How do I add a class during a scroll event in iOS? - javascript

The following script successfully adds or removes a "fix" class to an element (#sideBarWrapper) in desktop browsers, depending on the distance a user has scrolled.
(function (exocet, $, undefined) {
// Distance of sidebar from document top
function sideBarTop () {
return $eventSideBar.offset().top;
}
// Distance user has scrolled
function scrollDist () {
return $(window).scrollTop();
}
// Toggle sidebar class
function sideBarStick(sbt) {
if (sbt-30 < scrollDist()) {
$sideBarWrapper.addClass('fix');
} else{
$sideBarWrapper.removeClass('fix');
}
}
// Scroll events
function scroll() {
$eventSideBar = $('#eventSideBar');
$sideBarWrapper = $('#sideBarWrapper');
var sbt = sideBarTop();
return $(window).scroll(function () {
sideBarStick(sbt);
});
}
exocet.init = function () {
scroll();
};
}(window.exocet = window.exocet || {}, jQuery));
Invoked like so:
$(function() {
exocet.init();
});
The problem is, in Safari for iPad, the class doesn't seem to get added until the document has come to a halt, often long after the sidebar has scrolled out of view. How can I compensate for this?

Related

SharePoint back to top: not able to add class on page scroll

I am trying to add back to top to the SharePoint master page. Back to top functionality is working but on page scroll I am not able to add the class which is show/hide the icon. Below is the JS code
if ($('#back-to-top').length) {
var scrollTrigger = 100, // px
backToTop = function () {
var scrollTop = $(window).scrollTop();
if (scrollTop > scrollTrigger) {
$('#back-to-top').addClass('show');
} else {
$('#back-to-top').removeClass('show');
}
};
$(window).on('scroll', function () {
backToTop();
});
$('#back-to-top').on('click', function (e) {
e.preventDefault();
$('#s4-workspace').animate({scrollTop: 0}, 700);
});
}
Below HTML I have added in SharePoint master-page
↑
Issue: Icon is not visible on page because its not able to add class show on scroll.
For sharepoint instead of $(window) I used $('#s4-workspace') and its working
if ($('#back-to-top').length) {
var scrollTrigger = 100, // px
backToTop = function () {
var scrollTop = $('#s4-workspace').scrollTop();
if (scrollTop > scrollTrigger) {
$('#back-to-top').addClass('show');
} else {
$('#back-to-top').removeClass('show');
}
};
$('#s4-workspace').bind('scroll', function () {
backToTop();
});
$('#back-to-top').on('click', function (e) {
e.preventDefault();
$('#s4-workspace').animate({scrollTop: 0}, 700);
});
}

How to keep Skrollr-Menu at an even speed?

