--- /dev/null
+/*******************************************************************************\r
+ * Copyright (c) 2013 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
+ * Semantum Oy - initial API and implementation\r
+ *******************************************************************************/\r
+package org.simantics.browsing.ui.swt;\r
+\r
+import java.util.concurrent.atomic.AtomicBoolean;\r
+\r
+import org.eclipse.core.runtime.IProgressMonitor;\r
+import org.eclipse.core.runtime.IStatus;\r
+import org.eclipse.core.runtime.Status;\r
+import org.eclipse.core.runtime.jobs.Job;\r
+import org.eclipse.ui.progress.IProgressConstants;\r
+import org.simantics.DatabaseJob;\r
+\r
+/**\r
+ * @author Tuukka Lehtonen\r
+ */\r
+class ImageLoaderJob extends DatabaseJob {\r
+\r
+ private GraphExplorerImplBase ge;\r
+ private AtomicBoolean isScheduled = new AtomicBoolean();\r
+\r
+ public ImageLoaderJob(GraphExplorerImplBase ge) {\r
+ super("Image Loader");\r
+ this.ge = ge;\r
+ setSystem(true);\r
+ setUser(false);\r
+ setPriority(Job.DECORATE);\r
+ setProperty(IProgressConstants.NO_IMMEDIATE_ERROR_PROMPT_PROPERTY, Boolean.TRUE);\r
+ }\r
+\r
+ /**\r
+ * Schedules the job with {@link Job#schedule()} if necessary, i.e. if\r
+ * not already scheduled. This method avoids some unnecessary overhead\r
+ * caused by repeatedly invoking {@link Job#schedule()}.\r
+ * \r
+ * @return <code>true</code> if scheduled, <code>false</code> otherwise\r
+ */\r
+ public boolean scheduleIfNecessary(long delay) {\r
+ if (isScheduled.compareAndSet(false, true)) {\r
+ schedule(delay);\r
+ return true;\r
+ }\r
+ return false;\r
+ }\r
+\r
+ @Override\r
+ public boolean shouldRun() {\r
+ return ge != null;\r
+ }\r
+\r
+ @Override\r
+ public boolean shouldSchedule() {\r
+ return ge != null;\r
+ }\r
+\r
+ @Override\r
+ protected IStatus run(IProgressMonitor monitor) {\r
+ try {\r
+ isScheduled.set(false);\r
+ GraphExplorerImplBase ge = this.ge;\r
+ return (ge != null) ? ge.setPendingImages(monitor) : Status.CANCEL_STATUS;\r
+ } finally {\r
+ monitor.done();\r
+ }\r
+ }\r
+\r
+ public void dispose() {\r
+ ge = null;\r
+ }\r
+}
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