bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/registry/PerspectiveRegistry.java - platform/eclipse.platform.ui - Git at Google

 /*******************************************************************************
  * 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.registry;

 import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.Reader;
 import java.io.StringReader;
 import java.io.StringWriter;
 import java.io.Writer;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.List;

 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IExtension;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.core.runtime.dynamichelpers.IExtensionChangeHandler;
 import org.eclipse.core.runtime.dynamichelpers.IExtensionTracker;
 import org.eclipse.jface.dialogs.IDialogSettings;
 import org.eclipse.jface.preference.IPreferenceStore;
 import org.eclipse.jface.resource.StringConverter;
 import org.eclipse.jface.util.IPropertyChangeListener;
 import org.eclipse.jface.util.PropertyChangeEvent;
 import org.eclipse.ui.IMemento;
 import org.eclipse.ui.IPerspectiveDescriptor;
 import org.eclipse.ui.IPerspectiveRegistry;
 import org.eclipse.ui.IWorkbenchPage;
 import org.eclipse.ui.IWorkbenchPreferenceConstants;
 import org.eclipse.ui.IWorkbenchWindow;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.WorkbenchException;
 import org.eclipse.ui.XMLMemento;
 import org.eclipse.ui.activities.WorkbenchActivityHelper;
 import org.eclipse.ui.internal.IPreferenceConstants;
 import org.eclipse.ui.internal.Workbench;
 import org.eclipse.ui.internal.WorkbenchMessages;
 import org.eclipse.ui.internal.WorkbenchPage;
 import org.eclipse.ui.internal.WorkbenchPlugin;
 import org.eclipse.ui.internal.handlers.ClosePerspectiveHandler;
 import org.eclipse.ui.internal.misc.StatusUtil;
 import org.eclipse.ui.internal.util.PrefUtil;
 import org.eclipse.ui.statushandlers.StatusManager;

 /**
  * Perspective registry.
  */
 public class PerspectiveRegistry implements IPerspectiveRegistry,
 		IExtensionChangeHandler {
 	private String defaultPerspID;

 	private static final String EXT = "_persp.xml"; //$NON-NLS-1$

 	private static final String ID_DEF_PERSP = "PerspectiveRegistry.DEFAULT_PERSP"; //$NON-NLS-1$

 	private static final String PERSP = "_persp"; //$NON-NLS-1$

 	private static final char SPACE_DELIMITER = ' ';

 	private List perspectives = new ArrayList(10);

 	// keep track of the perspectives the user has selected to remove or revert
 	private ArrayList perspToRemove = new ArrayList(5);

 	private IPropertyChangeListener preferenceListener;

 	/**
 	 * Construct a new registry.
 	 */
 	public PerspectiveRegistry() {
 		IExtensionTracker tracker = PlatformUI.getWorkbench()
 				.getExtensionTracker();
 		tracker.registerHandler(this, null);

 		initializePreferenceChangeListener();
 		WorkbenchPlugin.getDefault().getPreferenceStore()
 				.addPropertyChangeListener(preferenceListener);

 	}

 	/**
 	 * Initialize the preference change listener.
 	 */
 	private void initializePreferenceChangeListener() {
 		preferenceListener = new IPropertyChangeListener() {
 			public void propertyChange(PropertyChangeEvent event) {
 				/*
 				 * To ensure the that no custom perspective definitions are
 				 * deleted when preferences are imported, merge old and new
 				 * values
 				 */
 				if (event.getProperty().endsWith(PERSP)) {
 					/* A Perspective is being changed, merge */
 					mergePerspectives(event);
 				} else if (event.getProperty().equals(
 						IPreferenceConstants.PERSPECTIVES)) {
 					/* The list of perpsectives is being changed, merge */
 					updatePreferenceList((IPreferenceStore) event.getSource());
 				}
 			}

 			private void mergePerspectives(PropertyChangeEvent event) {
 				IPreferenceStore store = (IPreferenceStore) event.getSource();
 				if (event.getNewValue() == null
 						|| event.getNewValue().equals("")) { //$NON-NLS-1$
 					/*
 					 * Perpsective is being removed; if the user has deleted or
 					 * reverted a custom perspective, let the change pass
 					 * through. Otherwise, restore the custom perspective entry
 					 */

 					// Find the matching descriptor in the registry
 					IPerspectiveDescriptor[] perspectiveList = getPerspectives();
 					for (int i = 0; i < perspectiveList.length; i++) {
 						String id = perspectiveList[i].getId();
 						if (event.getProperty().equals(id + PERSP)) { // found
 							// descriptor
 							// see if the perspective has been flagged for
 							// reverting or deleting
 							if (!perspToRemove.contains(id)) { // restore
 								store.setValue(id + PERSP, (String) event
 										.getOldValue());
 							} else { // remove element from the list
 								perspToRemove.remove(id);
 							}
 						}
 					}
 				} else if ((event.getOldValue() == null || event.getOldValue()
 						.equals(""))) { //$NON-NLS-1$

 					/*
 					 * New perspective is being added, update the
 					 * perspectiveRegistry to contain the new custom perspective
 					 */

 					String id = event.getProperty().substring(0,
 							event.getProperty().lastIndexOf(PERSP));
 					if (findPerspectiveWithId(id) == null) {
 						// perspective does not already exist in registry, add
 						// it
 						PerspectiveDescriptor desc = new PerspectiveDescriptor(
 								null, null, null);
 						StringReader reader = new StringReader((String) event
 								.getNewValue());
 						try {
 							XMLMemento memento = XMLMemento
 									.createReadRoot(reader);
 							desc.restoreState(memento);
 							addPerspective(desc);
 						} catch (WorkbenchException e) {
 							unableToLoadPerspective(e.getStatus());
 						}
 					}
 				}
 				/* If necessary, add to the list of perspectives */
 				updatePreferenceList(store);
 			}

