Div placement in javascript - javascript

I would like it to create the div where the mouse is. I have the following code:
var mouseisdown = false;
$(document).mousedown(function(event) {
mouseisdown = true;
doSomething();
}).mouseup(function(event) {
mouseisdown = false;
});
function doSomething(e){
var draw = document.createElement("div");
draw.className = "draw";
document.body.appendChild(draw);
draw.style.top = e.clientY + "px";
draw.style.left = e.clientX + "px";
if (mouseisdown)
doSomething();
}

Basically you already had it, but you overcomplicated it:
Remove the mouseisdown variable and the event listeners
Add doSomething as a click event listener
Don't call doSomething recursively
$(document).click(function doSomething(e){
var draw = document.createElement("div");
draw.className = "draw";
document.body.appendChild(draw);
draw.style.top = e.clientY + "px";
draw.style.left = e.clientX + "px";
});
.draw {
position: absolute;
height: 10px;
width: 10px;
margin: -5px;
background: red;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
Click somewhere

Related

How to use vanilla script to bounce elements from each other

I've tried adding the top and left changes, and margin (with different positioning changes too) changes to each element if one approaches another but only the margin change works once. Is there a way to make them work more consistently?
This is where I've used a function to add the event listeners:
var three = document.getElementById('three');
var test = document.getElementById('test');
var two = document.getElementById('two');
var obj = null;
function testmovea(object, event) {
obj = document.getElementById(object.id);
document.addEventListener("mousemove", move);
}
function move(event) {
obj.innerText = event.clientX + ' ' + event.clientY;
obj.style.position = 'absolute';
obj.style.left = event.clientX + "px";
obj.style.top = event.clientY + "px";
three.addEventListener('mouseover', borders);
three.addEventListener('mouseleave', bordersOff);
two.addEventListener('mouseenter', bTwo);
test.addEventListener('mouseenter', bTest);
two.addEventListener('mouseleave', bTwoReset);
test.addEventListener('mouseleave', bTestReset);
document.addEventListener("mouseup", stopMove);
}
function bTwo() {
two.style.margin = "10%";
}
function bTwoReset() {
two.style.margin = "0%";
}
function bTest() {
test.style.margin = "10%";
}
function bTestReset() {
test.style.margin = "0%"
}
This is the mouse stop event I use:
function stopMove() {
document.removeEventListener('mousemove', move);
test.removeEventListener('mouseover', bTest);
two.removeEventListener('mouseover', bTwo);
test.removeEventListener('mouseleave', bTestReset);
two.removeEventListener('mouseleave', bTwoReset);
}
the testmovea function relies on a onmousedown property defined for a DOM element of the page
Update:
I've managed to get it to partially work:
function collide(el1, el2) {
if(twoBoundX >= threeBoundY || threeBoundY >= twoBoundX) {
two.style.margin = + event.clientX + "px";
two.style.margin = + event.clientY + "px";
}
}
where twoBoundX and threeBoundY are getBoundingClientRect() of the respective elements
Here's the full code snippet:
<html>
<head>
<style type="text/css">
#two {
border: 1px solid black;
padding: 1%;
margin: 1%;
margin-top: 10%;
width: 10%;
}
#three {
border: 1px solid black;
padding: 1%;
margin-top: 2%;
}
</style>
</head>
<body>
<div id="two" onmousedown="testmovea(this, event)" onclick="currentTwoPos()">
stop movement
</div>
<div id="three" onmousedown="testmovea(this)">Expand div</div>
<div style="height: 30%" id="two" contenteditable="true">
some contenteditable</div>
</body>
<script>
var three = document.getElementById('three');
var two = document.getElementById('two');
const twoBound = two.getBoundingClientRect();
const threeBound = three.getBoundingClientRect();
var threeBoundX = threeBound.x;
var threeBoundY = threeBound.y;
var twoBoundX = twoBound.x;
var twoBoundY = twoBound.y;
var twoBoundBottom = null;
var twoBoundTop = null;
var obj = null;
function collide(el1, el2) {
if(twoBoundX >= threeBoundY || threeBoundY >= twoBoundX) {
two.style.left = event.clientX + "px";
two.style.top = event.clientY + "px";
