Source for java.awt.event.ComponentEvent

   1: /* ComponentEvent.java -- notification of events for components
   2:    Copyright (C) 1999, 2002, 2005, 2006  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 java.awt.event;
  40: 
  41: import java.awt.AWTEvent;
  42: import java.awt.Component;
  43: 
  44: /**
  45:  * This class is for events generated when a component is moved, resized,
  46:  * hidden, or shown.  These events normally do not need to be handled by the
  47:  * application, since the AWT system automatically takes care of them. This
  48:  * is also the superclass for other events on components, but
  49:  * ComponentListeners ignore such subclasses.
  50:  *
  51:  * @author Aaron M. Renn (arenn@urbanophile.com)
  52:  * @see ComponentAdapter
  53:  * @see ComponentListener
  54:  * @since 1.1
  55:  * @status updated to 1.4
  56:  */
  57: public class ComponentEvent extends AWTEvent
  58: {
  59:   /**
  60:    * Compatible with JDK 1.1+.
  61:    */
  62:   private static final long serialVersionUID = 8101406823902992965L;
  63: 
  64:   /** This is the first id in the range of ids used by this class. */
  65:   public static final int COMPONENT_FIRST = 100;
  66: 
  67:   /** This is the last id in the range of ids used by this class. */
  68:   public static final int COMPONENT_LAST = 103;
  69: 
  70:   /** This id indicates that a component was moved. */
  71:   public static final int COMPONENT_MOVED = 100;
  72: 
  73:   /** This id indicates that a component was resized. */
  74:   public static final int COMPONENT_RESIZED = 101;
  75: 
  76:   /** This id indicates that a component was shown. */
  77:   public static final int COMPONENT_SHOWN = 102;
  78: 
  79:   /** This id indicates that a component was hidden. */
  80:   public static final int COMPONENT_HIDDEN = 103;
  81: 
  82:   /**
  83:    * Initializes a new instance of <code>ComponentEvent</code> with the
  84:    * specified source and id. Note that an invalid id leads to unspecified
  85:    * results.
  86:    *
  87:    * @param source the source of the event
  88:    * @param id the event id
  89:    * @throws IllegalArgumentException if source is null
  90:    */
  91:   public ComponentEvent(Component source, int id)
  92:   {
  93:     super(source, id);
  94:   }
  95: 
  96:   /**
  97:    * This method returns the event source as a <code>Component</code>. If the
  98:    * source has subsequently been modified to a non-Component, this returns
  99:    * null.
 100:    *
 101:    * @return the event source as a <code>Component</code>, or null
 102:    */
 103:   public Component getComponent()
 104:   {
 105:     return source instanceof Component ? (Component) source : null;
 106:   }
 107: 
 108:   /**
 109:    * This method returns a string identifying this event. This is the field
 110:    * name of the id type, and for COMPONENT_MOVED or COMPONENT_RESIZED, the
 111:    * new bounding box of the component.
 112:    *
 113:    * @return a string identifying this event
 114:    */
 115:   public String paramString()
 116:   {
 117:     StringBuffer s = new StringBuffer();
 118:     
 119:     // Unlike Sun, we don't throw NullPointerException or ClassCastException
 120:     // when source was illegally changed.
 121:     if (id == COMPONENT_MOVED)
 122:       s.append("COMPONENT_MOVED ");
 123:     else if (id == COMPONENT_RESIZED) 
 124:       s.append("COMPONENT_RESIZED ");
 125:     else if (id == COMPONENT_SHOWN)
 126:       s.append("COMPONENT_SHOWN ");
 127:     else if (id == COMPONENT_HIDDEN)
 128:       s.append("COMPONENT_HIDDEN ");
 129:     else
 130:       return "unknown type";
 131: 
 132:     s.append("(").append(getComponent().getX()).append(",")
 133:       .append(getComponent().getY()).append(" ")
 134:       .append(getComponent().getWidth()).append("x")
 135:       .append(getComponent().getHeight()).append(")");
 136: 
 137:     return s.toString();
 138:   }
 139:   
 140: } // class ComponentEvent