| /******************************************************************************* |
| * Copyright (c) 2006, 2012 IBM Corporation and others. |
| * |
| * This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License 2.0 |
| * which accompanies this distribution, and is available at |
| * https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| * Pawel Piech (Wind River) - added support for a virtual tree model viewer (Bug 242489) |
| *******************************************************************************/ |
| package org.eclipse.debug.internal.ui.viewers.model; |
| |
| import org.eclipse.core.runtime.jobs.ISchedulingRule; |
| import org.eclipse.debug.internal.core.commands.Request; |
| import org.eclipse.debug.internal.ui.DebugUIPlugin; |
| import org.eclipse.debug.internal.ui.viewers.AsynchronousSchedulingRuleFactory; |
| import org.eclipse.debug.internal.ui.viewers.model.provisional.IElementContentProvider; |
| import org.eclipse.debug.internal.ui.viewers.model.provisional.IPresentationContext; |
| import org.eclipse.debug.internal.ui.viewers.model.provisional.ITreeModelViewer; |
| import org.eclipse.debug.internal.ui.viewers.model.provisional.IViewerUpdate; |
| import org.eclipse.jface.viewers.TreePath; |
| import org.eclipse.swt.widgets.Display; |
| |
| /** |
| * @since 3.3 |
| */ |
| public abstract class ViewerUpdateMonitor extends Request implements IViewerUpdate { |
| |
| private TreeModelContentProvider fContentProvider; |
| |
| /** |
| * Element's tree path |
| */ |
| private TreePath fElementPath; |
| |
| /** |
| * Element |
| */ |
| private Object fElement; |
| |
| /** |
| * Element content provider |
| */ |
| private IElementContentProvider fElementContentProvider; |
| |
| /** |
| * Whether this request's 'done' method has been called. |
| */ |
| private boolean fDone = false; |
| |
| /** |
| * Whether this request has been started |
| */ |
| private boolean fStarted = false; |
| |
| /** |
| * Viewer input at the time the request was made |
| */ |
| private Object fViewerInput = null; |
| |
| /** |
| * Whether this update has been delegated to another content provider |
| * @since 3.4 |
| */ |
| private boolean fIsDelegated = false; |
| |
| /** |
| * Presentation context |
| */ |
| private IPresentationContext fContext; |
| |
| /** |
| * Constructs an update for the given content provider |
| * |
| * @param contentProvider content provider |
| * @param viewerInput Viewer input for update |
| * @param elementPath path to associated model element - empty for root element |
| * @param element associated model element |
| * @param elementContentProvider Content provider for this update. |
| * @param context Presentation contest for this update |
| */ |
| public ViewerUpdateMonitor(TreeModelContentProvider contentProvider, Object viewerInput, TreePath elementPath, Object element, IElementContentProvider elementContentProvider, IPresentationContext context) { |
| fContext = context; |
| // Bug 380288: Catch and log a race condition where the viewer input is null. |
| if (viewerInput == null) { |
| DebugUIPlugin.log(new NullPointerException("Input to viewer update should not be null")); //$NON-NLS-1$ |
| } |
| fViewerInput = viewerInput; |
| fElementContentProvider = elementContentProvider; |
| fContentProvider = contentProvider; |
| fElement = element; |
| fElementPath = elementPath; |
| } |
| |
| /** |
| * 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 TreeModelContentProvider getContentProvider() { |
| return fContentProvider; |
| } |
| |
| /** |
| * Returns the element content provider to use for this request |
| * |
| * @return element content provider |
| */ |
| protected IElementContentProvider getElementContentProvider() { |
| return fElementContentProvider; |
| } |
| |
| @Override |
| public final void done() { |
| synchronized (this) { |
| if (isDone()) { |
| return; |
| } |
| fDone = true; |
| } |
| scheduleViewerUpdate(); |
| } |
| |
| /** |
| * Returns whether this request is done yet. |
| * |
| * @return True if this update is done. |
| */ |
| protected synchronized boolean isDone() { |
| return fDone; |
| } |
