001/* TextUI.java --
002   Copyright (C) 2002, 2003, 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.plaf;
040
041import java.awt.Point;
042import java.awt.Rectangle;
043import java.awt.Shape;
044
045import javax.swing.text.BadLocationException;
046import javax.swing.text.EditorKit;
047import javax.swing.text.JTextComponent;
048import javax.swing.text.Position;
049import javax.swing.text.View;
050
051/**
052 * An abstract base class for delegates that provide the user
053 * interface for text editors.
054 *
055 * @see javax.swing.text.JTextComponent
056 *
057 * @author Ronald Veldema (rveldema@cs.vu.nl)
058 * @author Sascha Brawer (brawer@dandelis.ch)
059 */
060public abstract class TextUI extends ComponentUI
061{
062  /**
063   * Constructs a new <code>TextUI</code>.
064   */
065  public TextUI()
066  {
067    // Nothing to do here.
068  }
069
070
071  /**
072   * Calculates the geometric extent of the character at the
073   * given offset.
074   *
075   * @param tc the <code>JTextComponent</code> for which this
076   *        delegate object provides the user interface.
077   *
078   * @param pos the zero-based index of the character into the
079   *        document model.
080   *
081   * @return the bounding box of the character at index
082   *         <code>pos</code>, in view coordinates.
083   *
084   * @throws BadLocationException if <code>pos</code> does not
085   *         designate a valid position in the document model.
086   *
087   * @see javax.swing.text.ComponentView#modelToView(int, Shape, Position.Bias)
088   */
089  public abstract Rectangle modelToView(JTextComponent tc, int pos)
090    throws BadLocationException;
091
092
093  /**
094   * Calculates the geometric extent of the character at the
095   * given offset.
096   *
097   * @param tc the <code>JTextComponent</code> for which this
098   *        delegate object provides the user interface.
099   *
100   * @param pos the zero-based index of the character into the
101   *        document model.
102   *
103   * @param bias whether to take the character before or after the
104   *        caret position indicated by <code>pos</code>.  The value
105   *        must be either {@link
106   *        javax.swing.text.Position.Bias#Backward} or {@link
107   *        javax.swing.text.Position.Bias#Forward}.
108   *
109   * @return the bounding box of the character at index
110   *         <code>pos</code>, in view coordinates.
111   *
112   * @throws BadLocationException if <code>pos</code> does not
113   *         designate a valid position in the document model.
114   *
115   * @see javax.swing.text.ComponentView#modelToView(int, Shape, Position.Bias)
116   */
117  public abstract Rectangle modelToView(JTextComponent tc, int pos,
118                                        Position.Bias bias)
119    throws BadLocationException;
120
121
122  /**
123   * Finds the caret position which is closest to the specified visual
124   * location.
125   *
126   * @param t the <code>JTextComponent</code> for which this
127   *        delegate object provides the user interface.
128   *
129   * @param pt the position in view coordinates.
130   *
131   * @return the caret position which is closest to <code>loc</code>.
132   *
133   * @see #viewToModel(JTextComponent, Point, Position.Bias[])
134   */
135  public abstract int viewToModel(JTextComponent t, Point pt);
136
137
138  /**
139   * Finds the caret position which is closest to the specified visual
140   * location.
141   *
142   * @param tc the <code>JTextComponent</code> for which this
143   *        delegate object provides the user interface.
144   *
145   * @param loc the position in view coordinates.
146   *
147   * @param outBias an array whose size must be at least one.
148   *        After the call, <code>outBias[0]</code> will indicate
149   *        whether <code>loc</code> is in the glyph before
150   *        (<code>Position.Bias.Backward</code>) or after
151   *        (<code>Position.Bias.Forward</code>) the returned
152   *        caret position.
153   *
154   * @return the caret position which is closest to <code>loc</code>.
155   */
156  public abstract int viewToModel(JTextComponent tc, Point loc,
157                                  Position.Bias[] outBias);
158
159
160
161  /**
162   * Calculates the caret position that is visually next to the given
163   * position. This is useful to determine where to move the caret
164   * after the user has pressed an arrow key.
