Drag Pictures Function - javascript

I added a function to my CodePen for dragging items across the canvas. However, when I do that some other pictures that I have on the canvas disappear whenever the dragged item touches them. **Does anyone have an idea why? **
This is my Live View page from CodePen: Snakes and Ladders you can try to drag the cat soldiers, and you will see that when they touch other images on the game board, they disappear!
This is my function code in JS:
`
function startDrag(e) {
if (!e) {
var e = window.event;
}
if (e.preventDefault) e.preventDefault();
var targ = e.target ? e.target : e.srcElement;
if (targ.className != "dragme") {
return;
}
offsetX = e.clientX;
offsetY = e.clientY;
if (!targ.style.left) {
targ.style.left = "0px";
}
if (!targ.style.top) {
targ.style.top = "0px";
}
coordX = parseInt(targ.style.left);
coordY = parseInt(targ.style.top);
drag = true;
document.onmousemove = dragDiv;
return false;
}
function dragDiv(e) {
if (!drag) {
return;
}
if (!e) {
var e = window.event;
}
var targ = e.target ? e.target : e.srcElement;
targ.style.left = coordX + e.clientX - offsetX + "px";
targ.style.top = coordY + e.clientY - offsetY + "px";
return false;
}
function stopDrag() {
drag = false;
}
window.onload = function () {
document.onmousedown = startDrag;
document.onmouseup = stopDrag;
};
`
I don't know what to do

Related

Drag multiple elements in JS

I'm new to JS so I need help to solve my problem :). I found a codepen that helped me drag one element of my website but the thing is that I would like to drag 4 elements separately. I applied the same class to all of them but it works only on the first one.
Link of the codepen : https://codepen.io/Coding-Artist/pen/zYWbYXV
I'm sure the solution is obvious to you (I would say a var or a for ?) but I'm learning and I really want to progress so if you could explain that would be perfect ! Thanks a lot
JS —
var draggableElem = document.querySelector(".draggable-elem");
let initialX = 0,
initialY = 0;
let moveElement = false;
//events object
let events = {
mouse: {
down: "mousedown",
move: "mousemove",
up: "mouseup"
},
touch: {
down: "touchstart",
move: "touchmove",
up: "touchend"
}
};
let deviceType = "";
//Detect touch device
const isTouchDevice = () => {
try {
//We try to create TouchEvent (it would fail for desktops and throw error)
document.createEvent("TouchEvent");
deviceType = "touch";
return true;
} catch (e) {
deviceType = "mouse";
return false;
}
};
isTouchDevice();
// start(mouse down/touch start)
draggableElem.addEventListener(events[deviceType].down, (e) => {
e.preventDefault();
//initial x and y points
initialX = !isTouchDevice() ? e.clientX : e.touches[0].clientX;
initialY = !isTouchDevice() ? e.clientY : e.touches[0].clientY;
// start movement
moveElement = true;
});
// Move
draggableElem.addEventListener(events[deviceType].move, (e) => {
//if movement==true then set top and left to new X and y while removing any offset
if (moveElement) {
e.preventDefault();
let newX = !isTouchDevice() ? e.clientX : e.touches[0].clientX;
let newY = !isTouchDevice() ? e.clientY : e.touches[0].clientY;
draggableElem.style.top = draggableElem.offsetTop - (initialY - newY) + "px";
draggableElem.style.left =
draggableElem.offsetLeft - (initialX - newX) + "px";
initialX = newX;
initialY = newY;
}
});
//mouse up/touch end
draggableElem.addEventListener(
events[deviceType].up,
(stopMovement = (e) => {
//stop movement
moveElement = false;
})
);
draggableElem.addEventListener("mouseleave", stopMovement);
document.addEventListener(events[deviceType].up, (e) => {
moveElement = false;
});
For it to work with multiple elements you should instantiate variables for each element and then add event listeners to them.
This can be done dynamically like in this codepen fork I made by using document.querySelectorAll and a for loop to iterate through the elements, instantiate variables, and add event listeners to each one.
My modified code (it's not perfect but it gets the job done):
let draggableElems = document.querySelectorAll("#draggable-elem");
let initialX = {},
initialY = {};
let moveElement = {};
//events object
let events = {
mouse: {
down: "mousedown",
move: "mousemove",
up: "mouseup"
},
touch: {
down: "touchstart",
move: "touchmove",
up: "touchend"
}
};
let deviceType = "";
//Detect touch device
const isTouchDevice = () => {
try {
//We try to create TouchEvent (it would fail for desktops and throw error)
document.createEvent("TouchEvent");
deviceType = "touch";
return true;
} catch (e) {
deviceType = "mouse";
return false;
}
};
isTouchDevice();
for (let i = 0; i < draggableElems.length; i++) {
var draggableElem = draggableElems[i];
// start(mouse down/touch start)
draggableElem.addEventListener(events[deviceType].down, (e) => {
e.preventDefault();
//initial x and y points
initialX[this] = !isTouchDevice() ? e.clientX : e.touches[0].clientX;
initialY[this] = !isTouchDevice() ? e.clientY : e.touches[0].clientY;
// start movement
moveElement[this] = true;
});
// Move
draggableElem.addEventListener(events[deviceType].move, (e) => {
//if movement==true then set top and left to new X and y while removing any offset
if (moveElement[this]) {
var elem = e.target;
e.preventDefault();
let newX = !isTouchDevice() ? e.clientX : e.touches[0].clientX;
let newY = !isTouchDevice() ? e.clientY : e.touches[0].clientY;
elem.style.top = elem.offsetTop - (initialY[this] - newY) + "px";
elem.style.left = elem.offsetLeft - (initialX[this] - newX) + "px";
initialX[this] = newX;
initialY[this] = newY;
}
});
//mouse up/touch end
draggableElem.addEventListener(
events[deviceType].up,
(stopMovement = (e) => {
//stop movement
moveElement[this] = false;
})
);
draggableElem.addEventListener("mouseleave", stopMovement);
document.addEventListener(events[deviceType].up, (e) => {
moveElement[this] = false;
});
}

