JavaScript setTimeout() can't trigger itself - javascript

How can a function, which is triggered by another function, get the mouse's position? Here's my code:
function myFunction(e){
setTimeout(function(){
if(isMouseDown == true){
mouseX = e.clientX;
mouseY = e.clientY;
document.getElementById('myElement').innerHTML = mouseX + ' , ' + mouseY;
myFunction(event);
} else {}
}, 100);
}
What this does is to display the coordinates when clicked. I need it to display them every 100ms if isMouseDown == true.
Thanks

There is no way in Javascript for a random Javascript function to get the mouse position. The current mouse position only comes from an event object for a mouse-related event. So, if you want to keep track of the mouse position, then you can register an event handler for the mousemove event and for mousedown and mouseup to keep track of the button state.
If you only want to display the mouse position, ever 100ms, then you can set a timer so that it is only displayed that often, but you will need to keep track of the current mouse position in a mousemove event handler.
Here's a simple code example:
var lastMouseX = 0, lastMouseY = 0;
document.addEventListener("mousemove", function(e) {
lastMouseX = e.clientX;
lastMouseY = e.clientY;
});
var mouseTimer;
document.addEventListener("mousedown", function() {
if (!mouseTimer) {
mouseTimer = setInterval(function() {
document.getElementById("x").innerHTML = lastMouseX;
document.getElementById("y").innerHTML = lastMouseY;
}, 100);
}
});
document.addEventListener("mouseup", function() {
clearInterval(mouseTimer);
mouseTimer = null;
});
<div id="x"></div>
<div id="y"></div>

It's a bit fuzzy what you're trying to achieve, however you're not going to get a periodic event if you're usingsetTimeout(). It sounds like you're looking for setInterval(). See the below example:
var mouseX = 0;
var mouseY = 0;
var isMouseDown = true;
document.onmousemove = function(e){
mouseX = e.pageX;
mouseY = e.pageY;
}
setInterval("myFunction()", 100);
function myFunction(){
if(isMouseDown) {
document.getElementById('myElement').innerHTML = mouseX + ' , ' + mouseY;
}
}
<div id="myElement"></div>

Related

Stop one event by another - Javascript/jQuery

I'm implementing drag and drop with jQuery.
So, after mousedown, event starts working:
On mousemove selected element moves with mouse.
Now, I want it to stop working on mouseup.
here's my code:
$(document).on("mousemove", widget, function() {
var newMouseX = event.pageX - mouseX;
var newMouseY = event.pageY - mouseY;
var newElemX = elemX + newMouseX;
var newElemY = elemY + newMouseY;
$(widget).offset({ top: newElemY , left: newElemX });
$(document).on("mouseup", widget, function(widget) {
// what to do here?
});
});
any suggestions?

Raphael: How to unbind the mousemove function on mouseup?

I am drawing a line with Raphael. I have a mousedown event where I store the starting position. While the mouse is down, if the user moves it, I have a mousemove event where I keep drawing the line as the mouse moves.
Now when the mouse button is released, the line should stop. This does not happen and line keeps going on if the mouse moves even though button is released. This line must stop on mouseup. If the user does mousedown again, it should begin a new line.
I have tried many combinations with the unmouse* events, but I am missing something here.
JSFiddle at: http://jsfiddle.net/zaphod013/P33FA/5/
(This is my first date with JS/Raphael. So if you think I am totally off track here, please tell me so)
var g_masterPaper;
var g_startX;
var g_startY;
var g_line;
function initDrawing() {
g_masterPaper = Raphael(10,10,700,500);
var masterBackground = g_masterPaper.rect(10,10,600,400);
masterBackground.attr("fill", "#eee");
var drawit = function(event) {
x = event.pageX - 10;
y = event.pageY - 10;
var linepath = ("M"+g_startX+" "+g_startY+" L"+x+" "+y);
g_line.attr("path", linepath);
};
var startit = function (event) {
g_startX = event.pageX - 10;
g_startY = event.pageY - 10;
g_line = g_masterPaper.path("M"+g_startX+" "+g_startY+" L"+g_startX+" "+g_startY);
masterBackground.mousemove(drawit);
};
masterBackground.mousedown(startit);
masterBackground.mouseup(function (event) {
this.unmousedown(startit);
this.unmousemove(drawit);
});
return g_masterPaper;
}
window.onload = function () {
var paper=initDrawing();
paper.text(15,475,'Use your mouse to draw.').attr({fill:'#ff0000', 'font-size':24, 'stroke-width':1,'text-anchor':'start' });
}
I think you're on track and mostly looks fine, I would possibly just simplify your handlers, and not keep removing/adding them, it keeps handlers hard to track and debug. So I would just have one handler for down/up/move...
Edit:
jsfiddle here or here which gets around other elements capturing the mouseup event and stopping it working properly.
var drawit = function(event) {
event.preventDefault();
x = event.pageX - 10;
y = event.pageY - 10;
var linepath = ("M"+g_startX+" "+g_startY+" L"+x+" "+y);
if( g_line ) { g_line.attr("path", linepath) };
};
var startit = function (event) {
event.preventDefault();
g_startX = event.pageX - 10;
g_startY = event.pageY - 10;
g_line = g_masterPaper.path("M"+g_startX+" "+g_startY+" L"+g_startX+" "+g_startY);
};
var finish = function ( event ) {
g_line = '';
}

