| /******************************************************************************* |
| * Copyright (c) 2007 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.model.elements; |
| |
| import org.eclipse.core.runtime.CoreException; |
| 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.core.runtime.jobs.Job; |
| import org.eclipse.debug.internal.ui.viewers.model.provisional.IPresentationContext; |
| import org.eclipse.debug.internal.ui.viewers.model.provisional.IViewerInputProvider; |
| import org.eclipse.debug.internal.ui.viewers.model.provisional.IViewerInputUpdate; |
| import org.eclipse.debug.internal.ui.viewers.model.provisional.IViewerUpdate; |
| |
| /** |
| * Common code for viewer input providers. Creates a job to process request asynchronously. |
| |
| * @since 3.4 |
| */ |
| public abstract class ViewerInputProvider implements IViewerInputProvider { |
| |
| protected static final Object[] EMPTY = new Object[0]; |
| |
| /* (non-Javadoc) |
| * @see org.eclipse.debug.internal.ui.viewers.model.provisional.IElementContentProvider#updateChildren(java.lang.Object, int, int, org.eclipse.debug.internal.ui.viewers.provisional.IPresentationContext, org.eclipse.debug.internal.ui.viewers.model.provisional.IElementRequestMonitor) |
| */ |
| public void update(final IViewerInputUpdate update) { |
| Job job = new Job("viewer input resolution") { //$NON-NLS-1$ |
| protected IStatus run(IProgressMonitor monitor) { |
| if (!update.isCanceled()) { |
| retrieveInput(update); |
| } |
| update.done(); |
| return Status.OK_STATUS; |
| } |
| }; |
| job.setSystem(true); |
| job.setRule(getRule(update)); |
| job.schedule(); |
| } |
| |
| /** |
| * Computes the viewer input for the specified context. |
| * |
| * @param update update request |
| */ |
| protected void retrieveInput(IViewerInputUpdate update) { |
| if (!update.isCanceled()) { |
| IStatus status = Status.OK_STATUS; |
| try { |
| IPresentationContext context = update.getPresentationContext(); |
| if (supportsContext(context)) { |
| update.setInputElement(getViewerInput(update.getElement(), context, update)); |
| } else { |
| update.setInputElement(update.getElement()); |
| } |
| } catch (CoreException e) { |
| status = e.getStatus(); |
| } |
| update.setStatus(status); |
| } |
| } |
| |
| |
| /** |
| * Returns the viewer input derived from the given source object in the specified |
| * context, possibly <code>null</code>. |
| * |
| * @param source element to derive a viewer input from |
| * @param context context for which an input is requested |
| * @param update viewer update request |
| * @throws CoreException if an exception occurs retrieving child |
| */ |
| protected abstract Object getViewerInput(Object source, IPresentationContext context, IViewerUpdate update) throws CoreException; |
| |
| |
| /** |
| * Returns whether this adapter supports the given context. |
| * |
| * @param context |
| * @return whether this adapter supports the given context |
| */ |
| protected boolean supportsContext(IPresentationContext context) { |
| return supportsContextId(context.getId()); |
| } |
| |
| /** |
| * Returns whether this adapter provides content in the specified context id. |
| * |
| * @param id part id |
| * @return whether this adapter provides content in the specified context id |
| */ |
| protected abstract boolean supportsContextId(String id); |
| |
| /** |
| * Returns a scheduling rule to use when performing the given updates or |
| * <code>null</code> if none. |
| * |
| * @param updates |
| * @return scheduling rule or <code>null</code> if none |
| */ |
| protected ISchedulingRule getRule(IViewerInputUpdate update) { |
| return null; |
| } |
| |
| } |