Scrolling button jQuery doesn't work instantly - javascript

I'm working on some web pages that use a button to scroll to the next div. I can get it to work on every page, except in this particular instance (see jsfiddle).
My problem is that the buttons don't work on loading the page, the user first has to start scrolling manually, before the buttons work. I'm assuming that's because of some fault in my jQuery coding, which I've looked over and over, but I can't seem to find the problem. Is there anyone who is a bit more familiar with jQuery than I am who can offer me a solution?
http://jsfiddle.net/y5wx7nst/3/
$(document).ready(function () {
var currentElement = $("#bodytext > div:nth-child(1)");
var onScroll = function () {
var container = $("#bodytext");
var children = $(".section");
for (var i = 0; i < children.length; i++) {
var child = $(children[i]);
var childLeft = container.offset().left < child.offset().left;
if (childLeft) {
currentElement = child;
console.log(currentElement);
return;
}
}
};
var scrollToElement = function ($element) {
var container = $("#bodytext");
var children = $(".section");
var width = 0;
for (var i = 0; i < children.length; i++) {
var child = $(children[i]);
if (child.get(0) == $element.get(0)) {
if (i === 0) {
width = 0;
}
container.animate({
scrollLeft: width
}, 500);
onScroll();
}
if (child.next().length > 0) {
width += child.next().offset().left - child.offset().left;
} else {
width += child.width();
}
}
};
var buttonright = function (e) {
scrollToElement(currentElement.next());
};
var buttonleft = function (e) {
var container = $("#bodytext");
if (currentElement.prev().length > 0) {
if (container.offset().left == currentElement.prev().offset().left) {
currentElement = currentElement.prev().prev().length > 0 ? currentElement.prev().prev() : currentElement.prev();
} else {
currentElement = currentElement.prev();
}
}
scrollToElement(currentElement);
};
$("#bodytext").scroll(onScroll);
$("#buttonright").click(buttonright);
$("#buttonleft").click(buttonleft);
});

You are only calling the onScroll() function after you initially scroll:
$("#bodytext").scroll(onScroll);
I added this before that declaration and it all worked:
onScroll();
jsfiddle: http://jsfiddle.net/y5wx7nst/5/

When code run value of currentElement is not correct. So you should calculate it calling a function onScroll();
...
$("#bodytext").scroll(onScroll);
$("#buttonright").click(buttonright);
$("#buttonleft").click(buttonleft);
onScroll();
});

