Source for javax.swing.PopupFactory

   1: /* PopupFactory.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
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  36: exception statement from your version. */
  37: 
  38: 
  39: package javax.swing;
  40: 
  41: import java.awt.Component;
  42: 
  43: 
  44: /**
  45:  * A factory for <code>Popup</code> objects. These are used to
  46:  * managed little windows that float over everything else,
  47:  * typically containing a popup menu.
  48:  *
  49:  * @since 1.4
  50:  *
  51:  * @author Sascha Brawer (brawer@dandelis.ch)
  52:  */
  53: public class PopupFactory
  54: {
  55:   /**
  56:    * The shared factory object.
  57:    *
  58:    * @see #getSharedFactory
  59:    * @see #setSharedFactory
  60:    */
  61:   private static PopupFactory sharedFactory;
  62: 
  63: 
  64:   /**
  65:    * Constructs a new <code>PopupFactory</code>. Usually, a single
  66:    * <code>PopupFactory</code> is shared among multiple consumers
  67:    * of <code>Popup</code>. Use {@link #getSharedInstance} to retrieve
  68:    * the current factory.
  69:    */
  70:   public PopupFactory()
  71:   {
  72:   }
  73: 
  74: 
  75:   /**
  76:    * Sets the shared factory.
  77:    *
  78:    * @param factory the PopupFactory that future invocations of
  79:    *        {@link #getSharedInstance} will return.
  80:    *
  81:    * @throws IllegalArgumentException if <code>factory</code>
  82:    *         is <code>null</code>.
  83:    */
  84:   public static void setSharedInstance(PopupFactory factory)
  85:   {
  86:     if (factory == null)
  87:       throw new IllegalArgumentException();
  88: 
  89:     /* Swing is not designed to be thread-safe, so there is no
  90:      * need to synchronize the access to the global variable.
  91:      */
  92:     sharedFactory = factory;
  93:   }
  94: 
  95: 
  96:   /**
  97:    * Retrieves the shared factory, creating a new factory if
  98:    * necessary.
  99:    *
 100:    * @return a <code>PopupFactory</code> that can be used
 101:    *         to create <code>Popup</code> objects.
 102:    */
 103:   public static PopupFactory getSharedInstance()
 104:   {
 105:     /* Swing is not designed to be thread-safe, so there is no
 106:      * need to synchronize the access to the global variable.
 107:      */
 108:     if (sharedFactory == null)
 109:       sharedFactory = new PopupFactory();
 110: 
 111:     return sharedFactory;
 112:   }
 113: 
 114: 
 115:   /**
 116:    * Creates a new <code>Popup</code> given its owner,
 117:    * contents and the screen position where the popup
 118:    * will appear.
 119:    *
 120:    * @param owner the Component to which <code>x</code> and
 121:    *        <code>y</code> are relative, or <code>null</code> for
 122:    *        placing the popup relative to the origin of the screen.
 123:    *
 124:    * @param contents the contents that will be displayed inside
 125:    *        the <code>Popup</code>.
 126:    *
 127:    * @param x the horizontal position where the Popup will appear.
 128:    *
 129:    * @param y the vertical position where the Popup will appear.
 130:    *
 131:    * @throws IllegalArgumentException if <code>contents</code>
 132:    *         is <code>null</code>.
 133:    */
 134:   public Popup getPopup(Component owner, Component contents,
 135:                         int x, int y)
 136:   {
 137:     return new Popup.JWindowPopup(owner, contents, x, y);
 138:   }
 139: }