Alan, grazie. Se qualcuno fosse interessato, l'ho formattato in base agli standard di John Pappa.
(function() {
'use strict';
var moduleId = 'common';
var serviceId = 'anchorSmoothScroll';
angular
.module(moduleId)
.service(serviceId, anchorSmoothScroll);
anchorSmoothScroll.$inject = ['$document', '$window'];
function anchorSmoothScroll($document, $window) {
var document = $document[0];
var window = $window;
var service = {
scrollDown: scrollDown,
scrollUp: scrollUp,
scrollTo: scrollTo,
scrollToTop: scrollToTop
};
return service;
function getCurrentPagePosition(currentWindow, doc) {
// Firefox, Chrome, Opera, Safari
if (currentWindow.pageYOffset) return currentWindow.pageYOffset;
// Internet Explorer 6 - standards mode
if (doc.documentElement && doc.documentElement.scrollTop)
return doc.documentElement.scrollTop;
// Internet Explorer 6, 7 and 8
if (doc.body.scrollTop) return doc.body.scrollTop;
return 0;
}
function getElementY(doc, element) {
var y = element.offsetTop;
var node = element;
while (node.offsetParent && node.offsetParent !== doc.body) {
node = node.offsetParent;
y += node.offsetTop;
}
return y;
}
function scrollDown(startY, stopY, speed, distance) {
var timer = 0;
var step = Math.round(distance / 25);
var leapY = startY + step;
for (var i = startY; i < stopY; i += step) {
setTimeout('window.scrollTo(0, ' + leapY + ')', timer * speed);
leapY += step;
if (leapY > stopY) leapY = stopY;
timer++;
}
};
function scrollUp(startY, stopY, speed, distance) {
var timer = 0;
var step = Math.round(distance / 25);
var leapY = startY - step;
for (var i = startY; i > stopY; i -= step) {
setTimeout('window.scrollTo(0, ' + leapY + ')', timer * speed);
leapY -= step;
if (leapY < stopY) leapY = stopY;
timer++;
}
};
function scrollToTop(stopY) {
scrollTo(0, stopY);
};
function scrollTo(elementId, speed) {
var element = document.getElementById(elementId);
if (element) {
var startY = getCurrentPagePosition(window, document);
var stopY = getElementY(document, element);
var distance = stopY > startY ? stopY - startY : startY - stopY;
if (distance < 100) {
this.scrollToTop(stopY);
} else {
var defaultSpeed = Math.round(distance / 100);
speed = speed || (defaultSpeed > 20 ? 20 : defaultSpeed);
if (stopY > startY) {
this.scrollDown(startY, stopY, speed, distance);
} else {
this.scrollUp(startY, stopY, speed, distance);
}
}
}
};
};
})();