Related

How to make horizontal margin between images constant in mosaic

I am trying to replicate a mosaic that can be found on many webpages. While looking for solutions to my problem I came accross a very good implementation on squarespace seen at https://native-demo.squarespace.com/images-native/. I have hosted my website containing the mosaic at http://alexstiles.000webhostapp.com.
My issue is that when you resize the window the horizontal spacing between the images flucuates like it has an animation instead of staying consistient. Although it sorts itself out if you resize slowly, rapid movements can cause the margin to be to large or small. This behavior is not present in the squarespace template. How can I remove this and make the margin consistient when resizing? I have already tried using css margins instead of javascript. I have added the javascript below to help.
let mosaic = document.getElementsByClassName("mosaic")[0]; // For a single mosaic for now
let numImages = 12;
let imageTopic = "design";
let originalImageTopic = "design";
let rowWidth = 3;
let scale = 1;
let mosaicLoader = document.getElementsByClassName("loader-container")[0]
let search = document.getElementById("search");
let searchBtn = document.getElementById("search-button");
let form = document.getElementsByTagName("form")[0];
function rem(rems) {
return rems * (16 * scale);
}
searchBtn.addEventListener("click", function(event) {
event.preventDefault();
searchResult(search.value);
});
search.addEventListener("click", function() {
form.classList.add("focused");
});
search.addEventListener("blur", function() {
form.classList.remove("focused");
});
document.onkeydown = checkKey;
function checkKey(e) {
e = e || window.event;
if (e.keyCode == '13' || e.which == '13' || e.key === "Enter") {
e.preventDefault();
searchResult(search.value);
}
}
if (window.location.hash) {
let hash = window.location.hash.substring(1); //Puts hash in variable, and removes the # character
search.value = hash;
searchResult(hash);
}
function searchResult(query) {
// Get and set query
query = ((query != "" && query != originalImageTopic) ? search.value : imageTopic);
imageTopic = query;
if (imageTopic != originalImageTopic) {
parent.location.hash = imageTopic;
document.getElementById("search-term").textContent = imageTopic + " pictures";
}
// Put up loader while fetching images
mosaicLoader.style.display = "flex";
// Remove old images
let length = mosaic.children.length;
while (mosaic.lastChild && length > 1) {
mosaic.removeChild(mosaic.lastChild);
length--;
}
// Create new images
let loadedImageNum = 0
for (let i = 0; i < numImages; i++) {
let image = document.createElement("img");
image.src = `https://source.unsplash.com/random?${imageTopic}/sig${i}/`;
mosaic.appendChild(image);
}
// Wait for all images to load
let loadedImages = 0;
let image = mosaic.querySelectorAll("img");
imageCheck = setInterval(function() {
for (let i = 0; i < numImages; i++) {
if (image[i].naturalHeight !== 0 && image[i].complete) {
loadedImages++;
}
if (loadedImages == numImages) {
clearInterval(imageCheck);
// alert("Loaded!")
// Lay them out
setTimeout(imagesLoaded, 2000); // Needs some time before laying out
// Break loop
break;
}
}
}, 200)
}
searchResult(imageTopic); // Inital images with no search query
window.onload = function() {
windowResizeEvents();
}
window.onresize = function() {
windowResizeEvents();
}
function windowResizeEvents() {
imagesLoaded();
}
function mosaicCalibration() {
let images = document.querySelectorAll(".mosaic img");
if (window.innerWidth < 750) {
mosaic.classList.add("column");
} else if (window.innerWidth < 1100) {
rowWidth = 2;
} else {
rowWidth = 3 // Math.round(window.innerWidth/(426 + (2/3)));
}
if (window.innerWidth > 750) {
mosaic.classList.remove("column");
for (let i = 0; i < images.length; i++) {
images[i].style.width = `calc((100% - ${((rowWidth - 1) * 1)}rem) / ${rowWidth})`;
}
}
}
function imagesLoaded() {
// Find out row width, image width, etc
mosaicCalibration();
// Remove loader and set height to 0 so new height can be calculated
mosaicLoader.style.display = "none";
mosaic.style.height = 0;
// Define variables
let images = document.querySelectorAll(".mosaic img");
let row = 0;
let rowNum = 0;
let margin = rem(1.25);
let imageWidth = ((mosaic.scrollWidth - (2 * margin)) / rowWidth);
let column = [];
for (let i = 0; i < images.length; i++) {
images[i].style.top = i > rowWidth - 1 ? column[i-rowWidth] + margin : 0;
if (row < rowWidth) {
if (window.innerWidth > 1100) {
images[i].style.left = row * imageWidth + (row >= 1 ? row * margin : 0);
} else {
images[i].style.left = row * imageWidth + (row >= 1 ? (row + 0.5) * margin : 0);
}
row++
} else {
images[i].style.left = 0;
row = 1;
rowNum++;
}
if (rowNum > 0) {
column.push(column[i-rowWidth] + images[i].scrollHeight + margin);
} else {
column.push(images[i].scrollHeight);
}
}
mosaic.style.height = mosaic.scrollHeight;
}

Running the animation after scrolling to the block

I have function that works after window.onload, but how to run it just after scrolled to the needed . I understand that using jQuery is easier, but I need to do in native JS.
window.onload = function move() {
var width = 1;
var elem = document.getElementsByClassName("myBar");
var maxValue = document.getElementsByClassName('max-value');
for(var i = 0; i < elem.length; i++) {
var params = {
elem: elem[i],
maxElem: maxValue[i],
width: width,
interval: null
};
params.interval = setInterval(frame, 20, params);
}
function frame(aParams) {
if (aParams.width >= aParams.maxElem.dataset.max) {
clearInterval(aParams.interval);
} else {
aParams.width++;
aParams.elem.style.backgroundColor = 'blue';
aParams.elem.style.width = aParams.width + '%';
aParams.maxElem.innerHTML = aParams.width + '%';
}
};
};
https://codepen.io/Slava91/pen/PjpGGr
Try this, it will trigger the animation again when you will scroll near to the ul element. #percentage is the id I have given to the ul element in your html.
window.onload = move();
function move() {
var width = 1;
var elem = document.getElementsByClassName("myBar");
var maxValue = document.getElementsByClassName('max-value');
for(var i = 0; i < elem.length; i++) {
var params = {
elem: elem[i],
maxElem: maxValue[i],
width: width,
interval: null
};
params.interval = setInterval(frame, 20, params);
}
function frame(aParams) {
if (aParams.width >= aParams.maxElem.dataset.max) {
clearInterval(aParams.interval);
} else {
aParams.width++;
aParams.elem.style.backgroundColor = 'blue';
aParams.elem.style.width = aParams.width + '%';
aParams.maxElem.innerHTML = aParams.width + '%';
}
};
}
isScrolled = false;
window.onscroll = function loadItBack(){
var rec = document.getElementById("percentage").getBoundingClientRect();
if(window.scrollY > 600 && !isScrolled){
isScrolled = true;
move();
}else if(window.scrollY < 600){
isScrolled = false;
}
};
For your every li, you can use getBoundingClientRect to execute your animation.
Don't forget to set a flag once animation completed, else, it will execute on every scroll.

