passwordentryaction.java

基于Eclipse RCP开发的管理工具

/*  
 * Copyright 2006 Marcel Schoffelmeer 
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); 
 * you may not use this file except in compliance with the License. 
 * You may obtain a copy of the License at 
 * 
 *    http://www.apache.org/licenses/LICENSE-2.0 
 *    
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, 
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.s10r.manager.actions;

import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.ui.ISelectionListener;
import org.eclipse.ui.IWorkbenchPart;
import org.eclipse.ui.IWorkbenchWindow;

import com.s10r.manager.model.PasswordEntry;

/**
 * Helper class for password entry specific actions. This class registers itself
 * as a selection listener to keep track of the selected password entry and to
 * enable/disable the action (only single selections of password entries are
 * allowed).
 * 
 * @author mms
 * 
 */
public abstract class PasswordEntryAction extends ManagerAction implements
        ISelectionListener
{
    private PasswordEntry selectedPasswordEntry;

    public PasswordEntryAction()
    {
        super();
    }

    public PasswordEntryAction(IWorkbenchWindow window)
    {
        super(window);
        window.getSelectionService().addSelectionListener(this);
    }

    /**
     * If 1 password entry is selected, this method calls passwordEntrySelected,
     * passing in the selected entry. In all other cases noPasswordEntrySelected
     * is called.
     * 
     * @param part
     * @param selection
     */
    public void selectionChanged(IWorkbenchPart part, ISelection selection)
    {
        this.selection = selection;

        boolean entrySelected = false;

        if (selection instanceof IStructuredSelection)
        {
            if (((IStructuredSelection) selection).size() == 1)
            {
                Object element = ((IStructuredSelection) selection)
                        .getFirstElement();
                if (element instanceof PasswordEntry)
                {
                    passwordEntrySelected((PasswordEntry) element);
                    entrySelected = true;
                }

            }
        }
        if (!entrySelected)
        {
            noPasswordEntrySelected();
        }
    }

    /**
     * Disables the action.
     */
    private void noPasswordEntrySelected()
    {
        this.setEnabled(false);
        selectedPasswordEntry = null;

    }

    /**
     * Enables the action, sets the selectedPasswordEntry for use by subclasses.
     */
    private void passwordEntrySelected(PasswordEntry entry)
    {
        this.setEnabled(true);
        selectedPasswordEntry = entry;
    }

    protected PasswordEntry getSelectedPasswordEntry()
    {
        return selectedPasswordEntry;
    }

    /**
     * Removes itself as a selection listener from the selection service.
     */
    public void dispose()
    {
        window.getSelectionService().removeSelectionListener(this);
    }

}