165   *
166   * @param tc the <code>JTextComponent</code> for which this
167   *        delegate object provides the user interface.
168   *
169   * @param pos the current caret position, a zero-based index
170   *        into the document model.
171   *
172   * @param bias whether to take the character before or after the
173   *        caret position indicated by <code>pos</code>.  The value
174   *        must be either {@link
175   *        javax.swing.text.Position.Bias#Backward} or {@link
176   *        javax.swing.text.Position.Bias#Forward}.
177   *
178   * @param direction the visual direction. Pass
179   *        {@link javax.swing.SwingConstants#WEST} for the left
180   *        arrow key, {@link javax.swing.SwingConstants#EAST}
181   *        for the right arrow key, {@link
182   *        javax.swing.SwingConstants#NORTH} for the up arrow
183   *        key, or {@link javax.swing.SwingConstants#SOUTH}
184   *        for the down arrow key.
185   *
186   * @throws BadLocationException if <code>pos</code> does not
187   *         designate a valid position in the document model.
188   *
189   * @throws IllegalArgumentException if <code>direction</code>
190   *         is not one of <code>Position.Bias.Forward</code>
191   *         or <code>Position.Bias.Backward</code>.
192   */
193  public abstract int getNextVisualPositionFrom(JTextComponent tc,
194                                                int pos,
195                                                Position.Bias bias,
196                                                int direction,
197                                                Position.Bias[] outBias)
198    throws BadLocationException;
199
200
201  /**
202   * Repaints a range of characters.
203   *
204   * @param tc the <code>JTextComponent</code> for which this
205   *        delegate object provides the user interface.
206   *
207   * @param start the first character in the range that needs
208   *        painting, indicated as an index into the document model.
209   *
210   * @param end the last character in the range that needs
211   *        painting, indicated as an index into the document model.
212   *        <code>end</code> must be greater than or equal to
213   *        <code>start</code>.
214   */
215  public abstract void damageRange(JTextComponent tc, int start, int end);
216
217
218  /**
219   * Repaints a range of characters, also specifying the bias for the
220   * start and end of the range.
221   *
222   * @param tc the <code>JTextComponent</code> for which this
223   *        delegate object provides the user interface.
224   *
225   * @param start the first character in the range that needs
226   *        painting, indicated as an index into the document model.
227   *
228   * @param end the last character in the range that needs
229   *        painting, indicated as an index into the document model.
230   *        <code>end</code> must be greater than or equal to
231   *        <code>start</code>.
232   */
233  public abstract void damageRange(JTextComponent tc,
234                                   int start, int end,
235                                   Position.Bias startBias,
236                                   Position.Bias endBias);
237
238
239  /**
240   * Retrieves the <code>EditorKit</code> managing policies and
241   * persistent state.
242   *
243   * @param tc the <code>JTextComponent</code> for which this
244   *        delegate object provides the user interface.
245   *
246   * @return the <code>EditorKit</code> used by <code>tc</code>.
247   */
248  public abstract EditorKit getEditorKit(JTextComponent tc);
249
250
251  /**
252   * Retrieves the root of the view tree that visually presents
253   * the text.
254   *
255   * @param tc the <code>JTextComponent</code> for which this
256   *        delegate object provides the user interface.
257   *
258   * @return the root <code>View</code> used by <code>tc</code>.
259   */
260  public abstract View getRootView(JTextComponent tc);
261
262
263  /**
264   * Returns a String for presenting a tool tip at the specified
265   * location.
266   *
267   * @param tc the <code>JTextComponent</code> for which this
268   *        delegate object provides the user interface.
269   *
270   * @param loc the location for which the tool tip is requested.
271   *
272   * @return the text for the tool tip, or <code>null</code> to
273   *         display no tool tip.
274   *
275   * @since 1.4
276   */
277  public String getToolTipText(JTextComponent tc, Point loc)
278  {
279    return null;
280  }
281}