libjava/javax/swing/plaf/PopupMenuUI.java

   1 /* PopupMenuUI.java --
   2    Copyright (C) 2002, 2003, 2004  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.plaf;
  40
  41 import java.awt.event.MouseEvent;
  42
  43 import javax.swing.JPopupMenu;
  44 import javax.swing.Popup;
  45 import javax.swing.PopupFactory;
  46
  47 /**
  48  * An abstract base class for delegates that implement the pluggable
  49  * look and feel for a <code>JPopupMenu</code>.
  50  *
  51  * @see javax.swing.JPopupMenu
  52  *
  53  * @author Andrew Selkirk (aselkirk@sympatico.ca)
  54  * @author Sascha Brawer (brawer@dandelis.ch)
  55  */
  56 public abstract class PopupMenuUI
  57   extends ComponentUI
  58 {
  59   /**
  60    * Constructs a new <code>PopupMenuUI</code>.
  61    */
  62   public PopupMenuUI()
  63   {
  64   }
  65
  66
  67   /**
  68    * Tests whether or not a mouse event triggers a popup menu.
  69    *
  70    * <p>The default implementation calls
  71    * <code>event.isPopupTrigger()</code>, which checks for the gesture
  72    * that is common for the platform on which the application runs. If
  73    * a look and feel wants to employ non-standard conventions for
  74    * triggering a popup menu, it can override this method.
  75    *
  76    * @param event the event to check.
  77    *
  78    * @return <code>true</code> if the event triggers a popup menu;
  79    *         <code>false</code> otherwise.
  80    *
  81    * @since 1.3
  82    */
  83   public boolean isPopupTrigger(MouseEvent event)
  84   {
  85     return event.isPopupTrigger();
  86   }
  87
  88
  89   /**
  90    * Creates a <code>Popup</code> for displaying the popup menu.  The
  91    * default implementation uses the {@link javax.swing.PopupFactory}
  92    * for retrieving a suitable <code>Popup</code>, but subclasses
  93    * might want to override this method if a LookAndFeel needs special
  94    * Popups.
  95    *
  96    * @param popup the <code>JPopupMenu</code> for whose display
  97    *        a <code>Popup</code> is needed.
  98    *
  99    * @param x the horizontal position where the popup will be
 100    *        displayed.
 101    *
 102    * @param y the vertical position where the popup will be
 103    *        displayed.
 104    *
 105    * @return a <code>Popup</code> for showing and hiding
 106    *         the menu.
 107    *
 108    * @since 1.4
 109    */
 110   public Popup getPopup(JPopupMenu popup, int x, int y)
 111   {
 112     return PopupFactory.getSharedInstance().getPopup(
 113       /* origin/owner of the popup */ popup.getInvoker(),
 114       /* contents */                  popup,
 115       x, y);
 116   }
 117 }