/*******************************************************************************
 * 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.jface.wizard;

import java.util.ArrayList;
import java.util.List;

/**
 * An abstract implementation of a wizard page that manages a
 * set of embedded wizards.
 * <p>
 * A wizard selection page should present a list of wizard nodes 
 * corresponding to other wizards. When the end user selects one of
 * them from the list, the first page of the selected wizard becomes
 * the next page. The only new methods introduced by this class are 
 * <code>getSelectedNode</code> and <code>setSelectedNode</code>. 
 * Otherwise, the subclass contract is the same as <code>WizardPage</code>.
 * </p>
 */
public abstract class WizardSelectionPage extends WizardPage {

	/**
	 * The selected node; <code>null</code> if none.
	 */
	private IWizardNode selectedNode = null;
	
	/**
	 * List of wizard nodes that have cropped up in the past
	 * (element type: <code>IWizardNode</code>).
	 */
	private List selectedWizardNodes = new ArrayList();
/**
 * Creates a new wizard selection page with the given name, and
 * with no title or image.
 *
 * @param pageName the name of the page
 */
protected WizardSelectionPage(String pageName) {
	super(pageName);
	// Cannot finish from this page
	setPageComplete(false);
}
/**
 * Adds the given wizard node to the list of selected nodes if
 * it is not already in the list.
 *
 * @param node the wizard node, or <code>null</code>
 */
private void addSelectedNode(IWizardNode node) {
	if (node == null)
		return;

	if (selectedWizardNodes.contains(node))
		return;
	
	selectedWizardNodes.add(node);
}
/**
 * The <code>WizardSelectionPage</code> implementation of 
 * this <code>IWizardPage</code> method returns <code>true</code>
 * if there is a selected node.
 */
public boolean canFlipToNextPage() {
	return selectedNode != null;
}
/**	
 * The <code>WizardSelectionPage</code> implementation of an <code>IDialogPage</code>
 * method disposes of all nested wizards. Subclasses may extend.
 */
public void dispose() {
	super.dispose();
	// notify nested wizards
	for (int i = 0; i < selectedWizardNodes.size(); i++) {
		((IWizardNode) selectedWizardNodes.get(i)).dispose();
	}
}
/**
 * The <code>WizardSelectionPage</code> implementation of 
 * this <code>IWizardPage</code> method returns the first page 
 * of the currently selected wizard if there is one.
 */
public IWizardPage getNextPage() {
	if (selectedNode == null)
		return null;

	boolean isCreated = selectedNode.isContentCreated();
		
	IWizard wizard = selectedNode.getWizard();

	if (wizard == null) {
		setSelectedNode(null);	
		return null;
	}	

	if (!isCreated)
		// Allow the wizard to create its pages
		wizard.addPages();
		
	return wizard.getStartingPage();
}
/**
 * Returns the currently selected wizard node within this page.
 * 
 * @return the wizard node, or <code>null</code> if no node is selected
 */
public IWizardNode getSelectedNode() {
	return selectedNode;
}
/**
 * Sets or clears the currently selected wizard node within this page. 
 * 
 * @param node the wizard node, or <code>null</code> to clear
 */
protected void setSelectedNode(IWizardNode node) {
	addSelectedNode(node);
	selectedNode = node;
	if (isCurrentPage()) 
		getContainer().updateButtons();
}
}