Source for javax.swing.plaf.PopupMenuUI

   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., 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.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 extends ComponentUI
  57: {
  58:   /**
  59:    * Constructs a new <code>PopupMenuUI</code>.
  60:    */
  61:   public PopupMenuUI()
  62:   {
  63:     // Nothing to do here.
  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: }