 			/*
 			 * Update the list of perspectives from the registry. This will be
 			 * called for each perspective during an import preferences, but is
 			 * necessary to ensure the perspectives list stays consistent with
 			 * the registry
 			 */
 			private void updatePreferenceList(IPreferenceStore store) {
 				IPerspectiveDescriptor[] perspectiveList = getPerspectives();
 				StringBuffer perspBuffer = new StringBuffer();
 				for (int i = 0; i < perspectiveList.length; i++) {
 					PerspectiveDescriptor desc = (PerspectiveDescriptor) perspectiveList[i];
 					if (hasCustomDefinition(desc)) {
 						perspBuffer.append(desc.getId())
 								.append(SPACE_DELIMITER);
 					}
 				}
 				String newList = perspBuffer.toString().trim();
 				store.setValue(IPreferenceConstants.PERSPECTIVES, newList);
 			}
 		};
 	}

 	/**
 	 * Adds a perspective. This is typically used by the reader.
 	 *
 	 * @param desc
 	 */
 	public void addPerspective(PerspectiveDescriptor desc) {
 		if (desc == null) {
 			return;
 		}
 		add(desc);
 	}

 	/**
 	 * @param desc
 	 */
 	private void add(PerspectiveDescriptor desc) {
 		perspectives.add(desc);
 		IConfigurationElement element = desc.getConfigElement();
 		if (element != null) {
 			PlatformUI.getWorkbench().getExtensionTracker().registerObject(
 					element.getDeclaringExtension(), desc,
 					IExtensionTracker.REF_WEAK);
 		}
 	}

 	/**
 	 * Create a new perspective.
 	 *
 	 * @param label
 	 *            the name of the new descriptor
 	 * @param originalDescriptor
 	 *            the descriptor on which to base the new descriptor
 	 * @return a new perspective descriptor or <code>null</code> if the
 	 *         creation failed.
 	 */
 	public PerspectiveDescriptor createPerspective(String label,
 			PerspectiveDescriptor originalDescriptor) {
 		// Sanity check to avoid invalid or duplicate labels.
 		if (!validateLabel(label)) {
 			return null;
 		}
 		if (findPerspectiveWithLabel(label) != null) {
 			return null;
 		}

 		// Calculate ID.
 		String id = label.replace(' ', '_');
 		id = id.trim();

 		// Create descriptor.
 		PerspectiveDescriptor desc = new PerspectiveDescriptor(id, label,
 				originalDescriptor);
 		add(desc);
 		return desc;
 	}

 	/**
 	 * Reverts a list of perspectives back to the plugin definition
 	 *
 	 * @param perspToRevert
 	 */
 	public void revertPerspectives(ArrayList perspToRevert) {
 		// indicate that the user is removing these perspectives
 		for (int i = 0; i < perspToRevert.size(); i++) {
 			PerspectiveDescriptor desc = (PerspectiveDescriptor) perspToRevert
 					.get(i);
 			perspToRemove.add(desc.getId());
 			desc.revertToPredefined();
 		}
 	}

 	/**
 	 * Deletes a list of perspectives
 	 *
 	 * @param perspToDelete
 	 */
 	public void deletePerspectives(ArrayList perspToDelete) {
 		for (int i = 0; i < perspToDelete.size(); i++) {
 			deletePerspective((IPerspectiveDescriptor) perspToDelete.get(i));
 		}
 	}

 	/**
 	 * Delete a perspective. Has no effect if the perspective is defined in an
 	 * extension.
 	 *
 	 * @param in
 	 */
 	public void deletePerspective(IPerspectiveDescriptor in) {
 		PerspectiveDescriptor desc = (PerspectiveDescriptor) in;
 		// Don't delete predefined perspectives
 		if (!desc.isPredefined()) {
 			perspToRemove.add(desc.getId());
 			perspectives.remove(desc);
 			desc.deleteCustomDefinition();
 			verifyDefaultPerspective();
 		}
 	}

 	/**
 	 * Delete a perspective. This will remove perspectives defined in
 	 * extensions.
 	 *
 	 * @param desc
 	 *            the perspective to delete
 	 * @since 3.1
 	 */
 	private void internalDeletePerspective(PerspectiveDescriptor desc) {
 		perspToRemove.add(desc.getId());
 		perspectives.remove(desc);
 		desc.deleteCustomDefinition();
 		verifyDefaultPerspective();
 	}

 	/**
 	 * Removes the custom definition of a perspective from the preference store
 	 *
 	 * @param desc
 	 */
 	/* package */
 	void deleteCustomDefinition(PerspectiveDescriptor desc) {
 		// remove the entry from the preference store.
 		IPreferenceStore store = WorkbenchPlugin.getDefault()
 				.getPreferenceStore();

 		/*
 		 * To delete the perspective definition from the preference store, use
 		 * the setToDefault method. Since no default is defined, this will
 		 * remove the entry
 		 */
 		store.setToDefault(desc.getId() + PERSP);

 	}

 	/**
 	 * Method hasCustomDefinition.
 	 *
 	 * @param desc
 	 */
 	/* package */
 	boolean hasCustomDefinition(PerspectiveDescriptor desc) {
 		IPreferenceStore store = WorkbenchPlugin.getDefault()
 				.getPreferenceStore();
 		return store.contains(desc.getId() + PERSP);
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.ui.IPerspectiveRegistry#findPerspectiveWithId(java.lang.String)
 	 */
 	public IPerspectiveDescriptor findPerspectiveWithId(String id) {
 		for (Iterator i = perspectives.iterator(); i.hasNext();) {
 		    PerspectiveDescriptor desc = (PerspectiveDescriptor) i.next();
 			if (desc.getId().equals(id)) {
 			    if (WorkbenchActivityHelper.restrictUseOf(desc)) {
 			        return null;
 			    }
 				return desc;
 			}
 		}

 		return null;
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.ui.IPerspectiveRegistry#findPerspectiveWithLabel(java.lang.String)
 	 */
 	public IPerspectiveDescriptor findPerspectiveWithLabel(String label) {
 		for (Iterator i = perspectives.iterator(); i.hasNext();) {
 			PerspectiveDescriptor desc = (PerspectiveDescriptor) i.next();
 			if (desc.getLabel().equals(label)) {
 			    if (WorkbenchActivityHelper.restrictUseOf(desc)) {
 			        return null;
 			    }
 				return desc;
 			}
 		}
 		return null;
 	}

