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.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
        // , AffineTransform worldToScreen
        ) {
                if (renderThread == null || !renderThread.isAlive()) {
                        // System.out.println("is vacant... starting thread!");
                        renderThread = null;

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

                        return true;
                } else {
                        // System.out.println("is busy... requesting stop!");
                        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,
                                // AffineTransform worldToScreen,
                                ReferencedEnvelope mapEnv) {
                        super(new RenderRun(paintArea, graphics, renderer, mapEnv
                        // , worldToScreen
                                        ));
                        this.renderer = renderer;

                        setName("Render" + getName());

                        // System.out.println("starting render thread " + 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 AffineTransform worldToScreen;
                private final GTRenderer renderer;
                private final ReferencedEnvelope mapEnv;

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

                @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);

                                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	alfonx	510	package skrueger.geotools;
2
3			import java.awt.Graphics2D;
4			import java.awt.Rectangle;
5	alfonx	529	import java.awt.geom.AffineTransform;
6	alfonx	510
7	alfonx	555	import org.apache.log4j.Logger;
8	alfonx	510	import org.geotools.geometry.jts.ReferencedEnvelope;
9			import org.geotools.renderer.GTRenderer;
10			import org.geotools.renderer.RenderListener;
11			import org.opengis.feature.simple.SimpleFeature;
12
13	alfonx	740	import schmitzm.geotools.gui.XMapPane;
14
15	alfonx	532	/**
16			* This class is used by {@link XMapPane} to start and stop the rendering a
17			* {@link Thread} for rendering.
18			*/
19	alfonx	740	public class RenderingExecutor {
20	alfonx	555	private final static Logger LOGGER = Logger.getLogger(RenderingExecutor.class);
21	alfonx	532	/**
22			* Instance to a {@link RenderThread} doing any work. It's volatile so the
23			* correct value will always be visible to any {@link Thread}
24			**/
25	alfonx	530	private volatile RenderThread renderThread;
26	alfonx	532
27	alfonx	530	private final XMapPane mapPane;
28
29	alfonx	529	public RenderingExecutor(XMapPane mapPane) {
30			this.mapPane = mapPane;
31	alfonx	530	}
32	alfonx	510
33	alfonx	530	/**
34			* Submit a new rendering task. If no rendering task is presently running
35	alfonx	532	* this new job will be accepted; otherwise it will be rejected and it
36			* returns <code>false</code>.
37	alfonx	530	*
38			* @param envelope
39	alfonx	532	* the map area (world coordinates) to be rendered.
40	alfonx	530	* @param graphics
41	alfonx	532	* the graphics object to draw on.
42			* @param paintArea
43			* size of the area to paint the world into.
44			* @param worldToScreen
45			* the {@link AffineTransform} from world coordinates to screen
46			* coordinates.
47			* @param renderer
48			* the {@link GTRenderer} to use.
49	alfonx	530	*
50			* @return true if the rendering task was accepted; false if it was rejected
51			*/
52			public synchronized boolean submit(ReferencedEnvelope envelope,
53	alfonx	555	Rectangle paintArea, Graphics2D graphics, final GTRenderer renderer
54			// , AffineTransform worldToScreen
55			) {
56	alfonx	530	if (renderThread == null \|\| !renderThread.isAlive()) {
57	alfonx	532	// System.out.println("is vacant... starting thread!");
58			renderThread = null;
59	alfonx	510
60	alfonx	530	renderThread = new RenderThread(paintArea, graphics, renderer,
61	alfonx	555	// worldToScreen,
62	alfonx	544	envelope);
63	alfonx	530	renderThread.start();
64	alfonx	510
65	alfonx	530	return true;
