/*******************************************************************************
* Copyright (c) 2000, 2008 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.texteditor.quickdiff;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.text.source.IAnnotationModel;
import org.eclipse.ui.internal.texteditor.TextEditorPlugin;
import org.eclipse.ui.internal.texteditor.quickdiff.DocumentLineDiffer;
import org.eclipse.ui.internal.texteditor.quickdiff.QuickDiffExtensionsRegistry;
import org.eclipse.ui.texteditor.ITextEditor;
/**
* Access class for the quick diff reference provider extension point.
* <p>
* This class may be instantiated, it is not intended to be subclassed.
* </p>
* @since 3.0
* @noextend This class is not intended to be subclassed by clients.
*/
public class QuickDiff {
/**
* Creates a new instance.
*/
public QuickDiff() {
}
/**
* Returns the descriptor of the "last saved version" reference provider.
* <p>
* Clients should not cache this value because it can change when plug-ins get dynamically added or removed.
* </p>
*
* @return the descriptor of "last saved version" reference provider or <code>null</code> if none
*/
public ReferenceProviderDescriptor getDefaultProvider() {
QuickDiffExtensionsRegistry registry= TextEditorPlugin.getDefault().getQuickDiffExtensionRegistry();
if (registry != null)
return registry.getDefaultProvider();
return null;
}
/**
* Returns a non-modifiable list of <code>ReferenceProviderDescriptor</code> describing all extension
* to the <code>quickDiffReferenceProvider</code> extension point.
* <p>
* Clients should not cache this list because it can change when plug-ins get dynamically added or removed.
* </p>
*
* @return the non-modifiable list of extensions to the <code>quickDiffReferenceProvider</code> extension point.
*/
public List getReferenceProviderDescriptors() {
QuickDiffExtensionsRegistry registry= TextEditorPlugin.getDefault().getQuickDiffExtensionRegistry();
if (registry != null)
return registry.getReferenceProviderDescriptors();
return Collections.EMPTY_LIST;
}
/**
* Returns the quick diff reference provider registered under <code>id</code>, or the default
* reference provider. The returned provider gets its editor set to <code>editor</code>. If neither
* the requested provider nor the default provider return <code>true</code> from <code>isEnabled</code> after
* having the editor set, <code>null</code> is returned.
* <p>
* Clients should not cache this value because it can change when plug-ins get dynamically added or removed.
* </p>
*
* @param editor the editor to be installed with the returned provider
* @param id the id as specified in the <code>plugin.xml</code> that installs the reference provider
* @return the reference provider registered under <code>id</code>, or the default reference provider, or <code>null</code>
*/
public IQuickDiffReferenceProvider getReferenceProviderOrDefault(ITextEditor editor, String id) {
Assert.isNotNull(editor);
Assert.isNotNull(id);
List descs= getReferenceProviderDescriptors();
// try to fetch preferred provider; load if needed
for (Iterator iter= descs.iterator(); iter.hasNext();) {
ReferenceProviderDescriptor desc= (ReferenceProviderDescriptor) iter.next();
if (desc.getId().equals(id)) {
IQuickDiffReferenceProvider provider= desc.createProvider();
if (provider != null) {
provider.setActiveEditor(editor);
if (provider.isEnabled())
return provider;
provider.dispose();
provider= null;
}
}
}
for (ListIterator iter= descs.listIterator(descs.size()); iter.hasPrevious();) {
ReferenceProviderDescriptor desc= (ReferenceProviderDescriptor) iter.previous();
IQuickDiffReferenceProvider provider= desc.createProvider();
if (provider != null) {
provider.setActiveEditor(editor);
if (provider.isEnabled())
return provider;
provider.dispose();
provider= null;
}
}
return null;
}
/**
* Creates a new line differ annotation model with its reference provider set to the reference provider
* obtained by calling <code>getReferenceProviderOrDefault(editor, id)</code>.
*
* @param editor the editor to be installed with the returned provider
* @param id the id as specified in the <code>plugin.xml</code> that installs the reference provider
* @return a quick diff annotation model
*/
public IAnnotationModel createQuickDiffAnnotationModel(ITextEditor editor, String id) {
IQuickDiffReferenceProvider provider= getReferenceProviderOrDefault(editor, id);
if (provider != null) {
DocumentLineDiffer differ= new DocumentLineDiffer();
differ.setReferenceProvider(provider);
return differ;
}
return null;
}
/**
* Returns the identifier of the quick diff provider installed with the given diff annotation
* model, or the empty string if it is not a diff annotation model or has no configured diff
* provider.
*
* @param differ a diff annotation model
* @return the reference provider id, or the empty string for none
* @since 3.2
*/
public Object getConfiguredQuickDiffProvider(IAnnotationModel differ) {
if (differ instanceof DocumentLineDiffer) {
DocumentLineDiffer lineDiffer= (DocumentLineDiffer) differ;
IQuickDiffReferenceProvider provider= lineDiffer.getReferenceProvider();
if (provider != null)
return provider.getId();
}
return ""; //$NON-NLS-1$
}
}