How to disable a JavaScript, with inner window width - javascript

The page I am working on has a tilt effect, which affects the orientation of the site body. I want to turn this off when the page reaches a mobile viewport; I have looked and tried a few thing but can't seem to get the effect I want. The code below is what i am using. This script runs separate from my main JS code.
window.addEventListener("mousemove",function(e) {
var width = window.innerWidth;
var height = window.innerHeight;
var clientHeight = document.body.clientHeight;
var skew = {};
skew.y = (20 * ((e.x / width) - 0.5));
skew.x = -(20 * ((e.y / height) - 0.5));
document.body.style.webkitTransform = "perspective("+clientHeight+"px) rotateX("+skew.x+"deg) rotateY("+skew.y+"deg)";
});

CSS changes won't remove themselves, so you'll have to remove the transform manually if the browser window is under your desired size.
Check on window resize,
window.addEventListener('resize', function() {
if (window.innerWidth < 568) {
document.body.style.webkitTransform = '';
}
});
And also make sure not to reapply it if the user moves their mouse.
// This is the function you already have
window.addEventListener('mousemove', function(e) {
if (window.innerWidth < 568) {
return;
}
...
}

Related

Use matchMedia to enable/disable script like a media query on load/viewport resize

I only want to run a script when the viewport width is greater than a set value. I would also like this to check as the browser resizes and disable/enable as required. I've tried to achieve this using matchMedia and rather than checking every pixel, the script only triggers when the viewport is less/greater than a set value.
If I load a narrow viewport (less than 1080px) the JS doesn't trigger - perfect! Enlarging the viewport to have a width greater than 1080px then runs the script - also perfect!
The problem I have is when I scale down from a larger viewport (greater than 1080px) to narrow/small. The script still functions until I refresh the page - I'm hoping someone can help me with that.
As an aside, is it possible to change const mediaQuery = window.matchMedia('(min-width: 1080px)') to include a min-height or a more complex media query if required (not essential for this).
My script:
const mediaQuery = window.matchMedia('(min-width: 1080px)')
function viewportChange(e) {
// Check if the media query is true
if (e.matches) {
$(document).ready(function() {
var num_children = $('.split-loop__left').children().length;
var child_height = $('.split-loop__right').height() / num_children;
var half_way = num_children * child_height / 2;
$(window).scrollTop(half_way);
function crisscross() {
var parent = $(".split-loop");//.first();
var clone = $(parent).clone();
var leftSide = $(clone).find('.split-loop__left');
var rightSide = $(clone).find('.split-loop__right');
if (window.scrollY > half_way ) {
//We are scrolling up
$(window).scrollTop(half_way - child_height);
var firstLeft = $(leftSide).children().first();
var lastRight = $(rightSide).children().last();
lastRight.appendTo(leftSide);
firstLeft.prependTo(rightSide);
} else if (window.scrollY < half_way - child_height) {
var lastLeft = $(leftSide).children().last();
var firstRight = $(rightSide).children().first();
$(window).scrollTop(half_way);
lastLeft.appendTo(rightSide);
firstRight.prependTo(leftSide);
}
$(leftSide).css('bottom', '-' + window.scrollY + 'px');
$(rightSide).css('bottom', '-' + window.scrollY + 'px');
$(parent).replaceWith(clone);
}
$(window).scroll(crisscross);
});
}
}
// Register event listener
mediaQuery.addListener(viewportChange)
// Initial check
viewportChange(mediaQuery)

I want to use javascript to resize my browser so that it doesn't scroll

I want to use a background color with Gradient on the intro page, but when I shrink my browser, I want to work to reduce the height value without scrolling.
I don't know what method to use when it's resizing.
The code is as follows.
function __screenResize () {
var innerHeight = window.innerHeight;
var availHeight = window.screen.availHeight;
document.getElementById('section').style.height = innerHeight + 'px';
window.onresize = function () {
document.getElementById('section').style.height = availHeight + 'px';
}
}

How to make the slide take 100% versus re-sizing according to browser?

