001 /* Caret.java -- 002 Copyright (C) 2002, 2004, 2005 Free Software Foundation, Inc. 003 004 This file is part of GNU Classpath. 005 006 GNU Classpath is free software; you can redistribute it and/or modify 007 it under the terms of the GNU General Public License as published by 008 the Free Software Foundation; either version 2, or (at your option) 009 any later version. 010 011 GNU Classpath is distributed in the hope that it will be useful, but 012 WITHOUT ANY WARRANTY; without even the implied warranty of 013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014 General Public License for more details. 015 016 You should have received a copy of the GNU General Public License 017 along with GNU Classpath; see the file COPYING. If not, write to the 018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 019 02110-1301 USA. 020 021 Linking this library statically or dynamically with other modules is 022 making a combined work based on this library. Thus, the terms and 023 conditions of the GNU General Public License cover the whole 024 combination. 025 026 As a special exception, the copyright holders of this library give you 027 permission to link this library with independent modules to produce an 028 executable, regardless of the license terms of these independent 029 modules, and to copy and distribute the resulting executable under 030 terms of your choice, provided that you also meet, for each linked 031 independent module, the terms and conditions of the license of that 032 module. An independent module is a module which is not derived from 033 or based on this library. If you modify this library, you may extend 034 this exception to your version of the library, but you are not 035 obligated to do so. If you do not wish to do so, delete this 036 exception statement from your version. */ 037 038 039 package javax.swing.text; 040 041 import java.awt.Graphics; 042 import java.awt.Point; 043 044 import javax.swing.event.ChangeListener; 045 046 /** 047 * Defines the method to be implemented by a caret that can be used in Swing 048 * text components. 049 * 050 * @author original author unknown 051 * @author Roman Kennke (roman@kennke.org) 052 */ 053 public interface Caret 054 { 055 /** 056 * Registers a {@link ChangeListener} that is notified whenever that state 057 * of this <code>Caret</code> changes. 058 * 059 * @param l the listener to register to this caret 060 */ 061 void addChangeListener(ChangeListener l); 062 063 /** 064 * Removes a {@link ChangeListener} from the list of registered listeners. 065 * 066 * @param l the listener to remove 067 */ 068 void removeChangeListener(ChangeListener l); 069 070 /** 071 * Installs this <code>Caret</code> on the specified text component. This 072 * usually involves setting up listeners. 073 * 074 * This method is called by {@link JTextComponent#setCaret(Caret)} after 075 * this caret has been set on the text component. 076 * 077 * @param c the text component to install this caret to 078 */ 079 void install(JTextComponent c); 080 081 /** 082 * Deinstalls this <code>Caret</code> from the specified text component. 083 * This usually involves removing listeners from the text component. 084 * 085 * This method is called by {@link JTextComponent#setCaret(Caret)} before 086 * this caret is removed from the text component. 087 * 088 * @param c the text component to deinstall this caret from 089 */ 090 void deinstall(JTextComponent c); 091 092 /** 093 * Returns the blink rate of this <code>Caret</code> in milliseconds. 094 * A value of <code>0</code> means that the caret does not blink. 095 * 096 * @return the blink rate of this <code>Caret</code> or <code>0</code> if 097 * this caret does not blink 098 */ 099 int getBlinkRate(); 100 101 /** 102 * Sets the blink rate of this <code>Caret</code> in milliseconds. 103 * A value of <code>0</code> means that the caret does not blink. 104 * 105 * @param rate the new blink rate to set 106 */ 107 void setBlinkRate(int rate); 108 109 /** 110 * Returns the current position of this <code>Caret</code> within the 111 * <code>Document</code>. 112 * 113 * @return the current position of this <code>Caret</code> within the 114 * <code>Document</code> 115 */ 116 int getDot(); 117 118 /** 119 * Sets the current position of this <code>Caret</code> within the 120 * <code>Document</code>. This also sets the <code>mark</code> to the 121 * new location. 122 * 123 * @param dot the new position to be set 124 * 125 * @see #moveDot(int) 126 */ 127 void setDot(int dot); 128 129 /** 130 * Moves the <code>dot</code> location without touching the 131 * <code>mark</code>. This is used when making a selection. 132 * 133 * @param dot the location where to move the dot 134 * 135 * @see #setDot(int) 136 */ 137 void moveDot(int dot); 138 139 /** 140 * Returns the current position of the <code>mark</code>. The 141 * <code>mark</code> marks the location in the <code>Document</code> that 142 * is the end of a selection. If there is no selection, the <code>mark</code> 143 * is the same as the <code>dot</code>. 144 * 145 * @return the current position of the mark 146 */ 147 int getMark(); 148 149 /** 150 * Returns the current visual position of this <code>Caret</code>. 151 * 152 * @return the current visual position of this <code>Caret</code> 153 * 154 * @see #setMagicCaretPosition 155 */ 156 Point getMagicCaretPosition(); 157 158 /** 159 * Sets the current visual position of this <code>Caret</code>. 160 * 161 * @param p the Point to use for the saved location. May be <code>null</code> 162 * to indicate that there is no visual location 163 */ 164 void setMagicCaretPosition(Point p); 165 166 /** 167 * Returns <code>true</code> if the selection is currently visible, 168 * <code>false</code> otherwise. 169 * 170 * @return <code>true</code> if the selection is currently visible, 171 * <code>false</code> otherwise 172 */ 173 boolean isSelectionVisible(); 174 175 /** 176 * Sets the visiblity state of the selection. 177 * 178 * @param v <code>true</code> if the selection should be visible, 179 * <code>false</code> otherwise 180 */ 181 void setSelectionVisible(boolean v); 182 183 /** 184 * Returns <code>true</code> if this <code>Caret</code> is currently visible, 185 * and <code>false</code> if it is not. 186 * 187 * @return <code>true</code> if this <code>Caret</code> is currently visible, 188 * and <code>false</code> if it is not 189 */ 190 boolean isVisible(); 191 192 /** 193 * Sets the visibility state of the caret. <code>true</code> shows the 194 * <code>Caret</code>, <code>false</code> hides it. 195 * 196 * @param v the visibility to set 197 */ 198 void setVisible(boolean v); 199 200 /** 201 * Paints this <code>Caret</code> to the specified <code>Graphics</code> 202 * context. 203 * 204 * @param g the graphics context to render to 205 */ 206 void paint(Graphics g); 207 }