HaxePunk/HaxePunk

package haxepunk.tweens.misc;

import haxepunk.Tween;
import haxepunk.utils.Ease.EaseFunction;

/**
 * Tweens a numeric public property of an Object.
 */
class VarTween extends Tween
{
    /**
     * Constructor.
     * @param    complete    Optional completion callback.
     * @param    type        Tween type.
     */
    public function new(?type:TweenType)
    {
        super(0, type);
    }

    /**
     * Tweens a numeric public property.
     * @param    object        The object containing the property.
     * @param    property    The name of the property (eg. "x").
     * @param    to            Value to tween to.
     * @param    duration    Duration of the tween.
     * @param    ease        Optional easer function.
     */
    public function tween(object:Dynamic, property:String, to:Float, duration:Float, ?ease:EaseFunction)
    {
        _object = object;
        _ease = ease;

        // Check to make sure we have valid parameters
        if (!Reflect.isObject(object))
            throw "A valid object was not passed.";

        _property = property;
        var a:Float = Reflect.getProperty(_object, property);

        // Check if the variable is a number
        if (Math.isNaN(a))
        {
            throw 'The property $property is not numeric.';
        }

        _start = a;
        _range = to - _start;
        _target = duration;
        start();
    }

    /** @private Updates the Tween. */
    @:dox(hide)
    override function updateInternal()
    {
        Reflect.setProperty(_object, _property, _start + _range * _t);
    }

    // Tween information.
    var _object:Dynamic;
    var _property:String;
    var _start:Float;
    var _range:Float;
}