Java tutorial
/* * $Id: WindowUtils.java,v 1.16 2009/05/25 16:37:52 kschaefe Exp $ * * Copyright 2004 Sun Microsystems, Inc., 4150 Network Circle, * Santa Clara, California 95054, U.S.A. All rights reserved. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ import java.awt.GraphicsConfiguration; import java.awt.GraphicsEnvironment; import java.awt.Insets; import java.awt.Point; import java.awt.Rectangle; import java.awt.Toolkit; import java.awt.Window; /** * Encapsulates various utilities for windows (ie: <code>Frame</code> and * <code>Dialog</code> objects and descendants, in particular). * * @author Richard Bair */ public class Utils { public static Point getPointForCentering(Window window) { Rectangle usableBounds = getUsableDeviceBounds(window); int screenWidth = usableBounds.width; int screenHeight = usableBounds.height; int width = window.getWidth(); int height = window.getHeight(); return new Point(((screenWidth - width) / 2) + usableBounds.x, ((screenHeight - height) / 2) + usableBounds.y); } /** * <p> * Returns the <code>Point</code> at which a window should be placed to * center that window on the screen. * </p> * <p> * Some thought was taken as to whether to implement a method such as this, * or to simply make a method that, given a window, will center it. It was * decided that it is better to not alter an object within a method. * </p> * * @param window The window to calculate the center point for. This object * can not be null. * * @return the <code>Point</code> at which the window should be placed to * center that window on the screen. */ private static Rectangle getUsableDeviceBounds(Window window) { Window owner = window.getOwner(); GraphicsConfiguration gc = null; if (owner == null) { gc = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice() .getDefaultConfiguration(); } else { gc = owner.getGraphicsConfiguration(); } Insets insets = Toolkit.getDefaultToolkit().getScreenInsets(gc); Rectangle bounds = gc.getBounds(); bounds.x += insets.left; bounds.y += insets.top; bounds.width -= (insets.left + insets.right); bounds.height -= (insets.top + insets.bottom); return bounds; } }