Create a draggable div in native javascript [duplicate]

This question already has answers here:
Moveable/draggable <div>
(9 answers)
Closed 5 years ago.
I want to create a movable/draggable div in native javascript without using jquery and libraries. Is there a tutorial or anythign?
OK, here's my personal code that I use for lightweight deployments (projects where using a library is either not allowed or overkill for some reason). First thing first, I always use this convenience function so that I can pass either an id or the actual dom element:
function get (el) {
if (typeof el == 'string') return document.getElementById(el);
return el;
}
As a bonus, get() is shorter to type than document.getElementById() and my code ends up shorter.
Second realize that what most libraries are doing is cross-browser compatibility. If all browsers behave the same the code is fairly trivial. So lets write some cross-browser functions to get mouse position:
function mouseX (e) {
if (e.pageX) {
return e.pageX;
}
if (e.clientX) {
return e.clientX + (document.documentElement.scrollLeft ?
document.documentElement.scrollLeft :
document.body.scrollLeft);
}
return null;
}
function mouseY (e) {
if (e.pageY) {
return e.pageY;
}
if (e.clientY) {
return e.clientY + (document.documentElement.scrollTop ?
document.documentElement.scrollTop :
document.body.scrollTop);
}
return null;
}
OK, the two functions above are identical. There're certainly better ways to write them but I'm keeping it (relatively) simple for now.
Now we can write the drag and drop code. The thing I like about this code is that everything's captured in a single closure so there are no global variables or helper functions littering the browser. Also, the code separates the drag handle from the object being dragged. This is useful for creating dialog boxes etc. But if not needed, you can always assign them the same object. Anyway, here's the code:
function dragable (clickEl,dragEl) {
var p = get(clickEl);
var t = get(dragEl);
var drag = false;
offsetX = 0;
offsetY = 0;
var mousemoveTemp = null;
if (t) {
var move = function (x,y) {
t.style.left = (parseInt(t.style.left)+x) + "px";
t.style.top = (parseInt(t.style.top) +y) + "px";
}
var mouseMoveHandler = function (e) {
e = e || window.event;
if(!drag){return true};
var x = mouseX(e);
var y = mouseY(e);
if (x != offsetX || y != offsetY) {
move(x-offsetX,y-offsetY);
offsetX = x;
offsetY = y;
}
return false;
}
var start_drag = function (e) {
e = e || window.event;
offsetX=mouseX(e);
offsetY=mouseY(e);
drag=true; // basically we're using this to detect dragging
// save any previous mousemove event handler:
if (document.body.onmousemove) {
mousemoveTemp = document.body.onmousemove;
}
document.body.onmousemove = mouseMoveHandler;
return false;
}
var stop_drag = function () {
drag=false;
// restore previous mousemove event handler if necessary:
if (mousemoveTemp) {
document.body.onmousemove = mousemoveTemp;
mousemoveTemp = null;
}
return false;
}
p.onmousedown = start_drag;
p.onmouseup = stop_drag;
}
}
There is a reason for the slightly convoluted offsetX/offsetY calculations. If you notice, it's just taking the difference between mouse positions and adding them back to the position of the div being dragged. Why not just use the mouse positions? Well, if you do that the div will jump to the mouse pointer when you click on it. Which is a behavior I did not want.
You can try this
HTML
<div id="one" style="height:50px; width:50px; border:1px solid #ccc; background:red;">
</div>
Js Script for draggable div
window.onload = function(){
draggable('one');
};
var dragObj = null;
function draggable(id)
{
var obj = document.getElementById(id);
obj.style.position = "absolute";
obj.onmousedown = function(){
dragObj = obj;
}
}
document.onmouseup = function(e){
dragObj = null;
};
document.onmousemove = function(e){
var x = e.pageX;
var y = e.pageY;
if(dragObj == null)
return;
dragObj.style.left = x +"px";
dragObj.style.top= y +"px";
};
Check this Demo
This code corrects the position of the mouse (so the dragged object doesn't jump when you start dragging) and works with touch screens/phones as well
var dragObj = null; //object to be moved
var xOffset = 0; //used to prevent dragged object jumping to mouse location
var yOffset = 0;
window.onload = function()
{
document.getElementById("menuBar").addEventListener("mousedown", startDrag, true);
document.getElementById("menuBar").addEventListener("touchstart", startDrag, true);
document.onmouseup = stopDrag;
document.ontouchend = stopDrag;
}
function startDrag(e)
/*sets offset parameters and starts listening for mouse-move*/
{
e.preventDefault();
e.stopPropagation();
dragObj = e.target;
dragObj.style.position = "absolute";
var rect = dragObj.getBoundingClientRect();
if(e.type=="mousedown")
{
xOffset = e.clientX - rect.left; //clientX and getBoundingClientRect() both use viewable area adjusted when scrolling aka 'viewport'
yOffset = e.clientY - rect.top;
window.addEventListener('mousemove', dragObject, true);
}
else if(e.type=="touchstart")
{
xOffset = e.targetTouches[0].clientX - rect.left; //clientX and getBoundingClientRect() both use viewable area adjusted when scrolling aka 'viewport'
yOffset = e.targetTouches[0].clientY - rect.top;
window.addEventListener('touchmove', dragObject, true);
}
}
function dragObject(e)
/*Drag object*/
{
e.preventDefault();
e.stopPropagation();
if(dragObj == null) return; // if there is no object being dragged then do nothing
else if(e.type=="mousemove")
{
dragObj.style.left = e.clientX-xOffset +"px"; // adjust location of dragged object so doesn't jump to mouse position
dragObj.style.top = e.clientY-yOffset +"px";
}
else if(e.type=="touchmove")
{
dragObj.style.left = e.targetTouches[0].clientX-xOffset +"px"; // adjust location of dragged object so doesn't jump to mouse position
dragObj.style.top = e.targetTouches[0].clientY-yOffset +"px";
}
}
function stopDrag(e)
/*End dragging*/
{
if(dragObj)
{
dragObj = null;
window.removeEventListener('mousemove', dragObject, true);
window.removeEventListener('touchmove', dragObject, true);
}
}
div{height:400px; width:400px; border:1px solid #ccc; background:blue; cursor: pointer;}
<div id="menuBar" >A</div>
<div draggable=true ondragstart="event.dataTransfer.setData('text/plain', '12345')">
drag me
</div>
<div ondragover="return false;" ondrop="this.innerHTML=event.dataTransfer.getData('text/plain')">
drop on me
</div>

