skrueger/geotools/RenderingExecutor.java

package skrueger.geotools;

import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.geom.AffineTransform;

import org.apache.log4j.Logger;
import org.geotools.filter.function.EnvFunction;
import org.geotools.geometry.jts.ReferencedEnvelope;
import org.geotools.renderer.GTRenderer;
import org.geotools.renderer.RenderListener;
import org.opengis.feature.simple.SimpleFeature;

import schmitzm.geotools.gui.XMapPane;

/**
 * This class is used by {@link XMapPane} to start and stop the rendering a
 * {@link Thread} for rendering.
 */
public class RenderingExecutor {
        private final static Logger LOGGER = Logger
                        .getLogger(RenderingExecutor.class);
        /**
         * Instance to a {@link RenderThread} doing any work. It's volatile so the
         * correct value will always be visible to any {@link Thread}
         **/
        private volatile RenderThread renderThread;

        private final XMapPane mapPane;

        public RenderingExecutor(XMapPane mapPane) {
                this.mapPane = mapPane;
        }

        /**
         * Submit a new rendering task. If no rendering task is presently running
         * this new job will be accepted; otherwise it will be rejected and it
         * returns <code>false</code>.
         * 
         * @param envelope
         *            the map area (world coordinates) to be rendered.
         * @param graphics
         *            the graphics object to draw on.
         * @param paintArea
         *            size of the area to paint the world into.
         * @param worldToScreen
         *            the {@link AffineTransform} from world coordinates to screen
         *            coordinates.
         * @param renderer
         *            the {@link GTRenderer} to use.
         * 
         * @return true if the rendering task was accepted; false if it was rejected
         */
        public synchronized boolean submit(ReferencedEnvelope envelope,
                        Rectangle paintArea, Graphics2D graphics, final GTRenderer renderer) {
                if (renderThread == null || !renderThread.isAlive()) {
                        // System.out.println("is vacant... starting thread!");
                        renderThread = null;

                        renderThread = new RenderThread(paintArea, graphics, renderer,
                                        envelope);
                        renderThread.start();

                        return true;
                } else {
                        renderThread.getRenderer().stopRendering();
                        return false;
                }
        }

        /**
         * For every new rendering job submitted and accepted, an instance of this
         * {@link Thread} will be started.
         * 
         */
        class RenderThread extends Thread {

                private final GTRenderer renderer;

                public RenderThread(final Rectangle paintArea,
                                final Graphics2D graphics, GTRenderer renderer,
                                ReferencedEnvelope mapEnv) {
                        super(new RenderRun(paintArea, graphics, renderer, mapEnv));
                        this.renderer = renderer;

                        setName("Render" + getName());

                }

                public GTRenderer getRenderer() {
                        return renderer;
                }

        }

        /**
         * This {@link Runnable} will actually start the rendering
         */
        class RenderRun implements Runnable, RenderListener {
                private final Rectangle paintArea;
                private final Graphics2D graphics;
                private final GTRenderer renderer;
                private final ReferencedEnvelope mapEnv;

                public RenderRun(Rectangle paintArea, Graphics2D graphics,
                                GTRenderer renderer, ReferencedEnvelope mapEnv) {
                        this.paintArea = paintArea;
                        this.graphics = graphics;
                        this.renderer = renderer;
                        this.mapEnv = mapEnv;
                }

                @Override
                public void run() {
                        long startT = System.currentTimeMillis();
                        try {
                                renderer.addRenderListener(this);
                                // LOGGER.debug("start rendering...");

                                // Clear the graphics context
                                graphics.setBackground(mapPane.getMapBackgroundColor());
                                graphics.clearRect(paintArea.x, paintArea.y, paintArea.width,
                                                paintArea.height);

                                // TODO It should be enough to set only the Local Value, but it isn't 
                                EnvFunction.setGlobalValue(XMapPane.ENV_LANG,
                                                mapPane.getRenderLanguage());
                                EnvFunction.setLocalValue(XMapPane.ENV_LANG,
                                                mapPane.getRenderLanguage());

//                              LOGGER.debug("Renderer language set to "
//                                              + mapPane.getRenderLanguage());

                                renderer.paint(graphics, paintArea, mapEnv);

                                // Kill the reference to this Thread so #isRunning will say
                                // false directly
                                renderThread = null;
                                mapPane.onRenderingCompleted(System.currentTimeMillis()
                                                - startT);
                        } catch (Exception e) {
                                mapPane.onRenderingFailed(e);
                        } finally {
                                renderer.removeRenderListener(this);
                        }
                }

                @Override
                public void errorOccurred(Exception e) {
                        mapPane.onRenderingFailed(e);
                }

                @Override
                public void featureRenderer(SimpleFeature feature) {
                }

        }

        /**
         * Ask to stop the rendering. May be called often.
         */
        public void cancelTask() {
                if (renderThread != null)
                        synchronized (renderThread) {
                                if (renderThread.isAlive()) {
                                        if (renderThread.getRenderer() != null)
                                                renderThread.getRenderer().stopRendering();
                                }
                        }
        }

        /**
         * @return <code>true</code> if the {@link Thread} is busy rendering.
         */
        public boolean isRunning() {
                return (renderThread != null && renderThread.isAlive());
        }

        /**
         * Will stop rendering and remove the reference to the {@link Thread}.
         */
        public void dispose() {
                if (renderThread != null) {
                        renderThread.renderer.stopRendering();
                        renderThread = null;
                }
        }

