001/* JToolTip.java --
002   Copyright (C) 2002, 2004  Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038
039package javax.swing;
040
041import gnu.java.lang.CPStringBuilder;
042
043import java.awt.AWTEvent;
044import java.beans.PropertyChangeEvent;
045
046import javax.accessibility.Accessible;
047import javax.accessibility.AccessibleContext;
048import javax.accessibility.AccessibleRole;
049import javax.swing.plaf.ToolTipUI;
050
051/**
052 * This class is used to display ToolTips. ToolTips are small floating windows
053 * that display text when the mouse comes to rest over a Component. ToolTips
054 * are set for JComponents using JComponent.setToolTipText(String).
055 */
056public class JToolTip extends JComponent implements Accessible
057{
058
059  private static final long serialVersionUID = -1138929898906751643L;
060
061  /**
062   * Provides the accessibility features for the <code>JToolTip</code>
063   * component.
064   */
065  protected class AccessibleJToolTip extends AccessibleJComponent
066  {
067    private static final long serialVersionUID = -6222548177795408476L;
068
069    /**
070     * Creates a new AccessibleJToolTip object.
071     */
072    protected AccessibleJToolTip()
073    {
074      // Nothing to do here.
075    }
076
077    /**
078     * Returns a description for the accessible component.
079     *
080     * @return A description for the accessible component.
081     */
082    public String getAccessibleDescription()
083    {
084      String result = super.getAccessibleDescription();
085      if (result == null)
086        result = text;
087      return result;
088    }
089
090    /**
091     * Returns the accessible role for the <code>JToolTip</code> component.
092     *
093     * @return {@link AccessibleRole#TOOL_TIP}.
094     */
095    public AccessibleRole getAccessibleRole()
096    {
097      return AccessibleRole.TOOL_TIP;
098    }
099  }
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}