I'm using Skrollr-menu to animate down a page on a button press using the following
HTML
<div class="trigger-scroll left">></div>
... the page i want to reveal, using scrolling ...
<section id="End" class="scroll-here">
<div class="hsContainer bottom"></div>
</section>
JavaScript
var s = skrollr.init();
skrollr.menu.init(s, {
animate: true,
//How long the animation should take in ms.
duration: function(currentTop, targetTop) {
//By default, the duration is hardcoded at 500ms.
return 18000;
//But you could calculate a value based on the current scroll position (`currentTop`) and the target scroll position (`targetTop`).
//return Math.abs(currentTop - targetTop) * 10;
},
//This event is triggered right before we jump/animate to a new hash.
change: function(newHash, newTopPosition) {
//Do stuff
},
//Add hash link (e.g. `#foo`) to URL or not.
updateUrl: false //defaults to `true`.
});
What happens when I click the button is that it works, that is not the problem.
The problem is that it seems to change speed as skrollr-menu animates the page. It starts off quite quickly, which means that the first few elements on the page (about the first 2000px) flash past without being readable. Then the speed evens out and is fine right until the last 3000px (approximately) where skrollr-menu is very slow. What I want is for the click of the button to resemble holding the down arrow on the keyboard or the scroll sidebar, which by default it seems skrollr-menu does not do.
I've tried using math equations to change the speed but the issue persists no matter what i try, and there doesn't seem to be any "simple" way to change the acceleration speed, and I suspect the problem is somewhere within the Skrollr.menu.js file, but I can't see where.
Is there any way which I can make the scrolling an even speed, rather than fast at the start and slow at the end?
Note: I'm not very experienced in JavaScript or jQuery, so it's probably something simple I've overlooked.
skrollr menu on github
https://github.com/Prinzhorn/skrollr-menu
Skrollr.menu.js
/*!
* Plugin for skrollr.
* This plugin makes hashlinks scroll nicely to their target position.
*
* Alexander Prinzhorn - https://github.com/Prinzhorn/skrollr
*
* Free to use under terms of MIT license
*/
(function(document, window) {
'use strict';
var DEFAULT_DURATION = 500;
var DEFAULT_EASING = 'sqrt';
var DEFAULT_SCALE = 1;
var MENU_TOP_ATTR = 'data-menu-top';
var MENU_OFFSET_ATTR = 'data-menu-offset';
var MENU_DURATION_ATTR = 'data-menu-duration';
var MENU_IGNORE_ATTR = 'data-menu-ignore';
var skrollr = window.skrollr;
var history = window.history;
var supportsHistory = !!history.pushState;
/*
Since we are using event bubbling, the element that has been clicked
might not acutally be the link but a child.
*/
var findParentLink = function(element) {
//We reached the top, no link found.
if(element === document) {
return false;
}
//Yay, it's a link!
if(element.tagName.toUpperCase() === 'A') {
return element;
}
//Maybe the parent is a link.
return findParentLink(element.parentNode);
};
/*
Handle the click event on the document.
*/
var handleClick = function(e) {
//Only handle left click.
if(e.which !== 1 && e.button !== 0) {
return;
}
var link = findParentLink(e.target);
//The click did not happen inside a link.
if(!link) {
return;
}
if(handleLink(link)) {
e.preventDefault();
}
};
/*
Handles the click on a link. May be called without an actual click event.
When the fake flag is set, the link won't change the url and the position won't be animated.
*/
var handleLink = function(link, fake) {
var hash;
//When complexLinks is enabled, we also accept links which do not just contain a simple hash.
if(_complexLinks) {
//The link points to something completely different.
if(link.hostname !== window.location.hostname) {
return false;
}
//The link does not link to the same page/path.
if(link.pathname !== document.location.pathname) {
return false;
}
hash = link.hash;
} else {
//Don't use the href property (link.href) because it contains the absolute url.
hash = link.getAttribute('href');
}
//Not a hash link.
if(!/^#/.test(hash)) {
return false;
}
//The link has the ignore attribute.
if(!fake && link.getAttribute(MENU_IGNORE_ATTR) !== null) {
return false;
}
//Now get the targetTop to scroll to.
var targetTop;
var menuTop;
