deleteaction.java

具有不同语法高亮的编辑器实例

/*
 * 11/14/2003
 *
 * DeleteAction.java - Action that deletes the selected text from a
 *                     JTextComponent.
 * Copyright (C) 2003 Robert Futrell
 * [e-mail]
 * www.website.com
 *
 * 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.fife.ui;

import java.awt.event.ActionEvent;
import javax.swing.ImageIcon;
import javax.swing.KeyStroke;
import javax.swing.UIManager;
import javax.swing.text.BadLocationException;
import javax.swing.text.Caret;
import javax.swing.text.Document;
import javax.swing.text.JTextComponent;
import javax.swing.text.TextAction;

/**
 * Action that deletes the current selection from a <code>JTextComponent</code>.
 *
 * @author Robert Futrell
 * @version 1.0
 */
public class DeleteAction extends TextAction {


	/**
	 * 
	 */
	private static final long serialVersionUID = -1410416480286886261L;


/*****************************************************************************/


	/**
	 * Creates a new <code>DeleteAction</code>.
	 *
	 * @param text The text associated with the action.
	 */
	public DeleteAction(String text) {
		super(text);
	}


/*****************************************************************************/


	/**
	 * Creates a new <code>DeleteAction</code>.
	 *
	 * @param text The text associated with the action.
	 * @param icon The icon associated with the action.
	 * @param desc The description of the action (used in tooltips???).
	 * @param mnemonic The mnemonic for the action.
	 * @param accelerator The accelerator key for the action.
	 */
	public DeleteAction(String text, ImageIcon icon, String desc,
					Integer mnemonic, KeyStroke accelerator) {
		super(text);
		putValue(SMALL_ICON, icon);
		putValue(SHORT_DESCRIPTION, desc);
		putValue(ACCELERATOR_KEY, accelerator);
		putValue(MNEMONIC_KEY, mnemonic);
	}


/*****************************************************************************/


	// Callback routine called when user uses this component.
	public void actionPerformed(ActionEvent e) {

		JTextComponent target = getTextComponent(e);

		boolean beep = true;

		if (target!=null && target.isEditable()) {

			try {

				Document doc = target.getDocument();
				Caret caret = target.getCaret();
				int dot = caret.getDot();
				int mark = caret.getMark();
				if (dot != mark) {
					doc.remove(Math.min(dot, mark), Math.abs(dot - mark));
					beep = false;
				}
				else if (dot < doc.getLength()) {
					int delChars = 1;
					if (dot < doc.getLength() - 1) {
						String dotChars = doc.getText(dot, 2);
						char c0 = dotChars.charAt(0);
						char c1 = dotChars.charAt(1);
						if (c0 >= '\uD800' && c0 <= '\uDBFF' &&
							c1 >= '\uDC00' && c1 <= '\uDFFF') {
							delChars = 2;
						}
					}
					doc.remove(dot, delChars);
					beep = false;
				}

			} catch (BadLocationException ble) {
				// Can't happen.
			}

		}

		if (beep)
			UIManager.getLookAndFeel().provideErrorFeedback(target);

		target.requestFocusInWindow();

	}


/*****************************************************************************/


}