libjava/classpath/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., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 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 import java.awt.FlowLayout;
  43 import java.awt.Point;
  44 import java.awt.Rectangle;
  45
  46
  47 /**
  48  * Manages a popup window that displays a Component on top of
  49  * everything else.
  50  *
  51  * <p>To obtain an instance of <code>Popup</code>, use the
  52  * {@link javax.swing.PopupFactory}.
  53  *
  54  * @since 1.4
  55  *
  56  * @author Sascha Brawer (brawer@dandelis.ch)
  57  */
  58 public class Popup
  59 {
  60   /**
  61    * Constructs a new <code>Popup</code> given its owner,
  62    * contents and the screen position where the popup
  63    * will appear.
  64    *
  65    * @param owner the Component to which <code>x</code> and
  66    *        <code>y</code> are relative, or <code>null</code> for
  67    *        placing the popup relative to the origin of the screen.
  68    *
  69    * @param contents the contents that will be displayed inside
  70    *        the <code>Popup</code>.
  71    *
  72    * @param x the horizontal position where the Popup will appear.
  73    *
  74    * @param y the vertical position where the Popup will appear.
  75    *
  76    * @throws IllegalArgumentException if <code>contents</code>
  77    *         is <code>null</code>.
  78    */
  79   protected Popup(Component owner, Component contents,
  80                   int x, int y)
  81   {
  82     if (contents == null)
  83       throw new IllegalArgumentException();
  84
  85     // The real stuff happens in the implementation of subclasses,
  86     // for instance JWindowPopup.
  87   }
  88
  89
  90   /**
  91    * Constructs a new <code>Popup</code>.
  92    */
  93   protected Popup()
  94   {
  95     // Nothing to do here.
  96   }
  97
  98
  99   /**
 100    * Displays the <code>Popup</code> on the screen.  Nothing happens
 101    * if it is currently shown.
 102    */
 103   public void show()
 104   {
 105     // Implemented by subclasses, for instance JWindowPopup.
 106   }
 107
 108
 109   /**
 110    * Removes the <code>Popup</code> from the screen.  Nothing happens
 111    * if it is currently hidden.
 112    */
 113   public void hide()
 114   {
 115     // Implemented by subclasses, for instance JWindowPopup.
 116   }
 117
 118
 119   /**
 120    * A <code>Popup</code> that uses a <code>JWindow</code> for
 121    * displaying its contents.
 122    *
 123    * @see PopupFactory#getPopup
 124    *
 125    * @author Sascha Brawer (brawer@dandelis.ch)
 126    */
 127   static class JWindowPopup
 128     extends Popup
 129   {
 130     /**
 131      * The <code>JWindow</code> used for displaying the contents
 132      * of the popup.
 133      */
 134     JWindow window;
 135
 136     private Component contents;
 137
 138     /**
 139      * Constructs a new <code>JWindowPopup</code> given its owner,
 140      * contents and the screen position where the popup
 141      * will appear.
 142      *
 143      * @param owner the Component to which <code>x</code> and
 144      *        <code>y</code> are relative, or <code>null</code> for
 145      *        placing the popup relative to the origin of the screen.
 146      *
 147      * @param contents the contents that will be displayed inside
 148      *        the <code>Popup</code>.
 149      *
 150      * @param x the horizontal position where the Popup will appear.
 151      *
 152      * @param y the vertical position where the Popup will appear.
 153      *
 154      * @throws IllegalArgumentException if <code>contents</code>
 155      *         is <code>null</code>.
 156      */
 157     public JWindowPopup(Component owner, Component contents,
 158                         int x, int y)
 159     {
 160       /* Checks whether contents is null. */
 161       super(owner, contents, x, y);
 162
 163       this.contents = contents;
 164       window = new JWindow(SwingUtilities.getWindowAncestor(owner));
 165       window.getContentPane().add(contents);
 166       window.setLocation(x, y);
 167       window.setFocusableWindowState(false);
 168     }
 169
 170
 171     /**
 172      * Displays the popup's <code>JWindow</code> on the screen.