//If there's a handleLink function, it overrides the actual anchor offset.
if(_handleLink) {
menuTop = _handleLink(link);
}
//If there's a data-menu-top attribute and no handleLink function, it overrides the actual anchor offset.
else {
menuTop = link.getAttribute(MENU_TOP_ATTR);
}
if(menuTop !== null) {
//Is it a percentage offset?
if(/p$/.test(menuTop)) {
targetTop = (menuTop.slice(0, -1) / 100) * document.documentElement.clientHeight;
} else {
targetTop = +menuTop * _scale;
}
} else {
var scrollTarget = document.getElementById(hash.substr(1));
//Ignore the click if no target is found.
if(!scrollTarget) {
return false;
}
targetTop = _skrollrInstance.relativeToAbsolute(scrollTarget, 'top', 'top');
var menuOffset = scrollTarget.getAttribute(MENU_OFFSET_ATTR);
if(menuOffset !== null) {
targetTop += +menuOffset;
}
}
if(supportsHistory && _updateUrl && !fake) {
history.pushState({top: targetTop}, '', hash);
}
var menuDuration = parseInt(link.getAttribute(MENU_DURATION_ATTR), 10);
var animationDuration = _duration(_skrollrInstance.getScrollTop(), targetTop);
if(!isNaN(menuDuration)) {
animationDuration = menuDuration;
}
//Trigger the change if event if there's a listener.
if(_change) {
_change(hash, targetTop);
}
//Now finally scroll there.
if(_animate && !fake) {
_skrollrInstance.animateTo(targetTop, {
duration: animationDuration,
easing: _easing
});
} else {
defer(function() {
_skrollrInstance.setScrollTop(targetTop);
});
}
return true;
};
var jumpStraightToHash = function() {
if(window.location.hash && document.querySelector) {
var link = document.querySelector('a[href="' + window.location.hash + '"]');
if(!link) {
// No link found on page, so we create one and then activate it
link = document.createElement('a');
link.href = window.location.hash;
}
handleLink(link, true);
}
};
var defer = function(fn) {
window.setTimeout(fn, 1);
};
/*
Global menu function accessible through window.skrollr.menu.init.
*/
skrollr.menu = {};
skrollr.menu.init = function(skrollrInstance, options) {
_skrollrInstance = skrollrInstance;
options = options || {};
_easing = options.easing || DEFAULT_EASING;
_animate = options.animate !== false;
_duration = options.duration || DEFAULT_DURATION;
_handleLink = options.handleLink;
_scale = options.scale || DEFAULT_SCALE;
_complexLinks = options.complexLinks === true;
_change = options.change;
_updateUrl = options.updateUrl !== false;
if(typeof _duration === 'number') {
_duration = (function(duration) {
return function() {
return duration;
};
}(_duration));
}
//Use event bubbling and attach a single listener to the document.
skrollr.addEvent(document, 'click', handleClick);
if(supportsHistory) {
skrollr.addEvent(window, 'popstate', function(e) {
var state = e.state || {};
var top = state.top || 0;
defer(function() {
_skrollrInstance.setScrollTop(top);
});
}, false);
}
jumpStraightToHash();
};
//Expose the handleLink function to be able to programmatically trigger clicks.
skrollr.menu.click = function(link) {
//We're not assigning it directly to `click` because of the second ("private") parameter.
handleLink(link);
};
//Private reference to the initialized skrollr.
var _skrollrInstance;
var _easing;
var _duration;
var _animate;
var _handleLink;
var _scale;
var _complexLinks;
var _change;
var _updateUrl;
//In case the page was opened with a hash, prevent jumping to it.
//http://stackoverflow.com/questions/3659072/jquery-disable-anchor-jump-when-loading-a-page
defer(function() {
if(window.location.hash) {
window.scrollTo(0, 0);
}
});
}(document, window));
The problem was the easing function found here
//Now finally scroll there.
if(_animate && !fake) {
_skrollrInstance.animateTo(targetTop, {
duration: animationDuration,
easing: _easing
});
} else {
defer(function() {
_skrollrInstance.setScrollTop(targetTop);
});
}
return true;
It seems that, even though Skrollr states that easing's default is linear (no easing), the default is ACTUALLY set to sqrt (or at least it was in my case). The problem can be solved by forcing easing to linear in skrollr.menu.init, or chaning the skrollr.menu.js file to remove easing from the function. The first of these two solutions is cleaner, and won't cause issues later.
skrollr.menu.init(s, {
duration: function(currentTop, targetTop) {return 20000;},
easing: 'linear'
});

