I set the following CSS at the top of my file:
#img1, #img2, #img3 {
background: url("bates-sprite.jpeg");
background-repeat: no-repeat;
object-fit: none;
}
#img1 {object-position: 0 0;
width: 816px; // full size 3264
height: 612px; // full size 2448
}
This is the relevant part of my JavaScript:
var tempDiv = document.createElement('div');
tempDiv.setAttribute("id", "bigImg" + figNum);
// Make tempDiv High enough to hold the scaled up image.
// This line is causing a problem
let imgHeight = document.getElementById("img1").clientHeight;
// let imgHeight = "1224px";
tempDiv.style.height = parseInt(imgHeight) + parseInt("400px") + "px";
If I set imgHeight explicitly to 1224 pixels, the function works perfectly. If instead I use clientHeight, it fails. How can I fix it?
Client height will only give a number, but you need to add the type of that, also like (px, %, rem), to make it work.
Related
I am working on a JavaScript animation library and ran into a problem: All values are usually returned in pixels using this default function:
window.getComputedStyle(element).getPropertyValue(property);
However, when getting the value for background-position like so:
window.getComputedStyle(element).getPropertyValue('background-position');
The result is 50% 50% (background-position: center). How can I convert the values to pixels? I wrote the following function, but it gives me the wrong result, the reason being is that percentages on background-position are also relative to the image size.
var pixelsX = (parseFloat(percentX) / 100 * element.offsetWidth) + 'px';
var pixelsY = (parseFloat(percentY) / 100 * element.offsetHeight) + 'px';
I also cannot get the size using Image() since the calculation has to happen in real time and I cannot wait for the image to load.
Thanks!
I actually did tried your code and it works...
Is this not the accurate sizes?
I checked it on different screen sizes and it seems accurate.
Please have a look:
var demoDiv = document.getElementById('divDemo');
var demoCalc = window.getComputedStyle(demoDiv).getPropertyValue('background-position');
var pixelsX = (parseFloat(demoCalc) / 100 * demoDiv.offsetWidth) + 'px';
var pixelsY = (parseFloat(demoCalc) / 100 * demoDiv.offsetHeight) + 'px';
console.log(demoCalc);
console.log(pixelsX);
console.log(pixelsY);
body {height: 100vh; width: 100vw; overflow: hidden}
#divDemo {
height: 100%; width: 100%;
background-image: url(https://images.unsplash.com/photo-1554056588-6c35fac03654?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=400&q=80);
background-position: 50% 50%;
background-repeat: no-repeat;
}
<div id="divDemo"></div>
More SO on this subject here
If you just need the position of the element, maybe try this:
element.getBoundingClientRect();
(source: https://developer.mozilla.org/en-US/docs/Web/API/Element/getBoundingClientRect)
You can get the position of each corner as well as dimensions of the element like so:
element.getBoundingClientRect().left;
This returns properties: left, top, right, bottom, x, y, width, and height.
All in pixels!
So I'm trying to make the height of my DIV's respond to the width of the window. The code:
var w = window.innerWidth;
var mathW = parseInt(w);
var divHeight = mathW*0.16;
document.getElementById('demoDiv').style.height = divHeight;
With the CSS being:
#demoDiv {
margin: auto;
background-color: red;
width: 100%;
height: 50px; //just to start with SOMETHING
}
Obviously I'm having trouble with that! I've played around with it and definitely can change the height if I just use regular integers, but even using parseInt('divHeight') did nothing for me!
You are calucalting the height in a correct way. But in order to set the height you need to add dimension to the value (say px).
You dont need to do parseInt as window.innerWidth is a property with typeof number.
var w = window.innerWidth;
var divHeight = mathW*0.16;
document.getElementById('demoDiv').style.height = divHeight+"px";
What stops you from applying a pure CSS solution?
#demoDiv {
height: 16vw;
}
Requires no Javascript, is much shorter and performs faster, and no need to apply any resize handler when window size changes.
Unfortunately 100vh is not always the same as 100% browser height as can be shown in the following example.
html,
body {
height: 100%;
}
body {
overflow: scroll;
}
.vh {
background-color: blue;
float: left;
height: 50vh;
width: 100px;
}
.pc {
background-color: green;
float: left;
height: 50%;
width: 100px;
}
<div class="vh"></div>
<div class="pc"></div>
The issue is more pronounced on iPhone 6+ with how the upper location bar and lower navigation bar expand and contract on scroll, but are not included in the calculation for 100vh.
The actual value of 100% height can be acquired by using window.innerHeight in JS.
Is there a convenient way to calculate the current conversion of 100vh to pixels in JS?
I'm trying to avoid needing to generate dummy elements with inline styles just to calculate 100vh.
For purposes of this question, assume a hostile environment where max-width or max-height may be producing incorrect values, and there isn't an existing element with 100vh anywhere on the page. Basically, assume that anything that can go wrong has with the exception of native browser functions, which are guaranteed to be clean.
The best I've come up with so far is:
function vh() {
var div,
h;
div = document.createElement('div');
div.style.height = '100vh';
div.style.maxHeight = 'none';
div.style.boxSizing = 'content-box';
document.body.appendChild(div);
h = div.clientHeight;
document.body.removeChild(div);
return h;
}
but it seems far too verbose for calculating the current value for 100vh, and I'm not sure if there are other issues with it.
How about:
function viewportToPixels(value) {
var parts = value.match(/([0-9\.]+)(vh|vw)/)
var q = Number(parts[1])
var side = window[['innerHeight', 'innerWidth'][['vh', 'vw'].indexOf(parts[2])]]
return side * (q/100)
}
Usage:
viewportToPixels('100vh') // window.innerHeight
viewportToPixels('50vw') // window.innerWidth / 2
The difference comes from the scrollbar scrollbar.
