// JavaScript Document

//pAnchor plugin for piwigo - ease to anchor javascript functions (uses jquery)
$(document).ready(function() {
        //check for pAnchor anchor - name of anchor can be customized in main.inc.php
        if ($('#pAnchor').attr('name')) {
            //alert('pAnchor exists');
            var url = window.location.href;
            if (url.indexOf('#') == -1) {
                //defaut values a=0.20, t=16 and delay=250
                easeToInit('pAnchor', 0.20, 16, 250);
            }
        }        
});


function easeTo(yDest, yTemp, a, t) {
	//easeTo function to scroll from 0 to yDest.  X will scroll to 0 also.
	//yDest is y value of destination
	//YTemp is temp value as scroll progresses to yDest
	//a = a || 0.2;	//about  0.2
	//t = t || 20;	//about 15-20 milliseconds

	var x1 = 0;
	var y1 = 0;
	var x2 = 0;
	var y2 = 0;
	var x3 = 0;
	var y3 = 0;

	if (document.documentElement) {
		x1 = document.documentElement.scrollLeft || 0;
		y1 = document.documentElement.scrollTop || 0;
	}
	if (document.body) {
		x2 = document.body.scrollLeft || 0;
		y2 = document.body.scrollTop || 0;
	}
	x3 = window.scrollX || 0;
	y3 = window.scrollY || 0;

	var x = Math.max(x1, Math.max(x2, x3));
	var y = Math.max(y1, Math.max(y2, y3));

	var speed = 1 + a;
	var yTemp =  Math.floor(yTemp / speed);
	window.scrollTo(Math.floor(x / speed), yDest - yTemp);
	if(x > 0 || yTemp > 1) {
		var f = "easeTo(" + yDest + ", " + yTemp + ", " +  a + ", " + t + ")";
		//alert(f);
		window.setTimeout(f, t);
	} else {
		//alert('done');
	}
}

function easeToInit(elem, a, t, delay){
        //easeToInit initializes and easeTo operation
        //elem is id of document element, a is psuedo-acceleration, t is timer for interative calls
        //delay is just a small time delay before easeTo actually begins.  give the page a chance to be static before
        //easeTo the desired element.  The position can be fined with params in the main.inc.php file.
        //ALSO NOTE:  DIFFERENT BROWSERS WILL YEILDLY SLIGHLY DIFFERENT RESULTS, but typically within a few pixels.
	y = document.getElementById(elem).offsetTop;
	var f = "easeTo(" + y + ", " + y + ", " +  a + ", " + t + ")";
	window.setTimeout(f, delay);
}