[javascript] How to get the mouse position without events (without moving the mouse)?

Is it possible to get the mouse position with JavaScript after page loads without any mouse movement event (without moving the mouse)?

@Tim Down's answer is not performant if you render 2,000 x 2,000 <a> elements:

OK, I have just thought of a way. Overlay your page with a div that covers the whole document. Inside that, create (say) 2,000 x 2,000 elements (so that the :hover pseudo-class will work in IE 6, see), each 1 pixel in size. Create a CSS :hover rule for those elements that changes a property (let's say font-family). In your load handler, cycle through each of the 4 million elements, checking currentStyle / getComputedStyle() until you find the one with the hover font. Extrapolate back from this element to get the co-ordinates within the document.

N.B. DON'T DO THIS.

But you don't have to render 4 million elements at once, instead use binary search. Just use 4 <a> elements instead:

• Step 1: Consider the whole screen as the starting search area
• Step 2: Split the search area into 2 x 2 = 4 rectangle <a> elements
• Step 3: Using the getComputedStyle() function determine in which rectangle mouse hovers
• Step 4: Reduce the search area to that rectangle and repeat from step 2.

This way you would need to repeat these steps max 11 times, considering your screen is not wider than 2048px.

So you will generate max 11 x 4 = 44 <a> elements.

If you don't need to determine the mouse position exactly to a pixel, but say 10px precision is OK. You would repeat the steps at most 8 times, so you would need to draw max 8 x 4 = 32 <a> elements.

Also generating and then destroying the <a> elements is not performat as DOM is generally slow. Instead, you can just reuse the initial 4 <a> elements and just adjust their top, left, width and height as you loop through steps.

Now, creating 4 <a> is an overkill as well. Instead, you can reuse the same one <a> element for when testing for getComputedStyle() in each rectangle. So, instead of splitting the search area into 2 x 2 <a> elements just reuse a single <a> element by moving it with top and left style properties.

So, all you need is a single <a> element change its width and height max 11 times, and change its top and left max 44 times and you will have the exact mouse position.

I think i may have a reasonable solution with out counting divs and pixels..lol

Simply use animation frame or a time interval of a function. you will still need a mouse event one time though just to initiate, but technically you position this where ever you like.

Essentially we are tracking a dummy div at all times with out mouse movement.

// create a div(#mydiv) 1px by 1px set opacity to 0 & position:absolute;

Below is the logic..

var x,y;


$('body').mousemove(function( e ) {

    var x = e.clientX - (window.innerWidth / 2);
    var y = e.clientY - (window.innerHeight / 2);
 }


function looping (){

   /* track my div position 60 x 60 seconds!
      with out the mouse after initiation you can still track the dummy div.x & y
      mouse doesn't need to move.*/

   $('#mydiv').x = x;    // css transform x and y to follow 
   $('#mydiv)'.y = y;

   console.log(#mydiv.x etc)

   requestAnimationFrame( looping , frame speed here);
}  

Here's my solution. It exports window.currentMouseX and window.currentMouseY properties you can use anywhere. It uses the position of a hovered element (if any) initially and afterwards listens to mouse movements to set the correct values.

(function () {
    window.currentMouseX = 0;
    window.currentMouseY = 0;

    // Guess the initial mouse position approximately if possible:
    var hoveredElement = document.querySelectorAll(':hover');
    hoveredElement = hoveredElement[hoveredElement.length - 1]; // Get the most specific hovered element

    if (hoveredElement != null) {
        var rect = hoveredElement.getBoundingClientRect();
        // Set the values from hovered element's position
        window.currentMouseX = window.scrollX + rect.x;
        window.currentMouseY = window.scrollY + rect.y;
    }

    // Listen for mouse movements to set the correct values
    document.addEventListener('mousemove', function (e) {
        window.currentMouseX = e.pageX;
        window.currentMouseY = e.pageY;
    });
}())

Composr CMS Source: https://github.com/ocproducts/composr/commit/a851c19f925be20bc16bfe016be42924989f262e#diff-b162dc9c35a97618a96748639ff41251R1202

I envision that maybe you have a parent page with a timer and after a certain amount of time or a task is completed, you forward the user to a new page. Now you want the cursor position, and because they are waiting, they aren't necessarily touching the mouse. So track the mouse on the parent page using standard events and pass the last value to the new page in a get or a post variable.

You can use JHarding's code on your parent page so that the latest position is always available in a global variable:

var cursorX;
var cursorY;
document.onmousemove = function(e){
    cursorX = e.pageX;
    cursorY = e.pageY;
}

This won't help users that navigate to this page by means other than your parent page.

