/*******************************************************************************
 * Copyright (c) 2004, 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.dialogs;

import com.ibm.icu.text.MessageFormat;
import java.util.Iterator;

import org.eclipse.jface.preference.IPreferenceNode;
import org.eclipse.jface.preference.PreferenceManager;
import org.eclipse.osgi.util.NLS;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Link;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.internal.WorkbenchMessages;
import org.eclipse.ui.preferences.IWorkbenchPreferenceContainer;

/**
 * The PreferenceLinkArea is the link area used to open a specific preference
 * page.
 * 
 * @since 3.1
 */
public class PreferenceLinkArea extends Object {

    private Link pageLink;

    /**
     * Create a new instance of the receiver
     * 
     * @param parent
     *            the parent Composite
     * @param style
     *            the SWT style
     * @param pageId
     *            the page id
     * @param message
     *            the message to use as text. If this message has {0} in 
     *            its value it will be bound with the displayed name of 
     *            the preference page. This message must be well formed
     *            html if you wish to link to another page.
     * @param pageContainer -
     *            The container another page will be opened in.
     * @param pageData -
     *            The data to apply to the page.
     */
    public PreferenceLinkArea(Composite parent, int style, final String pageId,
            String message, final IWorkbenchPreferenceContainer pageContainer,
            final Object pageData) {
        pageLink = new Link(parent, style);

        IPreferenceNode node = getPreferenceNode(pageId);
        String result;
        if (node == null) {
			result = NLS.bind(
                    WorkbenchMessages.PreferenceNode_NotFound, pageId);
		} else {
            result = MessageFormat.format(message, new String[] { node
                    .getLabelText() });
            
            //Only add the selection listener if the node is found
            pageLink.addSelectionListener(new SelectionAdapter() {
                /*
                 * (non-Javadoc)
                 * 
                 * @see org.eclipse.swt.events.SelectionListener#widgetSelected(org.eclipse.swt.events.SelectionEvent)
                 */
                public void widgetSelected(SelectionEvent e) {
                    pageContainer.openPage(pageId, pageData);
                }
            });
        }
        pageLink.setText(result);

    }

    /**
     * Get the preference node with pageId.
     * 
     * @param pageId
     * @return IPreferenceNode
     */
    private IPreferenceNode getPreferenceNode(String pageId) {
        Iterator iterator = PlatformUI.getWorkbench().getPreferenceManager()
                .getElements(PreferenceManager.PRE_ORDER).iterator();
        while (iterator.hasNext()) {
            IPreferenceNode next = (IPreferenceNode) iterator.next();
            if (next.getId().equals(pageId)) {
				return next;
			}
        }
        return null;
    }

    /**
     * Return the control for the receiver.
     * 
     * @return Control
     */
    public Control getControl() {
        return pageLink;
    }
}