 	/**
 	 * @see IPerspectiveRegistry#getDefaultPerspective()
 	 */
 	public String getDefaultPerspective() {
 		return defaultPerspID;
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.ui.IPerspectiveRegistry#getPerspectives()
 	 */
 	public IPerspectiveDescriptor[] getPerspectives() {
 		Collection descs = WorkbenchActivityHelper.restrictCollection(perspectives, new ArrayList());
 		return (IPerspectiveDescriptor[]) descs.toArray(new IPerspectiveDescriptor[descs.size()]);
 	}

 	/**
 	 * Loads the registry.
 	 */
 	public void load() {
 		// Load the registries.
 		loadPredefined();
 		loadCustom();

 		// Get default perspective.
 		// Get it from the R1.0 dialog settings first. Fixes bug 17039
 		IDialogSettings dialogSettings = WorkbenchPlugin.getDefault()
 				.getDialogSettings();
 		String str = dialogSettings.get(ID_DEF_PERSP);
 		if (str != null && str.length() > 0) {
 			setDefaultPerspective(str);
 			dialogSettings.put(ID_DEF_PERSP, ""); //$NON-NLS-1$
 		}
 		verifyDefaultPerspective();
 	}

 	/**
 	 * Read children from the file system.
 	 */
 	private void loadCustom() {
 		Reader reader = null;

 		/* Get the entries from the Preference store */
 		IPreferenceStore store = WorkbenchPlugin.getDefault()
 				.getPreferenceStore();

 		/* Get the space-delimited list of custom perspective ids */
 		String customPerspectives = store
 				.getString(IPreferenceConstants.PERSPECTIVES);
 		String[] perspectivesList = StringConverter.asArray(customPerspectives);

 		for (int i = 0; i < perspectivesList.length; i++) {
 			try {
 				String xmlString = store.getString(perspectivesList[i] + PERSP);
 				if (xmlString != null && xmlString.length() != 0) {
 					reader = new StringReader(xmlString);
 				}

 				// Restore the layout state.
 				XMLMemento memento = XMLMemento.createReadRoot(reader);
 				PerspectiveDescriptor newPersp = new PerspectiveDescriptor(
 						null, null, null);
 				newPersp.restoreState(memento);
 				String id = newPersp.getId();
 				IPerspectiveDescriptor oldPersp = findPerspectiveWithId(id);
 				if (oldPersp == null) {
 					add(newPersp);
 				}
 				reader.close();
 			} catch (IOException e) {
 				unableToLoadPerspective(null);
 			} catch (WorkbenchException e) {
 				unableToLoadPerspective(e.getStatus());
 			}
 		}

 		// Get the entries from files, if any
 		// if -data @noDefault specified the state location may not be
 		// initialized
 		IPath path = WorkbenchPlugin.getDefault().getDataLocation();
 		if (path == null) {
 			return;
 		}

 		File folder = path.toFile();

 		if (folder.isDirectory()) {
 			File[] fileList = folder.listFiles();
 			int nSize = fileList.length;
 			for (int nX = 0; nX < nSize; nX++) {
 				File file = fileList[nX];
 				if (file.getName().endsWith(EXT)) {
 					// get the memento
 					InputStream stream = null;
 					try {
 						stream = new FileInputStream(file);
 						reader = new BufferedReader(new InputStreamReader(
 								stream, "utf-8")); //$NON-NLS-1$

 						// Restore the layout state.
 						XMLMemento memento = XMLMemento.createReadRoot(reader);
 						PerspectiveDescriptor newPersp = new PerspectiveDescriptor(
 								null, null, null);
 						newPersp.restoreState(memento);
 						IPerspectiveDescriptor oldPersp = findPerspectiveWithId(newPersp
 								.getId());
 						if (oldPersp == null) {
 							add(newPersp);
 						}

 						// save to the preference store
 						saveCustomPersp(newPersp, memento);

 						// delete the file
 						file.delete();

 						reader.close();
 						stream.close();
 					} catch (IOException e) {
 						unableToLoadPerspective(null);
 					} catch (WorkbenchException e) {
 						unableToLoadPerspective(e.getStatus());
 					}
 				}
 			}
 		}
 	}

 	/**
 	 * @param status
 	 */
 	private void unableToLoadPerspective(IStatus status) {
 		String msg = WorkbenchMessages.Perspective_errorLoadingState;
 		if (status == null) {
 			IStatus errStatus = new Status(IStatus.ERROR, WorkbenchPlugin.PI_WORKBENCH, msg);
 	    	StatusManager.getManager().handle(errStatus, StatusManager.SHOW);
 		} else {
 			IStatus errStatus = StatusUtil.newStatus(status, msg);
 	    	StatusManager.getManager().handle(errStatus, StatusManager.SHOW);
 		}
 	}

 	/**
 	 * Saves a custom perspective definition to the preference store.
 	 *
 	 * @param desc
 	 *            the perspective
 	 * @param memento
 	 *            the memento to save to
 	 * @throws IOException
 	 */
 	public void saveCustomPersp(PerspectiveDescriptor desc, XMLMemento memento)
 			throws IOException {