How to use event listeners to make click, drag, and drop function? [duplicate]

Im struggling with seemingly a simple javascript exercise, writing a vanilla drag and drop. I think Im making a mistake with my 'addeventlisteners', here is the code:
var ele = document.getElementsByClassName ("target")[0];
var stateMouseDown = false;
//ele.onmousedown = eleMouseDown;
ele.addEventListener ("onmousedown" , eleMouseDown , false);
function eleMouseDown () {
stateMouseDown = true;
document.addEventListener ("onmousemove" , eleMouseMove , false);
}
function eleMouseMove (ev) {
do {
var pX = ev.pageX;
var pY = ev.pageY;
ele.style.left = pX + "px";
ele.style.top = pY + "px";
document.addEventListener ("onmouseup" , eleMouseUp , false);
} while (stateMouseDown === true);
}
function eleMouseUp () {
stateMouseDown = false;
document.removeEventListener ("onmousemove" , eleMouseMove , false);
document.removeEventListener ("onmouseup" , eleMouseUp , false);
}
Here's a jsfiddle with it working: http://jsfiddle.net/fpb7j/1/
There were 2 main issues, first being the use of onmousedown, onmousemove and onmouseup. I believe those are only to be used with attached events:
document.body.attachEvent('onmousemove',drag);
while mousedown, mousemove and mouseup are for event listeners:
document.body.addEventListener('mousemove',drag);
The second issue was the do-while loop in the move event function. That function's being called every time the mouse moves a pixel, so the loop isn't needed:
var ele = document.getElementsByClassName ("target")[0];
ele.addEventListener ("mousedown" , eleMouseDown , false);
function eleMouseDown () {
stateMouseDown = true;
document.addEventListener ("mousemove" , eleMouseMove , false);
}
function eleMouseMove (ev) {
var pX = ev.pageX;
var pY = ev.pageY;
ele.style.left = pX + "px";
ele.style.top = pY + "px";
document.addEventListener ("mouseup" , eleMouseUp , false);
}
function eleMouseUp () {
document.removeEventListener ("mousemove" , eleMouseMove , false);
document.removeEventListener ("mouseup" , eleMouseUp , false);
}
By the way, I had to make the target's position absolute for it to work.
you can try this fiddle too, http://jsfiddle.net/dennisbot/4AH5Z/
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>titulo de mi pagina</title>
<style>
#target {
width: 100px;
height: 100px;
background-color: #ffc;
border: 2px solid blue;
position: absolute;
}
</style>
<script>
window.onload = function() {
var el = document.getElementById('target');
var mover = false, x, y, posx, posy, first = true;
el.onmousedown = function() {
mover = true;
};
el.onmouseup = function() {
mover = false;
first = true;
};
el.onmousemove = function(e) {
if (mover) {
if (first) {
x = e.offsetX;
y = e.offsetY;
first = false;
}
posx = e.pageX - x;
posy = e.pageY - y;
this.style.left = posx + 'px';
this.style.top = posy + 'px';
}
};
}
</script>
</head>
<body>
<div id="target" style="left: 10px; top:20px"></div>
</body>
</html>
I've just made a simple drag.
It's a one liner usage, and it handles things like the offset of the mouse to the top left corner of the element, onDrag/onStop callbacks, and SVG elements dragging
Here is the code.
// simple drag
function sdrag(onDrag, onStop) {
var startX = 0;
var startY = 0;
var el = this;
var dragging = false;
function move(e) {
el.style.left = (e.pageX - startX ) + 'px';
el.style.top = (e.pageY - startY ) + 'px';
onDrag && onDrag(el, e.pageX, startX, e.pageY, startY);
}