66			} else {
67	alfonx	532	// System.out.println("is busy... requesting stop!");
68	alfonx	530	renderThread.getRenderer().stopRendering();
69	alfonx	532	return false;
70	alfonx	530	}
71			}
72
73	alfonx	532	/**
74			* For every new rendering job submitted and accepted, an instance of this
75			* {@link Thread} will be started.
76			*
77			*/
78	alfonx	530	class RenderThread extends Thread {
79
80			private final GTRenderer renderer;
81
82			public RenderThread(final Rectangle paintArea,
83			final Graphics2D graphics, GTRenderer renderer,
84	alfonx	555	// AffineTransform worldToScreen,
85	alfonx	544	ReferencedEnvelope mapEnv) {
86	alfonx	555	super(new RenderRun(paintArea, graphics, renderer, mapEnv
87			// , worldToScreen
88	alfonx	544	));
89	alfonx	529	this.renderer = renderer;
90	alfonx	530
91	alfonx	532	setName("Render" + getName());
92
93			// System.out.println("starting render thread " + getName());
94	alfonx	529	}
95	alfonx	530
96			public GTRenderer getRenderer() {
97	alfonx	529	return renderer;
98			}
99
100	alfonx	530	}
101
102	alfonx	532	/**
103			* This {@link Runnable} will actually start the rendering
104			*/
105	alfonx	530	class RenderRun implements Runnable, RenderListener {
106			private final Rectangle paintArea;
107	alfonx	529	private final Graphics2D graphics;
108	alfonx	555	// private final AffineTransform worldToScreen;
109	alfonx	529	private final GTRenderer renderer;
110	alfonx	533	private final ReferencedEnvelope mapEnv;
111	alfonx	510
112	alfonx	529	public RenderRun(Rectangle paintArea, Graphics2D graphics,
113	alfonx	544	GTRenderer renderer, ReferencedEnvelope mapEnv
114	alfonx	555	// ,
115			// AffineTransform worldToScreen
116			) {
117	alfonx	530	this.paintArea = paintArea;
118			this.graphics = graphics;
119			this.renderer = renderer;
120	alfonx	533	this.mapEnv = mapEnv;
121	alfonx	555	// this.worldToScreen = worldToScreen;
122	alfonx	529	}
123	alfonx	530
124	alfonx	529	@Override
125			public void run() {
126	alfonx	607	long startT = System.currentTimeMillis();
127	alfonx	529	try {
128	alfonx	530	renderer.addRenderListener(this);
129	alfonx	607	// LOGGER.debug("start rendering...");
130	alfonx	532
131			// Clear the graphics context
132			graphics.setBackground(mapPane.getMapBackgroundColor());
133			graphics.clearRect(paintArea.x, paintArea.y, paintArea.width,
134			paintArea.height);
135
136	alfonx	544	renderer.paint(graphics, paintArea, mapEnv);
137	alfonx	530
138	alfonx	539	// Kill the reference to this Thread so #isRunning will say
139			// false directly
140	alfonx	533	renderThread = null;
141	alfonx	607	mapPane.onRenderingCompleted(System.currentTimeMillis()-startT);
142	alfonx	539	} catch (Exception e) {
143			mapPane.onRenderingFailed(e);
144	alfonx	530	} finally {
145			renderer.removeRenderListener(this);
146			}
147	alfonx	529	}
148	alfonx	530
149	alfonx	529	@Override
150			public void errorOccurred(Exception e) {
151			mapPane.onRenderingFailed(e);
152			}
153	alfonx	510
154	alfonx	529	@Override
155			public void featureRenderer(SimpleFeature feature) {
156			}
157	alfonx	510
158	alfonx	530	}
159
160	alfonx	532	/**
161			* Ask to stop the rendering. May be called often.
162			*/
163	alfonx	529	public void cancelTask() {
164	alfonx	555	if (renderThread != null)
165			synchronized (renderThread) {
166			if (renderThread.isAlive()) {
167			if (renderThread.getRenderer() != null)
168			renderThread.getRenderer().stopRendering();
169			}
170			}
171	alfonx	529	}
172	alfonx	510
173	alfonx	532	/**
174			* @return <code>true</code> if the {@link Thread} is busy rendering.
175			*/
176	alfonx	529	public boolean isRunning() {
177	alfonx	530	return (renderThread != null && renderThread.isAlive());
178	alfonx	529	}
179	alfonx	510
180	alfonx	532	/**
181			* Will stop rendering and remove the reference to the {@link Thread}.
182			*/
183	alfonx	529	public void dispose() {
184	alfonx	530	if (renderThread != null) {
185			renderThread.renderer.stopRendering();
186			renderThread = null;
187	alfonx	529	}
188			}
189	alfonx	510
190			}