I have a fullscreen slideshow page, but the slides don't take up 100% of the background. Instead, they base size off of the browser. I want the slides to take 100% of the background. I THINK I narrowed it down to one function, but I'm not sure and not good with JavaScript yet. Here's the function:
// calculate image size, top and left position
jQuery.fn.superbgCalcSize = function(imgw, imgh) {
var options = $.extend($.fn.superbgimage.defaults, $.fn.superbgimage.options);
// get browser dimensions
var browserwidth = $(window).width();
var browserheight = $(window).height();
// use container dimensions when inlinemode is on
if (options.inlineMode === 1) {
browserwidth = $('#' + options.id).width();
browserheight = $('#' + options.id).height();
}
// calculate ratio
var ratio = imgh / imgw;
// calculate new size
var newheight = 0; var newwidth = 0;
if ((browserheight / browserwidth) > ratio) {
newheight = browserheight;
newwidth = Math.round(browserheight / ratio);
} else {
newheight = Math.round(browserwidth * ratio);
newwidth = browserwidth;
}
// calculate new left and top position
var newleft = Math.round((browserwidth - newwidth) / 2);
var newtop = Math.round((browserheight - newheight) / 2);
var rcarr = [newwidth, newheight, newleft, newtop];
return rcarr;
};
Let me know if there needs to be more code or even to link to the entire document, as I said I'm not at all experienced with JS and don't know where the problem resides.
*I've tried doing it with CSS, but I get a bug where as it's transitioning to the next image it bleeps the first image's actual size just before displaying the next and it's rather unsleek. Fixing this would also solve my question.

How can I inject a div into a webpage that moves on window resize?

Essentially, I'm creating a custom click & drag selection box. The problem is that the div is position absolutely, so it will scroll with the page, but it will not move with the page when the window is being resized. My attempted solution was to listen to the window resize, and move the div according to the change. The problem is that it will SEEM to work, but it will not move entirely accurately, so it will slowly move out of place if the window is resized slowly, or quickly move out of place if the window is resized quickly. It seems that the resize listener does not capture every resize event. I've narrowed the code down to the concept I'm using.
Try injecting this script into a page (I'm using the Chrome console and I haven't made any attempt for cross-compatibility because this will be used in a Chrome extension). It will attempt to resize only when the scrollbar is not active, to replicate the behavior of the page content. The client and scoll variables are interchangeable for recording the change in dimensions, but they are both there for testing purposes. I would love to see a solution which solves this problem using styling attributes. Thanks for your help!
var div = document.createElement("div");
div.style.position = "absolute";
div.style.backgroundColor = "#000";
div.style.width = div.style.height = div.style.left = div.style.top = "200px";
document.body.appendChild(div);
// get the highest z index of the document
function highestZIndex() {
var elems = document.getElementsByTagName("*");
var zIndex = 0;
var elem, value;
for (var i = 0; i < elems.length; i++) {
value = parseInt(document.defaultView.getComputedStyle(elems[i], null).zIndex, 10);
if (value > zIndex) {
zIndex = value;
elem = elems[i];
}
}
return {
elem: elem,
zIndex: zIndex
};
}
// set the div on top if it is not already
var highestZ = highestZIndex();
if (highestZ.elem != div) div.style.zIndex = highestZ.zIndex + 1;
// last width & height of client & scroll to calculate the change in dimensions
var clientWidth = document.body.clientWidth;
var clientHeight = document.body.clientHeight;
var scrollWidth = document.body.scrollWidth;
var scrollHeight = document.body.scrollHeight;
// move the div when the window is being resized
function resizeListener() {
var _clientWidth = document.body.clientWidth;
var _clientHeight = document.body.clientHeight;
var _scrollWidth = document.body.scrollWidth;
var _scrollHeight = document.body.scrollHeight;
// horizontal scrollbar is not enabled
if (_scrollWidth <= _clientWidth) {
div.style.left = parseInt(div.style.left.replace(/px/, ''), 10) + (_scrollWidth - scrollWidth) / 2 + 'px';
}
// vertical scrollbar is not enabled
if (_scrollHeight <= _clientHeight) {
div.style.top = parseInt(div.style.top.replace(/px/, ''), 10) + (_scrollHeight - scrollHeight) / 2 + 'px';
}
clientWidth = _clientWidth;
clientHeight = _clientHeight;
scrollWidth = _scrollWidth;
scrollHeight = _scrollHeight;
}
window.addEventListener("resize", resizeListener);
PS: Please, no jQuery solutions.
Since the resize listener isn't quite dependable with outside events, I've developed a simple "hack" to get the wanted results. The window overflow is forced to scroll and the body width & height are set to +1 so that the scrollbar is active, in which the div will then stay in place. Once the resize is complete, the overflow and body dimensions are restored. This may not be a desired solution for others who want the div to move on a manual window resize, but I am invoking the resize from JavaScript so it works perfectly for me.
The script in practice:
var overflow, overflowX, overflowY, bodyWidth, bodyHeight;
function startResize() {
// store the original overflow values
overflow = document.body.style.overflow;
overflowX = document.body.style.overflowX;
overflowY = document.body.style.overflowY;
bodyWidth = document.body.style.width;
bodyHeight = document.body.style.height;
// force the scrollbar
document.body.style.overflow = "scroll";
// activate the scrollbar
document.body.style.width = document.client.width + 1 + "px";
document.body.style.height = document.client.height + 1 + "px";
}
function stopResize() {
// restore the original overflow values; x & y are included because enabling the global overflow will update x and y
document.body.style.overflow = overflow;
document.body.style.overflowX = overflowX;
document.body.style.overflowY = overflowY;
// restore the original body width & height
document.body.style.width = bodyWidth;
document.body.style.height = bodyHeight;
}