function startDragging(e) {
if (e.currentTarget instanceof HTMLElement || e.currentTarget instanceof SVGElement) {
dragging = true;
var left = el.style.left ? parseInt(el.style.left) : 0;
var top = el.style.top ? parseInt(el.style.top) : 0;
startX = e.pageX - left;
startY = e.pageY - top;
window.addEventListener('mousemove', move);
}
else {
throw new Error("Your target must be an html element");
}
}
this.addEventListener('mousedown', startDragging);
window.addEventListener('mouseup', function (e) {
if (true === dragging) {
dragging = false;
window.removeEventListener('mousemove', move);
onStop && onStop(el, e.pageX, startX, e.pageY, startY);
}
});
}
Element.prototype.sdrag = sdrag;
and to use it:
document.getElementById('my_target').sdrag();
You can also use onDrag and onStop callbacks:
document.getElementById('my_target').sdrag(onDrag, onStop);
Check my repo here for more details:
https://github.com/lingtalfi/simpledrag
this is how I do it
var MOVE = {
startX: undefined,
startY: undefined,
item: null
};
function contentDiv(color, width, height) {
var result = document.createElement('div');
result.style.width = width + 'px';
result.style.height = height + 'px';
result.style.backgroundColor = color;
return result;
}
function movable(content) {
var outer = document.createElement('div');
var inner = document.createElement('div');
outer.style.position = 'relative';
inner.style.position = 'relative';
inner.style.cursor = 'move';
inner.style.zIndex = 1000;
outer.appendChild(inner);
inner.appendChild(content);
inner.addEventListener('mousedown', function(evt) {
MOVE.item = this;
MOVE.startX = evt.pageX;
MOVE.startY = evt.pageY;
})
return outer;
}
function bodyOnload() {
document.getElementById('td1').appendChild(movable(contentDiv('blue', 100, 100)));
document.getElementById('td2').appendChild(movable(contentDiv('red', 100, 100)));
document.addEventListener('mousemove', function(evt) {
if (!MOVE.item) return;
if (evt.which!==1){ return; }
var dx = evt.pageX - MOVE.startX;
var dy = evt.pageY - MOVE.startY;
MOVE.item.parentElement.style.left = dx + 'px';
MOVE.item.parentElement.style.top = dy + 'px';
});
document.addEventListener('mouseup', function(evt) {
if (!MOVE.item) return;
var dx = evt.pageX - MOVE.startX;
var dy = evt.pageY - MOVE.startY;
var sty = MOVE.item.style;
sty.left = (parseFloat(sty.left) || 0) + dx + 'px';
sty.top = (parseFloat(sty.top) || 0) + dy + 'px';
MOVE.item.parentElement.style.left = '';
MOVE.item.parentElement.style.top = '';
MOVE.item = null;
MOVE.startX = undefined;
MOVE.startY = undefined;
});
}
bodyOnload();
table {
user-select: none
}
<table>
<tr>
<td id='td1'></td>
<td id='td2'></td>
</tr>
</table>
While dragging, the left and right of the style of the parentElement of the dragged element are continuously updated. Then, on mouseup (='drop'), "the changes are committed", so to speak; we add the (horizontal and vertical) position changes (i.e., left and top) of the parent to the position of the element itself, and we clear left/top of the parent again. This way, we only need JavaScript variables for pageX, pageY (mouse position at drag start), while concerning the element position at drag start, we don't need JavaScript variables for that (just keeping that information in the DOM).
If you're dealing with SVG elements, you can use the same parent/child/commit technique. Just use two nested g, and use transform=translate(dx,dy) instead of style.left=dx, style.top=dy

