inputhandler.java

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/*
 * InputHandler.java - Manages key bindings and executes actions
 * Copyright (C) 1999 Slava Pestov
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

package org.gjt.sp.jedit.textarea;

import javax.swing.text.*;
import javax.swing.JPopupMenu;
import java.awt.event.*;
import java.awt.Component;
import java.util.*;

import org.jext.*;

/**
 * An input handler converts the user's key strokes into concrete actions.
 * It also takes care of macro recording and action repetition.<p>
 *
 * This class provides all the necessary support code for an input
 * handler, but doesn't actually do any key binding logic. It is up
 * to the implementations of this class to do so.
 *
 * @author Slava Pestov
 * @version $Id: InputHandler.java,v 1.4 2003/07/08 18:55:50 blaisorblade Exp $
 * @see org.gjt.sp.jedit.textarea.DefaultInputHandler
 */
public abstract class InputHandler extends KeyAdapter
{
  /**
   * If this client property is set to Boolean.TRUE on the text area,
   * the home/end keys will support 'smart' BRIEF-like behaviour
   * (one press = start/end of line, two presses = start/end of
   * viewscreen, three presses = start/end of document). By default,
   * this property is not set.
   */
  public static final String SMART_HOME_END_PROPERTY = "InputHandler.homeEnd";

  public static final ActionListener BACKSPACE = new backspace();
  public static final ActionListener BACKSPACE_WORD = new backspace_word();
  public static final ActionListener DELETE = new delete();
  public static final ActionListener DELETE_WORD = new delete_word();
  public static final ActionListener END = new end(false);
  public static final ActionListener DOCUMENT_END = new document_end(false);
  public static final ActionListener SELECT_END = new end(true);
  public static final ActionListener SELECT_DOC_END = new document_end(true);
  public static final ActionListener INSERT_BREAK = new insert_break();
  public static final ActionListener INSERT_TAB = new insert_tab();
  public static final ActionListener HOME = new home(false);
  public static final ActionListener DOCUMENT_HOME = new document_home(false);
  public static final ActionListener SELECT_HOME = new home(true);
  public static final ActionListener SELECT_DOC_HOME = new document_home(true);
  public static final ActionListener NEXT_CHAR = new next_char(false);
  public static final ActionListener NEXT_LINE = new next_line(false);
  public static final ActionListener NEXT_PAGE = new next_page(false);
  public static final ActionListener NEXT_WORD = new next_word(false);
  public static final ActionListener SELECT_NEXT_CHAR = new next_char(true);
  public static final ActionListener SELECT_NEXT_LINE = new next_line(true);
  public static final ActionListener SELECT_NEXT_PAGE = new next_page(true);
  public static final ActionListener SELECT_NEXT_WORD = new next_word(true);
  public static final ActionListener OVERWRITE = new overwrite();
  public static final ActionListener PREV_CHAR = new prev_char(false);
  public static final ActionListener PREV_LINE = new prev_line(false);
  public static final ActionListener PREV_PAGE = new prev_page(false);
  public static final ActionListener PREV_WORD = new prev_word(false);
  public static final ActionListener SELECT_PREV_CHAR = new prev_char(true);
  public static final ActionListener SELECT_PREV_LINE = new prev_line(true);
  public static final ActionListener SELECT_PREV_PAGE = new prev_page(true);
  public static final ActionListener SELECT_PREV_WORD = new prev_word(true);
  public static final ActionListener REPEAT = new repeat();

  // Default action
  public static final ActionListener INSERT_CHAR = new insert_char();

  private static Hashtable actions;

