SquirrelJME/SquirrelJME

// -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
// ---------------------------------------------------------------------------
// SquirrelJME
//     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
// ---------------------------------------------------------------------------
// SquirrelJME is under the GNU General Public License v3+, or later.
// See license.mkd for licensing and copyright information.
// ---------------------------------------------------------------------------

package com.nttdocomo.ui;

import java.lang.ref.Reference;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Displayable;

/**
 * This is used to handle shoulder buttons that are pressed and make it like
 * they are key events.
 *
 * @since 2022/02/14
 */
final class __ShoulderButtonEmitter__
    implements CommandListener
{
    /** The frame this references. */
    final Reference<Frame> _frame;
    
    /**
     * Initializes the button handler.
     *
     * @param __frame The frame to call into.
     * @throws NullPointerException On null arguments.
     * @since 2022/02/14
     */
    __ShoulderButtonEmitter__(Reference<Frame> __frame)
        throws NullPointerException
    {
        if (__frame == null)
            throw new NullPointerException("NARG");
        
        this._frame = __frame;
    }
    
    /**
     * {@inheritDoc}
     *
     * @since 2022/02/14
     */
    @Override
    public void commandAction(Command __command, Displayable __displayable)
    {
        // Ignore if missing
        Frame frame = this._frame.get();
        if (__command == null || !(frame instanceof Canvas))
            return;
        
        // Determine which key was pressed
        int whichKey;
        switch (__command.getPriority())
        {
            case 0:
                whichKey = Display.KEY_SOFT1;
                break;
            case 1:
                whichKey = Display.KEY_SOFT2;
                break;
            
            // Ignore, unknown
            default:
                return;
        }
        
        // Say that the shoulder button was pressed and released accordingly
        Canvas canvas = (Canvas)frame;
        canvas.processEvent(Display.KEY_PRESSED_EVENT, whichKey);
        canvas.processEvent(Display.KEY_RELEASED_EVENT, whichKey);
    }
}