Java tutorial
/******************************************************************************* * 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 * Jan-Hendrik Diederich, Bredex GmbH - bug 201052 *******************************************************************************/ package org.eclipse.ui.internal.dialogs; import java.util.Collection; import java.util.Iterator; import org.eclipse.core.runtime.IConfigurationElement; import org.eclipse.core.runtime.IExtension; import org.eclipse.core.runtime.IExtensionPoint; import org.eclipse.core.runtime.IRegistryChangeEvent; import org.eclipse.core.runtime.IRegistryChangeListener; import org.eclipse.core.runtime.IStatus; import org.eclipse.core.runtime.Platform; import org.eclipse.core.runtime.dynamichelpers.ExtensionTracker; import org.eclipse.core.runtime.dynamichelpers.IExtensionChangeHandler; import org.eclipse.core.runtime.dynamichelpers.IExtensionTracker; import org.eclipse.jface.preference.IPreferenceNode; import org.eclipse.jface.preference.PreferenceManager; import org.eclipse.ui.PlatformUI; import org.eclipse.ui.internal.WorkbenchPlugin; import org.eclipse.ui.internal.misc.StatusUtil; import org.eclipse.ui.internal.preferences.WorkbenchPreferenceExpressionNode; import org.eclipse.ui.internal.registry.IWorkbenchRegistryConstants; import org.eclipse.ui.internal.registry.PreferencePageRegistryReader; /** * The WorkbenchPreferenceManager is the manager that can handle categories and * preference nodes. */ public class WorkbenchPreferenceManager extends PreferenceManager implements IExtensionChangeHandler { /** * Create a new instance of the receiver with the specified seperatorChar * * @param separatorChar */ public WorkbenchPreferenceManager(char separatorChar) { super(separatorChar, new WorkbenchPreferenceExpressionNode("")); //$NON-NLS-1$ IExtensionTracker tracker = PlatformUI.getWorkbench().getExtensionTracker(); tracker.registerHandler(this, ExtensionTracker.createExtensionPointFilter(getExtensionPointFilter())); // add a listener for keyword deltas. If any occur clear all page caches Platform.getExtensionRegistry().addRegistryChangeListener(new IRegistryChangeListener() { /* * (non-Javadoc) * * @see org.eclipse.core.runtime.IRegistryChangeListener#registryChanged(org.eclipse.core.runtime.IRegistryChangeEvent) */ public void registryChanged(IRegistryChangeEvent event) { if (event.getExtensionDeltas(PlatformUI.PLUGIN_ID, IWorkbenchRegistryConstants.PL_KEYWORDS).length > 0) { for (Iterator j = getElements(PreferenceManager.POST_ORDER).iterator(); j.hasNext();) { ((WorkbenchPreferenceNode) j.next()).clearKeywords(); } } } }); } /** * Add the pages and the groups to the receiver. * * @param pageContributions */ public void addPages(Collection pageContributions) { // Add the contributions to the manager Iterator iterator = pageContributions.iterator(); while (iterator.hasNext()) { Object next = iterator.next(); if (next instanceof WorkbenchPreferenceNode) { WorkbenchPreferenceNode wNode = (WorkbenchPreferenceNode) next; addToRoot(wNode); registerNode(wNode); } } } /** * Register a node with the extension tracker. * * @param node * register the given node and its subnodes with the extension * tracker */ private void registerNode(WorkbenchPreferenceNode node) { PlatformUI.getWorkbench().getExtensionTracker().registerObject( node.getConfigurationElement().getDeclaringExtension(), node, IExtensionTracker.REF_WEAK); IPreferenceNode[] subNodes = node.getSubNodes(); for (int i = 0; i < subNodes.length; i++) { registerNode((WorkbenchPreferenceNode) subNodes[i]); } } /* (non-Javadoc) * @see org.eclipse.core.runtime.dynamicHelpers.IExtensionChangeHandler#addExtension(org.eclipse.core.runtime.dynamicHelpers.IExtensionTracker, org.eclipse.core.runtime.IExtension) */ public void addExtension(IExtensionTracker tracker, IExtension extension) { IConfigurationElement[] elements = extension.getConfigurationElements(); for (int i = 0; i < elements.length; i++) { WorkbenchPreferenceNode node = PreferencePageRegistryReader.createNode(elements[i]); if (node == null) { continue; } registerNode(node); String category = node.getCategory(); if (category == null) { addToRoot(node); } else { IPreferenceNode parent = null; for (Iterator j = getElements(PreferenceManager.POST_ORDER).iterator(); j.hasNext();) { IPreferenceNode element = (IPreferenceNode) j.next(); if (category.equals(element.getId())) { parent = element; break; } } if (parent == null) { // Could not find the parent - log String message = "Invalid preference category path: " + category + " (bundle: " //$NON-NLS-1$//$NON-NLS-2$ + node.getPluginId() + ", page: " + node.getId() + ")"; //$NON-NLS-1$ //$NON-NLS-2$ WorkbenchPlugin.log(StatusUtil.newStatus(IStatus.WARNING, message, null)); addToRoot(node); } else { parent.add(node); } } } } /* * (non-Javadoc) * * @see org.eclipse.core.runtime.dynamicHelpers.IExtensionAdditionHandler#getExtensionPointFilter() */ private IExtensionPoint getExtensionPointFilter() { return Platform.getExtensionRegistry().getExtensionPoint(PlatformUI.PLUGIN_ID, IWorkbenchRegistryConstants.PL_PREFERENCES); } /* (non-Javadoc) * @see org.eclipse.core.runtime.dynamicHelpers.IExtensionChangeHandler#removeExtension(org.eclipse.core.runtime.IExtension, java.lang.Object[]) */ public void removeExtension(IExtension extension, Object[] objects) { for (int i = 0; i < objects.length; i++) { if (objects[i] instanceof IPreferenceNode) { IPreferenceNode wNode = (IPreferenceNode) objects[i]; wNode.disposeResources(); deepRemove(getRoot(), wNode); } } } /** * Removes the node from the manager, searching through all subnodes. * * @param parent * the node to search * @param nodeToRemove * the node to remove * @return whether the node was removed */ private boolean deepRemove(IPreferenceNode parent, IPreferenceNode nodeToRemove) { if (parent == nodeToRemove) { if (parent == getRoot()) { removeAll(); // we're removing the root return true; } } if (parent.remove(nodeToRemove)) { return true; } IPreferenceNode[] subNodes = parent.getSubNodes(); for (int i = 0; i < subNodes.length; i++) { if (deepRemove(subNodes[i], nodeToRemove)) { return true; } } return false; } }