plugins/org.eclipse.emf.parsley.web.servlets/src/org/eclipse/swt/events/KeyEvent.java

/*******************************************************************************
 * Copyright (c) 2015 RCP Vision (http://www.rcp-vision.com) and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 * Vincenzo Caselli - Initial contribution and API
 * 
 *******************************************************************************/
package org.eclipse.swt.events;


import org.eclipse.swt.widgets.Event;

/**
 * Instances of this class are sent as a result of keys being pressed and released on the keyboard.
 * <p>
 * When a key listener is added to a control, the control will take part in widget traversal. By
 * default, all traversal keys (such as the tab key and so on) are delivered to the control. In
 * order for a control to take part in traversal, it should listen for traversal events. Otherwise,
 * the user can traverse into a control but not out. Note that native controls such as table and
 * tree implement key traversal in the operating system. It is not necessary to add traversal
 * listeners for these controls, unless you want to override the default traversal.
 * </p>
 *
 * @see KeyListener
 * @see TraverseListener
 * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
 */

public class KeyEvent extends TypedEvent {

    /**
     * the character represented by the key that was typed. This is the final character that results
     * after all modifiers have been applied. For example, when the user types Ctrl+A, the character
     * value is 0x01. It is important that applications do not attempt to modify the character value
     * based on a stateMask (such as SWT.CTRL) or the resulting character will not be correct.
     */
    public char character;

    /**
     * the key code of the key that was typed, as defined by the key code constants in class
     * <code>SWT</code>. When the character field of the event is ambiguous, this field contains the
     * unicode value of the original character. For example, typing Ctrl+M or Return both result in
     * the character '\r' but the keyCode field will also contain '\r' when Return was typed.
     * 
     * @see org.eclipse.swt.SWT
     */
    public int keyCode;

    /**
     * depending on the event, the location of key specified by the keyCode or character. The
     * possible values for this field are <code>SWT.LEFT</code>, <code>SWT.RIGHT</code>,
     * <code>SWT.KEYPAD</code>, or <code>SWT.NONE</code> representing the main keyboard area.
     * <p>
     * The location field can be used to differentiate key events that have the same key code and
     * character but are generated by different keys on the keyboard. For example, a key down event
     * with the key code equal to SWT.SHIFT can be generated by the left and the right shift keys on
     * the keyboard.
     * </p>
     * <p>
     * The location field can only be used to determine the location of the key code or character in
     * the current event. It does not include information about the location of modifiers in the
     * state mask.
     * </p>
     * 
     * @see org.eclipse.swt.SWT#LEFT
     * @see org.eclipse.swt.SWT#RIGHT
     * @see org.eclipse.swt.SWT#KEYPAD
     * 
     * @since 3.6
     */
    public int keyLocation;

    /**
     * the state of the keyboard modifier keys and mouse masks at the time the event was generated.
     * 
     * @see org.eclipse.swt.SWT#MODIFIER_MASK
     * @see org.eclipse.swt.SWT#BUTTON_MASK
     */
    public int stateMask;

    /**
     * A flag indicating whether the operation should be allowed. Setting this field to
     * <code>false</code> will cancel the operation.
     */
    public boolean doit;

    static final long serialVersionUID = 3256442491011412789L;

    /**
     * Constructs a new instance of this class based on the information in the given untyped event.
     *
     * @param e the untyped event containing the information
     */
    public KeyEvent(Event e) {
        super(e);
        this.character = e.character;
        this.keyCode = e.keyCode;
        this.keyLocation = e.keyLocation;
        this.stateMask = e.stateMask;
        this.doit = e.doit;
    }

    /**
     * Returns a string containing a concise, human-readable description of the receiver.
     *
     * @return a string representation of the event
     */
    @Override
    public String toString() {
        String string = super.toString();
        return string.substring(0, string.length() - 1) // remove trailing '}'
                        + " character='" + ((character == 0) ? "\\0" : String.valueOf(character)) + "'=0x" + Integer.toHexString(character) + " keyCode=0x" + Integer.toHexString(keyCode)
                        + " keyLocation=0x" + Integer.toHexString(keyLocation) + " stateMask=0x" + Integer.toHexString(stateMask) + " doit=" + doit + "}";
    }
}