  static
  {
    actions = new Hashtable();
    actions.put("backspace",BACKSPACE);
    actions.put("backspace-word",BACKSPACE_WORD);
    actions.put("delete",DELETE);
    actions.put("delete-word",DELETE_WORD);
    actions.put("end",END);
    actions.put("select-end",SELECT_END);
    actions.put("document-end",DOCUMENT_END);
    actions.put("select-doc-end",SELECT_DOC_END);
    actions.put("insert-break",INSERT_BREAK);
    actions.put("insert-tab",INSERT_TAB);
    actions.put("home",HOME);
    actions.put("select-home",SELECT_HOME);
    actions.put("document-home",DOCUMENT_HOME);
    actions.put("select-doc-home",SELECT_DOC_HOME);
    actions.put("next-char",NEXT_CHAR);
    actions.put("next-line",NEXT_LINE);
    actions.put("next-page",NEXT_PAGE);
    actions.put("next-word",NEXT_WORD);
    actions.put("select-next-char",SELECT_NEXT_CHAR);
    actions.put("select-next-line",SELECT_NEXT_LINE);
    actions.put("select-next-page",SELECT_NEXT_PAGE);
    actions.put("select-next-word",SELECT_NEXT_WORD);
    actions.put("overwrite",OVERWRITE);
    actions.put("prev-char",PREV_CHAR);
    actions.put("prev-line",PREV_LINE);
    actions.put("prev-page",PREV_PAGE);
    actions.put("prev-word",PREV_WORD);
    actions.put("select-prev-char",SELECT_PREV_CHAR);
    actions.put("select-prev-line",SELECT_PREV_LINE);
    actions.put("select-prev-page",SELECT_PREV_PAGE);
    actions.put("select-prev-word",SELECT_PREV_WORD);
    actions.put("repeat",REPEAT);
    actions.put("insert-char",INSERT_CHAR);
  }

  /**
   * Returns a named text area action.
   * @param name The action name
   */
  public static ActionListener getAction(String name)
  {
    return (ActionListener)actions.get(name);
  }

  /**
   * Returns the name of the specified text area action.
   * @param listener The action
   */
  public static String getActionName(ActionListener listener)
  {
    Enumeration enum = getActions();
    while(enum.hasMoreElements())
    {
      String name = (String)enum.nextElement();
      ActionListener _listener = getAction(name);
      if(_listener == listener)
        return name;
    }
    return null;
  }

  /**
   * Returns an enumeration of all available actions.
   */
  public static Enumeration getActions()
  {
    return actions.keys();
  }

  /**
   * Adds the default key bindings to this input handler.
   * This should not be called in the constructor of this
   * input handler, because applications might load the
   * key bindings from a file, etc.
   */
  public abstract void addDefaultKeyBindings();

  /**
   * Adds a key binding to this input handler.
   * @param keyBinding The key binding (the format of this is
   * input-handler specific)
   * @param action The action
   */
  public abstract void addKeyBinding(String keyBinding, ActionListener action);

  /**
   * Removes a key binding from this input handler.
   * @param keyBinding The key binding
   */
  public abstract void removeKeyBinding(String keyBinding);

  /**
   * Removes all key bindings from this input handler.
   */
  public abstract void removeAllKeyBindings();

  /**
   * Grabs the next key typed event and invokes the specified
   * action with the key as a the action command.
   * @param action The action
   */
  public void grabNextKeyStroke(ActionListener listener)
  {
    grabAction = listener;
  }

  /**
   * Returns if repeating is enabled. When repeating is enabled,
   * actions will be executed multiple times. This is usually
   * invoked with a special key stroke in the input handler.
   */
  public boolean isRepeatEnabled()
  {
    return repeat;
  }

  /**
   * Enables repeating. When repeating is enabled, actions will be
   * executed multiple times. Once repeating is enabled, the input
   * handler should read a number from the keyboard.
   */
  public void setRepeatEnabled(boolean repeat)
  {
    this.repeat = repeat;
    if(!repeat)
      repeatCount = 0;
  }

  /**
   * Returns the number of times the next action will be repeated.
   */
  public int getRepeatCount()
  {
    return (repeat ? Math.max(1,repeatCount) : 1);
  }

  /**
   * Sets the number of times the next action will be repeated.
   * @param repeatCount The repeat count
   */
  public void setRepeatCount(int repeatCount)
  {
    this.repeatCount = repeatCount;
  }

  /**
   * Returns the action used to handle text input.
   */
  public ActionListener getInputAction()
  {
    return inputAction;
  }

  /**
   * Sets the action used to handle text input.
   * @param inputAction The new input action
   */
  public void setInputAction(ActionListener inputAction)
  {
    this.inputAction = inputAction;
  }
  
