/*******************************************************************************
 * 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;

import org.eclipse.jface.dialogs.IDialogSettings;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.util.Assert;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.RGB;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Shell;
/**
 * An abstract base implementation of a wizard. A typical client subclasses 
 * <code>Wizard</code> to implement a particular wizard.
 * <p>
 * Subclasses may call the following methods to configure the wizard:
 * <ul>
 *  <li><code>addPage</code></li>
 *  <li><code>setHelpAvailable</code></li>
 *  <li><code>setDefaultPageImageDescriptor</code></li>
 *  <li><code>setDialogSettings</code></li>
 *  <li><code>setNeedsProgressMonitor</code></li>
 *  <li><code>setTitleBarColor</code></li>
 *  <li><code>setWindowTitle</code></li>
 * </ul>
 * </p>
 * <p>
 * Subclasses may override these methods if required:
 * <ul>
 *  <li>reimplement <code>createPageControls</code></li>
 *  <li>reimplement <code>performCancel</code></li>
 *  <li>extend <code>addPages</code></li>
 *  <li>reimplement <code>performFinish</code></li>
 *  <li>extend <code>dispose</code></li>
 * </ul>
 * </p>
 * <p>
 * Note that clients are free to implement <code>IWizard</code> from scratch
 * instead of subclassing <code>Wizard</code>. Correct implementations of
 * <code>IWizard</code> will work with any correct implementation of 
 * <code>IWizardPage</code>.
 * </p>
 */
public abstract class Wizard implements IWizard {
	/** 
	 * Image registry key of the default image for wizard pages
	 * (value <code>"org.eclipse.jface.wizard.Wizard.pageImage"</code>).
	 */
	public static final String DEFAULT_IMAGE= "org.eclipse.jface.wizard.Wizard.pageImage";//$NON-NLS-1$

	/* 
	 * Register the default page image
	 */
	static {
		JFaceResources.getImageRegistry().put(
			DEFAULT_IMAGE,
			ImageDescriptor.createFromFile(Wizard.class, "images/page.gif"));//$NON-NLS-1$
	}

	/**
	 * The wizard container this wizard belongs to; <code>null</code>
	 * if none.
	 */
	private IWizardContainer container = null;
	
	/**
	 * This wizard's list of pages (element type: <code>IWizardPage</code>).
	 */
	private List pages = new ArrayList();
	
	/**
	 * Indicates whether this wizard needs a progress monitor.
	 */
	private boolean needsProgressMonitor = false;
	
	/**
	 * Indicates whether this wizard needs previous and next buttons
	 * even if the wizard has only one page.
	 */
	private boolean forcePreviousAndNextButtons = false;

	/**
	 * Indicates whether this wizard supports help.
	 */
	private boolean isHelpAvailable = false;
	
	/**
	 * The default page image for pages without one of their one;
	 * <code>null</code> if none.
	 */
	private Image defaultImage = null;
	
	/**
	 * The default page image descriptor, used for creating a default page
	 * image if required; <code>null</code> if none.
	 */
	private ImageDescriptor defaultImageDescriptor = null;
	
	/**
	 * The color of the wizard title bar; <code>null</code> if none.
	 */
	private RGB titleBarColor = null;

	/**
	 * The window title string for this wizard; <code>null</code> if none.
	 */
	private String windowTitle = null;
	