three.style.left = event.clientX + "px";
three.style.top = event.clientY + "px";
}
}
function testmovea(object, event) {
obj = document.getElementById(object.id);
document.addEventListener("mousemove", move);
}
function move(event) {
obj.innerText = event.clientX + ' ' + event.clientY;
obj.style.position = 'absolute';
obj.style.left = event.clientX + "px";
obj.style.top = event.clientY + "px";
two.addEventListener('mouseover', collide);
three.addEventListener('mouseover', collide);
document.addEventListener("mouseup", stopMove);
}
function stopMove() {
mousemove = false;
document.removeEventListener('mousemove', move);
three.removeEventListener('mouseover', collide);
two.removeEventListener('mouseover', collide);
}
</script>
</html>
collision detection
You need to define a function that checks whether two of your shapes collide. If you only have rectangles whose vertex are parallel with the OX and OY vertexes, it would look like this:
function areColliding(r1, r2) {
return !(
(r1.x > r2.x + r2.w) ||
(r1.x + r1.w < r2.x) ||
(r1.y > r2.y + r2.h) ||
(r1.y + r1.h < r2.y)
);
}
Of course, if some rotation or even other shapes are involved into your problem, then you need to extend/adjust the collision detector accordingly.
a shared function
You need to create a function that would receive the current status of the elements and the move that happens. It would look like this:
function handleMove(currentPositions, proposedPositions) {
while (!validPositions(proposedPositions)) {
proposedPositions = generateNewPositions(currentPositions, handleCollisions(proposedPositions));
}
refreshUI(proposedPositions);
}
currentPositions is the set of positions your elements currently have
proposedPositions is the set of positions your elements are going to have if there are no collisions
validPositions checks for any pair of shapes that would collide and returns true if none of those pair collide and false if at least one such pair collides
proposedPositions is being refreshed while there are still collisions
generateNewPositions is your handler for collision-based changes
handleCollisions effectuates changes to avoid collision
refreshUI refreshes the UI
event handling
your mouse events should handle change updates by loading all the positions of your elements and calling this shared functionality.
Note: If you have further problems, then you might need to create a reproducible example so we could see your exact structure, styling and code as well.
<html>
<head>
<style type="text/css">
#two {
border: 1px solid black;
width: 10%;
padding: 1%;
margin: 1%;
margin-top: 10%;
}
#three {
border: 1px solid black;
padding: 1%;
margin-top: 2%;
}
</style>
</head>
<body>
<div id="two" onmousedown="testmovea(this, event)" style="position: relative;">
stop movement
</div>
<div id="three" onmousedown="testmovea(this)" style="position: relative;">Expand div</div>
<!--<div style="height: 30%; position: relative;" id="two" contenteditable="true">
some contenteditable</div>-->
</body>
<script>
var three = document.getElementById('three');
var two = document.getElementById('two');
let moveStarted = false;
function collide() {
const first = two.getBoundingClientRect();
const second = three.getBoundingClientRect();
if (!(
(first.x + first.width < second.x) ||
(second.x + second.width < first.x) ||
(first.y + first.height < second.y) ||
(second.y + second.height < first.y)
)) {
two.style.left = event.clientX + "px";
two.style.top = event.clientY + "px";
three.style.left = event.clientX + "px";
three.style.top = event.clientY + "px";
}
}
function testmovea(object, event) {
obj = document.getElementById(object.id);
if (!moveStarted) {
document.addEventListener("mousemove", move);
moveStarted = true;
}
}
function move(event) {
//obj.innerText = event.clientX + ' ' + event.clientY;
obj.style.left = event.clientX + "px";
obj.style.top = event.clientY + "px";
if (!obj.classList.contains("dragged")) obj.classList.add("dragged");
collide(obj);
}
function stopMove() {
mousemove = false;
if (moveStarted) {
document.removeEventListener('mousemove', move);
moveStarted = false;
}
}
document.addEventListener("mouseup", stopMove);
</script>
</html>

