/*
* DefaultInputHandler.java - Default implementation of an input handler
* Copyright (C) 1999 Slava Pestov
*
* You may use and modify this package for any purpose. Redistribution is
* permitted, in both source and binary form, provided that this notice
* remains intact in all source distributions of this package.
*/
import javax.swing.KeyStroke;
import java.awt.event.*;
import java.awt.Toolkit;
import java.util.Hashtable;
import java.util.StringTokenizer;
/**
* The default input handler. It maps sequences of keystrokes into actions
* and inserts key typed events into the text area.
* @author Slava Pestov
* @version $Id: DefaultInputHandler.java,v 1.18 1999/12/13 03:40:30 sp Exp $
*/
public class DefaultInputHandler extends InputHandler
{
/**
* Creates a new input handler with no key bindings defined.
*/
public DefaultInputHandler()
{
bindings = currentBindings = new Hashtable();
}
/**
* Sets up the default key bindings.
*/
public void addDefaultKeyBindings()
{
addKeyBinding("BACK_SPACE",BACKSPACE);
addKeyBinding("C+BACK_SPACE",BACKSPACE_WORD);
addKeyBinding("DELETE",DELETE);
addKeyBinding("C+DELETE",DELETE_WORD);
addKeyBinding("ENTER",INSERT_BREAK);
addKeyBinding("TAB",INSERT_TAB);
addKeyBinding("INSERT",OVERWRITE);
addKeyBinding("C+\\",TOGGLE_RECT);
addKeyBinding("HOME",HOME);
addKeyBinding("END",END);
addKeyBinding("S+HOME",SELECT_HOME);
addKeyBinding("S+END",SELECT_END);
addKeyBinding("C+HOME",DOCUMENT_HOME);
addKeyBinding("C+END",DOCUMENT_END);
addKeyBinding("CS+HOME",SELECT_DOC_HOME);
addKeyBinding("CS+END",SELECT_DOC_END);
addKeyBinding("PAGE_UP",PREV_PAGE);
addKeyBinding("PAGE_DOWN",NEXT_PAGE);
addKeyBinding("S+PAGE_UP",SELECT_PREV_PAGE);
addKeyBinding("S+PAGE_DOWN",SELECT_NEXT_PAGE);
addKeyBinding("LEFT",PREV_CHAR);
addKeyBinding("S+LEFT",SELECT_PREV_CHAR);
addKeyBinding("C+LEFT",PREV_WORD);
addKeyBinding("CS+LEFT",SELECT_PREV_WORD);
addKeyBinding("RIGHT",NEXT_CHAR);
addKeyBinding("S+RIGHT",SELECT_NEXT_CHAR);
addKeyBinding("C+RIGHT",NEXT_WORD);
addKeyBinding("CS+RIGHT",SELECT_NEXT_WORD);
addKeyBinding("UP",PREV_LINE);
addKeyBinding("S+UP",SELECT_PREV_LINE);
addKeyBinding("DOWN",NEXT_LINE);
addKeyBinding("S+DOWN",SELECT_NEXT_LINE);
addKeyBinding("C+ENTER",REPEAT);
}
/**
* Adds a key binding to this input handler. The key binding is
* a list of white space separated key strokes of the form
* <i>[modifiers+]key</i> where modifier is C for Control, A for Alt,
* or S for Shift, and key is either a character (a-z) or a field
* name in the KeyEvent class prefixed with VK_ (e.g., BACK_SPACE)
* @param keyBinding The key binding
* @param action The action
*/
public void addKeyBinding(String keyBinding, ActionListener action)
{
Hashtable current = bindings;
StringTokenizer st = new StringTokenizer(keyBinding);
while(st.hasMoreTokens())
{
KeyStroke keyStroke = parseKeyStroke(st.nextToken());
if(keyStroke == null)
return;
if(st.hasMoreTokens())
{
Object o = current.get(keyStroke);
if(o instanceof Hashtable)
current = (Hashtable)o;
else
{
o = new Hashtable();
current.put(keyStroke,o);
current = (Hashtable)o;
}
}
else
current.put(keyStroke,action);
}
}
/**
* Removes a key binding from this input handler. This is not yet
* implemented.
* @param keyBinding The key binding
*/
public void removeKeyBinding(String keyBinding)
{
throw new InternalError("Not yet implemented");
}
/**
* Removes all key bindings from this input handler.
*/
public void removeAllKeyBindings()
{
bindings.clear();
}
/**
* Returns a copy of this input handler that shares the same
* key bindings. Setting key bindings in the copy will also
* set them in the original.
*/
public InputHandler copy()
{
return new DefaultInputHandler(this);
}
/**
* Handle a key pressed event. This will look up the binding for
* the key stroke and execute it.