You'll need to add the height of the scrollbar to the window.innerHeight. There doesn't seem to be a super solid way of doing this, per this other question:
Getting scroll bar width using JavaScript
I'm using bxslider to have a carousel of images. The thing is though, the images it receives to display are of somewhat unpredictable sizes. The container size is 243x243. And we know that no image will have a side smaller than 243. So...I'd like to center the image in the container. And either zoom in until the shorter of the two dimensions (L vs W) fills the container at 243, and the longer dimension overflow is hidden.
For the images I'm working with, doing this will be perfect for getting the important details of the picture in the frame.
But I'm having trouble...
I've tried the following to center the picture in the frame:
jQuery(".bx-container").each(function() {
var img_w = jQuery(this).children("img").width();
var img_h = jQuery(this).children("img").height();
var pos_top = (img_h - containerHeight) / 2;
var pos_left = (img_w - containerWidth) / 2;
var pos_top = (243 - img_h) / 2;
var pos_left = (243 - img_w) / 2;
jQuery(this).children("img").css({
'top' : pos_top + 'px',
'left' : pos_left + 'px'
});
});
And I've tried this to position not square images into the frame:
jQuery(".bx-container").each(function(){
var refRatio = 1;
var imgH = jQuery(this).children("img").height();
var imgW = jQuery(this).children("img").width();
if ( (imgW/imgH) < refRatio ) {
jQuery(this).addClass("bx-portrait");
} else {
jQuery(this).addClass("bx-landscape");
}
});
});
I've messed with both scripts and the css but I just can't seem to get it work. It either centers but doesn't resize right. Or resizes but centers wrong. Or does both wrong.
Here's the jsfiddle: http://jsfiddle.net/vgJ9X/298/
Could someone help me out?
Thanks!
EDIT:
New jsfiddle...the portrait ones work right. The landscape images still squish. :(
http://jsfiddle.net/vgJ9X/307/
EDIT:
I THINK it has something to do with relatively positioned elements not being allowed to overlap. Trying to find a fix. If anyone knows, edit the last fiddle I posted.
jQuery(".bx-container img").each(function () {
var w = jQuery(this).width();
var h = jQuery(this).height();
if (w > h) $(this).addClass('bx-landscape');
else $(this).addClass('bx-portrait');
});
Check this Updated JSFiddle
Update
jQuery(".bx-container img").each(function () {
var w = jQuery(this).width();
var h = jQuery(this).height();
if (w > h){
$(this).addClass('bx-landscape');
var trans= -243/2;
$(this).css('-webkit-transform','translateZ('+trans+'px)');
}
else if(h > w){
$(this).addClass('bx-portrait');
var trans= -243/2;
$(this).css('-webkit-transform','translateY('+trans+'px)');
}
});
check this JSFiddle
Update of Update
Found the issue with landscape, the plugin is setting max-width:100%; overriding it with max-width:none; fixes the issue...
Update Of Updated Fiddle
Try this:
img{
position:relative;
height:100%;
width:300px;
}
Simple an clean.
Demo: http://jsfiddle.net/vgJ9X/302/
I did a couple things to your jsfiddle.
First I changed the order of your resize and center functions, so the resize comes first. This way, the smaller images get resized, then centered. I also uncommented the first portion of your code.
You also had a couple of errors in your css. There was an extra closing bracket after img style declaration. Your .bx-portrait img and .bx-landscape img declarations were set to 100%px;.
Update:
Change the css in your two .bx classes to:
.bx-portrait img {
height: 100%;
width: auto;
}
.bx-landscape img {
height: auto;
width: 100%;
}
And add a clearfix to your ul:
.bxslider:after {
content: '';
clear: both;
display: table;
padding: 0;
margin: 0;
}
The height is clipping because .bx-viewport has a set height of 243px but also has a 5px border, which makes the actual internal height 233px. You'll need to make the height 253px to account for the 10px of border. This is why they don't look centered vertically.
DEMO
Why don't you just use background images instead and center them. Here is a demo from your original code
http://jsfiddle.net/8y8df/
If you want to show the full size image, just remove the background-size:contain; from the css.
I have span, and it's styles are represented below. My problem is, it was designed to fill 60px*60px span. But now, I have to make it to fill another span with 50px*50px size. But it can't work with background position, because if i change the background-size, all position slips away. So is there any way (css or javascript hack) to resize an image or a block element with bacground-image after the image has been drawn? I want to avoid rewriting all background positions (I've got classes for each icons like ".entertainment").
<span class="icon icon2 entertainment"></span>
span.icon2 {
float: left;
width: 50px;
height: 50px;
margin: 5px 0 0 0;
}
#wrapper span.icon.entertainment {
background-position: -60px -360px;
}
#wrapper span.icon {
background: url(https://teeg.hu/image/icon.png);
}
Thanks for any help!
There is no pure css solution.
There is a js solution. Resize the background (background-size) as you did, then for each element move the position with the difference between sizes / 2 (in your case 5px).
You don't rewrite the classes, just iterate through elements.
Note: This might become an extensive operation, it is better to rewrite classes, even though that is what you want to avoid (40 is not so much... at most 30 min - testing included).
Ok, I've written some hack. I resized the background:
background-size: 100px 1550px;
and did it with jQuery:
$(function() {
$("span.icon2").each(function(index, value) {
var pos = $(this).css("background-position").split(' ');
var newPos = [];
newPos[0] = parseInt(pos[0].replace("px", "")) / 60 * 50;
newPos[1] = parseInt(pos[1].replace("px", "")) / 60 * 50;
$(this).css("background-position", newPos[0] + "px " + newPos[1] + "px");
});
});