My hover popup is flickering and moving when it shouldn't

Trying to create a popup that will show when hovering over an element. However it flickers and moves around when I move my mouse inside the element. It should also stay open if the mouse moves over the popup.
Trying to do this without library cheats like jQuery. You don't learn if you use them.
If you hover your mouse over one of the tags below, that's exactly what I'm trying to create.
Think the error is somewhere in this code:
function showPopup(e) {
var popup = document.getElementById('popup');
if (popup.style.display == 'none') {
popup.style.display = 'block';
var bodyRect = document.body.getBoundingClientRect(),
elemRect = e.target.getBoundingClientRect(),
offsetX = elemRect.left - bodyRect.left,
offsetY = elemRect.bottom - bodyRect.top;
popup.style.left = offsetX + 'px';
popup.style.top = offsetY + 'px';
//console.log(e);
}
}
function hidePopup(/*e*/) {
setTimeout(function() {
var popup = document.getElementById('popup');
if (popup.style.display == 'block' && !window.inside_popup) {
popup.style.display = 'none';
window.inside_popup = false;
console.log('hide');
} else {
setTimeout(hidePopup, 50); // try a little later
}
}, 50); // Give the events ability to catch up and tell us the mouse is inside the popup
}
var targ = document.querySelector('ul li')
targ.addEventListener('mouseover', showPopup);
targ.addEventListener('mouseout', hidePopup);
Full javascript code with a real test element:
https://jsfiddle.net/g8wvae8o/
As #epascarello said, mouseleave and mouseenter are what you're looking for. There's no need for setTimeout here either. In addition, you're targeting every li on the page (is that intentional?) I recommend targeting a specific class of element to reduce flickering.
This is close, but you'll need to massage the positioning.
function createPopup() {
var container = document.createElement('div');
container.id = 'popup';
container.style.width = '500px';
container.style.height = '700px';
container.style.display = 'none';
container.style.position = 'absolute';
container.style.borderRadius = '2px';
container.style.border = '1px solid #242729';
container.style.backgroundColor = '#535a60';
container.style.color = '#e4e6e8';
container.style.zIndex = '9999999';
container.addEventListener('xmouseenter', function() {
window.inside_popup = true;
//console.log('window.inside_popup = true;');
});
container.addEventListener('xmouseleave', function() {
window.inside_popup = false;
//console.log('window.inside_popup = false;');
});
container.appendChild(document.createTextNode('This is a test'));
(document.body || document.documentElement).appendChild(container);
}
window.inside_popup = false;
createPopup();
function showPopup(e) {
var popup = document.getElementById('popup');
if (popup.style.display == 'none') {
popup.style.display = 'block';
}
}
function hidePopup(/*e*/) {
console.log('hiding')
popup.style.display = 'none';
window.inside_popup = false;
}
var bodyRect = document.body.getBoundingClientRect()
function updatePopup(e) {
var elemRect = e.target.getBoundingClientRect(),
offsetY = elemRect.bottom - bodyRect.top,
offsetX = elemRect.left - bodyRect.left;
popup.style.left = (e.clientX + offsetX) + 'px';
popup.style.top = offsetY + 'px';
}
var targ = document.querySelector('ul li')
targ.addEventListener('mouseenter', showPopup);
targ.addEventListener('mouseleave', hidePopup);
targ.addEventListener('mousemove', updatePopup)
Fiddle
Here's a pure CSS solution (I only use JS to create the popup elements)
window.addEventListener("load", function () {
var els = document.querySelectorAll("li");
els.forEach(el => {
var popup = document.createElement("div");
popup.innerHTML = el.getAttribute("popup");
popup.className = "popup";
el.appendChild(popup);
});
});
*[popup]:hover > .popup {
border: 1px solid #fff;
padding: 0.5em;
width: 400px;
height: auto
}
.popup {
overflow: hidden;
box-sizing: border-box;
background-color: black;
color: #ccc;
border-radius: 3px;
position: absolute;
height: 0px;
}
li {
margin: 2em 0
}
<ul>
<li popup="Some more info about this product">Move the mouse here</li>
<li popup="Some more info about the 2nd product">Some other product</li>
</ul>
The key to this is that the popup is a child of the element that is hovered, thus moving the mouse over the popup still counts as hovering the element.

