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/*******************************************************************************
* Copyright (c) 2000, 2008 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.jface.text.link;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.Stack;
import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.text.IDocument;
/**
* A linked mode manager ensures exclusive access of linked position infrastructures to documents. There
* is at most one LinkedModeManager installed on the same document. The getManager
* methods will return the existing instance if any of the specified documents already have an installed
* manager.
*
* @since 3.0
*/
class LinkedModeManager {
/**
* Our implementation of ILinkedModeListener.
*/
private class Listener implements ILinkedModeListener {
@Override
public void left(LinkedModeModel model, int flags) {
LinkedModeManager.this.left(model, flags);
}
@Override
public void suspend(LinkedModeModel model) {
// not interested
}
@Override
public void resume(LinkedModeModel model, int flags) {
// not interested
}
}
/** Global map from documents to managers. */
private static Map fgManagers= new HashMap<>();
/**
* Returns whether there exists a LinkedModeManager on document.
*
* @param document the document of interest
* @return true if there exists a LinkedModeManager on document, false otherwise
*/
public static boolean hasManager(IDocument document) {
return fgManagers.get(document) != null;
}
/**
* Returns whether there exists a LinkedModeManager on any of the documents.
*
* @param documents the documents of interest
* @return true if there exists a LinkedModeManager on any of the documents, false otherwise
*/
public static boolean hasManager(IDocument[] documents) {
for (IDocument document : documents) {
if (hasManager(document))
return true;
}
return false;
}
/**
* Returns the manager for the given documents. If force is
* true, any existing conflicting managers are canceled, otherwise,
* the method may return null if there are conflicts.
*
* @param documents the documents of interest
* @param force whether to kill any conflicting managers
* @return a manager able to cover the requested documents, or null if there is a conflict and force was set to false
*/
public static LinkedModeManager getLinkedManager(IDocument[] documents, boolean force) {
if (documents == null || documents.length == 0)
return null;
Set mgrs= new HashSet<>();
LinkedModeManager mgr= null;
for (IDocument document : documents) {
mgr= fgManagers.get(document);
if (mgr != null)
mgrs.add(mgr);
}
if (mgrs.size() > 1)
if (force) {
for (LinkedModeManager m : mgrs) {
m.closeAllEnvironments();
}
} else {
return null;
}
if (mgrs.isEmpty())
mgr= new LinkedModeManager();
for (IDocument document : documents)
fgManagers.put(document, mgr);
return mgr;
}
/**
* Cancels any linked mode manager for the specified document.
*
* @param document the document whose LinkedModeManager should be canceled
*/
public static void cancelManager(IDocument document) {
LinkedModeManager mgr= fgManagers.get(document);
if (mgr != null)
mgr.closeAllEnvironments();
}
/** The hierarchy of environments managed by this manager. */
private Stack fEnvironments= new Stack<>();
private Listener fListener= new Listener();
/**
* Notify the manager about a leaving model.
*
* @param model the model to nest
* @param flags the reason and commands for leaving linked mode
*/
private void left(LinkedModeModel model, int flags) {
if (!fEnvironments.contains(model))
return;
while (!fEnvironments.isEmpty()) {
LinkedModeModel env= fEnvironments.pop();
if (env == model)
break;
env.exit(ILinkedModeListener.NONE);
}
if (fEnvironments.isEmpty()) {
removeManager();
}
}
private void closeAllEnvironments() {
while (!fEnvironments.isEmpty()) {
LinkedModeModel env= fEnvironments.pop();
env.exit(ILinkedModeListener.NONE);
}
removeManager();
}
private void removeManager() {
for (Iterator it= fgManagers.values().iterator(); it.hasNext();) {
if (it.next() == this)
it.remove();
}
}
/**
* Tries to nest the given LinkedModeModel onto the top of
* the stack of environments managed by the receiver. If force
* is true, any environments on the stack that create a conflict
* are killed.
*
* @param model the model to nest
* @param force whether to force the addition of the model
* @return true if nesting was successful, false otherwise (only possible if force is false
*/
public boolean nestEnvironment(LinkedModeModel model, boolean force) {
Assert.isNotNull(model);
try {
while (true) {
if (fEnvironments.isEmpty()) {
model.addLinkingListener(fListener);
fEnvironments.push(model);
return true;
}
LinkedModeModel top= fEnvironments.peek();
if (model.canNestInto(top)) {
model.addLinkingListener(fListener);
fEnvironments.push(model);
return true;
} else if (!force) {
return false;
} else { // force
fEnvironments.pop();
top.exit(ILinkedModeListener.NONE);
// continue;
}
}
} finally {
// if we remove any, make sure the new one got inserted
Assert.isTrue(!fEnvironments.isEmpty());
}
}
/**
* Returns the LinkedModeModel that is on top of the stack of
* environments managed by the receiver.
*
* @return the topmost LinkedModeModel
*/
public LinkedModeModel getTopEnvironment() {
if (fEnvironments.isEmpty())
return null;
return fEnvironments.peek();
}
}