libjava/javax/swing/text/DefaultCaret.java

   1 /* DefaultCaret.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., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 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 package javax.swing.text;
  39
  40 import java.awt.Graphics;
  41 import java.awt.Point;
  42 import java.awt.Rectangle;
  43 import java.awt.event.FocusEvent;
  44 import java.awt.event.FocusListener;
  45 import java.awt.event.MouseEvent;
  46 import java.awt.event.MouseListener;
  47 import java.awt.event.MouseMotionListener;
  48 import java.util.EventListener;
  49
  50 import javax.swing.event.ChangeEvent;
  51 import javax.swing.event.ChangeListener;
  52 import javax.swing.event.EventListenerList;
  53
  54
  55 public class DefaultCaret extends Rectangle
  56   implements Caret, FocusListener, MouseListener, MouseMotionListener
  57 {
  58   private static final long serialVersionUID = 228155774675466193L;
  59
  60   protected ChangeEvent changeEvent = new ChangeEvent(this);
  61   protected EventListenerList listenerList = new EventListenerList();
  62
  63   private JTextComponent textComponent;
  64
  65   private boolean selectionVisible = true;
  66   private int blinkRate = 0;
  67   private int dot = 0;
  68   private int mark = 0;
  69   private Point magicCaretPosition = null;
  70   private boolean visible = true;
  71   private Object highlightEntry;
  72
  73   public void mouseDragged(MouseEvent event)
  74   {
  75   }
  76
  77   public void mouseMoved(MouseEvent event)
  78   {
  79   }
  80
  81   public void mouseClicked(MouseEvent event)
  82   {
  83   }
  84
  85   public void mouseEntered(MouseEvent event)
  86   {
  87   }
  88
  89   public void mouseExited(MouseEvent event)
  90   {
  91   }
  92
  93   public void mousePressed(MouseEvent event)
  94   {
  95   }
  96
  97   public void mouseReleased(MouseEvent event)
  98   {
  99   }
 100
 101   public void focusGained(FocusEvent event)
 102   {
 103   }
 104
 105   public void focusLost(FocusEvent event)
 106   {
 107   }
 108
 109   protected void moveCaret(MouseEvent event)
 110   {
 111   }
 112
 113   protected void positionCaret(MouseEvent event)
 114   {
 115   }
 116
 117   public void deinstall(JTextComponent c)
 118   {
 119     textComponent.removeFocusListener(this);
 120     textComponent.removeMouseListener(this);
 121     textComponent.removeMouseMotionListener(this);
 122     textComponent = null;
 123   }
 124
 125   public void install(JTextComponent c)
 126   {
 127     textComponent = c;
 128     textComponent.addFocusListener(this);
 129     textComponent.addMouseListener(this);
 130     textComponent.addMouseMotionListener(this);
 131     repaint();
 132   }
 133
 134   public void setMagicCaretPosition(Point p)
 135   {
 136     magicCaretPosition = p;
 137   }
 138
 139   public Point getMagicCaretPosition()
 140   {
 141     return magicCaretPosition;
 142   }
 143
 144   public int getMark()
 145   {
 146     return mark;
 147   }
 148
 149   private void handleHighlight()
 150   {
 151     Highlighter highlighter = textComponent.getHighlighter();
 152
 153     if (highlighter == null)
 154       return;
 155
 156     int p0 = Math.min(dot, mark);
 157     int p1 = Math.max(dot, mark);
 158
 159     if (selectionVisible && p0 != p1)
 160       {
 161         try
 162           {
 163             if (highlightEntry == null)
 164               highlightEntry = highlighter.addHighlight(p0, p1, getSelectionPainter());
 165             else
 166               highlighter.changeHighlight(highlightEntry, p0, p1);
 167           }
 168         catch (BadLocationException e)
 169           {
 170             // This should never happen.
 171             throw new InternalError();
 172           }
 173       }
 174     else
 175       {
 176         if (highlightEntry != null)
 177           {
 178             highlighter.removeHighlight(highlightEntry);
 179             highlightEntry = null;
 180           }
 181       }
 182   }
 183
 184   public void setSelectionVisible(boolean v)
 185   {
 186     if (selectionVisible == v)
 187       return;
 188
 189     selectionVisible = v;
 190     handleHighlight();
 191     repaint();
 192   }
 193
 194   public boolean isSelectionVisible()
 195   {
 196     return selectionVisible;
 197   }
 198
 199   protected final void repaint()
 200   {
 201     if (textComponent != null)
 202       textComponent.repaint();
 203   }
 204
 205   public void paint(Graphics g)
 206   {
 207     if (textComponent == null)
 208       return;
 209
 210     int dot = getDot();
 211     Rectangle rect = null;
 212
 213     try
 214       {
 215         rect = textComponent.modelToView(dot);
 216       }
 217     catch (BadLocationException e)
 218       {
 219         // This should never happen as dot should be always valid.
 220         return;
 221       }
 222
 223     if (rect == null)
 224       return;
 225
 226     // First we need to delete the old caret.
 227     // FIXME: Implement deleting of old caret.
 228
 229     // Now draw the caret on the new position if visible.
 230     if (visible)
 231       {
 232         g.setColor(textComponent.getCaretColor());
 233         g.drawLine(rect.x, rect.y, rect.x, rect.y + rect.height);
 234       }
 235   }
 236
 237   public EventListener[] getListeners(Class listenerType)
 238   {
 239     return listenerList.getListeners(listenerType);
 240   }
 241
 242   public void addChangeListener(ChangeListener listener)
 243   {
 244     listenerList.add(ChangeListener.class, listener);
 245   }
 246
 247   public void removeChangeListener(ChangeListener listener)
 248   {
 249     listenerList.remove(ChangeListener.class, listener);
 250   }
 251
 252   public ChangeListener[] getChangeListeners()
 253   {
 254     return (ChangeListener[]) getListeners(ChangeListener.class);
 255   }
 256
 257   protected void fireStateChanged()
 258   {
 259     ChangeListener[] listeners = getChangeListeners();
 260
 261     for (int index = 0; index < listeners.length; ++index)
 262       listeners[index].stateChanged(changeEvent);
 263   }
 264
 265   protected final JTextComponent getComponent()
 266   {
 267     return textComponent;
 268   }
 269
 270   public int getBlinkRate()
 271   {
 272     return blinkRate;
 273   }
 274
 275   public void setBlinkRate(int rate)
 276   {
 277     blinkRate = rate;
 278   }
 279
 280   public int getDot()
 281   {
 282     return dot;
 283   }
 284
 285   public void moveDot(int dot)
 286   {
 287     this.dot = dot;
 288     handleHighlight();
 289     repaint();
 290   }
 291
 292   public void setDot(int dot)
 293   {
 294     this.dot = dot;
 295     this.mark = dot;
 296     handleHighlight();
 297     repaint();
 298   }
 299
 300   public boolean isVisible()
 301   {
 302     return visible;
 303   }
 304
 305   public void setVisible(boolean v)
 306   {
 307     visible = v;
 308     repaint();
 309   }
 310
 311   protected Highlighter.HighlightPainter getSelectionPainter()
 312   {
 313     return DefaultHighlighter.DefaultPainter;
 314   }
 315 }