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 net.multiphasicapps.squirrelquarrel.util;

import java.lang.ref.Reference;
import java.lang.ref.WeakReference;

/**
 * This is an immutable class which contains X and Y coordinates.
 *
 * @since 2017/02/17
 */
public final class Point
    implements Comparable<Point>
{
    /** X coordinate. */
    public final int x;
    
    /** Y coordinate. */
    public final int y;
    
    /** String form. */
    private Reference<String> _string;
    
    /**
     * Initializes the point.
     *
     * @param __x X coordinate.
     * @param __y Y coordinate.
     * @since 2017/02/17
     */
    public Point(int __x, int __y)
    {
        this.x = __x;
        this.y = __y;
    }
    
    /**
     * Parses a point from the given string.
     *
     * @param __s The string to parse.
     * @throws IllegalArgumentException If the string is not valid.
     * @throws NullPointerException On null arguments.
     * @since 2018/03/18
     */
    public Point(String __s)
        throws IllegalArgumentException, NullPointerException
    {
        if (__s == null)
            throw new NullPointerException("NARG");
        
        /* {@squirreljme.error BE0g Point must start and end with parenthesis.
        (The input string)} */
        if (!__s.startsWith("(") || !__s.endsWith(")"))
            throw new IllegalArgumentException("BE0g " + __s);
        
        // Trim those out
        __s = __s.substring(1, __s.length() - 1);
        
        /* {@squirreljme.error BE0h Point must have a comma between the
        units. (The input string)} */
        int com = __s.indexOf(',');
        if (com < 0)
            throw new IllegalArgumentException("BE0h " + __s);
        
        this.x = Integer.parseInt(__s.substring(0, com).trim(), 10);
        this.y = Integer.parseInt(__s.substring(com + 1).trim(), 10);
    }
    
    /**
     * {@inheritDoc}
     * @since 2017/02/17
     */
    @Override
    public int compareTo(Point __o)
    {
        int rv;
        
        // Compare x
        rv = this.x - __o.x;
        if (rv != 0)
            return rv;
        
        // Compare y
        return this.y - __o.y;
    }
    
    /**
     * {@inheritDoc}
     * @since 2017/02/17
     */
    @Override
    public boolean equals(Object __o)
    {
        // Check
        if (!(__o instanceof Point))
            return false;
        
        Point o = (Point)__o;
        return this.x == o.x && this.y == o.y;
    }
    
    /**
     * {@inheritDoc}
     * @since 2017/02/17
     */
    @Override
    public int hashCode()
    {
        return this.x ^ ~(this.y);
    }
    
    /**
     * {@inheritDoc}
     * @since 2017/02/17
     */
    @Override
    public String toString()
    {
        Reference<String> ref = this._string;
        String rv;
        
        // Cache?
        if (ref == null || null == (rv = ref.get()))
            this._string = new WeakReference<>(
                rv = String.format("(%d, %d)", this.x, this.y));
        
        return rv;
    }
}