auto clicker and auto key press in javascript console

i need a little help. i want to make something that you put in console and it press Enter bottom for 2000 times and auto click for 2000 times with no delay ! and a key for stop this action. anyone can help me ? thanks a lot !
With jQuery:
function enter_key(ctrl, alt, shift, which) {
var e = $.Event("keydown");
e.ctrlKey = false;
e.altKey = false;
e.shiftKey = false;
e.which = e.keyCode = 13;
$(document.documentElement || window).trigger(e);
}
var stop = false;
for (var i=0; i<2000; ++i) {
if (!stop) {
enter_key();
}
}
click is simpler:
var stop = false;
for (var i=0; i<2000; ++i) {
if (!stop) {
$('button').click();
}
}
and you can stop the iteration by setting:
stop = true;
i thing about this and i found a code that click on the specific position :
var elem = document.elementFromPoint(x, y);
elem.addEventListener('click', function() {
console.log('clicked')
}, false);
var support = true;
try {
if (new MouseEvent('click', {bubbles: false}).bubbles !== false) {
support = false;
} else if (new MouseEvent('click', {bubbles: true}).bubbles !== true) {
support = false;
}
} catch (e) {
support = false;
}
setInterval(function() {
if (support) {
var event = new MouseEvent('click');
}else{
var event = document.createEvent('Event');
event.initEvent('click', true, true);
}
elem.dispatchEvent(event);
},1000);
and i found this code for get mouse position :
function FindPosition(e) {
var posx = 0;
var posy = 0;
if (!e) var e = window.event;
if (e.pageX || e.pageY) {
posx = e.pageX;
posy = e.pageY;
}
else if (e.clientX || e.clientY) {
posx = e.clientX + document.body.scrollLeft
+ document.documentElement.scrollLeft;
posy = e.clientY + document.body.scrollTop
+ document.documentElement.scrollTop;
}
// posx and posy contain the mouse position relative to the document
// Do something with this information
}
so how can i use this code to import mouse position in auto click code ???

