bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/WWinPluginAction.java

/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.ui.internal;


import java.util.ArrayList;
import java.util.Iterator;

import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.jface.action.Action;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.swt.events.HelpEvent;
import org.eclipse.swt.events.HelpListener;
import org.eclipse.swt.widgets.Event;
import org.eclipse.ui.IActionDelegate;
import org.eclipse.ui.IWorkbenchPart;
import org.eclipse.ui.IWorkbenchWindow;
import org.eclipse.ui.IWorkbenchWindowActionDelegate;
import org.eclipse.ui.WorkbenchException;
import org.eclipse.ui.actions.LabelRetargetAction;
import org.eclipse.ui.actions.RetargetAction;

/**
 * This class extends regular plugin action with the
 * additional requirement that the delegate has
 * to implement interface IWorkbenchWindowActionDeelgate.
 * This interface has one additional method (init)
 * whose purpose is to initialize the delegate with
 * the window in which the action is intended to run.
 */
public class WWinPluginAction extends PluginAction implements IActionSetContributionItem {
	/**
	 * The help listener assigned to this action, or <code>null</code> if none.
	 */
	private HelpListener localHelpListener;

	private IWorkbenchWindow window;
	private String actionSetId;
	private RetargetAction retargetAction;
	private static String TRUE_VALUE = "true"; //$NON-NLS-1$

	private static ArrayList staticActionList = new ArrayList(50);

	/**
	 * Constructs a new WWinPluginAction object..
	 */
	public WWinPluginAction(IConfigurationElement actionElement, String runAttribute, IWorkbenchWindow window, String definitionId, int style) {
		super(actionElement, runAttribute, definitionId, style);
		this.window = window;

		// If config specifies a retarget action, create it now
		String retarget = actionElement.getAttribute(ActionDescriptor.ATT_RETARGET);
		if (retarget != null && retarget.equals(TRUE_VALUE)) {
			// create a retarget action
			String allowLabelUpdate = actionElement.getAttribute(ActionDescriptor.ATT_ALLOW_LABEL_UPDATE);
			String id = actionElement.getAttribute(ActionDescriptor.ATT_ID);
			String label = actionElement.getAttribute(ActionDescriptor.ATT_LABEL);

			if (allowLabelUpdate != null && allowLabelUpdate.equals(TRUE_VALUE))
				retargetAction = new LabelRetargetAction(id, label);
			else
				retargetAction = new RetargetAction(id, label);
			retargetAction.addPropertyChangeListener(new IPropertyChangeListener() {
				public void propertyChange(PropertyChangeEvent event) {
					if (event.getProperty().equals(Action.ENABLED)) {
						Object val = event.getNewValue();
						if (val instanceof Boolean) {
							setEnabled(((Boolean) val).booleanValue());
						}
					} else if (event.getProperty().equals(Action.CHECKED)) {
						Object val = event.getNewValue();
						if (val instanceof Boolean) {
							setChecked(((Boolean) val).booleanValue());
						}
					} else if (event.getProperty().equals(Action.TEXT)) {
						Object val = event.getNewValue();
						if (val instanceof String) {
							setText((String) val);
						}
					} else if (event.getProperty().equals(Action.TOOL_TIP_TEXT)) {
						Object val = event.getNewValue();
						if (val instanceof String) {
							setToolTipText((String) val);
						}
					}
				}
			});
			retargetAction.setEnabled(false);
			setEnabled(false);
			window.getPartService().addPartListener(retargetAction);
			IWorkbenchPart activePart = window.getPartService().getActivePart();
			if (activePart != null)
				retargetAction.partActivated(activePart);
		} else {
			// if we retarget the handler will look after selection changes
			window.getSelectionService().addSelectionListener(this);
			refreshSelection();
		}
		addToActionList(this);

		super.setHelpListener(new HelpListener() {
			public void helpRequested(HelpEvent e) {
				HelpListener listener = null;
				if (retargetAction != null)
					listener = retargetAction.getHelpListener();
				if (listener == null)
					// use our own help listener
					listener = localHelpListener;
				if (listener != null)
					// pass on the event
					listener.helpRequested(e);
			}
		});
	}

	/**
	 * Adds an item to the action list.
	 */
	private static void addToActionList(WWinPluginAction action) {
		staticActionList.add(action);
	}

	/**
	 * Removes an item from the action list.
	 */
	private static void removeFromActionList(WWinPluginAction action) {
		staticActionList.remove(action);
	}

	/**
	 * Creates any actions which belong to an activated plugin.
	 */
	public static void refreshActionList() {
		Iterator iter = staticActionList.iterator();
		while (iter.hasNext()) {
			WWinPluginAction action = (WWinPluginAction) iter.next();
			if ((action.getDelegate() == null) && action.isOkToCreateDelegate()) {
				action.createDelegate();
				// creating the delegate also refreshes its enablement
			}
		}
	}

	/* (non-Javadoc)
	 * Method declared on PluginAction.
	 */
	protected IActionDelegate validateDelegate(Object obj) throws WorkbenchException {
		if (obj instanceof IWorkbenchWindowActionDelegate)
			return (IWorkbenchWindowActionDelegate)obj;
		else
			throw new WorkbenchException("Action must implement IWorkbenchWindowActionDelegate"); //$NON-NLS-1$
	}

	/* (non-Javadoc)
	 * Method declared on PluginAction.
	 */
	protected void initDelegate() {
		super.initDelegate();
		((IWorkbenchWindowActionDelegate)getDelegate()).init(window);
	}

	/**
	 * Disposes of the action and any resources held.
	 */
	public void dispose() {
		removeFromActionList(this);
		if (retargetAction != null) {
			window.getPartService().removePartListener(retargetAction);
			retargetAction.dispose();
			retargetAction = null;
		}
		window.getSelectionService().removeSelectionListener(this);
		if (getDelegate() != null)
			((IWorkbenchWindowActionDelegate)getDelegate()).dispose();
	}
	/**
	 * Returns the action set id.
	 */
	public String getActionSetId() {
		return actionSetId;
	}
	/**
	 * Returns true if the window has been set.  
	 * The window may be null after the constructor is called and
	 * before the window is stored.  We cannot create the delegate
	 * at that time.
	 */
	public boolean isOkToCreateDelegate() {
		return super.isOkToCreateDelegate() && window != null && retargetAction == null;
	}

	/* (non-Javadoc)
	 * Method declared on IActionDelegate2.
	 */
	public void runWithEvent(Event event) {
		if (retargetAction == null) {
			super.runWithEvent(event);
			return;
		}

		if (event != null)
			retargetAction.runWithEvent(event);
		else
			retargetAction.run();
	}

	/**
	 * Sets the action set id.
	 */
	public void setActionSetId(String newActionSetId) {
		actionSetId = newActionSetId;
	}

	/** 
	 * The <code>WWinPluginAction</code> implementation of this method
	 * declared on <code>IAction</code> stores the help listener in
	 * a local field. The supplied listener is only used if there is
	 * no retarget action.
	 */
	public void setHelpListener(HelpListener listener) {
		localHelpListener = listener;
	}

	/* (non-Javadoc)
	 * Method declared on IAction.
	 */
	public void setChecked(boolean checked) {
		super.setChecked(checked);
		// This call may come from the SWT control event handler
		// itself, so notify the retarget action to keep things
		// in sync.
		if (retargetAction != null)
			retargetAction.setChecked(checked);
	}

	/**
	 * Refresh the selection for the action.
	 */
	protected void refreshSelection() {
		ISelection selection = window.getSelectionService().getSelection();
		selectionChanged(selection);
	}
}