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 contains immutable dimension information for width and height.
 *
 * @since 2017/02/17
 */
public final class Dimension
    implements Comparable<Dimension>
{
    /** Width. */
    public final int width;
    
    /** Height. */
    public final int height;
    
    /** String form. */
    private Reference<String> _string;
    
    /**
     * Initializes the dimension.
     *
     * @param __w Width.
     * @param __h Height.
     * @since 2017/02/17
     */
    public Dimension(int __w, int __h)
    {
        this.width = __w;
        this.height = __h;
    }
    
    /**
     * Parses a dimension 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 Dimension(String __s)
        throws IllegalArgumentException, NullPointerException
    {
        if (__s == null)
            throw new NullPointerException("NARG");
        
        /* {@squirreljme.error BE0d Dimension must start and end with square
        brackets. (The input string)} */
        if (!__s.startsWith("[") || !__s.endsWith("]"))
            throw new IllegalArgumentException("BE0d " + __s);
        
        // Trim those out
        __s = __s.substring(1, __s.length() - 1);
        
        /* {@squirreljme.error BE0e Dimension must have a comma between the
        units. (The input string)} */
        int com = __s.indexOf(',');
        if (com < 0)
            throw new IllegalArgumentException("BE0e " + __s);
        
        this.width = Integer.parseInt(__s.substring(0, com).trim(), 10);
        this.height = Integer.parseInt(__s.substring(com + 1).trim(), 10);
    }
    
    /**
     * {@inheritDoc}
     * @since 2017/02/17
     */
    @Override
    public int compareTo(Dimension __o)
    {
        int rv,
            aw = this.width,
            as = aw * this.height,
            bw = __o.width,
            bs = bw * __o.height;
        
        // Compare surface area first
        rv = as - bs;
        if (rv != 0)
            return rv;
        
        // Compare the width
        return aw - bw;
    }
    
    /**
     * {@inheritDoc}
     * @since 2017/02/17
     */
    @Override
    public boolean equals(Object __o)
    {
        // Check
        if (!(__o instanceof Dimension))
            return false;
        
        Dimension o = (Dimension)__o;
        return this.width == o.width && this.height == o.height;
    }
    
    /**
     * {@inheritDoc}
     * @since 2017/02/17
     */
    @Override
    public int hashCode()
    {
        return this.width ^ ~(this.height);
    }
    
    /**
     * {@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.width, this.height));
        
        return rv;
    }
}