Develop Reference

How to increase width and height on click of a button

I need to increase height actually to increase bottom and top of div each for 25px also left and right side each for 25px.I don't now is that even possible.
So this is just example but it is similar to my code:
function increaseDiv() {
var myDiv = document.querySelector(".box")
var currWidth = myDiv.clientWidth;
myDiv.style.width = currWidth + 100 + "px";
}
.box {
width: 300px;
height: 200px;
position: absolute;
left: 100px;
background: black;
}
<div class="box"></div>
<button onclick="increaseDiv()">Click</button>
Here is demo https://jsfiddle.net/SutonJ/0pdwm39a/14/

The problem is that position of your div are related to left side and this is why it looks like you increase only the right side; try to add positioning with transform by center or make it by flex(align-items + justify-content)
.box {
width: 300px;
height: 200px;
left: 50%;
position: absolute;
top: 50%;
transform: translate(-50%, -50%);
background: black;
}

If I am understanding you correctly, I think if you changed
var currWidth = myDiv.clientWidth;
myDiv.style.width = currWidth + 100 + "px";
to
var currWidth = myDiv.getBoundingClientRect().width;
myDiv.style.width = currWidth + 50 + "px";
and also added
var currHeight = myDiv.getBoundingClientRect().height;
myDiv.style.height = currHeight + 50 + "px";
I also noticed that your div is using absolute positioning, so you may also need to offset the left and top according to the size change. If you are getting an issue with the actual position when the size changes let me know.

What about CSS scale?
That will keep the actual position of the element and expand it in all directions, unless you specify a transform-origin value.
Edited with an ever growing effect...
let myDiv = document.querySelector(".box");
let orgiSize = myDiv.getBoundingClientRect().width;
let increments = 0;
function increaseDiv() {
increments += 50; // That is 25px on both sides...
// Make the math here
var percentage = Math.floor((orgiSize + increments) / orgiSize * 100) / 100
console.log(percentage);
myDiv.style.transform = `scale(${percentage})`; // That is a percentage value
}
.box {
width: 300px;
height: 200px;
position: absolute;
left: 100px;
background: black;
}
/* for the demo */
button {
position: absolute;
z-index: 9999;
}
<div class="box"></div>
<button onclick="increaseDiv()">Click</button>

Use an image as a mask for another image

I'm making a website that I wanted to be a white page that you could stamp to make another image appear under. So when you click, you make a holepunch.
Like this exemple :
So I managed to have a randomized image in the background as I click which is fine for what I want, and to be able to .append() the holepunches.
But I don't know how to do the mask thing I've been digging online for a few things and help, and managed to make it work in certain cases but not that one...
It should be like that (I guess) :
image in the background
white shape in front
the star shape is making a holepunch in the white shape
For now, the only thing I managed to do is to have the picture besides a bigger holepunch (which is my original img) but when I click it doesn't make any holepunch, it justs add the stamp.
Here is the code :
var images = ["https://icatcare.org/app/uploads/2018/07/Thinking-of-getting-a-cat.png", "https://ichef.bbci.co.uk/news/1024/cpsprodpb/151AB/production/_111434468_gettyimages-1143489763.jpg"];
$(document.body).click(function(c) {
var tw = 100 / 2;
var th = 30 / 2;
var x = Math.floor((Math.random() * images.length));
document.getElementById('random').src = images[x];
$("#random").css({
position: 'absolute',
display: "block",
left: 0,
top: 0
});
var tw = 50 / 2;
var th = tw;
$('#holepunch:last').clone().appendTo(this).css({
position: 'absolute',
display: "block",
left: c.pageX - tw - $(this).position().left,
top: c.pageY - th + $(this).scrollTop()
});
});
body{
background: lightgrey;
width: 100vw;
height: 100vh;
z-index: 1;
opacity: 1;
}
.fauxbody{
z-index: 100;
position: fixed;
width: 100vw;
height: 100vh;
background-color: white;
top: 0;
left: 0;
-webkit-mask:
-moz-element(#holepunch) 1vw 1vh no-repeat,
linear-gradient(#fff 0 0);
mask-composite:exclude;
}
#random{
z-index: -100;
width: 100vw;
height: auto;
}
#holepunch{
width: 50px;
height: auto;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<body>
<img id="random">
<div class ="fauxbody">
<img id="holepunch" src="https://oshi.at/iimtXg/Jqtz.png">
</div>
</body>