*/
public void keyPressed(KeyEvent evt)
{
int keyCode = evt.getKeyCode();
int modifiers = evt.getModifiers();
if(keyCode == KeyEvent.VK_CONTROL ||
keyCode == KeyEvent.VK_SHIFT ||
keyCode == KeyEvent.VK_ALT ||
keyCode == KeyEvent.VK_META)
return;
if((modifiers & ~KeyEvent.SHIFT_MASK) != 0
|| evt.isActionKey()
|| keyCode == KeyEvent.VK_BACK_SPACE
|| keyCode == KeyEvent.VK_DELETE
|| keyCode == KeyEvent.VK_ENTER
|| keyCode == KeyEvent.VK_TAB
|| keyCode == KeyEvent.VK_ESCAPE)
{
if(grabAction != null)
{
handleGrabAction(evt);
return;
}
KeyStroke keyStroke = KeyStroke.getKeyStroke(keyCode,
modifiers);
Object o = currentBindings.get(keyStroke);
if(o == null)
{
// Don't beep if the user presses some
// key we don't know about unless a
// prefix is active. Otherwise it will
// beep when caps lock is pressed, etc.
if(currentBindings != bindings)
{
Toolkit.getDefaultToolkit().beep();
// F10 should be passed on, but C+e F10
// shouldn't
repeatCount = 0;
repeat = false;
evt.consume();
}
currentBindings = bindings;
return;
}
else if(o instanceof ActionListener)
{
currentBindings = bindings;
executeAction(((ActionListener)o),
evt.getSource(),null);
evt.consume();
return;
}
else if(o instanceof Hashtable)
{
currentBindings = (Hashtable)o;
evt.consume();
return;
}
}
}
/**
* Handle a key typed event. This inserts the key into the text area.
*/
public void keyTyped(KeyEvent evt)
{
int modifiers = evt.getModifiers();
char c = evt.getKeyChar();
if(c != KeyEvent.CHAR_UNDEFINED &&
(modifiers & KeyEvent.ALT_MASK) == 0)
{
if(c >= 0x20 && c != 0x7f)
{
KeyStroke keyStroke = KeyStroke.getKeyStroke(
Character.toUpperCase(c));
Object o = currentBindings.get(keyStroke);
if(o instanceof Hashtable)
{
currentBindings = (Hashtable)o;
return;
}
else if(o instanceof ActionListener)
{
currentBindings = bindings;
executeAction((ActionListener)o,
evt.getSource(),
String.valueOf(c));
return;
}
currentBindings = bindings;
if(grabAction != null)
{
handleGrabAction(evt);
return;
}
// 0-9 adds another 'digit' to the repeat number
if(repeat && Character.isDigit(c))
{
repeatCount *= 10;
repeatCount += (c - '0');
return;
}
executeAction(INSERT_CHAR,evt.getSource(),
String.valueOf(evt.getKeyChar()));
repeatCount = 0;
repeat = false;
}
}
}
/**
* Converts a string to a keystroke. The string should be of the
* form <i>modifiers</i>+<i>shortcut</i> where <i>modifiers</i>
* is any combination of A for Alt, C for Control, S for Shift
* or M for Meta, and <i>shortcut</i> is either a single character,
* or a keycode name from the <code>KeyEvent</code> class, without
* the <code>VK_</code> prefix.
* @param keyStroke A string description of the key stroke
*/
public static KeyStroke parseKeyStroke(String keyStroke)
{
if(keyStroke == null)
return null;
int modifiers = 0;
int index = keyStroke.indexOf('+');
if(index != -1)
{
for(int i = 0; i < index; i++)
{
switch(Character.toUpperCase(keyStroke
.charAt(i)))
{
case 'A':
modifiers |= InputEvent.ALT_MASK;
break;
case 'C':
modifiers |= InputEvent.CTRL_MASK;
break;
case 'M':
modifiers |= InputEvent.META_MASK;
break;
case 'S':
modifiers |= InputEvent.SHIFT_MASK;
break;
}
}
}
String key = keyStroke.substring(index + 1);
if(key.length() == 1)
{
char ch = Character.toUpperCase(key.charAt(0));
if(modifiers == 0)
return KeyStroke.getKeyStroke(ch);
else
return KeyStroke.getKeyStroke(ch,modifiers);
}
else if(key.length() == 0)
{
System.err.println("Invalid key stroke: " + keyStroke);
return null;
}
else
{
int ch;
try
{
ch = KeyEvent.class.getField("VK_".concat(key))
.getInt(null);
}
catch(Exception e)
{
System.err.println("Invalid key stroke: "
+ keyStroke);
return null;
}
return KeyStroke.getKeyStroke(ch,modifiers);
}
}
// private members
private Hashtable bindings;
private Hashtable currentBindings;
private DefaultInputHandler(DefaultInputHandler copy)
{
bindings = currentBindings = copy.bindings;
}
}