jlibxinput/src/main/java/de/hardcode/jxinput/keyboard/JXKeyboardInputDevice.java

//**********************************************************************************************
//        (C) Copyright 2002 by Dipl. Phys. Joerg Plewe, HARDCODE Development
//        All rights reserved. Copying, modification,
//        distribution or publication without the prior written
//        consent of the author is prohibited.
//
//    Created on 9. April 2002, 22:40
//**********************************************************************************************
package de.hardcode.jxinput.keyboard;


import de.hardcode.jxinput.*;
import java.awt.Component;


/**
 * Virtual input device treating a AWT keyboard as a source for Buttons.
 *
 * @author  Herkules
 */
public class JXKeyboardInputDevice
    implements JXInputDevice
{
    private static final String DEVICENAME = "Swing Keyboard";

    /** The driver doing all the real work. */
    private final KeyboardDriver mDriver = new KeyboardDriver();

    /** The Component I am listening to. */
    private Component mComponent = null;
    
    /** Hold the biggest keycode for which a button has been created. */
    private int mMaxIdxCreated = 0;
    
    
    /**
     * Creates a new instance of JXKeyboardInputDevice.
     */
    public JXKeyboardInputDevice()
    {
    }

    
    /**
     * Creates a new instance of JXKeyboardInputDevice 
     * immediately listening to a JComponent.
     */
    public JXKeyboardInputDevice( Component comp )
    {
        listenTo( comp );
    }
    
    /** 
     * Makes this device listen to a certain JComponent.
     */
    public final void listenTo( Component comp )
    {
        shutdown();
        mComponent = comp;
        mComponent.addKeyListener( mDriver );
    }
    
    /**
     * Shut down. No longer listen to my JComponent.
     */
    public final void shutdown()
    {
        if ( null != mComponent )
            mComponent.removeKeyListener( mDriver );
    }
    
    
    /**
     * Create a button object for a certain keycode.
     */
    public Button createButton( int keycode )
    {    
        if ( 0 > keycode  ||  0x100 < keycode )
            throw new InvalidKeyCodeException();

        KeyButton b;
        if ( null == (b = mDriver.getButton( keycode ) ) )
        {
            b = new KeyButton( keycode );
            mDriver.registerKeyButton( b );
            if ( keycode > mMaxIdxCreated )
                mMaxIdxCreated = keycode;
        }
        return b;
    }
    

    public void removeButton( Button b )
    {
        mDriver.unregisterKeyButton( (KeyButton) b ); 
    }
    
    
    
    //*********************************************************************************************
    //
    // Implement JXInputDevice
    //
    //*********************************************************************************************
    
    public Axis getAxis(int idx)
    {
        // No axes on keyboard.
        return null;
    }
    
    
    public Button getButton(int idx)
    {
        // idx is interpreted as the keycode
        return mDriver.getButton( idx );
    }
    
    public Directional getDirectional(int idx)
    {
        // No directionals on keyboard.
        return null;
    }
    
    /** Maximum number of axes as an upper bound for index values.  */
    public int getMaxNumberOfAxes()
    {
        // No axes on keyboard.
        return 0;
    }
    
    /** Maximum number of buttons as an upper bound for index values.  */
    public int getMaxNumberOfButtons()
    {
        // Return biggest keycode (inclusive).
        return mMaxIdxCreated + 1;
    }
    
    /** Maximum number of directional features as an upper bound for index values.  */
    public int getMaxNumberOfDirectionals()
    {
        // No directionals on keyboard.
        return 0;
    }
    
    /**
     * Devices may have a name.
     * This name might be provided by a system dependant driver.
     */
    public String getName()
    {
        return DEVICENAME;
    }
    
    /** Actual number of available axes.  */
    public int getNumberOfAxes()
    {
        // No axes on keyboard.
        return 0;
    }
    
    /** Actual number of available buttons.  */
    public int getNumberOfButtons()
    {
        return mDriver.getNumberOfButtons();
    }
    
    /** Actual number of available directional features.  */
    public int getNumberOfDirectionals()
    {
        // No directionals on keyboard.
        return 0;
    }
    
}