$(function() {
$('.left-sidebar').StickySidebar({
// Settings
additionalMarginTop: 40
});
});
(function ($) {
$.fn.StickySidebar = function (options) {
var defaults = {
'containerSelector': '',
'additionalMarginTop': 0,
'additionalMarginBottom': 0,
'updateSidebarHeight': true,
'minWidth': 0,
'disableOnResponsiveLayouts': true,
'sidebarBehavior': 'modern'
};
options = $.extend(defaults, options);
// Validate options
options.additionalMarginTop = parseInt(options.additionalMarginTop) || 0;
options.additionalMarginBottom = parseInt(options.additionalMarginBottom) || 0;
tryInitOrHookIntoEvents(options, this);
// Try doing init, otherwise hook into window.resize and document.scroll and try again then.
function tryInitOrHookIntoEvents(options, $that) {
var success = tryInit(options, $that);
if (!success) {
console.log('TST: Body width smaller than options.minWidth. Init is delayed.');
$(document).scroll(function (options, $that) {
return function (evt) {
var success = tryInit(options, $that);
if (success) {
$(this).unbind(evt);
}
};
}(options, $that));
$(window).resize(function (options, $that) {
return function (evt) {
var success = tryInit(options, $that);
if (success) {
$(this).unbind(evt);
}
};
}(options, $that))
}
}
// Try doing init if proper conditions are met.
function tryInit(options, $that) {
if (options.initialized === true) {
return true;
}
if ($('body').width() < options.minWidth) {
return false;
}
init(options, $that);
return true;
}
// Init the sticky sidebar(s).
function init(options, $that) {
options.initialized = true;
// Add CSS
$('head').append($('<style>.StickySidebar:after {content: ""; display: table; clear: both;}</style>'));
$that.each(function () {
var o = {};
o.sidebar = $(this);
// Save options
o.options = options || {};
// Get container
o.container = $(o.options.containerSelector);
if (o.container.length == 0) {
o.container = o.sidebar.parent();
}
// Create sticky sidebar
o.sidebar.parents().css('-webkit-transform', 'none'); // Fix for WebKit bug - https://code.google.com/p/chromium/issues/detail?id=20574
o.sidebar.css({
'position': 'relative',
'overflow': 'visible',
// The "box-sizing" must be set to "content-box" because we set a fixed height to this element when the sticky sidebar has a fixed position.
'-webkit-box-sizing': 'border-box',
'-moz-box-sizing': 'border-box',
'box-sizing': 'border-box'
});
// Get the sticky sidebar element. If none has been found, then create one.
o.stickySidebar = o.sidebar.find('.StickySidebar');
if (o.stickySidebar.length == 0) {
o.sidebar.find('script').remove(); // Remove <script> tags, otherwise they will be run again on the next line.
o.stickySidebar = $('<div>').addClass('StickySidebar').append(o.sidebar.children());
o.sidebar.append(o.stickySidebar);
}
// Get existing top and bottom margins and paddings
o.marginTop = parseInt(o.sidebar.css('margin-top'));
o.marginBottom = parseInt(o.sidebar.css('margin-bottom'));
o.paddingTop = parseInt(o.sidebar.css('padding-top'));
o.paddingBottom = parseInt(o.sidebar.css('padding-bottom'));
// Add a temporary padding rule to check for collapsable margins.
var collapsedTopHeight = o.stickySidebar.offset().top;
var collapsedBottomHeight = o.stickySidebar.outerHeight();
o.stickySidebar.css('padding-top', 1);
o.stickySidebar.css('padding-bottom', 1);
collapsedTopHeight -= o.stickySidebar.offset().top;
collapsedBottomHeight = o.stickySidebar.outerHeight() - collapsedBottomHeight - collapsedTopHeight;
if (collapsedTopHeight == 0) {
o.stickySidebar.css('padding-top', 0);
o.stickySidebarPaddingTop = 0;
}
else {
o.stickySidebarPaddingTop = 1;
}
if (collapsedBottomHeight == 0) {
o.stickySidebar.css('padding-bottom', 0);
o.stickySidebarPaddingBottom = 0;
}
else {
o.stickySidebarPaddingBottom = 1;
}
// We use this to know whether the user is scrolling up or down.
o.previousScrollTop = null;
// Scroll top (value) when the sidebar has fixed position.
o.fixedScrollTop = 0;
// Set sidebar to default values.
resetSidebar();
o.onScroll = function (o) {
// Stop if the sidebar isn't visible.
if (!o.stickySidebar.is(":visible")) {
return;
}
// Stop if the window is too small.
if ($('body').width() < o.options.minWidth) {
resetSidebar();
return;
}
// Stop if the sidebar width is larger than the container width (e.g. the theme is responsive and the sidebar is now below the content)
if (o.options.disableOnResponsiveLayouts) {
var sidebarWidth = o.sidebar.outerWidth(o.sidebar.css('float') == 'none');
if (sidebarWidth + 50 > o.container.width()) {
resetSidebar();
return;
}
}
var scrollTop = $(document).scrollTop();
var position = 'static';
// If the user has scrolled down enough for the sidebar to be clipped at the top, then we can consider changing its position.
