--- /dev/null
+/*******************************************************************************\r
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
+ * in Industry THTH ry.\r
+ * All rights reserved. This program and the accompanying materials\r
+ * are made available under the terms of the Eclipse Public License v1.0\r
+ * which accompanies this distribution, and is available at\r
+ * http://www.eclipse.org/legal/epl-v10.html\r
+ *\r
+ * Contributors:\r
+ * VTT Technical Research Centre of Finland - initial API and implementation\r
+ *******************************************************************************/\r
+package org.simantics.g2d.diagram.participant;\r
+\r
+import java.util.HashSet;\r
+import java.util.Set;\r
+import java.util.concurrent.ScheduledExecutorService;\r
+import java.util.concurrent.ScheduledFuture;\r
+import java.util.concurrent.TimeUnit;\r
+\r
+import org.simantics.g2d.canvas.Hints;\r
+import org.simantics.g2d.canvas.ICanvasContext;\r
+import org.simantics.g2d.diagram.IDiagram;\r
+import org.simantics.g2d.diagram.IDiagram.CompositionListener;\r
+import org.simantics.g2d.diagram.handler.PickRequest.PickFilter;\r
+import org.simantics.g2d.element.IElement;\r
+import org.simantics.g2d.internal.DebugPolicy;\r
+import org.simantics.utils.datastructures.hints.IHintContext.Key;\r
+import org.simantics.utils.datastructures.hints.IHintListener;\r
+import org.simantics.utils.datastructures.hints.IHintObservable;\r
+import org.simantics.utils.threads.ThreadUtils;\r
+\r
+/**\r
+ * A diagram participant that is meant for keeping a selected set of diagram\r
+ * elements up-to-date. The difference to {@link ElementPainter} is that this\r
+ * participant throttles updates so that the selected set of elements is updated\r
+ * once in a specified time interval.\r
+ * \r
+ * <p>\r
+ * This class listens to {@link Hints#KEY_DIRTY} hint of elements accepted by\r
+ * the specified {@link #elementFilter}. If the key receives a value of\r
+ * {@link Hints#VALUE_SG_DELAYED_UPDATE}, this class will react by queueing the\r
+ * element to be updated after the current delay period is over. The delay\r
+ * period ensures that existing elements are not updated more frequently than\r
+ * the specified time period. When it becomes time to perform the actual\r
+ * updates, this class will set the {@link Hints#KEY_DIRTY} hint of all\r
+ * currently dirty elements to value {@link Hints#VALUE_SG_DIRTY}. This will\r
+ * signal other listeners ({@link ElementPainter}) to react.\r
+ * \r
+ * @author Tuukka Lehtonen\r
+ */\r
+public class DelayedBatchElementPainter extends AbstractDiagramParticipant {\r
+\r
+ private static final boolean DEBUG = DebugPolicy.DEBUG_DELAYED_ELEMENT_PAINTER;\r
+ private static final boolean DEBUG_MARKING = DebugPolicy.DEBUG_DELAYED_ELEMENT_PAINTER_MARKING;\r
+\r
+ ScheduledExecutorService executor = ThreadUtils.getNonBlockingWorkExecutor();\r
+\r
+ PickFilter elementFilter;\r
+ long delay;\r
+ TimeUnit delayUnit;\r
+\r
+ Set<IElement> dirtyElements = new HashSet<IElement>();\r
+ volatile ScheduledFuture<?> scheduled = null;\r
+ long lastUpdateTime = 0;\r
+\r
+ class ElementListener implements CompositionListener, IHintListener {\r
+ @Override\r
+ public void onElementAdded(IDiagram d, IElement e) {\r
+ if (DEBUG)\r
+ debug("onElementAdded(%s, %s)\n", d, e);\r
+ if (elementFilter.accept(e))\r
+ addElement(e);\r
+ }\r
+\r
+ @Override\r
+ public void onElementRemoved(IDiagram d, IElement e) {\r
+ if (DEBUG)\r
+ debug("onElementRemoved(%s, %s)\n", d, e);\r
+ if (elementFilter.accept(e))\r
+ removeElement(e);\r