	/**
	 * The dialog settings for this wizard; <code>null</code> if none.
	 */
	private IDialogSettings dialogSettings = null;
/**
 * Creates a new empty wizard.
 */
protected Wizard() {
	super();
}
/**
 * Adds a new page to this wizard. The page is inserted at the
 * end of the page list.
 *
 * @param page the new page
 */
public void addPage(IWizardPage page) {
	pages.add(page);
	page.setWizard(this);
}
/**
 * The <code>Wizard</code> implementation of this <code>IWizard</code>
 * method does nothing.
 * Subclasses should extend if extra pages need to be added before
 * the wizard opens. New pages should be added by calling <code>addPage</code>.
 */
public void addPages() {
}
/* (non-Javadoc)
 * Method declared on IWizard.
 */
public boolean canFinish() {
	// Default implementation is to check if all pages are complete.
	for (int i= 0; i < pages.size(); i++) {
		if (!((IWizardPage)pages.get(i)).isPageComplete())
			return false;
	}
	return true;
}
/**
 * The <code>Wizard</code> implementation of this <code>IWizard</code>
 * method creates all the pages controls using <code>IDialogPage.createControl</code>.
 * Subclasses should reimplement this method if they want to delay creating
 * one or more of the pages lazily. The framework ensures that the contents
 * of a page will be created before attempting to show it.
 */
public void createPageControls(Composite pageContainer) {
	// the default behavior is to create all the pages controls
	for (int i = 0; i < pages.size(); i++){
		IWizardPage page = (IWizardPage)pages.get(i);
		page.createControl(pageContainer);
		// page is responsible for ensuring the created control is accessable
		// via getControl.
		Assert.isNotNull(page.getControl());
	}
}
/**
 * The <code>Wizard</code> implementation of this <code>IWizard</code>
 * method disposes all the pages controls using <code>DialogPage.dispose</code>.
 * Subclasses should extend this method if the wizard instance maintains
 * addition SWT resource that need to be disposed.
 */
public void dispose() {
	// notify pages
	for (int i = 0; i < pages.size(); i++){
		((IWizardPage)pages.get(i)).dispose();
	}

	// dispose of image
	if (defaultImage != null) {
		defaultImage.dispose();
		defaultImage = null;
	}
}
/* (non-Javadoc)
 * Method declared on IWizard.
 */
public IWizardContainer getContainer() {
	return container;
}
/* (non-Javadoc)
 * Method declared on IWizard.
 */
public Image getDefaultPageImage() {
	if (defaultImage != null) 
		return defaultImage;

	if (defaultImageDescriptor != null) {
		defaultImage = defaultImageDescriptor.createImage();
		return defaultImage;
	}
	
	return JFaceResources.getImageRegistry().get(DEFAULT_IMAGE);
}
/* (non-Javadoc)
 * Method declared on IWizard.
 */
public IDialogSettings getDialogSettings() {
	return dialogSettings;
}
/* (non-Javadoc)
 * Method declared on IWizard.
 * The default behavior is to return the page that 
 * was added to this wizard after the given page.
 */
public IWizardPage getNextPage(IWizardPage page) {
	int index = pages.indexOf(page);
	if (index == pages.size() - 1 || index == -1)
		// last page or page not found
		return null;
		
	return (IWizardPage)pages.get(index + 1);
}
/* (non-Javadoc)
 * Method declared on IWizard.
 */
public IWizardPage getPage(String name) {
	for (int i= 0; i < pages.size(); i++) {
		IWizardPage page = (IWizardPage)pages.get(i);
		String pageName = page.getName();
		if (pageName.equals(name))
			return page;
	}
	return null;	
}
/* (non-Javadoc)
 * Method declared on IWizard.
 */
public int getPageCount() {
	return pages.size();
}
/* (non-Javadoc)
 * Method declared on IWizard.
 */
public IWizardPage[] getPages() {
	return (IWizardPage[])pages.toArray(new IWizardPage[pages.size()]);
}
/* (non-Javadoc)
 * Method declared on IWizard.
 * The default behavior is to return the page that 
 * was added to this wizard before the given page.
 */
public IWizardPage getPreviousPage(IWizardPage page) {
	int index = pages.indexOf(page);
	if (index == 0 || index == -1)
		// first page or page not found
		return null;
	else
		return (IWizardPage)pages.get(index - 1);
}
/**
 * Returns the wizard's shell if the wizard is visible. Otherwise
 * <code>null</code> is returned.
 */
public Shell getShell() {
	if (container == null)
		return null;