 		IPreferenceStore store = WorkbenchPlugin.getDefault()
 				.getPreferenceStore();

 		// Save it to the preference store.
 		Writer writer = new StringWriter();

 		memento.save(writer);
 		writer.close();
 		store.setValue(desc.getId() + PERSP, writer.toString());

 	}

 	/**
 	 * Gets the Custom perspective definition from the preference store.
 	 *
 	 * @param id
 	 *            the id of the perspective to find
 	 * @return IMemento a memento containing the perspective description
 	 *
 	 * @throws WorkbenchException
 	 * @throws IOException
 	 */
 	public IMemento getCustomPersp(String id) throws WorkbenchException,
 			IOException {
 		Reader reader = null;

 		IPreferenceStore store = WorkbenchPlugin.getDefault()
 				.getPreferenceStore();
 		String xmlString = store.getString(id + PERSP);
 		if (xmlString != null && xmlString.length() != 0) { // defined in store
 			reader = new StringReader(xmlString);
 		}
 		XMLMemento memento = XMLMemento.createReadRoot(reader);
 		reader.close();
 		return memento;
 	}

 	/**
 	 * Read children from the plugin registry.
 	 */
 	private void loadPredefined() {
 		PerspectiveRegistryReader reader = new PerspectiveRegistryReader(this);
 		reader.readPerspectives(Platform.getExtensionRegistry());
 	}

 	/**
 	 * @see IPerspectiveRegistry#setDefaultPerspective(String)
 	 */
 	public void setDefaultPerspective(String id) {
 		IPerspectiveDescriptor desc = findPerspectiveWithId(id);
 		if (desc != null) {
 			defaultPerspID = id;
 			PrefUtil.getAPIPreferenceStore().setValue(
 					IWorkbenchPreferenceConstants.DEFAULT_PERSPECTIVE_ID, id);
 		}
 	}

 	/**
 	 * Return <code>true</code> if a label is valid. This checks only the
 	 * given label in isolation. It does not check whether the given label is
 	 * used by any existing perspectives.
 	 *
 	 * @param label
 	 *            the label to test
 	 * @return whether the label is valid
 	 */
 	public boolean validateLabel(String label) {
 		label = label.trim();
 		if (label.length() <= 0) {
 			return false;
 		}
 		return true;
 	}

 	/**
 	 * Verifies the id of the default perspective. If the default perspective is
 	 * invalid use the workbench default.
 	 */
 	private void verifyDefaultPerspective() {
 		// Step 1: Try current defPerspId value.
 		IPerspectiveDescriptor desc = null;
 		if (defaultPerspID != null) {
 			desc = findPerspectiveWithId(defaultPerspID);
 		}
 		if (desc != null) {
 			return;
 		}

 		// Step 2. Read default value.
 		String str = PrefUtil.getAPIPreferenceStore().getString(
 				IWorkbenchPreferenceConstants.DEFAULT_PERSPECTIVE_ID);
 		if (str != null && str.length() > 0) {
 			desc = findPerspectiveWithId(str);
 		}
 		if (desc != null) {
 			defaultPerspID = str;
 			return;
 		}

 		// Step 3. Use application-specific default
 		defaultPerspID = Workbench.getInstance().getDefaultPerspectiveId();
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.ui.IPerspectiveRegistry#clonePerspective(java.lang.String,
 	 *      java.lang.String, org.eclipse.ui.IPerspectiveDescriptor)
 	 */
 	public IPerspectiveDescriptor clonePerspective(String id, String label,
 			IPerspectiveDescriptor originalDescriptor) {

 		// Check for invalid labels
 		if (label == null || !(label.trim().length() > 0)) {
 			throw new IllegalArgumentException();
 		}

 		// Check for duplicates
 		IPerspectiveDescriptor desc = findPerspectiveWithId(id);
 		if (desc != null) {
 			throw new IllegalArgumentException();
 		}

 		// Create descriptor.
 		desc = new PerspectiveDescriptor(id, label,
 				(PerspectiveDescriptor) originalDescriptor);
 		add((PerspectiveDescriptor) desc);
 		return desc;
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.ui.IPerspectiveRegistry#revertPerspective(org.eclipse.ui.IPerspectiveDescriptor)
 	 */
 	public void revertPerspective(IPerspectiveDescriptor perspToRevert) {
 		PerspectiveDescriptor desc = (PerspectiveDescriptor) perspToRevert;
 		perspToRemove.add(desc.getId());
 		desc.revertToPredefined();
 	}

 	/**
 	 * Dispose the receiver.
 	 */
 	public void dispose() {
 		PlatformUI.getWorkbench().getExtensionTracker().unregisterHandler(this);
 		WorkbenchPlugin.getDefault().getPreferenceStore()
 				.removePropertyChangeListener(preferenceListener);
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.core.runtime.dynamicHelpers.IExtensionChangeHandler#removeExtension(org.eclipse.core.runtime.IExtension,
 	 *      java.lang.Object[])
 	 */
 	public void removeExtension(IExtension source, Object[] objects) {
 		for (int i = 0; i < objects.length; i++) {
 			if (objects[i] instanceof PerspectiveDescriptor) {
 				// close the perspective in all windows
 				IWorkbenchWindow[] windows = PlatformUI.getWorkbench()
 						.getWorkbenchWindows();
 				PerspectiveDescriptor desc = (PerspectiveDescriptor) objects[i];
 				for (int w = 0; w < windows.length; ++w) {
 					IWorkbenchWindow window = windows[w];
 					IWorkbenchPage[] pages = window.getPages();
 					for (int p = 0; p < pages.length; ++p) {
 						WorkbenchPage page = (WorkbenchPage) pages[p];
 						ClosePerspectiveHandler.closePerspective(page, page
 								.findPerspective(desc));
 					}
 				}