Create and position divs relative to parent

I am trying to create(and position) rectangle divs on a parent div. The created div should be positioned relative. Here is a working jsfiddle example -> Just draw some rectangles by holding mouse button.
var newRect = null;
var offset = $('#page').offset();
function point(x, y) {
this.x = x;
this.y = y;
}
function rect(firstPoint) {
this.firstPoint = firstPoint;
this.div = document.createElement("div");
this.div.style.position = "relative";
this.div.style.border = "solid 1px grey";
this.div.style.top = this.firstPoint.y+"px";
this.div.style.left = this.firstPoint.x+"px";
this.div.style.width = "0px";
this.div.style.height = "0px";
$("#page").append(this.div);
}
$("#page").mousedown(function (e) {
if(e.which == 1) {
var x = e.pageX - offset.left;
var y = e.pageY - offset.top;
newRect = new rect(new point(x, y));
}
});
$("#page").mousemove(function (e) {
if(newRect) {
newRect.div.style.width = Math.abs(newRect.firstPoint.x-(e.pageX - offset.left))+"px";
newRect.div.style.height = Math.abs(newRect.firstPoint.y-(e.pageY - offset.top))+"px";
}
});
$("#page").mouseup(function (e) {
if(e.which == 1 && newRect != null) {
if(Math.abs(newRect.firstPoint.x-(e.pageX - offset.left)) < 10) {
$("#"+newRect.div.id).remove();
newRect = null;
return;
}
$("#"+newRect.div.id).on('mousedown', function (e) {
e.stopImmediatePropagation();
});
newRect = null;
}
});
#page{
width: 210mm;
height: 297mm;
border:solid 2px #6D6D6D;
cursor: crosshair;
background-color: white;
float:left;
background-repeat: no-repeat;
background-size: contain;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="page">
</div>
After drawing the first rectangle, which is positioned correctly, each rectangle is positioned false. I think that there is something wrong with the calculation of the position... maybe someone can give me a hint.
Change
this.div.style.position = "relative";
to
this.div.style.position = "absolute";
Bonus: Here's a version that allows you to draw in any direction: https://jsfiddle.net/g4z7sf5c/5/
I simply added this code to the mousemove function:
if (e.pageX < newRect.firstPoint.x) {
newRect.div.style.left = e.pageX + "px";
}
if (e.pageY < newRect.firstPoint.y) {
newRect.div.style.top = e.pageY + "px";
}