if (scrollTop >= o.container.offset().top + (o.paddingTop + o.marginTop - o.options.additionalMarginTop)) {
// The top and bottom offsets, used in various calculations.
var offsetTop = o.paddingTop + o.marginTop + options.additionalMarginTop;
var offsetBottom = o.paddingBottom + o.marginBottom + options.additionalMarginBottom;
// All top and bottom positions are relative to the window, not to the parent elemnts.
var containerTop = o.container.offset().top;
var containerBottom = o.container.offset().top + getClearedHeight(o.container);
// The top and bottom offsets relative to the window screen top (zero) and bottom (window height).
var windowOffsetTop = 0 + options.additionalMarginTop;
var windowOffsetBottom;
var sidebarSmallerThanWindow = (o.stickySidebar.outerHeight() + offsetTop + offsetBottom) < $(window).height();
if (sidebarSmallerThanWindow) {
windowOffsetBottom = windowOffsetTop + o.stickySidebar.outerHeight();
}
else {
windowOffsetBottom = $(window).height() - o.marginBottom - o.paddingBottom - options.additionalMarginBottom;
}
var staticLimitTop = containerTop - scrollTop + o.paddingTop + o.marginTop;
var staticLimitBottom = containerBottom - scrollTop - o.paddingBottom - o.marginBottom;
var top = o.stickySidebar.offset().top - scrollTop;
var scrollTopDiff = o.previousScrollTop - scrollTop;
// If the sidebar position is fixed, then it won't move up or down by itself. So, we manually adjust the top coordinate.
if (o.stickySidebar.css('position') == 'fixed') {
if (o.options.sidebarBehavior == 'modern') {
top += scrollTopDiff;
}
}
if (o.options.sidebarBehavior == 'stick-to-top') {
top = options.additionalMarginTop;
}
if (o.options.sidebarBehavior == 'stick-to-bottom') {
top = windowOffsetBottom - o.stickySidebar.outerHeight();
}
if (scrollTopDiff > 0) { // If the user is scrolling up.
top = Math.min(top, windowOffsetTop);
}
else { // If the user is scrolling down.
top = Math.max(top, windowOffsetBottom - o.stickySidebar.outerHeight());
}
top = Math.max(top, staticLimitTop);
top = Math.min(top, staticLimitBottom - o.stickySidebar.outerHeight());
// If the sidebar is the same height as the container, we won't use fixed positioning.
var sidebarSameHeightAsContainer = o.container.height() == o.stickySidebar.outerHeight();
if (!sidebarSameHeightAsContainer && top == windowOffsetTop) {
position = 'fixed';
}
else if (!sidebarSameHeightAsContainer && top == windowOffsetBottom - o.stickySidebar.outerHeight()) {
position = 'fixed';
}
else if (scrollTop + top - o.sidebar.offset().top - o.paddingTop <= options.additionalMarginTop) {
// Stuck to the top of the page. No special behavior.
position = 'static';
}
else {
// Stuck to the bottom of the page.
position = 'absolute';
}
}
/*
* Performance notice: It's OK to set these CSS values at each resize/scroll, even if they don't change.
* It's way slower to first check if the values have changed.
*/
if (position == 'fixed') {
o.stickySidebar.css({
'position': 'fixed',
'width': o.sidebar.width(),
'top': top,
'left': o.sidebar.offset().left + parseInt(o.sidebar.css('padding-left'))
});
}
else if (position == 'absolute') {
var css = {};
if (o.stickySidebar.css('position') != 'absolute') {
css.position = 'absolute';
css.top = scrollTop + top - o.sidebar.offset().top - o.stickySidebarPaddingTop - o.stickySidebarPaddingBottom;
}
css.width = o.sidebar.width();
css.left = '';
o.stickySidebar.css(css);
}
else if (position == 'static') {
resetSidebar();
}
if (position != 'static') {
if (o.options.updateSidebarHeight == true) {
o.sidebar.css({
'min-height': o.stickySidebar.outerHeight() + o.stickySidebar.offset().top - o.sidebar.offset().top + o.paddingBottom
});
}
}
o.previousScrollTop = scrollTop;
};
// Initialize the sidebar's position.
o.onScroll(o);
// Recalculate the sidebar's position on every scroll and resize.
$(document).scroll(function (o) {
return function () {
o.onScroll(o);
};
}(o));
$(window).resize(function (o) {
return function () {
o.stickySidebar.css({'position': 'static'});
o.onScroll(o);
};
}(o));
// Reset the sidebar to its default state
function resetSidebar() {
o.fixedScrollTop = 0;
o.sidebar.css({
'min-height': '1px'
});
o.stickySidebar.css({
'position': 'static',
'width': ''
});
}
// Get the height of a div as if its floated children were cleared. Note that this function fails if the floats are more than one level deep.
function getClearedHeight(e) {
var height = e.height();
e.children().each(function () {
height = Math.max(height, $(this).height());
});
return height;
}
});
}
}
})(jQuery);
!
