Center Within Parent : JWindow « Swing « Java Tutorial






/*
 * Copyright (C) 2001-2004 Colin Bell
 * colbell@users.sourceforge.net
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.FontMetrics;
import java.awt.Frame;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.Insets;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Toolkit;
import java.awt.Window;
import java.awt.geom.Rectangle2D;
import java.beans.PropertyVetoException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JInternalFrame;
import javax.swing.SwingUtilities;

/**
 * Common GUI utilities accessed via static methods.
 * 
 * @author <A HREF="mailto:colbell@users.sourceforge.net">Colin Bell</A>
 */
public class GUIUtils {

  private static JFrame _mainFrame;

  /**
   * Centers <CODE>wind</CODE> within its parent. If it has no parent then
   * center within the screen. If centering would cause the title bar to go
   * above the parent (I.E. cannot see the titlebar and so cannot move the
   * window) then move the window down.
   * 
   * @param wind
   *          The Window to be centered.
   * 
   * @throws IllegalArgumentException
   *           If <TT>wind</TT> is <TT>null</TT>.
   */
  public static void centerWithinParent(Window wind) {
    if (wind == null) {
      throw new IllegalArgumentException("null Window passed");
    }
    final Container parent = wind.getParent();
    if (parent != null && parent.isVisible()) {
      center(wind, new Rectangle(parent.getLocationOnScreen(), parent.getSize()));
    } else {
      centerWithinScreen(wind);
    }
  }

  /**
   * Centers passed internal frame within its desktop area. If centering would
   * cause the title bar to go off the top of the screen then move the window
   * down.
   * 
   * @param frame
   *          The internal frame to be centered.
   * 
   * @throws IllegalArgumentException
   *           If <TT>frame</TT> is <TT>null</TT>.
   */
  public static void centerWithinDesktop(JInternalFrame frame) {
    if (frame == null) {
      throw new IllegalArgumentException("null JInternalFrame passed");
    }
    final Container parent = frame.getDesktopPane();
    if (parent != null && parent.isVisible()) {
      center(frame, new Rectangle(new Point(0, 0), parent.getSize()));
    }
  }

  /**
   * Centers <CODE>wind</CODE> within the screen. If centering would cause the
   * title bar to go off the top of the screen then move the window down.
   * 
   * @param wind
   *          The Window to be centered.
   * 
   * @throws IllegalArgumentException
   *           If <TT>wind</TT> is <TT>null</TT>.
   */
  public static void centerWithinScreen(Window wind) {
    if (wind == null) {
      throw new IllegalArgumentException("null Window passed");
    }
    final Toolkit toolKit = Toolkit.getDefaultToolkit();
    final Rectangle rcScreen = new Rectangle(toolKit.getScreenSize());
    final Dimension windSize = wind.getSize();
    final Dimension parentSize = new Dimension(rcScreen.width, rcScreen.height);
    if (windSize.height > parentSize.height) {
      windSize.height = parentSize.height;
    }
    if (windSize.width > parentSize.width) {
      windSize.width = parentSize.width;
    }
    center(wind, rcScreen);
  }

  /**
   * Centers <CODE>wind</CODE> within the passed rectangle.
   * 
   * @param wind
   *          The Window to be centered.
   * @param rect
   *          The rectangle (in screen coords) to center <CODE>wind</CODE>
   *          within.
   * 
   * @throws IllegalArgumentException
   *           If <TT>Window</TT> or <TT>Rectangle</TT> is <TT>null</TT>.
   */
  private static void center(Component wind, Rectangle rect) {
    if (wind == null || rect == null) {
      throw new IllegalArgumentException("null Window or Rectangle passed");
    }
    Dimension windSize = wind.getSize();
    int x = ((rect.width - windSize.width) / 2) + rect.x;
    int y = ((rect.height - windSize.height) / 2) + rect.y;
    if (y < rect.y) {
      y = rect.y;
    }
    wind.setLocation(x, y);
  }
}








14.78.JWindow
14.78.1.Difference between JFrame and JWindow
14.78.2.Have borders on a JWindow/JFrame
14.78.3.Extending JWindowExtending JWindow
14.78.4.Center window
14.78.5.Center Within Parent