jQuery animate scrollLeft stops working after several clicks in FF and Chrome (but not Safari)

I have a very strange problem with some jquery code that scrolls a group of images. It seems to work in all browsers for the first several clicks, advancing the images by a number. And in Safari, it will work perfectly all the way to the end of the slideshow. But in FF and Chrome it will stop after a certain number of images. And this number is NOT always the same for some reason.
For example, on this page FF/Chrome will stop after clicking the next arrow 7 times.
And on this page, FF/Chrome will stop after clicking the next arrow 6 times.
Yet on this page, FF/Chrome will work all the way to the end as expected (and as Safari does all the time).
This is the code that controls the clicking:
<script>$(window).load(function(){
var currentElement = $("#ngg-gallery-list > div:nth-child(2)");
var onScroll = function () {
//get the current element
var container = $("#ngg-galleryoverview");
var wrapper = $("#ngg-gallery-list");
var children = wrapper.children();
var position = 0;
for (var i = 0; i < children.length; i++) {
var child = $(children[i]);
var childLeft = container.offset().left < child.offset().left;
if (childLeft) {
currentElement = child;
return;
}
}
}
var scrollToElement = function ($element) {
var container = $("#ngg-galleryoverview");
var wrapper = $("#ngg-gallery-list");
var children = wrapper.children();
var width = 0;
console.log(children.length);
for (var i = 0; i < children.length; i++) {
var child = $(children[i]);
if (child.get(0) == $element.get(0)) {
if (i == 0) {
width = 300;
}
container.animate({
scrollLeft: width
}, 300);
onScroll();
}
if (child.next().length > 0) {
//make sure we factor in borders/padding/margin in height
width += child.next().offset().left - child.offset().left
} else {
width += child.width();
}
}
}
var next = function(event) {
event.preventDefault();
scrollToElement(currentElement);
}
var prev = function(event) {
event.preventDefault();
var container = $("#ngg-galleryoverview");
if (currentElement.prev().length > 0) {
if (container.offset().left == currentElement.prev().offset().left) {
currentElement = currentElement.prev().prev().length > 0 ? currentElement.prev().prev() : currentElement.prev();
} else {
currentElement = currentElement.prev();
}
}
scrollToElement(currentElement);
}
$("#ngg-galleryoverview").on('scroll', onScroll);
$("#nexty").click(next);
$("#prevy").click(prev);
});
</script>
I'm stumped.
Well, making my code look more like what I found here fixed the problem. (Even if I am not entirely sure why). Hoping it helps someone else, here is the final code:
<script>
$(document).ready(function () {
var currentElement = $("#ngg-galleryoverview > div:nth-child(1)");
var onScroll = function () {
var container = $("#ngg-galleryoverview");
var children = $(".list");
for (var i = 0; i < children.length; i++) {
var child = $(children[i]);
var childLeft = container.offset().left < child.offset().left;
if (childLeft) {
currentElement = child;
//console.log(currentElement);
return;
}
}
};
var scrollToElement = function ($element) {
var container = $("#ngg-galleryoverview");
var children = $(".list");
var width = 0;
for (var i = 0; i < children.length; i++) {
var child = $(children[i]);
if (child.get(0) == $element.get(0)) {
if (i === 0) {
width = 0;
}
container.animate({
scrollLeft: width
}, 500);
onScroll();
}
if (child.next().length > 0) {
width += child.next().offset().left - child.offset().left;
} else {
width += child.width();
}
}
};
var buttonright = function (e) {
scrollToElement(currentElement.next());
};
var buttonleft = function (e) {
var container = $("#ngg-galleryoverview");
if (currentElement.prev().length > 0) {
if (container.offset().left == currentElement.prev().offset().left) {
currentElement = currentElement.prev().prev().length > 0 ? currentElement.prev().prev() : currentElement.prev();
} else {
currentElement = currentElement.prev();
}
}
scrollToElement(currentElement);
};
onScroll();
$("#ngg-galleryoverview").scroll(onScroll);
$("#nexty").click(buttonright);
$("#prevy").click(buttonleft);
});</script>