draggable without jQuery ui

How to make a element draggable without using jQuery UI?
I have this code:
<script type="text/javascript">
function show_coords(event)
{
var x=event.clientX;
var y=event.clientY;
var drag=document.getElementById('drag');
drag.style.left=x;
drag.style.top=y
}
</script>
<body style="height:100%;width:100%" onmousemove="show_coords(event)">
<p id="drag" style="position:absolute">drag me</p>
</body>
The problem is that I want to drag while the user the pressing the mouse button. I tried onmousedown but results were negative.
It will be quite easy as you get the concept.
function enableDragging(ele) {
var dragging = dragging || false, //Setup a bunch of variables
x, y, Ox, Oy,
enableDragging.z = enableDragging.z || 1,
current;
ele.onmousedown = function(ev) { //When mouse is down
current = ev.target;
dragging = true; //It is dragging time
x = ev.clientX; //Get mouse X and Y and store it
y = ev.clientY; // for later use.
Ox = current.offsetLeft; //Get element's position
Oy = current.offsetTop;
current.style.zIndex = ++enableDragging.z; //z-index thing
window.onmousemove = function(ev) {
if (dragging == true) { //when it is dragging
var Sx = ev.clientX - x + Ox, //Add the difference between
Sy = ev.clientY - y + Oy; // 2 mouse position to the
current.style.top = Sy + "px"; // element.
current.style.left = Sx + "px";
return false; //Don't care about this.
}
};
window.onmouseup = function(ev) {
dragging && (dragging = false); //Mouse up, dragging done!
}
};
}
enableDragging(document.getElementById("drag")); //draggable now!
var ele = document.getElementsByTagName("div");
for(var i = 0; i < ele.length; i++){ //Every div's is draggable
enableDragging(ele[i]); // (only when its "position"
} // is set to "absolute" or
// "relative")
http://jsfiddle.net/DerekL/NWU9G/
The reason why your code is not working is because the <div> will always follow where your cursor goes, and you are not actually dragging it. The top left corner will always follow your cursor, and this is not we wanted.
UPDATE
Now if you only want a grabber or something similar, just change this part of the script:
ele.onmousedown = function(ev) {
current = ev.target;
to
var grabber = document.createElement("div");
grabber.setAttribute("class", "grabber");
ele.appendChild(grabber);
grabber.onmousedown = function(ev) {
current = ev.target.parentNode;
Now you can only click on the grabber to start the dragging process.
http://jsfiddle.net/DerekL/NWU9G/7/

