libjava/classpath/javax/swing/JToolTip.java

   1 /* JToolTip.java --
   2    Copyright (C) 2002, 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;
  40
  41 import gnu.java.lang.CPStringBuilder;
  42
  43 import java.awt.AWTEvent;
  44 import java.beans.PropertyChangeEvent;
  45
  46 import javax.accessibility.Accessible;
  47 import javax.accessibility.AccessibleContext;
  48 import javax.accessibility.AccessibleRole;
  49 import javax.swing.plaf.ToolTipUI;
  50
  51 /**
  52  * This class is used to display ToolTips. ToolTips are small floating windows
  53  * that display text when the mouse comes to rest over a Component. ToolTips
  54  * are set for JComponents using JComponent.setToolTipText(String).
  55  */
  56 public class JToolTip extends JComponent implements Accessible
  57 {
  58
  59   private static final long serialVersionUID = -1138929898906751643L;
  60
  61   /**
  62    * Provides the accessibility features for the <code>JToolTip</code>
  63    * component.
  64    */
  65   protected class AccessibleJToolTip extends AccessibleJComponent
  66   {
  67     private static final long serialVersionUID = -6222548177795408476L;
  68
  69     /**
  70      * Creates a new AccessibleJToolTip object.
  71      */
  72     protected AccessibleJToolTip()
  73     {
  74       // Nothing to do here.
  75     }
  76
  77     /**
  78      * Returns a description for the accessible component.
  79      *
  80      * @return A description for the accessible component.
  81      */
  82     public String getAccessibleDescription()
  83     {
  84       String result = super.getAccessibleDescription();
  85       if (result == null)
  86         result = text;
  87       return result;
  88     }
  89
  90     /**
  91      * Returns the accessible role for the <code>JToolTip</code> component.
  92      *
  93      * @return {@link AccessibleRole#TOOL_TIP}.
  94      */
  95     public AccessibleRole getAccessibleRole()
  96     {
  97       return AccessibleRole.TOOL_TIP;
  98     }
  99   }
 100
 101   /** The text to display in the JToolTip. */
 102   String text;
 103
 104   /** The component that the tool tip is associated with. */
 105   JComponent component;
 106
 107   /**
 108    * Creates a new <code>JToolTip</code> instance.
 109    */
 110   public JToolTip()
 111   {
 112     disableEvents(AWTEvent.MOUSE_EVENT_MASK);
 113     updateUI();
 114   }
 115
 116   /**
 117    * Returns the text displayed by the tool tip.
 118    *
 119    * @return The text (possibly <code>null</code>).
 120    *
 121    * @see #setTipText(String)
 122    */
 123   public String getTipText()
 124   {
 125     return text;
 126   }
 127
 128   /**
 129    * Returns the object that provides accessibility features for this
 130    * <code>JToolTip</code> component.
 131    *
 132    * @return The accessible context (an instance of {@link AccessibleJToolTip}).
 133    */
 134   public AccessibleContext getAccessibleContext()
 135   {
 136     if (accessibleContext == null)
 137       accessibleContext = new AccessibleJToolTip();
 138     return accessibleContext;
 139   }
 140
 141   /**
 142    * Returns the component that the tool tip is associated with.
 143    *
 144    * @return The component (possibly <code>null</code>).
 145    *
 146    * @see #setComponent(JComponent)
 147    */
 148   public JComponent getComponent()
 149   {
 150     return component;
 151   }
 152
 153   /**
 154    * Returns the current UI delegate for this component.
 155    *
 156    * @return The UI delegate.
 157    */
 158   public ToolTipUI getUI()
 159   {
 160     return (ToolTipUI) ui;
 161   }
 162
 163   /**
 164    * Returns the string suffix used to identify the UI class, in this case
 165    * <code>"ToolTipUI"</code>.
 166    *
 167    * @return <code>"ToolTipUI"</code>.
 168    */
 169   public String getUIClassID()
 170   {
 171     return "ToolTipUI";
 172   }
 173
 174   /**
 175    * Returns a string describing the attributes for the <code>JToolTip</code>
 176    * component, for use in debugging.  The return value is guaranteed to be
 177    * non-<code>null</code>, but the format of the string may vary between
 178    * implementations.
 179    *
 180    * @return A string describing the attributes of the <code>JToolTip</code>.
 181    */
 182   protected String paramString()
 183   {
 184     CPStringBuilder sb = new CPStringBuilder(super.paramString());
 185     sb.append(",tiptext=");
 186     if (text != null)
 187       sb.append(text);
 188     return sb.toString();
 189   }
 190
 191   /**
 192    * Sets the component that the tool tip is associated with and sends a
 193    * {@link PropertyChangeEvent} (with the property name 'component') to all
 194    * registered listeners.
 195    *
 196    * @param c  the component (<code>null</code> permitted).
 197    *
 198    * @see #getComponent()
 199    */
 200   public void setComponent(JComponent c)
 201   {
 202     JComponent oldValue = component;
 203     component = c;
 204     firePropertyChange("component", oldValue, c);
 205   }
 206
 207   /**
 208    * Sets the text to be displayed by the tool tip and sends a
 209    * {@link PropertyChangeEvent} (with the property name 'tiptext') to all
 210    * registered listeners.
 211    *
 212    * @param tipText the text (<code>null</code> permitted).
 213    *
 214    * @see #getTipText()
 215    */
 216   public void setTipText(String tipText)
 217   {
 218     String oldValue = text;
 219     text = tipText;
 220     firePropertyChange("tiptext", oldValue, tipText);
 221   }
 222
 223   /**
 224    * This method resets the UI used to the Look and Feel default.
 225    */
 226   public void updateUI()
 227   {
 228     setUI((ToolTipUI) UIManager.getUI(this));
 229   }
 230
 231   /**
 232    * Returns <code>true</code> if the component is guaranteed to be painted
 233    * on top of others. This returns false by default and is overridden by
 234    * components like JMenuItem, JPopupMenu and JToolTip to return true for
 235    * added efficiency.
 236    *
 237    * @return <code>true</code> if the component is guaranteed to be painted
 238    *         on top of others
 239    */
 240   boolean onTop()
 241   {
 242     return true;
 243   }
 244 }