Same Height Elements but responsive variation

I found another question on this page about having two elements with the same height even if one of them doesn't have enough elements to cover the entire area. It works really fine but after reaching a max width of 600px I would like to disable this code, like getting back to height: auto; I'm trying to solve this but without any result. Any suggestion? here's actual javascript code.
HTML
<div id="section3a" data-same-height="blocks-resize">
</div>
<div id="section3b" data-same-height="blocks-resize">
</div>
JAVASCRIPT
$(document).ready(function() {
var equalize = function () {
var disableOnMaxWidth = 0; // 767 for bootstrap
var grouped = {};
var elements = $('*[data-same-height]');
elements.each(function () {
var el = $(this);
var id = el.attr('data-same-height');
if (!grouped[id]) {
grouped[id] = [];
}
grouped[id].push(el);
});
$.each(grouped, function (key) {
var elements = $('*[data-same-height="' + key + '"]');
elements.css('height', '');
var winWidth = $(window).width();
if (winWidth <= disableOnMaxWidth) {
return;
}
var maxHeight = 0;
elements.each(function () {
var eleq = $(this);
maxHeight = Math.max(eleq.height(), maxHeight);
});
elements.css('height', maxHeight + "px");
});
};
var timeout = null;
$(window).resize(function () {
if (timeout) {
clearTimeout(timeout);
timeout = null;
}
timeout = setTimeout(equalize, 250);
});
equalize();
});
Thanks to everyone!

How can i make a friendfeed like window scroll control system?

When you active real-time updates, new entries dynamically adding a div. At this stage scroll is automatically moving. This action provides the content you do not miss on visible area.
If you want to see this action, you can also watch this screencast; http://www.viddler.com/explore/itod/videos/45/
My method;
// Firstly, i am storing the first entry's(in view) positions in window object;
jQuery(window).scroll(function() {
var q = 0;
jQuery(".entry").each(function (i) {
if (jQuery(this).offset().top > jQuery(window).scrollTop()) {
if (q == 0) {
window.show_id = jQuery(this).attr("id");
window.pos_y = jQuery(this).offset().top - jQuery(window).scrollTop();
q = 1;
}
}
});
});
// After coming to the new entry, i call this function;
function scroll_control() {
var scroll_top = jQuery(window).scrollTop();
if (scroll_top != 0) {
if (jQuery('#'+window.show_id).length != 0) {
var scr = jQuery('#'+window.show_id).offset().top - window.pos_y;
window.scrollTo(0, scr);
}
}
}
// but this is due to flashing. I guess not fast enough
I assume you want to scroll smoothly to the top instead of jumping to solve 'flashing'. I would do something like this:
function scroll_control() {
var scroll_top = jQuery(window).scrollTop();
if (scroll_top != 0) {
if (jQuery('#'+window.show_id).length != 0) {
var scr = jQuery('#'+window.show_id).offset().top - window.pos_y;
// Instead of jumping to src use jQuery animate
// window.scrollTo(0, scr);
var scrollElem = scrollableElement('html', 'body');
$(scrollElem).animate({scrollTop: scr}, 400);
}
}
}
/*
* Use the first element that is "scrollable" (cross-browser fix?)
* http://css-tricks.com/snippets/jquery/smooth-scrolling/
*/
function scrollableElement(els) {
for (var i = 0, argLength = arguments.length; i <argLength; i++) {
var el = arguments[i],
$scrollElement = $(el);
if ($scrollElement.scrollTop()> 0) {
return el;
} else {
$scrollElement.scrollTop(1);
var isScrollable = $scrollElement.scrollTop()> 0;
$scrollElement.scrollTop(0);
if (isScrollable) {
return el;
}
}
}
return [];
}

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