/******************************************************************************* * Copyright (c) 2005, 2011 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 *******************************************************************************/ package org.eclipse.debug.internal.ui.viewers.provisional; 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.AsynchronousSchedulingRuleFactory; import org.eclipse.debug.internal.ui.viewers.model.provisional.IPresentationContext; /** * Abstract implementation of an asynchronous content adapter. *
* Clients may subclass this class. *
* @since 3.2 */ public abstract class AsynchronousContentAdapter implements IAsynchronousContentAdapter { protected static final Object[] EMPTY = new Object[0]; /* * (non-Javadoc) * @see org.eclipse.debug.internal.ui.viewers.provisional.IAsynchronousContentAdapter#retrieveChildren(java.lang.Object, org.eclipse.debug.internal.ui.viewers.provisional.IPresentationContext, org.eclipse.debug.internal.ui.viewers.provisional.IChildrenRequestMonitor) */ @Override public void retrieveChildren(final Object parent, final IPresentationContext context, final IChildrenRequestMonitor result) { Job job = new Job("Retrieving Children") { //$NON-NLS-1$ @Override protected IStatus run(IProgressMonitor monitor) { if (!monitor.isCanceled()) { computeChildren(parent, context, result); } return Status.OK_STATUS; } }; job.setSystem(true); job.setRule(getRetrieveChildrenRule(parent, context)); job.schedule(); } /** * Returns the scheduling rule for jobs retrieving children. * * @param parent the parent * @param context the presentation context * @return scheduling rule ornull
*/
protected ISchedulingRule getRetrieveChildrenRule(Object parent, IPresentationContext context) {
return AsynchronousSchedulingRuleFactory.getDefault().newSerialPerObjectRule(context);
}
/*
* (non-Javadoc)
* @see org.eclipse.debug.internal.ui.viewers.provisional.IAsynchronousContentAdapter#isContainer(java.lang.Object, org.eclipse.debug.internal.ui.viewers.provisional.IPresentationContext, org.eclipse.debug.internal.ui.viewers.provisional.IContainerRequestMonitor)
*/
@Override
public void isContainer(final Object element, final IPresentationContext context, final IContainerRequestMonitor result) {
Job job = new Job("Computing hasChildren") { //$NON-NLS-1$
@Override
protected IStatus run(IProgressMonitor monitor) {
if (!monitor.isCanceled()) {
computeIsContainer(element, context, result);
}
return Status.OK_STATUS;
}
};
job.setSystem(true);
job.setRule(getIsContainerRule(element, context));
job.schedule();
}
/**
* Returns the scheduling rule for jobs determining if an element is a container.
*
* @param parent the parent
* @param context the presentation context
* @return scheduling rule or null
*/
protected ISchedulingRule getIsContainerRule(Object parent, IPresentationContext context) {
return AsynchronousSchedulingRuleFactory.getDefault().newSerialPerObjectRule(context);
}
/**
* Computes the children for the given parent in the specified context.
*
* @param parent parent to retrieve children for
* @param context presentation context
* @param monitor result to report to
*/
protected void computeChildren(Object parent, IPresentationContext context, IChildrenRequestMonitor monitor) {
if (!monitor.isCanceled()) {
IStatus status = Status.OK_STATUS;
try {
if (supportsContext(context)) {
monitor.addChildren(getChildren(parent, context));
}
} catch (CoreException e) {
status = e.getStatus();
}
monitor.setStatus(status);
monitor.done();
}
}
/**
* Computes whether the given element is a container.
*
* @param parent potential parent
* @param context presentation context
* @param monitor result to report to
*/
protected void computeIsContainer(Object parent, IPresentationContext context, IContainerRequestMonitor monitor) {
if (!monitor.isCanceled()) {
IStatus status = Status.OK_STATUS;
try {
monitor.setIsContainer(hasChildren(parent, context));
} catch (CoreException e) {
status = e.getStatus();
}
monitor.setStatus(status);
monitor.done();
}
}
/**
* Returns the children for the given parent in the specified context.
*
* @param parent element to retrieve children for
* @param context context children will be presented in
* @return children
* @throws CoreException if an exception occurs retrieving children
*/
protected abstract Object[] getChildren(Object parent, IPresentationContext context) throws CoreException;
/**
* Returns whether the given element has children in the specified context.
*
* @param element element that may have children
* @param context context element will be presented in
* @return whether the given element has children in the specified context
* @throws CoreException if an exception occurs determining whether the
* element has children
*/
protected abstract boolean hasChildren(Object element, IPresentationContext context) throws CoreException;
/**
* Returns whether this adapter supports the given context.
*
* @param context the presentation context
* @return whether this adapter supports the given context
*/
protected boolean supportsContext(IPresentationContext context) {
return supportsPartId(context.getId());
}
/**
* Returns whether this adapter provides content in the specified part.
*
* @param id part id
* @return whether this adapter provides content in the specified part
*/
protected abstract boolean supportsPartId(String id);
}