 				// ((Workbench)PlatformUI.getWorkbench()).getPerspectiveHistory().removeItem(desc);

 				internalDeletePerspective(desc);
 			}

 		}
 	}

 	/*
 	 * (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 addedExtension) {
 		IConfigurationElement[] addedElements = addedExtension
 				.getConfigurationElements();
 		for (int i = 0; i < addedElements.length; i++) {
 			PerspectiveRegistryReader reader = new PerspectiveRegistryReader(
 					this);
 			reader.readElement(addedElements[i]);
 		}
 	}
 }
	/*******************************************************************************
	* 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.registry;

	import java.io.BufferedReader;
	import java.io.File;
	import java.io.FileInputStream;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.InputStreamReader;
	import java.io.Reader;
	import java.io.StringReader;
	import java.io.StringWriter;
	import java.io.Writer;
	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.Iterator;
	import java.util.List;

	import org.eclipse.core.runtime.IConfigurationElement;
	import org.eclipse.core.runtime.IExtension;
	import org.eclipse.core.runtime.IPath;
	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.Platform;
	import org.eclipse.core.runtime.Status;
	import org.eclipse.core.runtime.dynamichelpers.IExtensionChangeHandler;
	import org.eclipse.core.runtime.dynamichelpers.IExtensionTracker;
	import org.eclipse.jface.dialogs.IDialogSettings;
	import org.eclipse.jface.preference.IPreferenceStore;
	import org.eclipse.jface.resource.StringConverter;
	import org.eclipse.jface.util.IPropertyChangeListener;
	import org.eclipse.jface.util.PropertyChangeEvent;
	import org.eclipse.ui.IMemento;
	import org.eclipse.ui.IPerspectiveDescriptor;
	import org.eclipse.ui.IPerspectiveRegistry;
	import org.eclipse.ui.IWorkbenchPage;
	import org.eclipse.ui.IWorkbenchPreferenceConstants;
	import org.eclipse.ui.IWorkbenchWindow;
	import org.eclipse.ui.PlatformUI;
	import org.eclipse.ui.WorkbenchException;
	import org.eclipse.ui.XMLMemento;
	import org.eclipse.ui.activities.WorkbenchActivityHelper;
	import org.eclipse.ui.internal.IPreferenceConstants;
	import org.eclipse.ui.internal.Workbench;
	import org.eclipse.ui.internal.WorkbenchMessages;
	import org.eclipse.ui.internal.WorkbenchPage;
	import org.eclipse.ui.internal.WorkbenchPlugin;
	import org.eclipse.ui.internal.handlers.ClosePerspectiveHandler;
	import org.eclipse.ui.internal.misc.StatusUtil;
	import org.eclipse.ui.internal.util.PrefUtil;
	import org.eclipse.ui.statushandlers.StatusManager;

	/**
	* Perspective registry.
	*/
	public class PerspectiveRegistry implements IPerspectiveRegistry,
	IExtensionChangeHandler {
	private String defaultPerspID;

	private static final String EXT = "_persp.xml"; //$NON-NLS-1$

	private static final String ID_DEF_PERSP = "PerspectiveRegistry.DEFAULT_PERSP"; //$NON-NLS-1$

	private static final String PERSP = "_persp"; //$NON-NLS-1$

	private static final char SPACE_DELIMITER = ' ';

	private List perspectives = new ArrayList(10);

	// keep track of the perspectives the user has selected to remove or revert
	private ArrayList perspToRemove = new ArrayList(5);

	private IPropertyChangeListener preferenceListener;

	/**
	* Construct a new registry.
	*/
	public PerspectiveRegistry() {
	IExtensionTracker tracker = PlatformUI.getWorkbench()
	.getExtensionTracker();
	tracker.registerHandler(this, null);

	initializePreferenceChangeListener();
	WorkbenchPlugin.getDefault().getPreferenceStore()
	.addPropertyChangeListener(preferenceListener);

	}

	/**
	* Initialize the preference change listener.
	*/
	private void initializePreferenceChangeListener() {
	preferenceListener = new IPropertyChangeListener() {
	public void propertyChange(PropertyChangeEvent event) {
	/*
	* To ensure the that no custom perspective definitions are
	* deleted when preferences are imported, merge old and new
	* values
	*/
	if (event.getProperty().endsWith(PERSP)) {
	/* A Perspective is being changed, merge */
	mergePerspectives(event);
	} else if (event.getProperty().equals(
	IPreferenceConstants.PERSPECTIVES)) {
	/* The list of perpsectives is being changed, merge */
	updatePreferenceList((IPreferenceStore) event.getSource());
	}
	}

	private void mergePerspectives(PropertyChangeEvent event) {
	IPreferenceStore store = (IPreferenceStore) event.getSource();
	if (event.getNewValue() == null
	\|\| event.getNewValue().equals("")) { //$NON-NLS-1$
	/*
	* Perpsective is being removed; if the user has deleted or
	* reverted a custom perspective, let the change pass
	* through. Otherwise, restore the custom perspective entry
	*/

	// Find the matching descriptor in the registry
	IPerspectiveDescriptor[] perspectiveList = getPerspectives();
	for (int i = 0; i < perspectiveList.length; i++) {
	String id = perspectiveList[i].getId();
	if (event.getProperty().equals(id + PERSP)) { // found
	// descriptor
	// see if the perspective has been flagged for
	// reverting or deleting
	if (!perspToRemove.contains(id)) { // restore
	store.setValue(id + PERSP, (String) event
	.getOldValue());
	} else { // remove element from the list
	perspToRemove.remove(id);
	}
	}
	}
	} else if ((event.getOldValue() == null \|\| event.getOldValue()
	.equals(""))) { //$NON-NLS-1$

