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;

/**
 * This contains the desired command policy layout state.
 *
 * @since 2020/09/27
 */
final class __Layout__
    implements AutoCloseable
{
    /** The number of possible placements. */
    private static final int _MAX_PLACEMENTS =
        (Display.SOFTKEY_INDEX_MASK * 5);
    
    /** The placements used. */
    private final __Action__[] _placements =
        new __Action__[__Layout__._MAX_PLACEMENTS];
    
    /**
     * {@inheritDoc}
     * @since 2020/09/27
     */
    @Override
    public void close()
    {
        // Has no effect
    }
    
    /**
     * Gets the item at the given position.
     * 
     * @param __pos The position to get from.
     * @return The action at the given position or null.
     * @throws IllegalArgumentException If the position is not valid.
     * @since 2020/09/27
     */
    public final __Action__ get(int __pos)
        throws IllegalArgumentException
    {
        return this._placements[__Layout__.__posToIndex(__pos)];
    }
    
    /**
     * Gets the priority of the item at the given position.
     * 
     * @param __pos The position to get from.
     * @return The priority of the given item at the position.
     * @throws IllegalArgumentException If the position is not valid.
     * @since 2020/09/27
     */
    public final int getPriority(int __pos)
        throws IllegalArgumentException
    {
        // Blank items always get the lowest priority
        __Action__ action = this.get(__pos);
        if (action == null)
            return Integer.MAX_VALUE;
        
        return __Action__.__getPriority(action);
    }
    
    /**
     * Sets the action at the given position.
     * 
     * @param __act The action to set, may be {@code null}.
     * @param __pos The position to set.
     * @throws IllegalArgumentException If the position is not valid.
     * @since 2020/09/27
     */
    public final void set(__Action__ __act, int __pos)
        throws IllegalArgumentException
    {
        this._placements[__Layout__.__posToIndex(__pos)] = __act;
    }
    
    /**
     * Maps the position to an index.
     * 
     * @param __pos The position to map.
     * @return The index of the position.
     * @throws IllegalArgumentException If the position is not valid.
     * @since 2020/09/27
     */
    private static int __posToIndex(int __pos)
        throws IllegalArgumentException
    {
        int border = __pos & (~Display.SOFTKEY_INDEX_MASK);
        int index = (__pos & Display.SOFTKEY_INDEX_MASK);
        
        // Determine if the grouping is valid, the border is always a
        // multiple of 20 so if there is a remainder left over then we know
        // it is not a valid placement
        /* {@squirreljme.error EB3m Invalid position. (The position)} */
        int groupId = (border - Display.SOFTKEY_BOTTOM) / 20;
        int xvDiv = (border - Display.SOFTKEY_BOTTOM) % 20;
        if (index <= 0 || xvDiv != 0 || groupId < 0 || groupId > 4)
            throw new IllegalArgumentException("EB3m " + __pos);
        
        return (groupId * Display.SOFTKEY_INDEX_MASK) + (index - 1);
    }
}