Auto-scroll to the bottom of a div

I have a div with overflow set to scroll which essentially streams data line by line off a file. I'd like to scroll automatically to the bottom of the div whenever the stream overflows, but without using a "Click here to scroll to bottom" button.
I already know of the scrollTop = scrollHeight solution, but that requires some kind of event trigger on the client's side. I don't want this element to be interactive; it should scroll by itself.
Is there any way to achieve this?
A lot of the scrollHeight implementations didn't work for me, offsetHeight seemed to do the trick.
Pretty sure that scrollHeight tries to move it to the bottom of the height of the static element, not the height of the scrollable area.
var pane = document.getElementById('pane');
pane.scrollTop = pane.offsetHeight;
There's no way to automatically scroll an element to the bottom. Use element.scrollTop = element.scrollHeight.
If you don't know when the element is going to resize, you could add a poller:
(function(){
var element = document.getElementById("myElement");
var lastHeight = element.scrollHeight;
function detectChange(){
var currentHeight = element.scrollHeight;
if(lastHeight != currentHeight){
element.scrollTop = currentHeight;
lastHeight = currentHeight;
}
}
detectChange();
setInterval(detectChange, 200); //Checks each 200ms = 5 times a second
})();
Some old code of mine with a running example that will stay at the bottom when new content is added, if the user scrolls it will not more it to the bottom.
var chatscroll = new Object();
chatscroll.Pane =
function(scrollContainerId)
{
this.bottomThreshold = 25;
this.scrollContainerId = scrollContainerId;
}
chatscroll.Pane.prototype.activeScroll =
function()
{
var scrollDiv = document.getElementById(this.scrollContainerId);
var currentHeight = 0;
if (scrollDiv.scrollHeight > 0)
currentHeight = scrollDiv.scrollHeight;
else
if (objDiv.offsetHeight > 0)
currentHeight = scrollDiv.offsetHeight;
if (currentHeight - scrollDiv.scrollTop - ((scrollDiv.style.pixelHeight) ? scrollDiv.style.pixelHeight : scrollDiv.offsetHeight) < this.bottomThreshold)
scrollDiv.scrollTop = currentHeight;
scrollDiv = null;
}

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