Here is an idea using multiple mask and CSS variables. The trick is to add an extra layer on each click. I removed the code related to background generation since it's irrelevant and quite easy to be added
var mask = "";
w = 60;
h = 60;
document.documentElement.addEventListener("click", function (c) {
mask+="url(https://i.ibb.co/FzmCjLL/Jqtz.png)"+(c.pageX-w/2)+"px "+(c.pageY-h/2)+"px/"+w+"px "+h+"px no-repeat,";
document.documentElement.style.setProperty("--mask", mask)
});
html {
background:url(https://picsum.photos/800/800) center/cover;
}
html::before {
content:"";
position: fixed;
background-color: #f3f3f3;
inset: 0;
-webkit-mask:
var(--mask)
linear-gradient(#fff 0 0);
-webkit-mask-reepat: no-repeat;
-webkit-mask-composite: destination-out;
mask-composite: exclude;
}
Also like below without mask-composite:
var mask = "";
w = 60;
h = 60;
document.documentElement.addEventListener("click", function(c) {
if (mask != "")
mask += ",";
mask += "url(https://i.ibb.co/FzmCjLL/Jqtz.png)" + (c.pageX - w / 2) + "px " + (c.pageY - h / 2) + "px/" + w + "px " + h + "px no-repeat";
document.documentElement.style.setProperty("--mask", mask)
});
html::before {
content: "";
position: fixed;
background: url(https://picsum.photos/800/800) center/cover;
inset: 0;
-webkit-mask: var(--mask, linear-gradient(#0000 0 0));
}

I would try to use canvas with white background and add a mouseclick event listener, which cuts out the canvas. I found another question on stack overflow what may can help you:
HTML5 Cut out circle from previous drawn strokes

More than 1 modal?

I have this modal, and would like to make many of them on the same page. I tried a lot, but nope. Any idea how to do this? Thanks.
Here the code:
HTML
<div class="containerofelements">
<div id="s2-01" class="resizeratio">1.00</div>
<div id="s-wrap" class="wrap" style="transform: scale(0.04);">
<div class="elements" style="transform: scale(0.04);">
<div id="s-rr"class="resizeratio">0.04</div>
<div id="s-001" class="slider16" midicc="1, 80" colour="#ff3300"></div>
</div>
</div>
</div>
CSS
.containerofelements {
}
.resizeratio {
display: inline-block;
cursor: pointer;
border-style: solid;
color: red;
width: 50px;
height: 20px;
}
.wrap {
background-color: rgba(0, 80, 128, 1);
transform-origin: 1880px 0;
}
.elements {
width: 1600px;
height: 800px;
transform-origin: 1880px 0;
}
JS
$(document).ready(function() {
$(".resizeratio").click(function() {
var el = $('.elements');
var scale = $(this).text();
el.css({
transform: "scale(" + scale + ")"
});
});
});
$(document).ready(function() {
$(".resizeratio").click(function() {
var el = $('.wrap');
var scale = $(this).text();
el.css({
transform: "scale(" + scale + ")"
});
});
});
I tried to apply separate names, IDs, but no good results without replicating everything which is not a good practice I suppose, a waste of code.

Javascript: Create draggable elements that push each other out of the way

I would like to have a series of boxes that can be dragged around in a frame. When when they touch another box, it is pushed out of the way - repelled if you will.
I just don't even know where to start beyond making them draggable!!

To expand on my comment and show you a possible proof of concept, I have created this small bit of code:
https://jsfiddle.net/Twisty/L03rks0y/
HTML
<div id="move-frame">
<div id="obj-1" class="drag">
<span class="top">T: 2</span>
<span class="left">L: 2</span>
<span class="bottom">B:</span>
<span class="right">R:</span>
</div>
<div id="obj-2" class="no-drag">
<span class="top">T: 125</span>
<span class="left">L: 175</span>
</div>
</div>
CSS
#move-frame {
border: 1px solid #000;
margin: 20px;
padding: 2px;
width: 300px;
height: 300px;
position: relative;
}
.drag,
.no-drag {
border: 0px solid #666;
width: 75px;
height: 75px;
}
.top,
.left,
.bottom,
.right {
display: block;
font-size: 85%;
font-family: Arial;
width: 100%;
text-align: center;
}
#obj-1 {
background: #6f6;
}
#obj-2 {
background: #ccf;
position: absolute;
top: 125px;
left: 175px;
}
jQuery UI
$(function() {
var stuff = {};
$(".no-drag").each(function(k, v) {
var id = $(v).attr("id");
var top = $(v).position().top;
var left = $(v).position().left;
var bottom = top + $(v).height();
var right = left + $(v).width();
stuff[k] = {
id: id,
top: top,
left: left,
bottom: bottom,
right: right
};
});
console.log(stuff);
$("#obj-1").draggable({
containment: '#move-frame',
drag: function(e, ui) {
var objW = ui.helper.width();
var objH = ui.helper.height();
var objP = ui.position;
var buffer = 2;
objP.right = objP.left + objW;
objP.bottom = objP.top + objH;
$(this).find(".top").html("T: " + objP.top);
$(this).find(".left").html("L: " + objP.left);
$(this).find(".bottom").html("B: " + objP.bottom);
$(this).find(".right").html("R: " + objP.right);
$.each(stuff, function(k, v) {
if (objP.right == v.left - buffer) {
var $el = $("#" + v.id);
$el.css("left", v.left + buffer);
v.left += buffer;
$el.find(".top").html("T: " + $el.position().top);
$el.find(".left").html("L: " + $el.position().left);
}
if (objP.bottom == v.top - buffer) {
var $el = $("#" + v.id);
$el.css("top", v.top + buffer);
v.top += buffer;
$el.find(".top").html("T: " + $el.position().top);
$el.find(".left").html("L: " + $el.position().left);
}
});
}
});
});
There are lots of ways to improve upon this. You can see that it's very easy to drag pas the buffer, yet if moved slowly, you nudge the blue box around with the green box. You can also see some gapping issues, like if you slowly bring the green box over, but are not on the same Y plane, the blue box can still be moved.

