Tray.java

/*******************************************************************************
 * Copyright (c) 2000, 2009, 2012 IBM Corporation, Gerhardt Informatics Kft. 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
 *     Gerhardt Informatics Kft. - GEFGWT port
 *******************************************************************************/
package org.eclipse.swt.widgets;

import org.eclipse.swt.SWT;
import org.eclipse.swt.SWTException;

/**
 * Instances of this class represent the system tray that is part of the task
 * bar status area on some operating systems.
 * 
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>(none)</dd>
 * <dt><b>Events:</b></dt>
 * <dd>(none)</dd>
 * </dl>
 * <p>
 * IMPORTANT: This class is <em>not</em> intended to be subclassed.
 * </p>
 * 
 * @see Display#getSystemTray
 * @see <a href="http://www.eclipse.org/swt/snippets/#tray">Tray, TrayItem
 *      snippets</a>
 * @see <a href="http://www.eclipse.org/swt/">Sample code and further
 *      information</a>
 * 
 * @since 3.0
 * @noextend This class is not intended to be subclassed by clients.
 */
public class Tray extends Widget {
	int itemCount;
	TrayItem[] items = new TrayItem[4];

	Tray(Display display, int style) {
		if (display == null)
			display = Display.getCurrent();
		if (display == null)
			display = Display.getDefault();
		if (!display.isValidThread()) {
			error(SWT.ERROR_THREAD_INVALID_ACCESS);
		}
		this.display = display;
		reskinWidget();
	}

	void createItem(TrayItem item, int index) {
		if (!(0 <= index && index <= itemCount))
			error(SWT.ERROR_INVALID_RANGE);
		if (itemCount == items.length) {
			TrayItem[] newItems = new TrayItem[items.length + 4];
			System.arraycopy(items, 0, newItems, 0, items.length);
			items = newItems;
		}
		System.arraycopy(items, index, items, index + 1, itemCount++ - index);
		items[index] = item;
	}

	void destroyItem(TrayItem item) {
		int index = 0;
		while (index < itemCount) {
			if (items[index] == item)
				break;
			index++;
		}
		if (index == itemCount)
			return;
		System.arraycopy(items, index + 1, items, index, --itemCount - index);
		items[itemCount] = null;
	}

	/**
	 * Returns the item at the given, zero-relative index in the receiver.
	 * Throws an exception if the index is out of range.
	 * 
	 * @param index
	 *            the index of the item to return
	 * @return the item at the given index
	 * 
	 * @exception IllegalArgumentException
	 *                <ul>
	 *                <li>ERROR_INVALID_RANGE - if the index is not between 0
	 *                and the number of elements in the list minus 1 (inclusive)
	 *                </li>
	 *                </ul>
	 * @exception SWTException
	 *                <ul>
	 *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
	 *                disposed</li>
	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	 *                thread that created the receiver</li>
	 *                </ul>
	 */
	public TrayItem getItem(int index) {
		checkWidget();
		if (!(0 <= index && index < itemCount))
			error(SWT.ERROR_INVALID_RANGE);
		return items[index];
	}

	/**
	 * Returns the number of items contained in the receiver.
	 * 
	 * @return the number of items
	 * 
	 * @exception SWTException
	 *                <ul>
	 *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
	 *                disposed</li>
	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	 *                thread that created the receiver</li>
	 *                </ul>
	 */
	public int getItemCount() {
		checkWidget();
		return itemCount;
	}

	/**
	 * Returns an array of <code>TrayItem</code>s which are the items in the
	 * receiver.
	 * <p>
	 * Note: This is not the actual structure used by the receiver to maintain
	 * its list of items, so modifying the array will not affect the receiver.
	 * </p>
	 * 
	 * @return the items in the receiver
	 * 
	 * @exception SWTException
	 *                <ul>
	 *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
	 *                disposed</li>
	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	 *                thread that created the receiver</li>
	 *                </ul>
	 */
	public TrayItem[] getItems() {
		checkWidget();
		TrayItem[] result = new TrayItem[itemCount];
		System.arraycopy(items, 0, result, 0, result.length);
		return result;
	}

	void releaseChildren(boolean destroy) {
		if (items != null) {
			for (int i = 0; i < items.length; i++) {
				TrayItem item = items[i];
				if (item != null && !item.isDisposed()) {
					item.release(false);
				}
			}
			items = null;
		}
		super.releaseChildren(destroy);
	}

	void releaseParent() {
		super.releaseParent();
		if (display.tray == this)
			display.tray = null;
	}

	void reskinChildren(int flags) {
		if (items != null) {
			for (int i = 0; i < items.length; i++) {
				TrayItem item = items[i];
				if (item != null)
					item.reskin(flags);
			}
		}
		super.reskinChildren(flags);
	}

}