	/*
	* New perspective is being added, update the
	* perspectiveRegistry to contain the new custom perspective
	*/

	String id = event.getProperty().substring(0,
	event.getProperty().lastIndexOf(PERSP));
	if (findPerspectiveWithId(id) == null) {
	// perspective does not already exist in registry, add
	// it
	PerspectiveDescriptor desc = new PerspectiveDescriptor(
	null, null, null);
	StringReader reader = new StringReader((String) event
	.getNewValue());
	try {
	XMLMemento memento = XMLMemento
	.createReadRoot(reader);
	desc.restoreState(memento);
	addPerspective(desc);
	} catch (WorkbenchException e) {
	unableToLoadPerspective(e.getStatus());
	}
	}
	}
	/* If necessary, add to the list of perspectives */
	updatePreferenceList(store);
	}

	/*
	* Update the list of perspectives from the registry. This will be
	* called for each perspective during an import preferences, but is
	* necessary to ensure the perspectives list stays consistent with
	* the registry
	*/
	private void updatePreferenceList(IPreferenceStore store) {
	IPerspectiveDescriptor[] perspectiveList = getPerspectives();
	StringBuffer perspBuffer = new StringBuffer();
	for (int i = 0; i < perspectiveList.length; i++) {
	PerspectiveDescriptor desc = (PerspectiveDescriptor) perspectiveList[i];
	if (hasCustomDefinition(desc)) {
	perspBuffer.append(desc.getId())
	.append(SPACE_DELIMITER);
	}
	}
	String newList = perspBuffer.toString().trim();
	store.setValue(IPreferenceConstants.PERSPECTIVES, newList);
	}
	};
	}

	/**
	* Adds a perspective. This is typically used by the reader.
	*
	* @param desc
	*/
	public void addPerspective(PerspectiveDescriptor desc) {
	if (desc == null) {
	return;
	}
	add(desc);
	}

	/**
	* @param desc
	*/
	private void add(PerspectiveDescriptor desc) {
	perspectives.add(desc);
	IConfigurationElement element = desc.getConfigElement();
	if (element != null) {
	PlatformUI.getWorkbench().getExtensionTracker().registerObject(
	element.getDeclaringExtension(), desc,
	IExtensionTracker.REF_WEAK);
	}
	}

	/**
	* Create a new perspective.
	*
	* @param label
	* the name of the new descriptor
	* @param originalDescriptor
	* the descriptor on which to base the new descriptor
	* @return a new perspective descriptor or <code>null</code> if the
	* creation failed.
	*/
	public PerspectiveDescriptor createPerspective(String label,
	PerspectiveDescriptor originalDescriptor) {
	// Sanity check to avoid invalid or duplicate labels.
	if (!validateLabel(label)) {
	return null;
	}
	if (findPerspectiveWithLabel(label) != null) {
	return null;
	}

	// Calculate ID.
	String id = label.replace(' ', '_');
	id = id.trim();

	// Create descriptor.
	PerspectiveDescriptor desc = new PerspectiveDescriptor(id, label,
	originalDescriptor);
	add(desc);
	return desc;
	}

	/**
	* Reverts a list of perspectives back to the plugin definition
	*
	* @param perspToRevert
	*/
	public void revertPerspectives(ArrayList perspToRevert) {
	// indicate that the user is removing these perspectives
	for (int i = 0; i < perspToRevert.size(); i++) {
	PerspectiveDescriptor desc = (PerspectiveDescriptor) perspToRevert
	.get(i);
	perspToRemove.add(desc.getId());
	desc.revertToPredefined();
	}
	}

	/**
	* Deletes a list of perspectives
	*
	* @param perspToDelete
	*/
	public void deletePerspectives(ArrayList perspToDelete) {
	for (int i = 0; i < perspToDelete.size(); i++) {
	deletePerspective((IPerspectiveDescriptor) perspToDelete.get(i));
	}
	}

	/**
	* Delete a perspective. Has no effect if the perspective is defined in an
	* extension.
	*
	* @param in
	*/
	public void deletePerspective(IPerspectiveDescriptor in) {
	PerspectiveDescriptor desc = (PerspectiveDescriptor) in;
	// Don't delete predefined perspectives
	if (!desc.isPredefined()) {
	perspToRemove.add(desc.getId());
	perspectives.remove(desc);
	desc.deleteCustomDefinition();
	verifyDefaultPerspective();
	}
	}

	/**
	* Delete a perspective. This will remove perspectives defined in
	* extensions.
	*
	* @param desc
	* the perspective to delete
	* @since 3.1
	*/
	private void internalDeletePerspective(PerspectiveDescriptor desc) {
	perspToRemove.add(desc.getId());
	perspectives.remove(desc);
	desc.deleteCustomDefinition();
	verifyDefaultPerspective();
	}

	/**
	* Removes the custom definition of a perspective from the preference store
	*
	* @param desc
	*/
	/* package */
	void deleteCustomDefinition(PerspectiveDescriptor desc) {
	// remove the entry from the preference store.
	IPreferenceStore store = WorkbenchPlugin.getDefault()
	.getPreferenceStore();

	/*
	* To delete the perspective definition from the preference store, use
	* the setToDefault method. Since no default is defined, this will
	* remove the entry
	*/
	store.setToDefault(desc.getId() + PERSP);