Android + jQuery - second on swipeleft wont execute

I have to do some Special things for my Webpage to work on Android the correct way. Some Images are displayed (one visible, the other unvisible) and through swipe it should be possible to Change them. No Problem so far on all OS.
But it also should be possible to zoom. Now Android starts to be Buggy. It stops the zoom-gesture because of the swipe callback. The callback itself doesn't Change the page because the view is zoomed, so there should be no break.
Now I work arround through turning my swipeleft and swiperight off while two fingers touching the Display, and tourning back on if the fingers leave the Display.
On First run I can swipe, then I can zoom with no break, but then I can't swipe anymore. The function to set the callbacks back on again is called, it set's the callbacks, but they won't be executed...
Here's the code:
app.utils.scroll = (function(){
var $viewport = undefined;
var swipeDisabled = false;
var init = function(){
$viewport = $('#viewport');
$viewport.mousewheel(mayChangePage);
// On touchstart with two fingers, remove the swipe listeners.
$viewport.on('touchstart', function (e) {
if (e.originalEvent.touches.length > 1) {
removeSwipe();
swipeDisabled = true;
}
});
// On touchend, re-define the swipe listeners, if they where removed through two-finger-gesture.
$viewport.on('touchend', function (e) {
if (swipeDisabled === true) {
swipeDisabled = false;
initSwipe();
}
});
initSwipe();
}
var mayChangePage = function(e){
// If page is not zoomed, change page (next or prev).
if (app.utils.zoom.isZoomed() === false) {
if (e.deltaY > 0) {
app.utils.pagination.prev(e);
} else {
app.utils.pagination.next(e);
}
}
// Stop scrolling page through mouse wheel.
e.preventDefault();
e.stopPropagation();
};
var next = function (e) {
// If page is not zoomed, switch to next page.
if (app.utils.zoom.isZoomed() === false) {
app.utils.pagination.next(e);
}
};
var prev = function (e) {
// If page is not zoomed, switch to prev page.
if (app.utils.zoom.isZoomed() === false) {
app.utils.pagination.prev(e);
}
};
var initSwipe = function () {
// Listen to swipeleft / swiperight-Event to change page.
$viewport.on('swipeleft.next', next);
$viewport.on('swiperight.prev', prev);
};
var removeSwipe = function () {
// Remove listen to swipeleft / swiperight-Event for changing page to prevent android-bug.
$viewport.off('swipeleft.next');
$viewport.off('swiperight.prev');
};
$(document).ready(init);
}());
Pastebin
Any ideas what I can do to get the Events back on again?
Thanks for all Ideas.
Regards
lippoliv
Fixed it:
jQuery Mobile itself prevents the swipe Event if an handler is registered, to kill an "scroll".
So I overwrote the $.event.special.swipe.scrollSupressionThreshold value and set it to 10000, to prevent jQueryMobile's preventDefault-call:
$.event.special.swipe.scrollSupressionThreshold = 10000;
Now my Code Looks like
app.utils.scroll = (function(){
var $viewport = undefined;
var swipeDisabled = false;
var init = function(){
$viewport = $('#viewport');
$viewport.mousewheel(mayChangePage);
// See #23.
$.event.special.swipe.scrollSupressionThreshold = 10000;
// Listen to swipeleft / swiperight-Event to change page.
$viewport.on('swipeleft.next', next);
$viewport.on('swiperight.prev', prev);
}
var mayChangePage = function(e){
// If page is not zoomed, change page (next or prev).
if (app.utils.zoom.isZoomed() === false) {
if (e.deltaY > 0) {
app.utils.pagination.prev(e);
} else {
app.utils.pagination.next(e);
}
}
// Stop scrolling page through mouse wheel.
e.preventDefault();
e.stopPropagation();
};
var next = function (e) {
// If page is not zoomed, switch to next page.
if (app.utils.zoom.isZoomed() === false) {
app.utils.pagination.next(e);
}
};
var prev = function (e) {
// If page is not zoomed, switch to prev page.
if (app.utils.zoom.isZoomed() === false) {
app.utils.pagination.prev(e);
}
};
$(document).ready(init);
}());
Thanks to Omar- who wrote with me several minutes / hours in the jquery IRC and gave some suggestions regarding overwriting Standard values for jQueryMobile.

Navbar Irregularly Appearing and Disapearing

I have a code that is intended to make a navbar disappear when the mouse is still, and when the mouse moves, it is supposed to fade in. The code works, except that when the mouse is still, the navbar will fade out, but then will fade in a couple seconds later, and continue fading out and in at regular intervals. The website with the problem is here.
My code is below
$("#header").hide();
$("html").mousemove(function( event ) {
$("#header").fadeIn(1500);
myStopFunction();
myFunction();
});
function myFunction() {
myVar = setTimeout(function(){
$("#header").fadeOut(1500);
}, 2000);
}
function myStopFunction() {
if(typeof myVar != 'undefined'){
clearTimeout(myVar);
}
}
Try this (pattern)
$(function () {
var _toggle = function () {
$(document).one("mousemove.t", function (e) {
e.target = $("#header");
$(e.target).toggle(1500).delay(2000).toggle(1500, function () {
_toggle()
})
})
};
$.when(_toggle())
})
jsfiddle http://jsfiddle.net/guest271314/8VeDN/

How to get page scrolling position (y axis)

How can i get the current scrolling position of my browser?, i want to fire events base on page position.This is what I tried:
var scroll_position=document.viewport.getScrollOffsets();
window.onscroll = function (event) {
if(scroll_position>1000)
{
alert('xxxxxxxxxxx');
}
Assuming that you're always going to be testing with window, you can use window.scrollY:
window.onscroll = function (event)
{
if(this.scrollY > 1000)
{
alert('xxxxxxxxxxx');
}
}
jsFiddle Demo
Try with:
window.onscroll = function (event) {
if (window.scrollY > 1000) {
alert('xxxxxxxxxxx');
}
}
As hsz said, do
window.onscroll = function (event) {
var scroll_position = document.viewport.getScrollOffsets();
if (scroll_position > 1000)
{
alert('xxxxxxxxxxx');
}
}
The problem with your code:
var scroll_position=document.viewport.getScrollOffsets();
scroll_position is only set once, when the page loads - therefore it stays the same (probably 0) and the alert never comes up because scroll_position is less than 1000.
hsz put the statement that sets scroll_position into the window.onscroll function, so it is updated every time the page scrolls.

Categories