package it.tref.eclipse.wicket.plugin.editors;
import java.util.HashMap;
import java.util.Map;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.ListenerList;
import org.eclipse.core.runtime.NullProgressMonitor;
import org.eclipse.core.runtime.OperationCanceledException;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.jobs.Job;
import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.ITypeRoot;
import org.eclipse.jdt.core.dom.AST;
import org.eclipse.jdt.core.dom.ASTParser;
import org.eclipse.jdt.core.dom.CompilationUnit;
import org.eclipse.jdt.internal.ui.JavaUIMessages;
import org.eclipse.jdt.internal.ui.javaeditor.EditorUtility;
import org.eclipse.jdt.internal.ui.viewsupport.ISelectionListenerWithAST;
import org.eclipse.jface.text.ITextSelection;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.ISelectionChangedListener;
import org.eclipse.jface.viewers.ISelectionProvider;
import org.eclipse.jface.viewers.SelectionChangedEvent;
import org.eclipse.ui.ISelectionListener;
import org.eclipse.ui.IWorkbenchPart;
import org.eclipse.ui.texteditor.ITextEditor;
/**
* Selection listener that can manage AST from MultiPage editor
* This class is a bug fix of the original one in the Eclipse source
*
* @author Andrea Fantappi�
*/
@SuppressWarnings("restriction")
public class SelectionListenerWithASTManager
{
private static SelectionListenerWithASTManager fgDefault;
/**
* @return Returns the default manager instance.
*/
public static SelectionListenerWithASTManager getDefault() {
if (fgDefault == null) {
fgDefault= new SelectionListenerWithASTManager();
}
return fgDefault;
}
private final static class PartListenerGroup
{
private ITextEditor fPart;
private ISelectionListener fPostSelectionListener;
private ISelectionChangedListener fSelectionListener;
private Job fCurrentJob;
private ListenerList fAstListeners;
/**
* Lock to avoid having more than one calculateAndInform job in parallel.
* Only jobs may synchronize on this as otherwise deadlocks are possible.
*/
private final Object fJobLock = new Object();
public PartListenerGroup(ITextEditor editorPart)
{
fPart= editorPart;
fCurrentJob= null;
fAstListeners= new ListenerList(ListenerList.IDENTITY);
fSelectionListener= new ISelectionChangedListener()
{
public void selectionChanged(SelectionChangedEvent event) {
ISelection selection= event.getSelection();
if (selection instanceof ITextSelection) {
fireSelectionChanged((ITextSelection) selection);
}
}
};
fPostSelectionListener= new ISelectionListener()
{
public void selectionChanged(IWorkbenchPart part, ISelection selection) {
if (part instanceof WicketFunEditor && selection instanceof ITextSelection)
firePostSelectionChanged((ITextSelection) selection);
}
};
}
public boolean isEmpty() {
return fAstListeners.isEmpty();
}
public void install(ISelectionListenerWithAST listener)
{
if (isEmpty()) {
fPart.getEditorSite().getPage().addPostSelectionListener(fPostSelectionListener);
ISelectionProvider selectionProvider= fPart.getSelectionProvider();
if (selectionProvider != null)
selectionProvider.addSelectionChangedListener(fSelectionListener);
}
fAstListeners.add(listener);
}
public void uninstall(ISelectionListenerWithAST listener)
{
fAstListeners.remove(listener);
if (isEmpty()) {
fPart.getEditorSite().getPage().removePostSelectionListener(fPostSelectionListener);
ISelectionProvider selectionProvider= fPart.getSelectionProvider();
if (selectionProvider != null)
selectionProvider.removeSelectionChangedListener(fSelectionListener);
}
}
/**
* A selection event has occurred.
*
* @param selection the selection
*/
public void fireSelectionChanged(final ITextSelection selection)
{
if (fCurrentJob != null) {
fCurrentJob.cancel();
}
}
/**
* A post selection event has occurred.
*
* @param selection the selection
*/
public void firePostSelectionChanged(final ITextSelection selection)
{
if (fCurrentJob != null) {
fCurrentJob.cancel();
}
IJavaElement input= EditorUtility.getEditorInputJavaElement(fPart, false);
if (!(input instanceof ITypeRoot)) {
return;
}
final ITypeRoot typeRoot= (ITypeRoot) input;
fCurrentJob= new Job(JavaUIMessages.SelectionListenerWithASTManager_job_title)
{
public IStatus run(IProgressMonitor monitor)
{
if (monitor == null) {
monitor= new NullProgressMonitor();
}
synchronized (fJobLock) {
return calculateASTandInform(typeRoot, selection, monitor);
}
}
};
fCurrentJob.setPriority(Job.DECORATE);
fCurrentJob.setSystem(true);
fCurrentJob.schedule();
}
protected final IStatus calculateASTandInform(ITypeRoot input, ITextSelection selection, IProgressMonitor monitor)
{
if (monitor.isCanceled()) {
return Status.CANCEL_STATUS;
}
// create AST
try
{
// use the parser directly, the use of static shared classes don't work with multipage editor
ASTParser parser = ASTParser.newParser(AST.JLS3);
parser.setResolveBindings(true);
parser.setStatementsRecovery(true);
parser.setBindingsRecovery(true);
parser.setSource(input);
CompilationUnit astRoot = (CompilationUnit)parser.createAST(monitor);
if (astRoot != null && !monitor.isCanceled()) {
Object[] listeners;
synchronized (PartListenerGroup.this) {
listeners= fAstListeners.getListeners();
}
for (int i= 0; i < listeners.length; i++)
{
((ISelectionListenerWithAST) listeners[i]).selectionChanged(fPart, selection, astRoot);
if (monitor.isCanceled()) {
return Status.CANCEL_STATUS;
}
}
return Status.OK_STATUS;
}
} catch (OperationCanceledException e) {
// thrown when canceling the AST creation
}
return Status.CANCEL_STATUS;
}
}
@SuppressWarnings("rawtypes")
private Map fListenerGroups;
@SuppressWarnings("rawtypes")
private SelectionListenerWithASTManager() {
fListenerGroups = new HashMap();
}
/**
* Registers a selection listener for the given editor part.
* @param part The editor part to listen to.
* @param listener The listener to register.
*/
@SuppressWarnings({ "unchecked" })
public void addListener(ITextEditor part, ISelectionListenerWithAST listener)
{
synchronized (this)
{
PartListenerGroup partListener= (PartListenerGroup) fListenerGroups.get(part);
if (partListener == null) {
partListener= new PartListenerGroup(part);
fListenerGroups.put(part, partListener);
}
partListener.install(listener);
}
}
/**
* Unregisters a selection listener.
* @param part The editor part the listener was registered.
* @param listener The listener to unregister.
*/
public void removeListener(ITextEditor part, ISelectionListenerWithAST listener)
{
synchronized (this)
{
PartListenerGroup partListener= (PartListenerGroup) fListenerGroups.get(part);
if (partListener != null) {
partListener.uninstall(listener);
if (partListener.isEmpty()) {
fListenerGroups.remove(part);
}
}
}
}
}