Move an image with Javascript using mouse events

This should be simple enough, but every time I try I end up with a different issue.
I am trying to move an image around the screen using mouse events such as mousedown, mouseup, mousemove, clientX and clientY. I am then trying to apply it to the image using absolute positioning.
I thought the below code would work as I get the coordinates on the initial click, and then the idea was to update them with mouse movement, but this does not work.
var image;
var dog = document.getElementById("dogPic");
var cat = document.getElementById("catPic");
dog.addEventListener("mousedown", initialClick, false);
cat.addEventListener("mousedown", initialClick, false);
function initialClick(e) {
var initialX = e.clientX;
var initialY = e.clientY;
image = document.getElementById(this.id);
document.addEventListener("mousemove", function(e){
var newX = e.clientX - initialX;
var newY = e.clientY - initialY;
image.style.left = newX;
image.style.top = newY;
}, false);
}
I am not asking for a complete answer, but can anyone direct me as to how I can approach dragging an image around the screen using the mouse movement events?
Thanks
var dog = document.getElementById("dogPic");
var cat = document.getElementById("catPic");
var moving = false;
dog.addEventListener("mousedown", initialClick, false);
cat.addEventListener("mousedown", initialClick, false);
function move(e){
var newX = e.clientX - 10;
var newY = e.clientY - 10;
image.style.left = newX + "px";
image.style.top = newY + "px";
}
function initialClick(e) {
if(moving){
document.removeEventListener("mousemove", move);
moving = !moving;
return;
}
moving = !moving;
image = this;
document.addEventListener("mousemove", move, false);
}
#dogPic, #catPic {
width: 20px;
height: 20px;
position: absolute;
background: red;
top: 10px;
left: 10px;
}
#dogPic {
background: blue;
top: 50px;
left: 50px;
}
<div id="dogPic"></div>
<div id="catPic"></div>
I made a modification to have a more realistic dragging experience. This required adding an X and Y offset so instead of jumping when picked up, the object seems to just move as expected.
let gMouseDownX = 0;
let gMouseDownY = 0;
let gMouseDownOffsetX = 0;
let gMouseDownOffsetY = 0;
function addListeners() {
document.getElementById('cursorImage').addEventListener('mousedown', mouseDown, false);
window.addEventListener('mouseup', mouseUp, false);
}
function mouseUp() {
window.removeEventListener('mousemove', divMove, true);
}
function mouseDown(e) {
gMouseDownX = e.clientX;
gMouseDownY = e.clientY;
var div = document.getElementById('cursorImage');
//The following block gets the X offset (the difference between where it starts and where it was clicked)
let leftPart = "";
if(!div.style.left)
leftPart+="0px"; //In case this was not defined as 0px explicitly.
else
leftPart = div.style.left;
let leftPos = leftPart.indexOf("px");
let leftNumString = leftPart.slice(0, leftPos); // Get the X value of the object.
gMouseDownOffsetX = gMouseDownX - parseInt(leftNumString,10);
//The following block gets the Y offset (the difference between where it starts and where it was clicked)
let topPart = "";
if(!div.style.top)
topPart+="0px"; //In case this was not defined as 0px explicitly.
else
topPart = div.style.top;
let topPos = topPart.indexOf("px");
let topNumString = topPart.slice(0, topPos); // Get the Y value of the object.
gMouseDownOffsetY = gMouseDownY - parseInt(topNumString,10);
window.addEventListener('mousemove', divMove, true);
}
function divMove(e){
var div = document.getElementById('cursorImage');
div.style.position = 'absolute';
let topAmount = e.clientY - gMouseDownOffsetY;
div.style.top = topAmount + 'px';
let leftAmount = e.clientX - gMouseDownOffsetX;
div.style.left = leftAmount + 'px';
}
addListeners();
<div style="height:500px;width:500;background-color:blue;">
<img src="http://placehold.it/100x100" id="cursorImage" ondragstart="return false;"/>
</div>
This code work with just plain javascript
function addListeners() {
document.getElementById('image').addEventListener('mousedown', mouseDown, false);
window.addEventListener('mouseup', mouseUp, false);
}
function mouseUp() {
window.removeEventListener('mousemove', divMove, true);
}
function mouseDown() {
window.addEventListener('mousemove', divMove, true);
}
function divMove(e){
var div = document.getElementById('image');
div.style.position = 'absolute';
div.style.top = e.clientY + 'px';
div.style.left = e.clientX + 'px';
}
addListeners();
<div style="height:500px;width:500;background-color:blue;">
<img src="http://placehold.it/100x100" id="image" />
</div>
Super simple working code with Jquery. Live demo: http://jsfiddle.net/djjL16p2/
<div id="content" style="margin-top: 100px">
<img id="lolcat" src="http://obeythekitty.com/wp-content/uploads/2015/01/lolcat_airplane.jpg" style="height: 100px; width: 120px; position: absolute;" draggable="false" />
</div>
JS:
$("#lolcat").mousedown(function() {
$(this).data("dragging", true);
});
$("#lolcat").mouseup(function() {
$(this).data("dragging", false);
});
$("#lolcat").mousemove(function(e) {
if (!$(this).data("dragging"))
return;
$(this).css("left", e.clientX - $(this).width()/2);
$(this).css("top", e.clientY - $(this).height()/2);
});

