1 /*
2 * Copyright (c) 2012, 2017, 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.scene.DirtyBits;
36 import com.sun.javafx.scene.NodeHelper;
37 import com.sun.javafx.scene.canvas.CanvasHelper;
38 import com.sun.javafx.sg.prism.GrowableDataBuffer;
39 import com.sun.javafx.sg.prism.NGCanvas;
40 import com.sun.javafx.sg.prism.NGNode;
41
42 /**
43 * {@code Canvas} is an image that can be drawn on using a set of graphics
44 * commands provided by a {@link GraphicsContext}.
45 *
46 * <p>
47 * A {@code Canvas} node is constructed with a width and height that specifies the size
48 * of the image into which the canvas drawing commands are rendered. All drawing
49 * operations are clipped to the bounds of that image.
50 * </p>
51 *
52 * <p>Example:</p>
53 *
54 * <pre>
55 import javafx.scene.*;
56 import javafx.scene.paint.*;
57 import javafx.scene.canvas.*;
58
59 Group root = new Group();
60 Scene s = new Scene(root, 300, 300, Color.BLACK);
61
62 final Canvas canvas = new Canvas(250,250);
63 GraphicsContext gc = canvas.getGraphicsContext2D();
64
65 gc.setFill(Color.BLUE);
66 gc.fillRect(75,75,100,100);
67
68 root.getChildren().add(canvas);
69 * </pre>
70 *
71 * @see GraphicsContext
72 * @since JavaFX 2.2
73 */
74 public class Canvas extends Node {
75 static {
76 CanvasHelper.setCanvasAccessor(new CanvasHelper.CanvasAccessor() {
77 @Override
78 public NGNode doCreatePeer(Node node) {
79 return ((Canvas) node).doCreatePeer();
80 }
81
82 @Override
83 public void doUpdatePeer(Node node) {
84 ((Canvas) node).doUpdatePeer();
85 }
86
87 @Override
88 public BaseBounds doComputeGeomBounds(Node node,
89 BaseBounds bounds, BaseTransform tx) {
90 return ((Canvas) node).doComputeGeomBounds(bounds, tx);
91 }
92
93 @Override
94 public boolean doComputeContains(Node node, double localX, double localY) {
95 return ((Canvas) node).doComputeContains(localX, localY);
96 }
97 });
98 }
99 static final int DEFAULT_VAL_BUF_SIZE = 1024;
100 static final int DEFAULT_OBJ_BUF_SIZE = 32;
101 private static final int SIZE_HISTORY = 5;
102
103 private GrowableDataBuffer current;
104 private boolean rendererBehind;
105 private int recentvalsizes[];
106 private int recentobjsizes[];
107 private int lastsizeindex;
108
109 private GraphicsContext theContext;
110
111 {
112 // To initialize the class helper at the begining each constructor of this class
113 CanvasHelper.initHelper(this);
114 }
115
116 /**
117 * Creates an empty instance of Canvas.
118 */
119 public Canvas() {
120 this(0, 0);
121 }
122
123 /**
124 * Creates a new instance of Canvas with the given size.
125 *
126 * @param width width of the canvas
127 * @param height height of the canvas
128 */
129 public Canvas(double width, double height) {
130 this.recentvalsizes = new int[SIZE_HISTORY];
131 this.recentobjsizes = new int[SIZE_HISTORY];
132 setNodeOrientation(NodeOrientation.LEFT_TO_RIGHT);
133 setWidth(width);
134 setHeight(height);
135 }
136
137 private static int max(int sizes[], int defsize) {
138 for (int s : sizes) {
139 if (defsize < s) defsize = s;
140 }
141 return defsize;
142 }
143
144 GrowableDataBuffer getBuffer() {
145 NodeHelper.markDirty(this, DirtyBits.NODE_CONTENTS);
146 NodeHelper.markDirty(this, DirtyBits.NODE_FORCE_SYNC);
147 if (current == null) {
148 int vsize = max(recentvalsizes, DEFAULT_VAL_BUF_SIZE);
149 int osize = max(recentobjsizes, DEFAULT_OBJ_BUF_SIZE);
150 current = GrowableDataBuffer.getBuffer(vsize, osize);
151 theContext.updateDimensions();
152 }
153 return current;
154 }
155
156 boolean isRendererFallingBehind() {
157 return rendererBehind;
158 }
159
160 /**
161 * returns the {@code GraphicsContext} associated with this {@code Canvas}.