 173      * Nothing happens if it is already visible.
 174      */
 175     public void show()
 176     {
 177       window.setSize(contents.getSize());
 178       window.show();
 179     }
 180
 181
 182     /**
 183      * Removes the popup's <code>JWindow</code> from the
 184      * screen.  Nothing happens if it is currently not visible.
 185      */
 186     public void hide()
 187     {
 188       /* Calling dispose() instead of hide() will conserve native
 189        * system resources, for example memory in an X11 server.
 190        * They will automatically be re-allocated by a call to
 191        * show().
 192        */
 193       window.dispose();
 194     }
 195   }
 196
 197   /**
 198    * A popup that displays itself within the JLayeredPane of a JRootPane of
 199    * the containment hierarchy of the owner component.
 200    *
 201    * @author Roman Kennke (kennke@aicas.com)
 202    */
 203   static class LightweightPopup extends Popup
 204   {
 205     /**
 206      * The owner component for this popup.
 207      */
 208     Component owner;
 209
 210     /**
 211      * The contents that should be shown.
 212      */
 213     Component contents;
 214
 215     /**
 216      * The X location in screen coordinates.
 217      */
 218     int x;
 219
 220     /**
 221      * The Y location in screen coordinates.
 222      */
 223     int y;
 224
 225     /**
 226      * The panel that holds the content.
 227      */
 228     private JPanel panel;
 229
 230     /**
 231      * The layered pane of the owner.
 232      */
 233     private JLayeredPane layeredPane;
 234
 235     /**
 236      * Constructs a new <code>LightweightPopup</code> given its owner,
 237      * contents and the screen position where the popup
 238      * will appear.
 239      *
 240      * @param owner the component that should own the popup window; this
 241      *        provides the JRootPane in which we place the popup window
 242      *
 243      * @param contents the contents that will be displayed inside
 244      *        the <code>Popup</code>.
 245      *
 246      * @param x the horizontal position where the Popup will appear in screen
 247      *        coordinates
 248      *
 249      * @param y the vertical position where the Popup will appear in screen
 250      *        coordinates
 251      *
 252      * @throws IllegalArgumentException if <code>contents</code>
 253      *         is <code>null</code>.
 254      */
 255     public LightweightPopup(Component owner, Component  contents, int x, int y)
 256     {
 257       super(owner, contents, x, y);
 258       this.owner = owner;
 259       this.contents = contents;
 260       this.x = x;
 261       this.y = y;
 262
 263       JRootPane rootPane = SwingUtilities.getRootPane(owner);
 264       JLayeredPane layeredPane = rootPane.getLayeredPane();
 265       this.layeredPane = layeredPane;
 266     }
 267
 268     /**
 269      * Places the popup within the JLayeredPane of the owner component and
 270      * makes it visible.
 271      */
 272     public void show()
 273     {
 274       // We insert a JPanel between the layered pane and the contents so we
 275       // can fiddle with the setLocation() method without disturbing a
 276       // JPopupMenu (which overrides setLocation in an unusual manner).
 277       if (panel == null)
 278         {
 279           panel = new JPanel();
 280           panel.setLayout(new FlowLayout(0, 0, 0));
 281         }
 282
 283       panel.add(contents);
 284       panel.setSize(contents.getSize());
 285       Point layeredPaneLoc = layeredPane.getLocationOnScreen();
 286       panel.setLocation(x - layeredPaneLoc.x, y - layeredPaneLoc.y);
 287       layeredPane.add(panel, JLayeredPane.POPUP_LAYER);
 288       panel.repaint();
 289     }
 290
 291     /**
 292      * Removes the popup from the JLayeredPane thus making it invisible.
 293      */
 294     public void hide()
 295     {
 296       Rectangle bounds = panel.getBounds();
 297       layeredPane.remove(panel);
 298       layeredPane.repaint(bounds.x, bounds.y, bounds.width, bounds.height);
 299     }
 300   }
 301 }