}
1	package skrueger.geotools;
2
3	import java.awt.Graphics2D;
4	import java.awt.Rectangle;
5	import java.awt.geom.AffineTransform;
6
7	import org.apache.log4j.Logger;
8	import org.geotools.filter.function.EnvFunction;
9	import org.geotools.geometry.jts.ReferencedEnvelope;
10	import org.geotools.renderer.GTRenderer;
11	import org.geotools.renderer.RenderListener;
12	import org.opengis.feature.simple.SimpleFeature;
13
14	import schmitzm.geotools.gui.XMapPane;
15
16	/**
17	* This class is used by {@link XMapPane} to start and stop the rendering a
18	* {@link Thread} for rendering.
19	*/
20	public class RenderingExecutor {
21	private final static Logger LOGGER = Logger
22	.getLogger(RenderingExecutor.class);
23	/**
24	* Instance to a {@link RenderThread} doing any work. It's volatile so the
25	* correct value will always be visible to any {@link Thread}
26	**/
27	private volatile RenderThread renderThread;
28
29	private final XMapPane mapPane;
30
31	public RenderingExecutor(XMapPane mapPane) {
32	this.mapPane = mapPane;
33	}
34
35	/**
36	* Submit a new rendering task. If no rendering task is presently running
37	* this new job will be accepted; otherwise it will be rejected and it
38	* returns <code>false</code>.
39	*
40	* @param envelope
41	* the map area (world coordinates) to be rendered.
42	* @param graphics
43	* the graphics object to draw on.
44	* @param paintArea
45	* size of the area to paint the world into.
46	* @param worldToScreen
47	* the {@link AffineTransform} from world coordinates to screen
48	* coordinates.
49	* @param renderer
50	* the {@link GTRenderer} to use.
51	*
52	* @return true if the rendering task was accepted; false if it was rejected
53	*/
54	public synchronized boolean submit(ReferencedEnvelope envelope,
55	Rectangle paintArea, Graphics2D graphics, final GTRenderer renderer) {
56	if (renderThread == null \|\| !renderThread.isAlive()) {
57	// System.out.println("is vacant... starting thread!");
58	renderThread = null;
59
60	renderThread = new RenderThread(paintArea, graphics, renderer,
61	envelope);
62	renderThread.start();
63
64	return true;
65	} else {
66	renderThread.getRenderer().stopRendering();
67	return false;
68	}
69	}
70
71	/**
72	* For every new rendering job submitted and accepted, an instance of this
73	* {@link Thread} will be started.
74	*
75	*/
76	class RenderThread extends Thread {
77
78	private final GTRenderer renderer;
79
80	public RenderThread(final Rectangle paintArea,
81	final Graphics2D graphics, GTRenderer renderer,
82	ReferencedEnvelope mapEnv) {
83	super(new RenderRun(paintArea, graphics, renderer, mapEnv));
84	this.renderer = renderer;
85
86	setName("Render" + getName());
87
88	}
89
90	public GTRenderer getRenderer() {
91	return renderer;
92	}
93
94	}
95
96	/**
97	* This {@link Runnable} will actually start the rendering
98	*/
99	class RenderRun implements Runnable, RenderListener {
100	private final Rectangle paintArea;
101	private final Graphics2D graphics;
102	private final GTRenderer renderer;
103	private final ReferencedEnvelope mapEnv;
104
105	public RenderRun(Rectangle paintArea, Graphics2D graphics,
106	GTRenderer renderer, ReferencedEnvelope mapEnv) {
107	this.paintArea = paintArea;
108	this.graphics = graphics;
109	this.renderer = renderer;
110	this.mapEnv = mapEnv;
111	}
112
113	@Override
114	public void run() {
115	long startT = System.currentTimeMillis();
116	try {
117	renderer.addRenderListener(this);
118	// LOGGER.debug("start rendering...");
119
120	// Clear the graphics context
121	graphics.setBackground(mapPane.getMapBackgroundColor());
122	graphics.clearRect(paintArea.x, paintArea.y, paintArea.width,
123	paintArea.height);
124
125	// TODO It should be enough to set only the Local Value, but it isn't
126	EnvFunction.setGlobalValue(XMapPane.ENV_LANG,
127	mapPane.getRenderLanguage());
128	EnvFunction.setLocalValue(XMapPane.ENV_LANG,
129	mapPane.getRenderLanguage());
130
131	// LOGGER.debug("Renderer language set to "
132	// + mapPane.getRenderLanguage());
133
134	renderer.paint(graphics, paintArea, mapEnv);
135
136	// Kill the reference to this Thread so #isRunning will say
137	// false directly
138	renderThread = null;
139	mapPane.onRenderingCompleted(System.currentTimeMillis()
140	- startT);
141	} catch (Exception e) {
142	mapPane.onRenderingFailed(e);
143	} finally {
144	renderer.removeRenderListener(this);
145	}
146	}
147
148	@Override
149	public void errorOccurred(Exception e) {
150	mapPane.onRenderingFailed(e);
151	}
152
153	@Override
154	public void featureRenderer(SimpleFeature feature) {
155	}
156
157	}
158
159	/**
160	* Ask to stop the rendering. May be called often.
161	*/
162	public void cancelTask() {
163	if (renderThread != null)
164	synchronized (renderThread) {
165	if (renderThread.isAlive()) {
166	if (renderThread.getRenderer() != null)
167	renderThread.getRenderer().stopRendering();
168	}
169	}
170	}
171
172	/**
173	* @return <code>true</code> if the {@link Thread} is busy rendering.
174	*/
175	public boolean isRunning() {
176	return (renderThread != null && renderThread.isAlive());
177	}
178
179	/**
180	* Will stop rendering and remove the reference to the {@link Thread}.
181	*/
182	public void dispose() {
183	if (renderThread != null) {
184	renderThread.renderer.stopRendering();
185	renderThread = null;
186	}
187	}
188
189	}