/*******************************************************************************

 * Copyright (c) 2000, 2007 IBM Corporation and others.

 * Portion Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).

 * 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

 *     Nokia Corporation - Qt implementation

 *******************************************************************************/

package org.eclipse.swt.widgets;

import org.eclipse.swt.SWT;

import org.eclipse.swt.SWTException;

import org.eclipse.swt.events.DisposeEvent;

import org.eclipse.swt.events.DisposeListener;

import org.eclipse.swt.internal.qt.OS;

/**

 * Instances of this class allow the user to navigate the file system and select

 * a directory.

 * <dl>

 * <dt><b>Styles:</b></dt>

 * <dd>(none)</dd>

 * <dt><b>Events:</b></dt>

 * <dd>(none)</dd>

 * </dl>

 * <p>

 * IMPORTANT: This class is intended to be subclassed <em>only</em> within the

 * SWT implementation.

 * </p>

 */

public class DirectoryDialog extends Dialog {

	String message = "", filterPath = "";

	static final char SEPARATOR = System.getProperty("file.separator")

			.charAt(0);

	String dialogID;

	static int dialogCount;

	/**

	 * Constructs a new instance of this class given only its parent.

	 * 

	 * @param parent

	 *            a shell which will be the parent of the new instance

	 * 

	 * @exception IllegalArgumentException

	 *                <ul>

	 *                <li>ERROR_NULL_ARGUMENT - if the parent is null</li>

	 *                </ul>

	 * @exception SWTException

	 *                <ul>

	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the

	 *                thread that created the parent</li>

	 *                <li>ERROR_INVALID_SUBCLASS - if this class is not an

	 *                allowed subclass</li>

	 *                </ul>

	 */

	public DirectoryDialog(Shell parent) {

		this(parent, SWT.NULL);

	}

	/**

	 * Constructs a new instance of this class given its parent and a style

	 * value describing its behavior and appearance.

	 * <p>

	 * The style value is either one of the style constants defined in class

	 * <code>SWT</code> which is applicable to instances of this class, or must

	 * be built by <em>bitwise OR</em>'ing together (that is, using the

	 * <code>int</code> "|" operator) two or more of those <code>SWT</code>

	 * style constants. The class description lists the style constants that are

	 * applicable to the class. Style bits are also inherited from superclasses.

	 * </p>

	 * 

	 * @param parent

	 *            a shell which will be the parent of the new instance

	 * @param style

	 *            the style of dialog to construct

	 * 

	 * @exception IllegalArgumentException

	 *                <ul>

	 *                <li>ERROR_NULL_ARGUMENT - if the parent is null</li>

	 *                </ul>

	 * @exception SWTException

	 *                <ul>

	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the

	 *                thread that created the parent</li>

	 *                <li>ERROR_INVALID_SUBCLASS - if this class is not an

	 *                allowed subclass</li>

	 *                </ul>

	 */

	public DirectoryDialog(Shell parent, int style) {

		super(parent, checkStyle(parent, style));

		checkSubclass();

		dialogCount++;

		dialogID = toString() + String.valueOf(dialogCount);

	}

	static int checkStyle(Shell parent, int style) {

		style &= ~SWT.MIRRORED;

		if ((style & SWT.RIGHT_TO_LEFT) == 0) {

			if (parent != null) {

				if ((parent.style & SWT.RIGHT_TO_LEFT) != 0)

					style |= SWT.RIGHT_TO_LEFT;

			}

		}

		if ((style & SWT.LEFT_TO_RIGHT) != 0

				&& (style & SWT.RIGHT_TO_LEFT) != 0) {

			style &= ~SWT.LEFT_TO_RIGHT;

		}

		return style;

	}

	/**

	 * Returns the path which the dialog will use to filter the directories it

	 * shows.

	 * 

	 * @return the filter path

	 * 

	 * @see #setFilterPath

	 */

	public String getFilterPath() {

		return filterPath;

	}

	/**

	 * Returns the dialog's message, which is a description of the purpose for

	 * which it was opened. This message will be visible on the dialog while it

	 * is open.

	 * 

	 * @return the message

	 */

	public String getMessage() {

		return message;

	}

	/**

	 * Makes the dialog visible and brings it to the front of the display.

	 * 

	 * @return a string describing the absolute path of the selected directory,

	 *         or null if the dialog was cancelled or an error occurred

	 * 

	 * @exception SWTException

	 *                <ul>

	 *                <li>ERROR_WIDGET_DISPOSED - if the dialog has been

	 *                disposed</li>

	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the

	 *                thread that created the dialog</li>

	 *                </ul>

	 */

	public String open() {

		checkDialog();

		DisposeListener listener = new DisposeListener() {

			public void widgetDisposed(DisposeEvent e) {

				if (e.widget == parent) {

					/*

					 * close dialogs which opened on top of parent

					 */

					OS.QDialog_swt_closeDialogs(parent.handle, dialogID);

				}

			}

		};

		/*

		 * listen to parent dispose event

		 */

		parent.addDisposeListener(listener);

		int qtLayoutDirection = (style & SWT.RIGHT_TO_LEFT) != 0 ? OS.QT_RIGHTTOLEFT

				: OS.QT_LEFTTORIGHT;

		String resultString = OS.QFileDialog_swt_getOpenDirectoryName(parent.handle,

				title, filterPath, dialogID, qtLayoutDirection);

		if (parent != null && !parent.isDisposed()) {

			parent.removeDisposeListener(listener);

		}

		if (resultString != null) {

			filterPath = resultString;

			int len = resultString.length();

			if (len > 0) {

				if (resultString.charAt(len - 1) == SEPARATOR) {

					filterPath = resultString.substring(0, len - 1);

				}

			}

		} else {

			filterPath = null;

		}

		return filterPath;

	}

	/**

	 * Sets the path that the dialog will use to filter the directories it shows

	 * to the argument, which may be null. If the string is null, then the

	 * operating system's default filter path will be used.

	 * <p>

	 * Note that the path string is platform dependent. For convenience, either

	 * '/' or '\' can be used as a path separator.

	 * </p>

	 * 

	 * @param string

	 *            the filter path

	 */

	public void setFilterPath(String string) {

		filterPath = string;

	}

	/**

	 * Sets the dialog's message, which is a description of the purpose for

	 * which it was opened. This message will be visible on the dialog while it

	 * is open.

	 * 

	 * @param string

	 *            the message

	 * 

	 * @exception IllegalArgumentException

	 *                <ul>

	 *                <li>ERROR_NULL_ARGUMENT - if the string is null</li>

	 *                </ul>

	 */

	public void setMessage(String string) {

		if (string == null)

			error(SWT.ERROR_NULL_ARGUMENT);

		message = string;

	}

	void checkDialog() {

		if (parent == null)

			error(SWT.ERROR_WIDGET_DISPOSED);

		if (parent.isDisposed())

			error(SWT.ERROR_WIDGET_DISPOSED);

		Display display = parent.display;

		if (display == null)

			error(SWT.ERROR_WIDGET_DISPOSED);

		if (display.thread != Thread.currentThread())

			error(SWT.ERROR_THREAD_INVALID_ACCESS);

	}

}