/*******************************************************************************
* Copyright (c) 2003, 2015 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.ui.internal.ide;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.IResourceChangeListener;
import org.eclipse.core.resources.IResourceDelta;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IExtension;
import org.eclipse.core.runtime.IExtensionPoint;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.Status;
import org.eclipse.ui.IPluginContribution;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.activities.ITriggerPoint;
import org.eclipse.ui.activities.IWorkbenchActivitySupport;
import org.eclipse.ui.activities.WorkbenchActivityHelper;
import org.eclipse.ui.progress.WorkbenchJob;
/**
* Utility class that manages promotion of activites in response to workspace changes.
*
* @since 3.0
*/
public class IDEWorkbenchActivityHelper {
private static final String NATURE_POINT = "org.eclipse.ui.ide.natures"; //$NON-NLS-1$
/**
* Resource listener that reacts to new projects (and associated natures)
* coming into the workspace.
*/
private IResourceChangeListener listener;
/**
* Mapping from composite nature ID to IPluginContribution. Used for proper
* activity mapping of natures.
*/
private Map natureMap;
/**
* Lock for the list of nature ids to be processed.
*/
private final IDEWorkbenchActivityHelper lock;
/**
* The update job.
*/
private WorkbenchJob fUpdateJob;
/**
* The collection of natures to process.
*/
private HashSet fPendingNatureUpdates= new HashSet();
/**
* Singleton instance.
*/
private static IDEWorkbenchActivityHelper singleton;
/**
* Get the singleton instance of this class.
* @return the singleton instance of this class.
* @since 3.0
*/
public static IDEWorkbenchActivityHelper getInstance() {
if (singleton == null) {
singleton = new IDEWorkbenchActivityHelper();
}
return singleton;
}
/**
* Create a new <code>IDEWorkbenchActivityHelper</code> which will listen
* for workspace changes and promote activities accordingly.
*/
private IDEWorkbenchActivityHelper() {
lock = this;
natureMap = new HashMap();
// for dynamic UI
Platform.getExtensionRegistry().addRegistryChangeListener(
event -> {
if (event.getExtensionDeltas(
"org.eclipse.core.resources", "natures").length > 0) { //$NON-NLS-1$ //$NON-NLS-2$
loadNatures();
}
}, "org.eclipse.core.resources"); //$NON-NLS-1$
loadNatures();
listener = getChangeListener();
ResourcesPlugin.getWorkspace().addResourceChangeListener(listener);
// crawl the initial projects to set up nature bindings
IProject[] projects = ResourcesPlugin.getWorkspace().getRoot()
.getProjects();
processProjects(new HashSet(Arrays.asList(projects)));
}
/**
* For dynamic UI. Clears the cache of known natures and recreates it.
*/
public void loadNatures() {
natureMap.clear();
IExtensionPoint point = Platform.getExtensionRegistry()
.getExtensionPoint("org.eclipse.core.resources.natures"); //$NON-NLS-1$
for (IExtension extension : point.getExtensions()) {
final String localId = extension.getSimpleIdentifier();
final String pluginId = extension.getNamespaceIdentifier();
String natureId = extension.getUniqueIdentifier();
natureMap.put(natureId, new IPluginContribution() {
@Override
public String getLocalId() {
return localId;
}
@Override
public String getPluginId() {
return pluginId;
}
});
}
}
/**
* Get a change listener for listening to resource changes.
*
* @return the resource change listeners
*/
private IResourceChangeListener getChangeListener() {
return event -> {
if (!WorkbenchActivityHelper.isFiltering()) {
return;
}
IResourceDelta mainDelta = event.getDelta();
if (mainDelta == null) {
return;
}
//Has the root changed?
if (mainDelta.getKind() == IResourceDelta.CHANGED
&& mainDelta.getResource().getType() == IResource.ROOT) {
Set projectsToUpdate = new HashSet();
for (IResourceDelta delta : mainDelta.getAffectedChildren()) {
if (delta.getResource().getType() == IResource.PROJECT) {
IProject project = (IProject) delta.getResource();
if (project.isOpen()) {
projectsToUpdate.add(project);
}
}
}
processProjects(projectsToUpdate);
}
};
}
/**
* Drain the queue and consult the helper.
*/
protected void runPendingUpdates() {
String[] ids = null;
synchronized (lock) {
ids = (String[]) fPendingNatureUpdates
.toArray(new String[fPendingNatureUpdates.size()]);
fPendingNatureUpdates.clear();
}
IWorkbenchActivitySupport workbenchActivitySupport = PlatformUI
.getWorkbench().getActivitySupport();
for (String id : ids) {
final IPluginContribution contribution = (IPluginContribution) natureMap.get(id);
if (contribution == null) {
continue; // bad nature ID.
}
final ITriggerPoint triggerPoint = workbenchActivitySupport
.getTriggerPointManager().getTriggerPoint(NATURE_POINT);
// consult the advisor - if the activities need enabling, they will
// be
WorkbenchActivityHelper.allowUseOf(triggerPoint, contribution);
}
}
/**
* Unhooks the <code>IResourceChangeListener</code>.
*/
public void shutdown() {
if (listener != null) {
ResourcesPlugin.getWorkspace().removeResourceChangeListener(
listener);
}
}
/**
* @param projectsToUpdate
*/
private void processProjects(Set projectsToUpdate) {
boolean needsUpdate = false;
for (Iterator i = projectsToUpdate.iterator(); i.hasNext();) {
try {
IProject project = (IProject) i.next();
String[] ids = project.getDescription().getNatureIds();
if (ids.length == 0) {
continue;
}
synchronized (lock) {
needsUpdate = fPendingNatureUpdates.addAll(Arrays
.asList(ids)) | needsUpdate;
}
} catch (CoreException e) {
// Do nothing if there is a CoreException
}
}
if (needsUpdate) {
if (fUpdateJob == null) {
fUpdateJob = new WorkbenchJob(IDEWorkbenchMessages.IDEWorkbenchActivityHelper_jobName) {
@Override
public IStatus runInUIThread(
IProgressMonitor monitor) {
runPendingUpdates();
return Status.OK_STATUS;
}
};
fUpdateJob.setSystem(true);
}
fUpdateJob.schedule();
}
}
}