Bug 153500 Asynchronous model viewer

1 files changed, 136 insertions, 0 deletions

diff --git a/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/viewers/model/ViewerUpdateMonitor.java b/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/viewers/model/ViewerUpdateMonitor.java
new file mode 100644
index 000000000..8014e05a3
--- /dev/null
+++ b/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/viewers/model/ViewerUpdateMonitor.java
@@ -0,0 +1,136 @@
+/*******************************************************************************
+ * Copyright (c) 2006 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.debug.internal.ui.viewers.model;
+
+import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.Status;
+import org.eclipse.core.runtime.jobs.ISchedulingRule;
+import org.eclipse.debug.internal.ui.commands.actions.AbstractRequestMonitor;
+import org.eclipse.debug.internal.ui.viewers.AsynchronousSchedulingRuleFactory;
+import org.eclipse.debug.internal.ui.viewers.model.provisional.IPresentationContext;
+import org.eclipse.debug.internal.ui.viewers.model.provisional.IViewerUpdate;
+import org.eclipse.jface.viewers.TreePath;
+import org.eclipse.ui.progress.WorkbenchJob;
+
+/**
+ * @since 3.3
+ */
+abstract class ViewerUpdateMonitor extends AbstractRequestMonitor implements IViewerUpdate {
+
+	private ModelContentProvider fContentProvider;
+    
+    /**
+     * Whether this request's 'done' method has been called.
+     */
+    private boolean fDone = false;
+    
+    protected WorkbenchJob fViewerUpdateJob = new WorkbenchJob("Asynchronous viewer update") { //$NON-NLS-1$
+        public IStatus runInUIThread(IProgressMonitor monitor) {
+            // necessary to check if viewer is disposed
+        	try {
+	            if (!isCanceled() && !getContentProvider().isDisposed()) {
+	            	IStatus status = getStatus();
+	                if (status == null || status.isOK()) {
+	                	performUpdate();
+	                }
+	            }
+        	} finally {
+        		getContentProvider().updateComplete(ViewerUpdateMonitor.this);
+        	}
+            return Status.OK_STATUS;
+        }
+    };
+    
+    /**
+     * Constructs an update for the given content provider
+     * 
+     * @param contentProvider content provider
+     */
+    public ViewerUpdateMonitor(ModelContentProvider contentProvider) {
+        fContentProvider = contentProvider;
+        // serialize updates per viewer
+        fViewerUpdateJob.setRule(getUpdateSchedulingRule());
+        fViewerUpdateJob.setSystem(true);
+        contentProvider.updateStarted(this);
+    }
+    
+    /**
+     * Returns the scheduling rule for viewer update job.
+     * 
+     * @return rule or <code>null</code>
+     */
+    protected ISchedulingRule getUpdateSchedulingRule() {
+    	return AsynchronousSchedulingRuleFactory.getDefault().newSerialPerObjectRule(getContentProvider());
+    }
+    
+    /**
+     * Returns the model content provider this update is being performed for.
+     * 
+     * @return the model content provider this update is being performed for
+     */
+    protected ModelContentProvider getContentProvider() {
+        return fContentProvider;
+    }    
+    
+    /* (non-Javadoc)
+     * @see org.eclipse.core.runtime.IProgressMonitor#done()
+     */
+    public final void done() {
+    	synchronized (this) {
+    		fDone = true;
+		}
+		scheduleViewerUpdate(0L);
+	}
+    
+    /**
+     * Returns whether this request is done yet.
+     * 
+     * @return
+     */
+    protected synchronized boolean isDone() {
+    	return fDone;
+    }
+
+    protected void scheduleViewerUpdate(long ms) {
+        if(!isCanceled()) {
+            fViewerUpdateJob.schedule(ms);
+        } else {
+        	getContentProvider().updateComplete(this);
+        }
+    }
+    
+    /**
+	 * Notification this update has been completed and should now be applied to
+	 * this update's viewer. This method is called in the UI thread.
+	 */
+    protected abstract void performUpdate();
+    
+	/* (non-Javadoc)
+	 * @see org.eclipse.debug.internal.ui.viewers.model.provisional.IViewerUpdate#getPresentationContext()
+	 */
+	public IPresentationContext getPresentationContext() {
+		return fContentProvider.getPresentationContext();
+	}
+
+	public Object getElement(TreePath path) {
+		return fContentProvider.getElement(path);
+	}
+	
+	/**
+	 * Whether this update is rooted at or below the given path.
+	 * 
+	 * @param path
+	 * @return whether this update is rooted at or below the given path
+	 */
+	abstract boolean isContained(TreePath path);
+	
+}