162 * @return the {@code GraphicsContext} associated with this {@code Canvas}
163 */
164 public GraphicsContext getGraphicsContext2D() {
165 if (theContext == null) {
166 theContext = new GraphicsContext(this);
167 }
168 return theContext;
169 }
170
171 /**
172 * Defines the width of the canvas.
173 *
174 * @defaultValue 0.0
175 */
176 private DoubleProperty width;
177
178 public final void setWidth(double value) {
179 widthProperty().set(value);
180 }
181
182 public final double getWidth() {
183 return width == null ? 0.0 : width.get();
184 }
185
186 public final DoubleProperty widthProperty() {
187 if (width == null) {
188 width = new DoublePropertyBase() {
189
190 @Override
191 public void invalidated() {
192 NodeHelper.markDirty(Canvas.this, DirtyBits.NODE_GEOMETRY);
193 NodeHelper.geomChanged(Canvas.this);
194 if (theContext != null) {
195 theContext.updateDimensions();
196 }
197 }
198
199 @Override
200 public Object getBean() {
201 return Canvas.this;
202 }
203
204 @Override
205 public String getName() {
206 return "width";
207 }
208 };
209 }
210 return width;
211 }
212
213 /**
214 * Defines the height of the canvas.
215 *
216 * @defaultValue 0.0
217 */
218 private DoubleProperty height;
219
220 public final void setHeight(double value) {
221 heightProperty().set(value);
222 }
223
224 public final double getHeight() {
225 return height == null ? 0.0 : height.get();
226 }
227
228 public final DoubleProperty heightProperty() {
229 if (height == null) {
230 height = new DoublePropertyBase() {
231
232 @Override
233 public void invalidated() {
234 NodeHelper.markDirty(Canvas.this, DirtyBits.NODE_GEOMETRY);
235 NodeHelper.geomChanged(Canvas.this);
236 if (theContext != null) {
237 theContext.updateDimensions();
238 }
239 }
240
241 @Override
242 public Object getBean() {
243 return Canvas.this;
244 }
245
246 @Override
247 public String getName() {
248 return "height";
249 }
250 };
251 }
252 return height;
253 }
254
255 private NGNode doCreatePeer() {
256 return new NGCanvas();
257 }
258
259 /*
260 * Note: This method MUST only be called via its accessor method.
261 */
262 private void doUpdatePeer() {
263 if (NodeHelper.isDirty(this, DirtyBits.NODE_GEOMETRY)) {
264 NGCanvas peer = NodeHelper.getPeer(this);
265 peer.updateBounds((float)getWidth(),
266 (float)getHeight());
267 }
268 if (NodeHelper.isDirty(this, DirtyBits.NODE_CONTENTS)) {
269 NGCanvas peer = NodeHelper.getPeer(this);
270 if (current != null && !current.isEmpty()) {
271 if (--lastsizeindex < 0) {
272 lastsizeindex = SIZE_HISTORY - 1;
273 }
274 recentvalsizes[lastsizeindex] = current.writeValuePosition();
275 recentobjsizes[lastsizeindex] = current.writeObjectPosition();
276 rendererBehind = peer.updateRendering(current);
277 current = null;
278 }
279 }
280 }
281
282 /*
283 * Note: This method MUST only be called via its accessor method.
284 */
285 private boolean doComputeContains(double localX, double localY) {
286 double w = getWidth();
287 double h = getHeight();
288 return (w > 0 && h > 0 &&
289 localX >= 0 && localY >= 0 &&
290 localX < w && localY < h);
291 }
292
293 /*
294 * Note: This method MUST only be called via its accessor method.
295 */
296 private BaseBounds doComputeGeomBounds(BaseBounds bounds, BaseTransform tx) {
297 bounds = new RectBounds(0f, 0f, (float) getWidth(), (float) getHeight());
298 bounds = tx.transform(bounds, bounds);
299 return bounds;
300 }
301 }