package org.eclipse.swt.widgets;

/*
 * (c) Copyright IBM Corp. 2000, 2001.
 * All Rights Reserved
 */

import org.eclipse.swt.*;
import org.eclipse.swt.internal.*;
import org.eclipse.swt.internal.gtk.*;
import org.eclipse.swt.widgets.*;

/**
 * Instances of this class allow the user to navigate
 * the file system and select a directory.
 * <p>
 * IMPORTANT: This class is intended to be subclassed <em>only</em>
 * within the SWT implementation.
 * </p>
 */

public class DirectoryDialog extends GtkFileDialog {
	String message = "", filterPath = "";

/**
 * Constructs a new instance of this class given only its
 * parent.
 * <p>
 * Note: Currently, null can be passed in for the parent.
 * This has the effect of creating the dialog on the currently active
 * display if there is one. If there is no current display, the 
 * dialog is created on a "default" display. <b>Passing in null as
 * the parent is not considered to be good coding style,
 * and may not be supported in a future release of SWT.</b>
 * </p>
 *
 * @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.PRIMARY_MODAL);
}
/**
 * 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
 * for all SWT dialog classes should include a comment which
 * describes the style constants which are applicable to the class.
 * </p>
 * Note: Currently, null can be passed in for the parent.
 * This has the effect of creating the dialog on the currently active
 * display if there is one. If there is no current display, the 
 * dialog is created on a "default" display. <b>Passing in null as
 * the parent is not considered to be good coding style,
 * and may not be supported in a future release of SWT.</b>
 * </p>
 *
 * @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, int style) {
	super (parent, style);
	checkSubclass ();
}
/**
 * Returns the path which the dialog will use to filter
 * the directories it shows.
 *
 * @return the filter path
 */
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 () {
	return super.open();
}

/**
 * Sets the path which the dialog will use to filter
 * the directories it shows to the argument, which may be
 * null.
 *
 * @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
 */
public void setMessage (String string) {
	/*
	 * The native Gtk file selection dialog does not support message
	 * strings other than the dialog title.  However, we maintain the set
	 * message so at least the application programs get back the same string.
	 */
	message = string;
}

void interpretOsAnswer(String osAnswer) {
	if (osAnswer==null) return;
	int separatorIndex = calculateLastSeparatorIndex(osAnswer);
	if (separatorIndex+1 != osAnswer.length()) {
		/*
		 * the selected thing is a file
		 */
		answer = null;
		return;
	}
	answer = osAnswer;
}
void preset() {
	if (filterPath != null) {
		byte [] filterBytes = Converter.wcsToMbcs (null, filterPath, true);
		OS.gtk_file_selection_set_filename (handle, filterBytes);
	}
}
}