Javascript mouse event issue

Here's my simple code:
<!DOCTYPE html>
<html>
<head></head>
<body>
<style>
</style>
<script>
var exit = 0;
document.onmousedown = function (e) {
exit = 0;
document.onmousemove = function (e) {
if (exit == 1) {
return;
} else {
var x = e.pageX;
var y = e.pageY;
var e = document.createElement("div");
e.style.width = 10 + "px";
e.style.height = 10 + "px";
e.style.background = "red";
e.style.top = y + "px";
e.style.left = x + "px";
e.style.position = "absolute";
document.body.appendChild(e);
}
};
};
document.onmouseup = function (e) {
exit = 1;
};
</script>
</body>
</html>
It's like painter.You hold left mouse button down and when you move mouse, it should draw line made of div elements and when you release button, it stops.It actually works...sometimes.First time it works perfect, but after letting left mouse button go up, and after additional press, only one element is drawn and moving mouse does not do anything.To be exact- sometimes it does and sometimes doesn't.Best would be if you could try this code and see what happens.Thanks.
It seems to be because it conflicts dragging with selection. Both events involve mousedown and subsequent mousemove.
You will need to prevent default of event and then run your code.
Updated fiddle: http://jsfiddle.net/L4KhJ/2/
Prevent the default on both events, like this:
document.onmousedown = function (e) {
stopDefault(e); // *** prevent default here
exit = 0;
document.onmousemove = function (e) {
stopDefault(e); // *** prevent default here
if (exit == 1) { ...
Where stopDefault is:
function stopDefault(e) {
if (e && e.preventDefault) {
e.preventDefault();
}
else {
window.event.returnValue = false;
}
return false;
}
Code for above function taken from this thread here: https://stackoverflow.com/a/891616/1355315
When you add some log output, you see that sometimes after a mouseup event, you get a mousedown shortly after.
Maybe this is a timing related problem. I moved the assignment to onmousemove outside the onmousedown function and now it works properly
var exit = 1;
document.onmousemove = function (e) {
if (exit == 1)
return;
var x = e.pageX;
var y = e.pageY;
var el = document.createElement("div");
el.style.width = 10 + "px";
el.style.height = 10 + "px";
el.style.background = "red";
el.style.top = y + "px";
el.style.left = x + "px";
el.style.position = "absolute";
document.body.appendChild(el);
};
document.onmousedown = function (e) {
exit = 0;
};
document.onmouseup = function (e) {
exit = 1;
};
See JSFiddle

Dragging div does not work in IE 7 & 8

I am using the following function to drag a div by a handle:
function enableDragging(ele) {
var dragging = dragging || false,
x, y, Ox, Oy,
current;
enableDragging.z = enableDragging.z || 1;
var grabber = document.getElementById("myHandelDiv");
grabber.onmousedown = function(ev) {
current = ev.target.parentNode;
dragging = true;
x = ev.clientX;
y = ev.clientY;
Ox = current.offsetLeft;
Oy = current.offsetTop;
current.style.zIndex = ++enableDragging.z;
console.log(dragging);
window.onmousemove = function(ev) {
pauseEvent(ev);
if (dragging == true) {
var Sx = ev.clientX - x + Ox,
Sy = ev.clientY - y + Oy;
current.style.top = Sy + "px";
current.style.left = Sx + "px";
document.body.focus();
// prevent text selection in IE
document.onselectstart = function () { return false; };
// prevent IE from trying to drag an image
ev.ondragstart = function() { return false; };
return false;
}
};
window.onmouseup = function(ev) {
dragging && (dragging = false);
}
};
}
function pauseEvent(e){
if(e.stopPropagation) e.stopPropagation();
if(e.preventDefault) e.preventDefault();
e.cancelBubble=true;
e.returnValue=false;
return false;
}
I have two problems:
Does not work in IE 7 & 8, for some reason i get no errors whatsoever.
Text is selected on some browsers while dragging causing the drag to appear laggy
I initiate the drag like this:
var ele = document.getElementById("divDragWrapper");
enableDragging(ele);
Update, am now getting this error in IE:
SCRIPT5007: Unable to get value of the property 'target': object is
null or undefined
On this line: current = ev.target.parentNode;
You need to add ev = ev || window.event to all eventhander functions. Older IEs don't pass the event object within arguments. Also target is rather srcElement in those browsers.
For example:
grabber.onmousedown = function(ev) {
ev = ev || window.event;
var target = ev.target || ev.srcElement;
current = target.parentNode;
...
}
Another thing is, that older IEs can't attach onmousemove to the window. You can use document or document.body instead.
See the code in action at jsFiddle.

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