	}

	/**
	* Method hasCustomDefinition.
	*
	* @param desc
	*/
	/* package */
	boolean hasCustomDefinition(PerspectiveDescriptor desc) {
	IPreferenceStore store = WorkbenchPlugin.getDefault()
	.getPreferenceStore();
	return store.contains(desc.getId() + PERSP);
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.ui.IPerspectiveRegistry#findPerspectiveWithId(java.lang.String)
	*/
	public IPerspectiveDescriptor findPerspectiveWithId(String id) {
	for (Iterator i = perspectives.iterator(); i.hasNext();) {
	PerspectiveDescriptor desc = (PerspectiveDescriptor) i.next();
	if (desc.getId().equals(id)) {
	if (WorkbenchActivityHelper.restrictUseOf(desc)) {
	return null;
	}
	return desc;
	}
	}

	return null;
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.ui.IPerspectiveRegistry#findPerspectiveWithLabel(java.lang.String)
	*/
	public IPerspectiveDescriptor findPerspectiveWithLabel(String label) {
	for (Iterator i = perspectives.iterator(); i.hasNext();) {
	PerspectiveDescriptor desc = (PerspectiveDescriptor) i.next();
	if (desc.getLabel().equals(label)) {
	if (WorkbenchActivityHelper.restrictUseOf(desc)) {
	return null;
	}
	return desc;
	}
	}
	return null;
	}

	/**
	* @see IPerspectiveRegistry#getDefaultPerspective()
	*/
	public String getDefaultPerspective() {
	return defaultPerspID;
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.ui.IPerspectiveRegistry#getPerspectives()
	*/
	public IPerspectiveDescriptor[] getPerspectives() {
	Collection descs = WorkbenchActivityHelper.restrictCollection(perspectives, new ArrayList());
	return (IPerspectiveDescriptor[]) descs.toArray(new IPerspectiveDescriptor[descs.size()]);
	}

	/**
	* Loads the registry.
	*/
	public void load() {
	// Load the registries.
	loadPredefined();
	loadCustom();

	// Get default perspective.
	// Get it from the R1.0 dialog settings first. Fixes bug 17039
	IDialogSettings dialogSettings = WorkbenchPlugin.getDefault()
	.getDialogSettings();
	String str = dialogSettings.get(ID_DEF_PERSP);
	if (str != null && str.length() > 0) {
	setDefaultPerspective(str);
	dialogSettings.put(ID_DEF_PERSP, ""); //$NON-NLS-1$
	}
	verifyDefaultPerspective();
	}

	/**
	* Read children from the file system.
	*/
	private void loadCustom() {
	Reader reader = null;

	/* Get the entries from the Preference store */
	IPreferenceStore store = WorkbenchPlugin.getDefault()
	.getPreferenceStore();

	/* Get the space-delimited list of custom perspective ids */
	String customPerspectives = store
	.getString(IPreferenceConstants.PERSPECTIVES);
	String[] perspectivesList = StringConverter.asArray(customPerspectives);

	for (int i = 0; i < perspectivesList.length; i++) {
	try {
	String xmlString = store.getString(perspectivesList[i] + PERSP);
	if (xmlString != null && xmlString.length() != 0) {
	reader = new StringReader(xmlString);
	}

	// Restore the layout state.
	XMLMemento memento = XMLMemento.createReadRoot(reader);
	PerspectiveDescriptor newPersp = new PerspectiveDescriptor(
	null, null, null);
	newPersp.restoreState(memento);
	String id = newPersp.getId();
	IPerspectiveDescriptor oldPersp = findPerspectiveWithId(id);
	if (oldPersp == null) {
	add(newPersp);
	}
	reader.close();
	} catch (IOException e) {
	unableToLoadPerspective(null);
	} catch (WorkbenchException e) {
	unableToLoadPerspective(e.getStatus());
	}
	}

	// Get the entries from files, if any
	// if -data @noDefault specified the state location may not be
	// initialized
	IPath path = WorkbenchPlugin.getDefault().getDataLocation();
	if (path == null) {
	return;
	}

	File folder = path.toFile();

	if (folder.isDirectory()) {
	File[] fileList = folder.listFiles();
	int nSize = fileList.length;
	for (int nX = 0; nX < nSize; nX++) {
	File file = fileList[nX];
	if (file.getName().endsWith(EXT)) {
	// get the memento
	InputStream stream = null;
	try {
	stream = new FileInputStream(file);
	reader = new BufferedReader(new InputStreamReader(
	stream, "utf-8")); //$NON-NLS-1$

	// Restore the layout state.
	XMLMemento memento = XMLMemento.createReadRoot(reader);
	PerspectiveDescriptor newPersp = new PerspectiveDescriptor(
	null, null, null);
	newPersp.restoreState(memento);
	IPerspectiveDescriptor oldPersp = findPerspectiveWithId(newPersp
	.getId());
	if (oldPersp == null) {
	add(newPersp);
	}

	// save to the preference store
	saveCustomPersp(newPersp, memento);

	// delete the file
	file.delete();

	reader.close();
	stream.close();
	} catch (IOException e) {
	unableToLoadPerspective(null);
	} catch (WorkbenchException e) {
	unableToLoadPerspective(e.getStatus());
	}
	}
	}
	}
	}

	/**
	* @param status
	*/
	private void unableToLoadPerspective(IStatus status) {
	String msg = WorkbenchMessages.Perspective_errorLoadingState;
	if (status == null) {
	IStatus errStatus = new Status(IStatus.ERROR, WorkbenchPlugin.PI_WORKBENCH, msg);
	StatusManager.getManager().handle(errStatus, StatusManager.SHOW);
	} else {
	IStatus errStatus = StatusUtil.newStatus(status, msg);
	StatusManager.getManager().handle(errStatus, StatusManager.SHOW);
	}
	}

	/**
	* Saves a custom perspective definition to the preference store.
	*
	* @param desc
	* the perspective
	* @param memento
	* the memento to save to
	* @throws IOException
	*/
	public void saveCustomPersp(PerspectiveDescriptor desc, XMLMemento memento)
	throws IOException {

	IPreferenceStore store = WorkbenchPlugin.getDefault()
	.getPreferenceStore();