jitter when using jquery to alter background-position

Here's the jsfiddle.
It's the interface to cropping an image. As you can see the selection div takes the same background image and positions it to the negative of the top and left attributes of the selection div. In theory this should give a perfect overlap, but there's a jitter as you move the selection div around, and I can't seem to figure out what is causing it.
html
<div id="main">
<div id="selection"></div>
</div>
css
#main {
width: 600px;
height: 450px;
position: relative;
background: url("http://cdn-2.historyguy.com/celebrity_history/Scarlett_Johansson.jpg");
background-size: contain;
}
#selection {
width: 100px;
height: 100px;
position: absolute;
background: url("http://cdn-2.historyguy.com/celebrity_history/Scarlett_Johansson.jpg");
border: 1px dotted white;
background-size: 600px 450px;
}
jquery
$(document).ready(function () {
var move = false;
var offset = [];
var selection = null;
$("#selection").mousedown(function (e) {
move = true;
selection = $(this);
offset = [e.pageX - selection.offset().left, e.pageY - selection.offset().top];
});
$("#selection").mousemove(function (e) {
if (move == true) {
selection.css("left", e.pageX - offset[0]);
selection.css("top", e.pageY - offset[1]);
selection.css("background-position", (((-selection.position().left) - 1) + "px " + ((-selection.position().top ) - 1) + "px"));
}
});
$("#selection").mouseup(function (e) {
move = false;
});
})

It would appear that there is a value of 5 offset that needs to be added to ensure seamlessness
DEMO http://jsfiddle.net/nzx0fcp5/2/
offset = [e.pageX - selection.offset().left + 5, e.pageY - selection.offset().top + 5];

So, while experimenting I discovered that this was only a problem at certain sizes of the image. At the original size it is no problem, neither at half nor a quarter of this size. It wasn't simply a matter of keeping the image in proportion not having the image square or using even pixel sizes. I'm assuming this had something to do with partial pixel sizes, but I'm not sure, and I couldn't see any way to work around this, at least none that seemed worth the effort.
So while checking out the code of other croppers I took a look at POF's image cropper, they seem to have got round the problem by not using the background-position property at all (I'm not sure if it's plugin or they coded it themselves). They just set the image down and then used a transparent selection div with 4 divs stuck to each edge for the shading. So there's no pixel crunching on the fly at all. I like the simplicity and lightweight nature of this design and knocked up a version myself in jsfiddle to see if I could get it to work well.
new jitter free jsfiddle with no pixel crunching
I liked the solution for the preview box as well.
html
<body>
<div id="main">
<img src="http://flavorwire.files.wordpress.com/2012/01/scarlett_johansson.jpg" />
<div id="upperShade" class="shade" > </div>
<div id="leftShade" class="shade" > </div>
<div id="selection"></div>
<div id="rightShade" class="shade"></div>
<div id="lowerShade" class="shade" ></div>
</div>
</body>
css
#main {
position:relative;
width: 450px;
height: 600px;
}
#selection {
width: 148px;
height: 148px;
position: absolute;
border: 1px dotted white;
top: 0px;
left: 0px;
z-index: 1;
}
.shade {
background-color: black;
opacity: 0.5;
position: absolute;
}
#upperShade {
top: 0px;
left: 0px;
width: 600px;
}
#leftShade {
left: 0px;
top: 0px;
height: 150px;
width: auto;
}
#rightShade {
left: 150px;
top: 0px;
height: 150px;
width: 450px;
}
#lowerShade {
left:0px;
top: 150px;
width: 600px;
height: 300px;
}
jquery
$(document).ready(function () {
var move = false;
var offset = [];
var selection = null;
$("#selection").mousedown(function (e) {
move = true;
selection = $(this);
offset = [e.pageX - selection.offset().left, e.pageY - selection.offset().top];
});
$("#selection").mousemove(function (e) {
if (move == true) {
selection.css("left", e.pageX - offset[0]);
selection.css("top", e.pageY - offset[1]);
setShade();
}
});
function setShade() {
$("#upperShade").css("height", selection.position().top);
$("#lowerShade").css("height", 600 - (selection.position().top + 150));
$("#lowerShade").css("top", selection.position().top + 150);
$("#leftShade").css("top", selection.position().top);
$("#leftShade").css("width", selection.position().left);
$("#rightShade").css("top", selection.position().top);
$("#rightShade").css("left", selection.position().left + 150);
$("#rightShade").css("width", 450 - selection.position().left);
}
$("#selection").mouseup(function (e) {
move = false;
});
});