libjava/javax/swing/Popup.java

   1 /* Popup.java --
   2    Copyright (C) 2003 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package javax.swing;
  40
  41 import java.awt.Component;
  42
  43
  44 /**
  45  * Manages a popup window that displays a Component on top of
  46  * everything else.
  47  *
  48  * <p>To obtain an instance of <code>Popup</code>, use the
  49  * {@link javax.swing.PopupFactory}.
  50  *
  51  * @since 1.4
  52  *
  53  * @author Sascha Brawer (brawer@dandelis.ch)
  54  */
  55 public class Popup
  56 {
  57   /**
  58    * Constructs a new <code>Popup</code> given its owner,
  59    * contents and the screen position where the popup
  60    * will appear.
  61    *
  62    * @param owner the Component to which <code>x</code> and
  63    *        <code>y</code> are relative, or <code>null</code> for
  64    *        placing the popup relative to the origin of the screen.
  65    *
  66    * @param contents the contents that will be displayed inside
  67    *        the <code>Popup</code>.
  68    *
  69    * @param x the horizontal position where the Popup will appear.
  70    *
  71    * @param y the vertical position where the Popup will appear.
  72    *
  73    * @throws IllegalArgumentException if <code>contents</code>
  74    *         is <code>null</code>.
  75    */
  76   protected Popup(Component owner, Component contents,
  77                   int x, int y)
  78   {
  79     if (contents == null)
  80       throw new IllegalArgumentException();
  81
  82     // The real stuff happens in the implementation of subclasses,
  83     // for instance JWindowPopup.
  84   }
  85
  86
  87   /**
  88    * Constructs a new <code>Popup</code>.
  89    */
  90   protected Popup()
  91   {
  92   }
  93
  94
  95   /**
  96    * Displays the <code>Popup</code> on the screen.  Nothing happens
  97    * if it is currently shown.
  98    */
  99   public void show()
 100   {
 101     // Implemented by subclasses, for instance JWindowPopup.
 102   }
 103
 104
 105   /**
 106    * Removes the <code>Popup</code> from the screen.  Nothing happens
 107    * if it is currently hidden.
 108    */
 109   public void hide()
 110   {
 111     // Implemented by subclasses, for instance JWindowPopup.
 112   }
 113
 114
 115   /**
 116    * A <code>Popup</code> that uses a <code>JWindow</code> for
 117    * displaying its contents.
 118    *
 119    * @see PopupFactory#getPopup
 120    *
 121    * @author Sascha Brawer (brawer@dandelis.ch)
 122    */
 123   static class JWindowPopup
 124     extends Popup
 125   {
 126     /**
 127      * The <code>JWindow</code> used for displaying the contents
 128      * of the popup.
 129      */
 130     JWindow window;
 131
 132
 133     /**
 134      * Constructs a new <code>JWindowPopup</code> given its owner,
 135      * contents and the screen position where the popup
 136      * will appear.
 137      *
 138      * @param owner the Component to which <code>x</code> and
 139      *        <code>y</code> are relative, or <code>null</code> for
 140      *        placing the popup relative to the origin of the screen.
 141      *
 142      * @param contents the contents that will be displayed inside
 143      *        the <code>Popup</code>.
 144      *
 145      * @param x the horizontal position where the Popup will appear.
 146      *
 147      * @param y the vertical position where the Popup will appear.
 148      *
 149      * @throws IllegalArgumentException if <code>contents</code>
 150      *         is <code>null</code>.
 151      */
 152     public JWindowPopup(Component owner, Component contents,
 153                         int x, int y)
 154     {
 155       /* Checks whether contents is null. */
 156       super(owner, contents, x, y);
 157
 158       window = new JWindow();
 159       window.getRootPane().add(contents);
 160       window.setLocation(x, y);
 161       window.pack();
 162     }
 163
 164
 165     /**
 166      * Displays the popup&#x2019;s <code>JWindow</code> on the screen.
 167      * Nothing happens if it is already visible.
 168      */
 169     public void show()
 170     {
 171       window.show();
 172     }
 173
 174
 175     /**
 176      * Removes the popup&#x2019;s <code>JWindow</code> from the
 177      * screen.  Nothing happens if it is currently not visible.
 178      */
 179     public void hide()
 180     {
 181       /* Calling dispose() instead of hide() will conserve native
 182        * system resources, for example memory in an X11 server.
 183        * They will automatically be re-allocated by a call to
 184        * show().
 185        */
 186       window.dispose();
 187     }
 188   }
 189 }