InputEvent.isControlDown() has the following syntax.
public boolean isControlDown()
In the following code shows how to use InputEvent.isControlDown() method.
/*from ww w.j a va 2 s. c o m*/ /* * Copyright (c) 1995 - 2008 Sun Microsystems, Inc. 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 Sun Microsystems nor 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. */ /* * KeyEventDemo */ import java.awt.BorderLayout; import java.awt.Dimension; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyEvent; import java.awt.event.KeyListener; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JScrollPane; import javax.swing.JTextArea; import javax.swing.JTextField; public class Main extends JFrame implements KeyListener, ActionListener { JTextArea displayArea; JTextField typingArea; static final String newline = System.getProperty("line.separator"); public static void main(String[] args) { // Create and set up the window. Main frame = new Main(); 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); } /** 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); System.out.println(e.isControlDown()); 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()); } }