Listening for addEventListener calls for a custom event

I'm trying to build a custom drag event. Here's my initial pseudocode, note that I left event cleaning up out.
var dragEvent = new CustomEvent("drag");
var anArbitrairyElement = document.querySelector(".box");
anArbitrairyElement.addEventListener("drag", function () {
console.log("event received");
});
(function () {
var dragEventListeners = [];
window.addEventListener("mousedown", function (mousedownEvent) {
dragEventListeners.forEach(function (target) {
if (mousedownEvent.target === target) {
window.addEventListener("mousemove", function (mousemoveEvent) {
target.dispatchEvent(dragEvent);
});
}
// ...
});
});
// does something like this exist?
onDragEventAdded(function (listenerElement) {
dragEventListeners.push(listenerElement);
});
}());
Is there any way I can listen to addEventListener calls without overwriting the addEventListener function itself? The solution needs to end-up in this being possible:
document.querySelector(".someElement").addEventListener("drag", ...);
Otherwise, is there another way how I could achieve the desired behavior of creating a custom drag event?
Do it the following way.
window.addEventListener("mousedown", function (mousedownEvent) {
var mouseMoveHandler =
function(element) {
return function(mouseMoveEvent) {
element.dispatchEvent(dragEvent);
}
}(mousedownEvent.target);
window.addEventListener("mousemove", mouseMoveHandler);
});
});
So in this case on mousedown event you create closure that will trigger drag event on the clicked element. You do not need the array of elements that were clicked. Clicked element is already injected to the handler.
Don't forget to clean listeners on mouseup. Just drop the mousemove listener on window
For anyone who wants to use the drag event, here's an example utilizing it.
var box1 = document.createElement("div");
var box2 = document.createElement("div");
var box3 = document.createElement("div");
document.body.appendChild(box1);
document.body.appendChild(box2);
document.body.appendChild(box3);
box1.className = "box";
box2.className = "box";
box3.className = "box";
box1.innerHTML = "Drag me";
box2.innerHTML = "No drag";
box3.innerHTML = "Drag me";
function dragElement(event) {
event.target.style.top = parseInt(event.target.style.top.split("px")[0] || 0) + event.dy + "px";
event.target.style.left = parseInt(event.target.style.left.split("px")[0] || 0) + event.dx + "px";
}
box1.addEventListener("drag", dragElement);
box3.addEventListener("drag", dragElement);
// custom event logic starting here
var dragEvent = new CustomEvent("drag");
window.addEventListener("mousedown", function (mousedownEvent) {
var mousePosition = {x: mousedownEvent.clientX, y: mousedownEvent.clientY};
(function () {
var target = mousedownEvent.target;
console.log(target);
function moveHandler(event) {
var newMousePosition = {x: event.clientX, y: event.clientY};
dragEvent.dx = newMousePosition.x - mousePosition.x;
dragEvent.dy = newMousePosition.y - mousePosition.y;
dragEvent.clientX = event.clientX;
dragEvent.clientY = event.clientY;
target.dispatchEvent(dragEvent);
mousePosition = newMousePosition;
}
function releaseHandler() {
window.removeEventListener("mousemove", moveHandler);
window.removeEventListener("mouseup", releaseHandler);
}
window.addEventListener("mousemove", moveHandler);
window.addEventListener("mouseup", releaseHandler);
}());
});
.box {
width: 75px;
height: 75px;
background-color: skyblue;
display: inline-block;
margin: 10px;
position: relative;
text-align: center;
font-family: helvetica;
color: white;
vertical-align: middle;
line-height: 75px;
font-weight: bold;
}

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