	return container.getShell();
}
/* (non-Javadoc)
 * Method declared on IWizard.
 * By default this is the first page inserted into the wizard.
 */
public IWizardPage getStartingPage() {
	if (pages.size() == 0)
		return null;
	
	return (IWizardPage)pages.get(0);
}
/* (non-Javadoc)
 * Method declared on IWizard.
 */
public RGB getTitleBarColor() {
	return titleBarColor;
}
/* (non-Javadoc)
 * Method declared on IWizard.
 */
public String getWindowTitle() {
	return windowTitle;
}
/* (non-Javadoc)
 * Method declared on IWizard.
 */
public boolean isHelpAvailable() {
	return isHelpAvailable;
}
/* (non-Javadoc)
 * Method declared on IWizard.
 */
public boolean needsPreviousAndNextButtons() {
	return forcePreviousAndNextButtons || pages.size() > 1;
}
/* (non-Javadoc)
 * Method declared on IWizard.
 */
public boolean needsProgressMonitor() {
	return needsProgressMonitor;
}
/**
 * The <code>Wizard</code> implementation of this <code>IWizard</code>
 * method does nothing and returns <code>true</code>.
 * Subclasses should reimplement this method if they need to perform 
 * any special cancel processing for their wizard.
 */
public boolean performCancel() {
	return true;
}
/**
 * Subclasses must implement this <code>IWizard</code> method 
 * to perform any special finish processing for their wizard.
 */
public abstract boolean performFinish();
/* (non-Javadoc)
 * Method declared on IWizard.
 */
public void setContainer(IWizardContainer wizardContainer) {
	container = wizardContainer;
}
/**
 * Sets the default page image descriptor for this wizard.
 * <p>
 * This image descriptor will be used to generate an image for a page 
 * with no image of its own; the image will be computed once and cached.
 * </p>
 *
 * @param imageDescriptor the default page image descriptor
 */
public void setDefaultPageImageDescriptor(ImageDescriptor imageDescriptor) {
	defaultImageDescriptor = imageDescriptor;
}
/**
 * Sets the dialog settings for this wizard.
 * <p>
 * The dialog settings is used to record state between
 * wizard invocations (for example, radio button selection,
 * last import directory, etc.)
 * </p>
 *
 * @param settings the dialog settings, or <code>null</code> if none
 * @see #getDialogSettings
 * 
 */
public void setDialogSettings(IDialogSettings settings) {
	dialogSettings = settings;
}
/**
 * Controls whether the wizard needs Previous and Next 
 * buttons even if it currently contains only one page.
 * <p>
 * This flag should be set on wizards where the first wizard page
 * adds follow-on wizard pages based on user input.
 * </p>
 *
 * @param b <code>true</code> to always show Next and Previous
 *   buttons, and <code>false</code> to suppress Next and Previous
 *   buttons for single page wizards
 */
public void setForcePreviousAndNextButtons(boolean b) {
	forcePreviousAndNextButtons = b;
}
/**
 * Sets whether help is available for this wizard.
 * <p>
 * The result of this method is typically used by the container to
 * show or hide the Help button.
 * </p>
 *
 * @param b <code>true</code> if help is available,
 *   and <code>false</code> if this wizard is helpless
 * @see #isHelpAvailable
 */
public void setHelpAvailable(boolean b) {
	isHelpAvailable = b;
}
/**
 * Sets whether this wizard needs a progress monitor.
 *
 * @param b <code>true</code> if a progress monitor is required,
 *   and <code>false</code> if none is needed
 * @see #needsProgressMonitor()
 */
public void setNeedsProgressMonitor(boolean b) {
	needsProgressMonitor = b;
}
/**
 * Sets the title bar color for this wizard.
 *
 * @param color the title bar color
 */
public void setTitleBarColor(RGB color) {
	titleBarColor = color;
}
/**
 * Sets the window title for the container that hosts this page to 
 * the given string.
 *
 * @param newTitle the window title for the container
 */
public void setWindowTitle(String newTitle) {
	windowTitle = newTitle;
	if (container != null)
		container.updateWindowTitle();
}
}