getName() {
213 return "width";
214 }
215 };
216 }
217 return width;
218 }
219
220 /**
221 * Defines the height of the canvas.
222 *
223 * @profile common
224 * @defaultvalue 0.0
225 */
226 private DoubleProperty height;
227
228 public final void setHeight(double value) {
229 heightProperty().set(value);
230 }
231
232 public final double getHeight() {
233 return height == null ? 0.0 : height.get();
234 }
235
236 public final DoubleProperty heightProperty() {
237 if (height == null) {
238 height = new DoublePropertyBase() {
239
240 @Override
241 public void invalidated() {
242 NodeHelper.markDirty(Canvas.this, DirtyBits.NODE_GEOMETRY);
243 NodeHelper.geomChanged(Canvas.this);
244 if (theContext != null) {
245 theContext.updateDimensions();
246 }
247 }
248
249 @Override
250 public Object getBean() {
251 return Canvas.this;
252 }
253
254 @Override
255 public String getName() {
256 return "height";
257 }
258 };
259 }
260 return height;
261 }
262
263 private NGNode doCreatePeer() {
264 return new NGCanvas();
265 }
266
267 /*
268 * Note: This method MUST only be called via its accessor method.
269 */
270 private void doUpdatePeer() {
271 if (NodeHelper.isDirty(this, DirtyBits.NODE_GEOMETRY)) {
272 NGCanvas peer = NodeHelper.getPeer(this);
273 peer.updateBounds((float)getWidth(),
274 (float)getHeight());
275 }
276 if (NodeHelper.isDirty(this, DirtyBits.NODE_CONTENTS)) {
277 NGCanvas peer = NodeHelper.getPeer(this);
278 if (current != null && !current.isEmpty()) {
279 if (--lastsizeindex < 0) {
280 lastsizeindex = SIZE_HISTORY - 1;
281 }
282 recentvalsizes[lastsizeindex] = current.writeValuePosition();
283 recentobjsizes[lastsizeindex] = current.writeObjectPosition();
284 rendererBehind = peer.updateRendering(current);
285 current = null;
286 }
287 }
288 }
289
290 /*
291 * Note: This method MUST only be called via its accessor method.
292 */
293 private boolean doComputeContains(double localX, double localY) {
294 double w = getWidth();
295 double h = getHeight();
296 return (w > 0 && h > 0 &&
297 localX >= 0 && localY >= 0 &&
298 localX < w && localY < h);
299 }
300
301 /*
302 * Note: This method MUST only be called via its accessor method.
303 */
304 private BaseBounds doComputeGeomBounds(BaseBounds bounds, BaseTransform tx) {
305 bounds = new RectBounds(0f, 0f, (float) getWidth(), (float) getHeight());
306 bounds = tx.transform(bounds, bounds);
307 return bounds;
308 }
309
310 /*
311 * Note: This method MUST only be called via its accessor method.
312 */
313 private Object doProcessMXNode(MXNodeAlgorithm alg,
314 MXNodeAlgorithmContext ctx) {
315 return alg.processLeafNode(this, ctx);
316 }
317 }