+ }\r
+\r
+ @Override\r
+ public void hintChanged(IHintObservable sender, Key key, Object oldValue, Object newValue) {\r
+ if (key == Hints.KEY_DIRTY && newValue == Hints.VALUE_SG_DELAYED_UPDATE && sender instanceof IElement) {\r
+ markDirty((IElement) sender);\r
+ }\r
+ }\r
+\r
+ @Override\r
+ public void hintRemoved(IHintObservable sender, Key key, Object oldValue) {\r
+ }\r
+ }\r
+\r
+ private final ElementListener elementListener = new ElementListener();\r
+\r
+ public DelayedBatchElementPainter(PickFilter elementFilter, long delay, TimeUnit delayUnit) {\r
+ this.elementFilter = elementFilter;\r
+ this.delay = delay;\r
+ this.delayUnit = delayUnit;\r
+ }\r
+\r
+ @Override\r
+ public void removedFromContext(ICanvasContext ctx) {\r
+ ScheduledFuture<?> s = scheduled;\r
+ if (s != null)\r
+ s.cancel(false);\r
+\r
+ super.removedFromContext(ctx);\r
+ }\r
+\r
+ @Override\r
+ protected void onDiagramSet(IDiagram newValue, IDiagram oldValue) {\r
+ if (oldValue == newValue)\r
+ return;\r
+\r
+ if (oldValue != null) {\r
+ for (IElement e : oldValue.getElements()) {\r
+ if (elementFilter.accept(e))\r
+ removeElement(e);\r
+ }\r
+ oldValue.removeCompositionListener(elementListener);\r
+ }\r
+\r
+ if (newValue != null) {\r
+ for (IElement e : newValue.getElements()) {\r
+ if (elementFilter.accept(e))\r
+ addElement(e);\r
+ }\r
+ newValue.addCompositionListener(elementListener);\r
+ }\r
+ }\r
+\r
+ protected void addElement(IElement e) {\r
+ if (DEBUG)\r
+ debug("addElement(%s)\n", e);\r
+ e.addKeyHintListener(Hints.KEY_DIRTY, elementListener);\r
+ }\r
+\r
+ protected void removeElement(IElement e) {\r
+ if (DEBUG)\r
+ debug("removeElement(%s)\n", e);\r
+ e.removeKeyHintListener(Hints.KEY_DIRTY, elementListener);\r
+ }\r
+\r
+ protected void markDirty(IElement e) {\r
+ if (DEBUG_MARKING)\r
+ debug("Marking element dirty: %s\n", e);\r
+ dirtyElements.add(e);\r
+ scheduleUpdate();\r
+ }\r
+\r
+ private Runnable updater = new Runnable() {\r
+ @Override\r
+ public void run() {\r
+ if (DEBUG)\r
+ debug("marking %d elements dirty\n", dirtyElements.size());\r
+ for (IElement e : dirtyElements)\r
+ e.setHint(Hints.KEY_DIRTY, Hints.VALUE_SG_DIRTY);\r
+ dirtyElements.clear();\r
+ scheduled = null;\r
+ lastUpdateTime = System.currentTimeMillis();\r
+ if (DEBUG)\r
+ debug("marking last update time %d\n", lastUpdateTime);\r
+\r
+ if (!isRemoved())\r
+ setDirty();\r
+ }\r
+ };\r
+\r
+ private Runnable delayedUpdater = new Runnable() {\r
+ @Override\r
+ public void run() {\r
+ if (DEBUG)\r
+ debug("scheduling updater\n");\r
+ asyncExec(updater);\r
+ }\r
+ };\r
+\r
+ private void scheduleUpdate() {\r
+ if (scheduled == null) {\r
+ long timeNow = System.currentTimeMillis();\r
+ long timeSinceLastUpdate = timeNow - lastUpdateTime;\r
+ long requestedDelay = delayUnit.toMillis(delay);\r
+ long scheduleDelay = Math.max(0, Math.min(requestedDelay, requestedDelay - timeSinceLastUpdate));\r
+\r
+ if (DEBUG)\r
+ debug("scheduling update with delay %dms (time=%d, time passed=%dms)\n", scheduleDelay, timeNow, timeSinceLastUpdate);\r
+\r
+ if (scheduleDelay == 0) {\r
+ asyncExec(updater);\r
+ } else {\r
+ scheduled = executor.schedule(delayedUpdater, scheduleDelay, TimeUnit.MILLISECONDS);\r
+ }\r
+ }\r
+ }\r
+\r
+\r
+ private void debug(String format, Object... args) {\r
+ if (DEBUG) {\r
+ System.out.format(getClass().getSimpleName()\r
+ + "[filter=" + elementFilter\r
+ + ", delay=" + delayUnit.toMillis(delay) + "ms] "\r
+ + format, args);\r
+ }\r
+ }\r
+\r
+}
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Code Review / simantics / platform.git / blobdiff