Java tutorial
/* * Copyright (c) 1995, 2008, Oracle and/or its affiliates. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * - Neither the name of Oracle or the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ package events; /* * KeyEventDemo */ import java.awt.BorderLayout; import java.awt.Container; import java.awt.Dimension; import java.awt.event.*; import javax.swing.*; public class KeyEventDemo extends JFrame implements KeyListener, ActionListener { JTextArea displayArea; JTextField typingArea; static final String newline = System.getProperty("line.separator"); public static void main(String[] args) { /* Use an appropriate Look and Feel */ try { //UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel"); //UIManager.setLookAndFeel("com.sun.java.swing.plaf.gtk.GTKLookAndFeel"); UIManager.setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel"); } catch (UnsupportedLookAndFeelException ex) { ex.printStackTrace(); } catch (IllegalAccessException ex) { ex.printStackTrace(); } catch (InstantiationException ex) { ex.printStackTrace(); } catch (ClassNotFoundException ex) { ex.printStackTrace(); } /* Turn off metal's use of bold fonts */ UIManager.put("swing.boldMetal", Boolean.FALSE); //Schedule a job for event dispatch thread: //creating and showing this application's GUI. javax.swing.SwingUtilities.invokeLater(new Runnable() { public void run() { createAndShowGUI(); } }); } /** * Create the GUI and show it. For thread safety, * this method should be invoked from the * event-dispatching thread. */ private static void createAndShowGUI() { //Create and set up the window. KeyEventDemo frame = new KeyEventDemo("KeyEventDemo"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //Set up the content pane. frame.addComponentsToPane(); //Display the window. frame.pack(); frame.setVisible(true); } private void addComponentsToPane() { JButton button = new JButton("Clear"); button.addActionListener(this); typingArea = new JTextField(20); typingArea.addKeyListener(this); //Uncomment this if you wish to turn off focus //traversal. The focus subsystem consumes //focus traversal keys, such as Tab and Shift Tab. //If you uncomment the following line of code, this //disables focus traversal and the Tab events will //become available to the key event listener. //typingArea.setFocusTraversalKeysEnabled(false); displayArea = new JTextArea(); displayArea.setEditable(false); JScrollPane scrollPane = new JScrollPane(displayArea); scrollPane.setPreferredSize(new Dimension(375, 125)); getContentPane().add(typingArea, BorderLayout.PAGE_START); getContentPane().add(scrollPane, BorderLayout.CENTER); getContentPane().add(button, BorderLayout.PAGE_END); } public KeyEventDemo(String name) { super(name); } /** Handle the key typed event from the text field. */ public void keyTyped(KeyEvent e) { displayInfo(e, "KEY TYPED: "); } /** Handle the key pressed event from the text field. */ public void keyPressed(KeyEvent e) { displayInfo(e, "KEY PRESSED: "); } /** Handle the key released event from the text field. */ public void keyReleased(KeyEvent e) { displayInfo(e, "KEY RELEASED: "); } /** Handle the button click. */ public void actionPerformed(ActionEvent e) { //Clear the text components. displayArea.setText(""); typingArea.setText(""); //Return the focus to the typing area. typingArea.requestFocusInWindow(); } /* * We have to jump through some hoops to avoid * trying to print non-printing characters * such as Shift. (Not only do they not print, * but if you put them in a String, the characters * afterward won't show up in the text area.) */ private void displayInfo(KeyEvent e, String keyStatus) { //You should only rely on the key char if the event //is a key typed event. int id = e.getID(); String keyString; if (id == KeyEvent.KEY_TYPED) { char c = e.getKeyChar(); keyString = "key character = '" + c + "'"; } else { int keyCode = e.getKeyCode(); keyString = "key code = " + keyCode + " (" + KeyEvent.getKeyText(keyCode) + ")"; } int modifiersEx = e.getModifiersEx(); String modString = "extended modifiers = " + modifiersEx; String tmpString = KeyEvent.getModifiersExText(modifiersEx); if (tmpString.length() > 0) { modString += " (" + tmpString + ")"; } else { modString += " (no extended modifiers)"; } String actionString = "action key? "; if (e.isActionKey()) { actionString += "YES"; } else { actionString += "NO"; } String locationString = "key location: "; int location = e.getKeyLocation(); if (location == KeyEvent.KEY_LOCATION_STANDARD) { locationString += "standard"; } else if (location == KeyEvent.KEY_LOCATION_LEFT) { locationString += "left"; } else if (location == KeyEvent.KEY_LOCATION_RIGHT) { locationString += "right"; } else if (location == KeyEvent.KEY_LOCATION_NUMPAD) { locationString += "numpad"; } else { // (location == KeyEvent.KEY_LOCATION_UNKNOWN) locationString += "unknown"; } displayArea.append(keyStatus + newline + " " + keyString + newline + " " + modString + newline + " " + actionString + newline + " " + locationString + newline); displayArea.setCaretPosition(displayArea.getDocument().getLength()); } }