/*******************************************************************************
* Copyright (c) 2000, 2006 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.internal;
import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.ui.IEditorDescriptor;
import org.eclipse.ui.IEditorInput;
import org.eclipse.ui.IEditorRegistry;
import org.eclipse.ui.IElementFactory;
import org.eclipse.ui.IMemento;
import org.eclipse.ui.IPersistableElement;
import org.eclipse.ui.PlatformUI;
/**
* An item in the editor history.
*/
public class EditorHistoryItem {
private IEditorInput input;
private IEditorDescriptor descriptor;
private IMemento memento;
/**
* Constructs a new item.
*/
public EditorHistoryItem(IEditorInput input, IEditorDescriptor descriptor) {
this.input = input;
this.descriptor = descriptor;
}
/**
* Constructs a new item from a memento.
*/
public EditorHistoryItem(IMemento memento) {
this.memento = memento;
}
/**
* Returns the editor descriptor.
*
* @return the editor descriptor.
*/
public IEditorDescriptor getDescriptor() {
return descriptor;
}
/**
* Returns the editor input.
*
* @return the editor input.
*/
public IEditorInput getInput() {
return input;
}
/**
* Returns whether this item has been restored from the memento.
*/
public boolean isRestored() {
return memento == null;
}
/**
* Returns the name of this item, either from the input if restored,
* otherwise from the memento.
*/
public String getName() {
if (isRestored() && getInput() != null) {
return getInput().getName();
} else if (memento != null) {
String name = memento.getString(IWorkbenchConstants.TAG_NAME);
if (name != null) {
return name;
}
}
return ""; //$NON-NLS-1$
}
/**
* Returns the tooltip text of this item, either from the input if restored,
* otherwise from the memento.
*/
public String getToolTipText() {
if (isRestored() && getInput() != null) {
return getInput().getToolTipText();
} else if (memento != null) {
String name = memento.getString(IWorkbenchConstants.TAG_TOOLTIP);
if (name != null) {
return name;
}
}
return ""; //$NON-NLS-1$
}
/**
* Returns whether this item matches the given editor input.
*/
public boolean matches(IEditorInput input) {
if (isRestored()) {
return input.equals(getInput());
}
// if not restored, compare name, tool tip text and factory id,
// avoiding as much work as possible
if (!getName().equals(input.getName())) {
return false;
}
if (!getToolTipText().equals(input.getToolTipText())) {
return false;
}
IPersistableElement persistable = input.getPersistable();
String inputId = persistable == null ? null : persistable
.getFactoryId();
String myId = getFactoryId();
return myId == null ? inputId == null : myId.equals(inputId);
}
/**
* Returns the factory id of this item, either from the input if restored,
* otherwise from the memento.
* Returns <code>null</code> if there is no factory id.
*/
public String getFactoryId() {
if (isRestored()) {
if (input != null) {
IPersistableElement persistable = input.getPersistable();
if (persistable != null) {
return persistable.getFactoryId();
}
}
} else if (memento != null) {
return memento.getString(IWorkbenchConstants.TAG_FACTORY_ID);
}
return null;
}
/**
* Restores the object state from the memento.
*/
public IStatus restoreState() {
Assert.isTrue(!isRestored());
Status result = new Status(IStatus.OK, PlatformUI.PLUGIN_ID, 0,
"", null); //$NON-NLS-1$
IMemento memento = this.memento;
this.memento = null;
String factoryId = memento
.getString(IWorkbenchConstants.TAG_FACTORY_ID);
if (factoryId == null) {
WorkbenchPlugin
.log("Unable to restore mru list - no input factory ID.");//$NON-NLS-1$
return result;
}
IElementFactory factory = PlatformUI.getWorkbench().getElementFactory(
factoryId);
if (factory == null) {
return result;
}
IMemento persistableMemento = memento
.getChild(IWorkbenchConstants.TAG_PERSISTABLE);
if (persistableMemento == null) {
WorkbenchPlugin
.log("Unable to restore mru list - no input element state: " + factoryId);//$NON-NLS-1$
return result;
}
IAdaptable adaptable = factory.createElement(persistableMemento);
if (adaptable == null || (adaptable instanceof IEditorInput) == false) {
return result;
}
input = (IEditorInput) adaptable;
// Get the editor descriptor.
String editorId = memento.getString(IWorkbenchConstants.TAG_ID);
if (editorId != null) {
IEditorRegistry registry = WorkbenchPlugin.getDefault()
.getEditorRegistry();
descriptor = registry.findEditor(editorId);
}
return result;
}
/**
* Returns whether this history item can be saved.
*/
public boolean canSave() {
return !isRestored()
|| (getInput() != null && getInput().getPersistable() != null);
}
/**
* Saves the object state in the given memento.
*
* @param memento the memento to save the object state in
*/
public IStatus saveState(IMemento memento) {
if (!isRestored()) {
memento.putMemento(this.memento);
} else if (input != null) {
IPersistableElement persistable = input.getPersistable();
if (persistable != null) {
/*
* Store IPersistable of the IEditorInput in a separate section
* since it could potentially use a tag already used in the parent
* memento and thus overwrite data.
*/
IMemento persistableMemento = memento
.createChild(IWorkbenchConstants.TAG_PERSISTABLE);
persistable.saveState(persistableMemento);
memento.putString(IWorkbenchConstants.TAG_FACTORY_ID,
persistable.getFactoryId());
if (descriptor != null && descriptor.getId() != null) {
memento.putString(IWorkbenchConstants.TAG_ID, descriptor
.getId());
}
// save the name and tooltip separately so they can be restored
// without having to instantiate the input, which can activate plugins
memento
.putString(IWorkbenchConstants.TAG_NAME, input
.getName());
memento.putString(IWorkbenchConstants.TAG_TOOLTIP, input
.getToolTipText());
}
}
return new Status(IStatus.OK, PlatformUI.PLUGIN_ID, 0, "", null); //$NON-NLS-1$
}
}