SquirrelJME/SquirrelJME

// -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
// ---------------------------------------------------------------------------
// SquirrelJME
//     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
// ---------------------------------------------------------------------------
// SquirrelJME is under the Mozilla Public License Version 2.0.
// See license.mkd for licensing and copyright information.
// ---------------------------------------------------------------------------

package javax.microedition.lcdui;

import cc.squirreljme.runtime.cldc.annotation.Api;

/**
 * A ticker contains an infinitely scrolling message.
 *
 * Any {@link Displayable} may have tickers associated with them in which
 * they will be shown at the top of the screen accordingly. As such these can
 * be used to convey information as needed.
 *
 * @since 2018/03/26
 */
@Api
public class Ticker
{
    /** {@code Displayable}s this ticker is attached to. */
    final __VolatileList__<Displayable> _displayables =
        new __VolatileList__<>();
    
    /** The text used. */
    volatile String _text;
    
    /**
     * Initializes the ticker with the given string.
     *
     * @param __s The string to use for the ticker.
     * @throws NullPointerException On null arguments.
     * @since 2018/03/26
     */
    @Api
    public Ticker(String __s)
        throws NullPointerException
    {
        if (__s == null)
            throw new NullPointerException("NARG");
        
        // Use internal title set
        this.__setString(__s);
    }
    
    /**
     * Returns the string which is currently being displayed in the ticker.
     *
     * @return The string contained within the ticker.
     * @since 2018/03/26
     */
    @Api
    public String getString()
    {
        return this._text;
    }
    
    /**
     * Sets the string that is displayed within the ticker.
     *
     * @param __s The string to use for the ticker.
     * @throws NullPointerException On null arguments.
     * @since 2018/03/26
     */
    @Api
    public void setString(String __s)
        throws NullPointerException
    {
        if (__s == null)
            throw new NullPointerException("NARG");
        
        this.__setString(__s);
    }
    
    /**
     * Sets the text to be displayed on the ticker and performs updating on
     * the form and otherwise.
     * 
     * @param __s The string to set.
     * @since 2021/11/27
     */
    private void __setString(String __s)
    {
        // Set new
        this._text = __s;
        
        // Adjust the ticker item for all the displayables which are showing
        // this ticker
        for (Displayable di : this._displayables)
            di.__updateTicker();
    }
}