Getting mouse position in keyboard event

I'm trying to have a selection wheel appear when the user holds down the Shift key.
The wheel should be centred on the mouse's position.
However when I test this, pageX and clientX are both undefined on the event object.
Is it possible to get the mouse coordinates on a keyboard event?
No, simply track mousemove events and continuously save the current position in case you get a keyboard event.
Cache mouse position in a global variable in every mousemove event and use it when a key event fires:
var mousePosition = {x:0, y:0};
$(document).bind('mousemove',function(mouseMoveEvent){
mousePosition.x = mouseMoveEvent.pageX;
mousePosition.y = mouseMoveEvent.pageY;
});
$(document).bind('keyup', function(keyUpEvent){
$('body').append($('<p/>').text('x:' + mousePosition.x + ' * y: ' + mousePosition.y));
});
JSBIN: http://jsbin.com/uxecuj/4
JavaScript without jQuery:
var mousePosition = {x:0, y:0};
document.addEventListener('mousemove', function(mouseMoveEvent){
mousePosition.x = mouseMoveEvent.pageX;
mousePosition.y = mouseMoveEvent.pageY;
}, false);
document.addEventListener('keyup', function(keyUpEvent){
var divLog = document.querySelector('#log'),
log = 'x:' + mousePosition.x + ' * y: ' + mousePosition.y,
p = document.createElement('p').innerHTM = log;
divLog.appendChild(p);
}, false);
Here's the POJS equivalent of other answers that is cross browser back to IE 6 (and probably IE 5 but I don't have it to test any more). No global variables even:
function addEvent(el, evt, fn) {
if (el.addEventListener) {
el.addEventListener(evt, fn, false);
} else if (el.attachEvent) {
el.attachEvent('on' + evt, fn);
}
}
(function () {
var x, y;
window.onload = function() {
addEvent(document.body, 'mousemove', function(e) {
// Support IE event model
e = e || window.event;
x = e.pageX || e.clientX;
y = e.pageY || e.clientY;
});
// Show coords, assume element with id "d0" exists
addEvent(document.body, 'keypress', function() {
document.getElementById('d0').innerHTML = x + ',' + y;
});
}
}());
But there are bigger issues. Key events are only dispatched if an element that can receive keyboard input is focused (input, textarea, and so on). Also, if the user scrolls the screen without moving the mouse, the coordinates will probably be wrong.
An alternative solution is to use CSS to replace the cursor with a custom animation.
If you're using jQuery, you can do the following (assuming you have an image with id="wheelImage" and whose position is set to absolute), write the following inside your keydown event. Here we use the global properties pageX and pageY that are passed to any handler. You can also use jQuery's shiftKey property to check if the shift key has been pressed.
$().keydown(function(e) {
if (e.shiftKey) {
e.preventDefault();
$('#wheelImage').css('left',e.pageX ).css('top', e.pageY);
}
});
Cache the mouse position.
var x = 0, y = 0;
document.addEventListener('mousemove', function(e){
x = e.pageX
y = e.pageY;
}, false);
document.addEventListener('keyup', function(e){
console.log(x + ' ' + y);
}, false);
Or with JS Ninja Library.
var x = 0, y = 0;
$(document).mousemove(function(e){
x = e.pageX
y = e.pageY;
});
$(document).keypressed(function() {
console.log(x + ' ' + y);
});

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