134 lines
4.9 KiB
JavaScript
134 lines
4.9 KiB
JavaScript
/**
|
|
* author Christopher Blum
|
|
* - based on the idea of Remy Sharp, http://remysharp.com/2009/01/26/element-in-view-event-plugin/
|
|
* - forked from http://github.com/zuk/jquery.inview/
|
|
*/
|
|
(function ($) {
|
|
var inviewObjects = {}, viewportSize, viewportOffset,
|
|
d = document, w = window, documentElement = d.documentElement, expando = $.expando, isFiring = false, $elements = {};
|
|
|
|
$.event.special.inview = {
|
|
add: function(data) {
|
|
var inviewObject = { data: data, $element: $(this) }
|
|
inviewObjects[data.guid + "-" + this[expando]] = inviewObject;
|
|
var selector = inviewObject.data.selector,
|
|
$element = inviewObject.$element;
|
|
var hash = parseInt(getHash( data.guid + this[expando]));
|
|
$elements[hash] = selector ? $element.find(selector) : $element;
|
|
},
|
|
|
|
remove: function(data) {
|
|
try { delete inviewObjects[data.guid + "-" + this[expando]]; } catch(e) {}
|
|
try {
|
|
var hash = parseInt(getHash(data.guid + this[expando]));
|
|
delete($elements[hash]);
|
|
} catch (e){}
|
|
}
|
|
};
|
|
|
|
|
|
function getHash(str){
|
|
str = str+'';
|
|
var hash = 0;
|
|
if (str.length == 0) return hash;
|
|
for (i = 0; i < str.length; i++) {
|
|
char = str.charCodeAt(i);
|
|
hash = ((hash<<5)-hash)+char;
|
|
hash = hash & hash; // Convert to 32bit integer
|
|
}
|
|
return Math.abs(hash);
|
|
}
|
|
|
|
function getViewportSize() {
|
|
var mode, domObject, size = { height: w.innerHeight, width: w.innerWidth };
|
|
|
|
// if this is correct then return it. iPad has compat Mode, so will
|
|
// go into check clientHeight/clientWidth (which has the wrong value).
|
|
if (!size.height) {
|
|
mode = d.compatMode;
|
|
if (mode || !$.support.boxModel) { // IE, Gecko
|
|
domObject = mode === 'CSS1Compat' ?
|
|
documentElement : // Standards
|
|
d.body; // Quirks
|
|
size = {
|
|
height: domObject.clientHeight,
|
|
width: domObject.clientWidth
|
|
};
|
|
}
|
|
}
|
|
|
|
return size;
|
|
}
|
|
|
|
function getViewportOffset() {
|
|
return {
|
|
top: w.pageYOffset || documentElement.scrollTop || (d.body?d.body.scrollTop:0),
|
|
left: w.pageXOffset || documentElement.scrollLeft || (d.body?d.body.scrollLeft:0)
|
|
};
|
|
}
|
|
|
|
function checkInView() {
|
|
if (isFiring){
|
|
return;
|
|
}
|
|
isFiring = true;
|
|
viewportSize = viewportSize || getViewportSize();
|
|
viewportOffset = viewportOffset || getViewportOffset();
|
|
|
|
for (var i in $elements) {
|
|
if (isNaN(parseInt(i))) {
|
|
continue;
|
|
}
|
|
|
|
var $element = $($elements[i]),
|
|
elementSize = { height: $element.height(), width: $element.width() },
|
|
elementOffset = $element.offset(),
|
|
inView = $element.data('inview'),
|
|
visiblePartX,
|
|
visiblePartY,
|
|
visiblePartsMerged;
|
|
|
|
// Don't ask me why because I haven't figured out yet:
|
|
// viewportOffset and viewportSize are sometimes suddenly null in Firefox 5.
|
|
// Even though it sounds weird:
|
|
// It seems that the execution of this function is interferred by the onresize/onscroll event
|
|
// where viewportOffset and viewportSize are unset
|
|
if (!viewportOffset || !viewportSize) {
|
|
isFiring = false;
|
|
return;
|
|
}
|
|
|
|
if (elementOffset.top + elementSize.height > viewportOffset.top &&
|
|
elementOffset.top < viewportOffset.top + viewportSize.height &&
|
|
elementOffset.left + elementSize.width > viewportOffset.left &&
|
|
elementOffset.left < viewportOffset.left + viewportSize.width) {
|
|
visiblePartX = (viewportOffset.left > elementOffset.left ?
|
|
'right' : (viewportOffset.left + viewportSize.width) < (elementOffset.left + elementSize.width) ?
|
|
'left' : 'both');
|
|
visiblePartY = (viewportOffset.top > elementOffset.top ?
|
|
'bottom' : (viewportOffset.top + viewportSize.height) < (elementOffset.top + elementSize.height) ?
|
|
'top' : 'both');
|
|
visiblePartsMerged = visiblePartX + "-" + visiblePartY;
|
|
if (!inView || inView !== visiblePartsMerged) {
|
|
$element.data('inview', visiblePartsMerged).trigger('inview', [true, visiblePartX, visiblePartY]);
|
|
}
|
|
} else if (inView) {
|
|
$element.data('inview', false).trigger('inview', [false]);
|
|
}
|
|
}
|
|
isFiring = false;
|
|
}
|
|
|
|
$(w).bind("scroll resize", function() {
|
|
viewportSize = viewportOffset = null;
|
|
});
|
|
|
|
// Use setInterval in order to also make sure this captures elements within
|
|
// "overflow:scroll" elements or elements that appeared in the dom tree due to
|
|
// dom manipulation and reflow
|
|
// old: $(window).scroll(checkInView);
|
|
//
|
|
// By the way, iOS (iPad, iPhone, ...) seems to not execute, or at least delays
|
|
// intervals while the user scrolls. Therefore the inview event might fire a bit late there
|
|
setInterval(checkInView, 250);
|
|
})(jQuery);
|