001/* MetalToolTipUI.java
002   Copyright (C) 2005 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.plaf.metal;
040
041import java.awt.Color;
042import java.awt.Dimension;
043import java.awt.Font;
044import java.awt.FontMetrics;
045import java.awt.Graphics;
046import java.awt.event.InputEvent;
047import java.awt.event.KeyEvent;
048
049import javax.swing.AbstractButton;
050import javax.swing.JComponent;
051import javax.swing.JMenuItem;
052import javax.swing.JToolTip;
053import javax.swing.KeyStroke;
054import javax.swing.UIManager;
055import javax.swing.border.Border;
056import javax.swing.plaf.ComponentUI;
057import javax.swing.plaf.UIResource;
058import javax.swing.plaf.basic.BasicToolTipUI;
059
060/**
061 * A UI delegate for the {@link JToolTip} component.
062 */
063public class MetalToolTipUI
064  extends BasicToolTipUI
065{
066  /**
067   * The amount of space between the tool tip text and the accelerator
068   * description (if visible).
069   */
070  public static final int padSpaceBetweenStrings = 12;
071
072  /** The shared UI instance. */
073  private static MetalToolTipUI instance;
074
075  /** A flag controlling the visibility of the accelerator (if there is one). */
076  private boolean isAcceleratorHidden;
077
078  /** A string representing the accelerator key for the component. */
079  private String acceleratorString;
080
081  /**
082   * The delimiter for the accelerator string.
083   */
084  private String acceleratorDelimiter;
085
086  /** The font for the accelerator string. */
087  private Font acceleratorFont;
088
089  /** The color for the accelerator string. */
090  private Color acceleratorForeground;
091
092  /** The active border. */
093  private Border activeBorder;
094
095  /** The inactive border. */
096  private Border inactiveBorder;
097
098  /**
099   * Constructs a new instance of <code>MetalToolTipUI</code>.
100   */
101  public MetalToolTipUI()
102  {
103    super();
104    activeBorder = UIManager.getBorder("ToolTip.border");
105    inactiveBorder = UIManager.getBorder("ToolTip.borderInactive");
106    isAcceleratorHidden = UIManager.getBoolean("ToolTip.hideAccelerator");
107    acceleratorFont = UIManager.getFont("MenuItem.acceleratorFont");
108    acceleratorForeground = UIManager.getColor("MenuItem.acceleratorForeground");
109    acceleratorDelimiter = UIManager.getString("MenuItem.acceleratorDelimiter");
110  }
111
112  /**
113   * Returns a shared instance of the <code>MetalToolTipUI</code> class.
114   * Although this UI delegate does maintain state information, there is never
115   * more than one tool tip visible, so it is OK to use a shared instance.
116   *
117   * @param component  the component (a {@link JToolTip}).
118   *
119   * @return A shared instance of the <code>MetalToolTipUI</code> class.
120   */
121  public static ComponentUI createUI(JComponent component)
122  {
123    if (instance == null)
124      instance = new MetalToolTipUI();
125    return instance;
126  }
127
128  /**
129   * Returns a string representing the accelerator key (if there is one) for
130   * the component that the tool tip belongs to.
131   *
132   * @return A string representing the accelerator key.
133   */
134  public String getAcceleratorString()
135  {
136    return acceleratorString;
137  }
138
139  /**
140   * Installs the UI for the specified component (a {@link JToolTip}).
141   *
142   * @param c  the {@link JToolTip} component.
143   */
144  public void installUI(JComponent c)
145  {
146    super.installUI(c);
147    Border existingBorder = c.getBorder();
148    if (existingBorder == null || existingBorder instanceof UIResource)
149      {
150        if (c.isEnabled())
151          c.setBorder(activeBorder);
152        else
153          c.setBorder(inactiveBorder);
154      }
155  }
156
157  /**
158   * Clears the defaults set in {@link #installUI(JComponent)}.
159   *
160   * @param c  the component.
161   */
162  public void uninstallUI(JComponent c)
163  {
164    super.uninstallUI(c);
165    if (c.getBorder() instanceof UIResource)
166      c.setBorder(null);
167  }
168
169  /**
170   * Returns <code>true</code> if the accelerator string is hidden, and
171   * <code>false</code> otherwise.  This setting is controlled by the
172   * <code>ToolTip.hideAccelerator</code> entry in the UI defaults table.
173   *
174   * @return A boolean.
175   */
176  protected boolean isAcceleratorHidden()
177  {
178    return isAcceleratorHidden;
179  }
180
181  /**
182   * Returns the preferred size for the {@link JToolTip} component.
183   *
184   * @param c  the component (a {@link JToolTip}).
185   *
186   * @return The preferred size.
187   */
188  public Dimension getPreferredSize(JComponent c)
189  {
190    Dimension d = super.getPreferredSize(c);
191    String acc = getAcceleratorString();
192    if (acc != null && ! acc.equals(""))
193      {
194        FontMetrics fm = c.getFontMetrics(c.getFont());
195        d.width += fm.stringWidth(acc);
196      }
197    return d;
198  }
199
200  /**
201   * Paints the tool tip.
202   *
203   * @param g  the graphics context.
204   * @param c  the {@link JToolTip} component.
205   */
206  public void paint(Graphics g, JComponent c)
207  {
208    super.paint(g, c);
209    // Somehow paint accelerator. Keep care for possible HTML rendering.
210  }
211
212  /**
213   * Returns a string representing the accelerator for the component, or
214   * <code>null</code> if the component has no accelerator.
215   *
216   * @param c  the component.
217   *
218   * @return A string representing the accelerator (possibly
219   *         <code>null</code>).
220   */
221  private String fetchAcceleratorString(JComponent c)
222  {
223    String result = null;
224    if (c instanceof JToolTip)
225      {
226        JToolTip toolTip = (JToolTip) c;
227        JComponent component = toolTip.getComponent();
228        KeyStroke ks = null;
229        int mne = 0;
230        if (component instanceof JMenuItem)
231          {
232            JMenuItem item = (JMenuItem) component;
233            ks = item.getAccelerator();
234            if (ks == null)
235                mne = item.getMnemonic();
236          }
237        else if (component instanceof AbstractButton)
238          {
239            AbstractButton button = (AbstractButton) component;
240            mne = button.getMnemonic();
241          }
242        if (mne > 0)
243          ks = KeyStroke.getKeyStroke(Character.toUpperCase((char) mne),
244                InputEvent.ALT_MASK, false);
245        if (ks != null)
246          result = acceleratorToString(ks);
247      }
248    return result;
249  }
250
251  /**
252   * Returns a string representing an accelerator.
253   *
254   * @param accelerator  the accelerator (<code>null</code> not permitted).
255   *
256   * @return A string representing an accelerator.
257   */
258  private String acceleratorToString(KeyStroke accelerator)
259  {
260    // convert keystroke into string format
261    String modifiersText = "";
262    int modifiers = accelerator.getModifiers();
263    char keyChar = accelerator.getKeyChar();
264    int keyCode = accelerator.getKeyCode();
265
266    if (modifiers != 0)
267      modifiersText = KeyEvent.getKeyModifiersText(modifiers)
268          + acceleratorDelimiter;
269
270    if (keyCode == KeyEvent.VK_UNDEFINED)
271      return modifiersText + keyChar;
272    else
273      return modifiersText + KeyEvent.getKeyText(keyCode);
274  }
275
276}