I implemented a horizontal/vertical search, (first make a div full of vertical line links arranged horizontally, then make a div full of horizontal line links arranged vertically, and simply see which one has the hover state) like Tim Down's idea above, and it works pretty fast. Sadly, does not work on Chrome 32 on KDE.

jsfiddle.net/5XzeE/4/

The most simple solution but not 100% accurate

$(':hover').last().offset()

Result: {top: 148, left: 62.5}
The result depend on the nearest element size and return undefined when user switched the tab

You do not have to move the mouse to get the cursor's location. The location is also reported on events other than mousemove. Here's a click-event as an example:

document.body.addEventListener('click',function(e)
{
    console.log("cursor-location: " + e.clientX + ',' + e.clientY);
});

Not mouse position, but, if you're looking for current cursor postion (for use cases like getting last typed character etc) then, below snippet works fine.
This will give you the cursor index related to text content.

window.getSelection().getRangeAt(0).startOffset

var x = 0;
var y = 0;

document.addEventListener('mousemove', onMouseMove, false)

function onMouseMove(e){
    x = e.clientX;
    y = e.clientY;
}

function getMouseX() {
    return x;
}

function getMouseY() {
    return y;
}

Edit 2020: This does not work any more. It seems so, that the browser vendors patched this out. Because the most browsers rely on chromium, it might be in its core.

Old answer: You can also hook mouseenter (this event is fired after page reload, when the mousecursor is inside the page). Extending Corrupted's code should do the trick:

var x = null;_x000D_
var y = null;_x000D_
    _x000D_
document.addEventListener('mousemove', onMouseUpdate, false);_x000D_
document.addEventListener('mouseenter', onMouseUpdate, false);_x000D_
    _x000D_
function onMouseUpdate(e) {_x000D_
  x = e.pageX;_x000D_
  y = e.pageY;_x000D_
  console.log(x, y);_x000D_
}_x000D_
_x000D_
function getMouseX() {_x000D_
  return x;_x000D_
}_x000D_
_x000D_
function getMouseY() {_x000D_
  return y;_x000D_
}

You can also set x and y to null on mouseleave-event. So you can check if the user is on your page with it's cursor.

Riffing on @SuperNova's answer, here's an approach using ES6 classes that keeps the context for this correct in your callback:

class Mouse {_x000D_
  constructor() {_x000D_
    this.x = 0;_x000D_
    this.y = 0;_x000D_
    this.callbacks = {_x000D_
      mouseenter: [],_x000D_
      mousemove: [],_x000D_
    };_x000D_
  }_x000D_
_x000D_
  get xPos() {_x000D_
    return this.x;_x000D_
  }_x000D_
_x000D_
  get yPos() {_x000D_
    return this.y;_x000D_
  }_x000D_
_x000D_
  get position() {_x000D_
    return `${this.x},${this.y}`;_x000D_
  }_x000D_
_x000D_
  addListener(type, callback) {_x000D_
    document.addEventListener(type, this); // Pass `this` as the second arg to keep the context correct_x000D_
    this.callbacks[type].push(callback);_x000D_
  }_x000D_
_x000D_
  // `handleEvent` is part of the browser's `EventListener` API._x000D_
  // https://developer.mozilla.org/en-US/docs/Web/API/EventListener/handleEvent_x000D_
  handleEvent(event) {_x000D_
    const isMousemove = event.type === 'mousemove';_x000D_
    const isMouseenter = event.type === 'mouseenter';_x000D_
_x000D_
    if (isMousemove || isMouseenter) {_x000D_
      this.x = event.pageX;_x000D_
      this.y = event.pageY;_x000D_
    }_x000D_
_x000D_
    this.callbacks[event.type].forEach((callback) => {_x000D_
      callback();_x000D_
    });_x000D_
  }_x000D_
}_x000D_
_x000D_
const mouse = new Mouse();_x000D_
_x000D_
mouse.addListener('mouseenter', () => console.log('mouseenter', mouse.position));_x000D_
mouse.addListener('mousemove', () => console.log('mousemove A', mouse.position));_x000D_
mouse.addListener('mousemove', () => console.log('mousemove B', mouse.position));

You could try something similar to what Tim Down suggested - but instead of having elements for each pixel on the screen, create just 2-4 elements (boxes), and change their location, width, height dynamically to divide the yet possible locations on screen by 2-4 recursively, thus finding the mouse real location quickly.

For example - first elements take right and left half of screen, afterwards the upper and lower half. By now we already know in which quarter of screen the mouse is located, are able to repeat - discover which quarter of this space...

What you can do is create variables for the x and y coordinates of your cursor, update them whenever the mouse moves and call a function on an interval to do what you need with the stored position.

The downside to this of course is that at least one initial movement of the mouse is required to have it work. As long as the cursor updates its position at least once, we are able to find its position regardless of whether it moves again.

var cursor_x = -1;
var cursor_y = -1;
document.onmousemove = function(event)
{
 cursor_x = event.pageX;
 cursor_y = event.pageY;
}
setInterval(check_cursor, 1000);
function check_cursor(){console.log('Cursor at: '+cursor_x+', '+cursor_y);}

The preceding code updates once a second with a message of where your cursor is. I hope this helps.