| |
| protected void scheduleViewerUpdate() { |
| getContentProvider().scheduleViewerUpdate(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(); |
| |
| @Override |
| public IPresentationContext getPresentationContext() { |
| return fContext; |
| } |
| |
| @Override |
| public Object getElement() { |
| return fElement; |
| } |
| |
| @Override |
| public TreePath getElementPath() { |
| return fElementPath; |
| } |
| |
| /** |
| * Returns whether this request can coalesce the given request, and performs the |
| * coalesce if it can. |
| * |
| * @param update request to coalesce with this request |
| * @return whether it worked |
| */ |
| abstract boolean coalesce(ViewerUpdateMonitor update); |
| |
| /** |
| * Returns whether this update or any coalesced updates is for an |
| * element at the given path. |
| * @param path Element path to check. |
| * @return True if this update contains the given update path. |
| * |
| * @since 3.6 |
| */ |
| abstract boolean containsUpdate(TreePath path); |
| |
| /** |
| * Starts this request. Subclasses must override startRequest(). |
| */ |
| protected void start() { |
| synchronized (this) { |
| if (fStarted) { |
| return; |
| } |
| fStarted = true; |
| } |
| getContentProvider().updateStarted(this); |
| if (!isCanceled()) { |
| startRequest(); |
| } else { |
| done(); |
| } |
| } |
| |
| @Override |
| public Object getViewerInput() { |
| return fViewerInput; |
| } |
| |
| /** |
| * Subclasses must override to initiate specific request types. |
| */ |
| abstract void startRequest(); |
| |
| /** |
| * Returns the priority of this request. Subclasses must override. The |
| * highest priority is 1. Priorities indicate the order that waiting |
| * requests should be started in (for example, 'hasChildren' before 'update child count'). |
| * |
| * @return priority |
| */ |
| abstract int getPriority(); |
| |
| /** |
| * Returns a path used to schedule this request - i.e. based on this path, this |
| * request will be scheduled to run when no requests are running against the |
| * same element or a parent of the element denoted by the path. |
| * |
| * @return path used to schedule request |
| */ |
| abstract TreePath getSchedulingPath(); |
| |
| /** |
| * Sets whether this update has been delegated to another content provider |
| * @param delegated whether the update has been delegated |
| * @since 3.4 |
| */ |
| public void setDelegated(boolean delegated) { |
| fIsDelegated = delegated; |
| } |
| |
| /** |
| * @return whether this update has been delegated to another content provider |
| * @since 3.4 |
| */ |
| public boolean isDelegated() { |
| return fIsDelegated; |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (obj instanceof ViewerUpdateMonitor) { |
| return doEquals((ViewerUpdateMonitor)obj); |
| } |
| return false; |
| } |
| |
| @Override |
| public int hashCode() { |
| return doHashCode(); |
| } |
| |
| /** |
| * Checks whether the given update is equal as this. The update is equal if it's |
| * the same type of update and its updating the same elements. |
| * @param update Update to compare to. |
| * @return True if the given update is equals |
| * @since 3.8 |
| */ |
| abstract protected boolean doEquals(ViewerUpdateMonitor update); |
| |
| /** |
| * Calculates the hash code of the given update using the same parameters as doEquals(). |
| * @return Update's hash code. |
| * @since 3.8 |
| */ |
| abstract protected int doHashCode(); |
| |
| /** |
| * Executes the given runnable in the UI thread. If method is called in |
| * UI thread, then runnable is executed immediately, otherwise it's executed |
| * using <code>Display.asyncExec()</code>. Runnable is not executed if update is |
| * canceled or content provider is disposed. |
| * @since 3.8 |
| */ |
| protected void execInDisplayThread(Runnable runnable) { |
| ITreeModelViewer viewer = getContentProvider().getViewer(); |
| if (viewer != null && !isCanceled()) { |
| Display display = viewer.getDisplay(); |
| if (Thread.currentThread() == display.getThread()) { |
| runnable.run(); |
| } else { |
| display.asyncExec(runnable); |
| } |
| } |
| } |
| |
| } |