  /**
   * Returns the macro recorder. If this is non-null, all executed
   * actions should be forwarded to the recorder.
   */
  public InputHandler.MacroRecorder getMacroRecorder()
  {
    return recorder;
  }

  /**
   * Sets the macro recorder. If this is non-null, all executed
   * actions should be forwarded to the recorder.
   * @param recorder The macro recorder
   */
  public void setMacroRecorder(InputHandler.MacroRecorder recorder)
  {
    this.recorder = recorder;
  }

  public void executeOneClickAction(org.jext.OneClickAction listener, Object source,
    String actionCommand)
  {
    // create event
    ActionEvent evt = new ActionEvent(source,
      ActionEvent.ACTION_PERFORMED,
      actionCommand);

    listener.oneClickActionPerformed(evt);
  }

  /**
   * Executes the specified action, repeating and recording it as
   * necessary.
   * @param listener The action listener
   * @param source The event source
   * @param actionCommand The action command
   */
  public void executeAction(ActionListener listener, Object source, String actionCommand)
  {
    // create event
    ActionEvent evt = new ActionEvent(source, ActionEvent.ACTION_PERFORMED, actionCommand);

    if (listener instanceof EditAction && !getTextArea(evt).isEditable())
      return;

    getTextArea(evt).setOneClick(null);

    // don't do anything if the action is a wrapper
    // (like EditAction.Wrapper)
    if(listener instanceof Wrapper)
    {
      listener.actionPerformed(evt);
      return;
    }

    // remember old values, in case action changes them
    boolean _repeat = repeat;
    int _repeatCount = getRepeatCount();

    // execute the action
    if(listener instanceof InputHandler.NonRepeatable)
      listener.actionPerformed(evt);
    else
    {
      for (int i = 0; i < Math.max(1, _repeatCount); i++)
        listener.actionPerformed(evt);
    }

    // do recording. Notice that we do no recording whatsoever
    // for actions that grab keys
    if(grabAction == null)
    {
      if(recorder != null)
      {
        if(!(listener instanceof InputHandler.NonRecordable))
        {
          if(_repeatCount != 1)
            recorder.actionPerformed(REPEAT,String.valueOf(_repeatCount));

          recorder.actionPerformed(listener,actionCommand);
        }
      }

      // If repeat was true originally, clear it
      // Otherwise it might have been set by the action, etc
      if(_repeat)
        setRepeatEnabled(false);
    }
  }

  /**
   * Returns the text area that fired the specified event.
   * @param evt The event
   */
  public static JEditTextArea getTextArea(EventObject evt)
  {
    if(evt != null)
    {
      Object o = evt.getSource();
      if(o instanceof Component)
      {
        // find the parent text area
        Component c = (Component)o;
        for(;;)
        {
          if(c instanceof JEditTextArea)
            return (JEditTextArea)c;
          else if(c == null)
            break;
          if(c instanceof JPopupMenu)
            c = ((JPopupMenu)c).getInvoker();
          else if (c instanceof JextFrame)
            c = ((JextFrame) c).getTextArea();
          else
            c = c.getParent();
        }
      }
    }

    // this shouldn't happen
    System.err.println("BUG: getTextArea() returning null");
    System.err.println("Report this to Romain Guy <[e-mail]>");
    return null;
  }

  // protected members
  protected ActionListener inputAction = INSERT_CHAR;
  protected ActionListener grabAction;
  protected boolean repeat;
  protected int repeatCount;
  protected InputHandler.MacroRecorder recorder;

  /**
   * If a key is being grabbed, this method should be called with
   * the appropriate key event. It executes the grab action with
   * the typed character as the parameter.
   */
  protected void handleGrabAction(KeyEvent evt)
  {
    // Clear it *before* it is executed so that executeAction()
    // resets the repeat count
    ActionListener _grabAction = grabAction;
    grabAction = null;

    char keyChar = evt.getKeyChar();
    int keyCode = evt.getKeyCode();

    String arg;

    if(keyChar != KeyEvent.VK_UNDEFINED)
      arg = String.valueOf(keyChar);
    else if(keyCode == KeyEvent.VK_TAB)
      arg = "\t";
    else if(keyCode == KeyEvent.VK_ENTER)
      arg = "\n";