	// Save it to the preference store.
	Writer writer = new StringWriter();

	memento.save(writer);
	writer.close();
	store.setValue(desc.getId() + PERSP, writer.toString());

	}

	/**
	* Gets the Custom perspective definition from the preference store.
	*
	* @param id
	* the id of the perspective to find
	* @return IMemento a memento containing the perspective description
	*
	* @throws WorkbenchException
	* @throws IOException
	*/
	public IMemento getCustomPersp(String id) throws WorkbenchException,
	IOException {
	Reader reader = null;

	IPreferenceStore store = WorkbenchPlugin.getDefault()
	.getPreferenceStore();
	String xmlString = store.getString(id + PERSP);
	if (xmlString != null && xmlString.length() != 0) { // defined in store
	reader = new StringReader(xmlString);
	}
	XMLMemento memento = XMLMemento.createReadRoot(reader);
	reader.close();
	return memento;
	}

	/**
	* Read children from the plugin registry.
	*/
	private void loadPredefined() {
	PerspectiveRegistryReader reader = new PerspectiveRegistryReader(this);
	reader.readPerspectives(Platform.getExtensionRegistry());
	}

	/**
	* @see IPerspectiveRegistry#setDefaultPerspective(String)
	*/
	public void setDefaultPerspective(String id) {
	IPerspectiveDescriptor desc = findPerspectiveWithId(id);
	if (desc != null) {
	defaultPerspID = id;
	PrefUtil.getAPIPreferenceStore().setValue(
	IWorkbenchPreferenceConstants.DEFAULT_PERSPECTIVE_ID, id);
	}
	}

	/**
	* Return <code>true</code> if a label is valid. This checks only the
	* given label in isolation. It does not check whether the given label is
	* used by any existing perspectives.
	*
	* @param label
	* the label to test
	* @return whether the label is valid
	*/
	public boolean validateLabel(String label) {
	label = label.trim();
	if (label.length() <= 0) {
	return false;
	}
	return true;
	}

	/**
	* Verifies the id of the default perspective. If the default perspective is
	* invalid use the workbench default.
	*/
	private void verifyDefaultPerspective() {
	// Step 1: Try current defPerspId value.
	IPerspectiveDescriptor desc = null;
	if (defaultPerspID != null) {
	desc = findPerspectiveWithId(defaultPerspID);
	}
	if (desc != null) {
	return;
	}

	// Step 2. Read default value.
	String str = PrefUtil.getAPIPreferenceStore().getString(
	IWorkbenchPreferenceConstants.DEFAULT_PERSPECTIVE_ID);
	if (str != null && str.length() > 0) {
	desc = findPerspectiveWithId(str);
	}
	if (desc != null) {
	defaultPerspID = str;
	return;
	}

	// Step 3. Use application-specific default
	defaultPerspID = Workbench.getInstance().getDefaultPerspectiveId();
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.ui.IPerspectiveRegistry#clonePerspective(java.lang.String,
	* java.lang.String, org.eclipse.ui.IPerspectiveDescriptor)
	*/
	public IPerspectiveDescriptor clonePerspective(String id, String label,
	IPerspectiveDescriptor originalDescriptor) {

	// Check for invalid labels
	if (label == null \|\| !(label.trim().length() > 0)) {
	throw new IllegalArgumentException();
	}

	// Check for duplicates
	IPerspectiveDescriptor desc = findPerspectiveWithId(id);
	if (desc != null) {
	throw new IllegalArgumentException();
	}

	// Create descriptor.
	desc = new PerspectiveDescriptor(id, label,
	(PerspectiveDescriptor) originalDescriptor);
	add((PerspectiveDescriptor) desc);
	return desc;
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.ui.IPerspectiveRegistry#revertPerspective(org.eclipse.ui.IPerspectiveDescriptor)
	*/
	public void revertPerspective(IPerspectiveDescriptor perspToRevert) {
	PerspectiveDescriptor desc = (PerspectiveDescriptor) perspToRevert;
	perspToRemove.add(desc.getId());
	desc.revertToPredefined();
	}

	/**
	* Dispose the receiver.
	*/
	public void dispose() {
	PlatformUI.getWorkbench().getExtensionTracker().unregisterHandler(this);
	WorkbenchPlugin.getDefault().getPreferenceStore()
	.removePropertyChangeListener(preferenceListener);
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.core.runtime.dynamicHelpers.IExtensionChangeHandler#removeExtension(org.eclipse.core.runtime.IExtension,
	* java.lang.Object[])
	*/
	public void removeExtension(IExtension source, Object[] objects) {
	for (int i = 0; i < objects.length; i++) {
	if (objects[i] instanceof PerspectiveDescriptor) {
	// close the perspective in all windows
	IWorkbenchWindow[] windows = PlatformUI.getWorkbench()
	.getWorkbenchWindows();
	PerspectiveDescriptor desc = (PerspectiveDescriptor) objects[i];
	for (int w = 0; w < windows.length; ++w) {
	IWorkbenchWindow window = windows[w];
	IWorkbenchPage[] pages = window.getPages();
	for (int p = 0; p < pages.length; ++p) {
	WorkbenchPage page = (WorkbenchPage) pages[p];
	ClosePerspectiveHandler.closePerspective(page, page
	.findPerspective(desc));
	}
	}

	// ((Workbench)PlatformUI.getWorkbench()).getPerspectiveHistory().removeItem(desc);

	internalDeletePerspective(desc);
	}

	}
	}

	/*
	* (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 addedExtension) {
	IConfigurationElement[] addedElements = addedExtension
	.getConfigurationElements();
	for (int i = 0; i < addedElements.length; i++) {
	PerspectiveRegistryReader reader = new PerspectiveRegistryReader(
	this);
	reader.readElement(addedElements[i]);
	}
	}
	}