com.aptana.ide.core.ui.actions.ActionDelegate.java Source code

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Here is the source code for com.aptana.ide.core.ui.actions.ActionDelegate.java

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/**
 * This file Copyright (c) 2005-2008 Aptana, Inc. This program is
 * dual-licensed under both the Aptana Public License and the GNU General
 * Public license. You may elect to use one or the other of these licenses.
 * 
 * This program is distributed in the hope that it will be useful, but
 * AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
 * NONINFRINGEMENT. Redistribution, except as permitted by whichever of
 * the GPL or APL you select, is prohibited.
 *
 * 1. For the GPL license (GPL), you can redistribute and/or modify this
 * program under the terms of the GNU General Public License,
 * Version 3, as published by the Free Software Foundation.  You should
 * have received a copy of the GNU General Public License, Version 3 along
 * with this program; if not, write to the Free Software Foundation, Inc., 51
 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 * 
 * Aptana provides a special exception to allow redistribution of this file
 * with certain other free and open source software ("FOSS") code and certain additional terms
 * pursuant to Section 7 of the GPL. You may view the exception and these
 * terms on the web at http://www.aptana.com/legal/gpl/.
 * 
 * 2. For the Aptana Public License (APL), this program and the
 * accompanying materials are made available under the terms of the APL
 * v1.0 which accompanies this distribution, and is available at
 * http://www.aptana.com/legal/apl/.
 * 
 * You may view the GPL, Aptana's exception and additional terms, and the
 * APL in the file titled license.html at the root of the corresponding
 * plugin containing this source file.
 * 
 * Any modifications to this file must keep this entire header intact.
 */
package com.aptana.ide.core.ui.actions;

import org.eclipse.jface.action.IAction;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.ui.IActionDelegate;

/**
 * A basic action delegate with some nice convenience methods
 * 
 * @author Ingo Muschenetz
 */
public abstract class ActionDelegate implements IActionDelegate {
    /**
     * @see org.eclipse.ui.IActionDelegate#run(org.eclipse.jface.action.IAction)
     */
    public abstract void run(IAction action);

    /**
     * @see org.eclipse.ui.IActionDelegate#selectionChanged(org.eclipse.jface.action.IAction,
     *      org.eclipse.jface.viewers.ISelection)
     */
    public abstract void selectionChanged(IAction action, ISelection selection);

    /**
     * Returns a valid selection
     * 
     * @param selection
     * @return Object
     */
    protected Object getValidSingleSelection(ISelection selection) {
        if (selection instanceof IStructuredSelection == false) {
            return null;
        }

        IStructuredSelection structuredSelection = ((IStructuredSelection) selection);

        if (structuredSelection.size() > 1) {
            return null;
        }

        return structuredSelection.getFirstElement();
    }

    /**
     * Returns a valid array of selections
     * 
     * @param selection
     * @return Object[]
     */
    protected Object[] getValidSelection(ISelection selection) {
        if (selection instanceof IStructuredSelection == false) {
            return null;
        }

        IStructuredSelection structuredSelection = ((IStructuredSelection) selection);

        if (structuredSelection.size() == 0) {
            return new Object[0];
        } else {
            return structuredSelection.toArray();
        }
    }
}