Element: mousemove event
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
The mousemove
event is fired at an element when a pointing device (usually a mouse) is moved while the cursor's hotspot is inside it.
Syntax
Use the event name in methods like addEventListener()
, or set an event handler property.
addEventListener("mousemove", (event) => {});
onmousemove = (event) => {};
Event type
A MouseEvent
. Inherits from UIEvent
and Event
.
Event properties
This interface also inherits properties of its parents, UIEvent
and Event
.
MouseEvent.altKey
Read only-
Returns
true
if the alt key was down when the mouse event was fired. -
The button number that was pressed (if applicable) when the mouse event was fired.
-
The buttons being pressed (if any) when the mouse event was fired.
MouseEvent.clientX
Read only-
The X coordinate of the mouse pointer in viewport coordinates.
MouseEvent.clientY
Read only-
The Y coordinate of the mouse pointer in viewport coordinates.
MouseEvent.ctrlKey
Read only-
Returns
true
if the control key was down when the mouse event was fired. MouseEvent.layerX
Non-standard Read only-
Returns the horizontal coordinate of the event relative to the current layer.
MouseEvent.layerY
Non-standard Read only-
Returns the vertical coordinate of the event relative to the current layer.
MouseEvent.metaKey
Read only-
Returns
true
if the meta key was down when the mouse event was fired. MouseEvent.movementX
Read only-
The X coordinate of the mouse pointer relative to the position of the last
mousemove
event. MouseEvent.movementY
Read only-
The Y coordinate of the mouse pointer relative to the position of the last
mousemove
event. MouseEvent.offsetX
Read only-
The X coordinate of the mouse pointer relative to the position of the padding edge of the target node.
MouseEvent.offsetY
Read only-
The Y coordinate of the mouse pointer relative to the position of the padding edge of the target node.
MouseEvent.pageX
Read only-
The X coordinate of the mouse pointer relative to the whole document.
MouseEvent.pageY
Read only-
The Y coordinate of the mouse pointer relative to the whole document.
-
The secondary target for the event, if there is one.
MouseEvent.screenX
Read only-
The X coordinate of the mouse pointer in screen coordinates.
MouseEvent.screenY
Read only-
The Y coordinate of the mouse pointer in screen coordinates.
MouseEvent.shiftKey
Read only-
Returns
true
if the shift key was down when the mouse event was fired. MouseEvent.mozInputSource
Non-standard Read only-
The type of device that generated the event (one of the
MOZ_SOURCE_*
constants). This lets you, for example, determine whether a mouse event was generated by an actual mouse or by a touch event (which might affect the degree of accuracy with which you interpret the coordinates associated with the event). MouseEvent.webkitForce
Non-standard Read only-
The amount of pressure applied when clicking.
MouseEvent.x
Read only-
Alias for
MouseEvent.clientX
. MouseEvent.y
Read only-
Alias for
MouseEvent.clientY
.
Examples
The following example uses the mousedown
, mousemove
, and mouseup
events to allow the user to draw on an HTML canvas. Its functionality is simple: the thickness of the line is set to 1, and the color is always black.
When the page loads, constants myPics
and context
are created to store a reference to the canvas and the 2d context we will use to draw.
Drawing begins when the mousedown
event fires. First we store the x and y coordinates of the mouse pointer in the variables x
and y
, and then set isDrawing
to true.
As the mouse moves over the page, the mousemove
event fires. If isDrawing
is true, the event handler calls the drawLine
function to draw a line from the stored x
and y
values to the current location.
When the drawLine()
function returns, we adjust the coordinates and then save them in x
and y
.
The mouseup
event draws the final line segment, sets x
and y
to 0
, and stops further drawing by setting isDrawing
to false
.
HTML
<h1>Drawing with mouse events</h1>
<canvas id="myPics" width="560" height="360"></canvas>
CSS
canvas {
border: 1px solid black;
width: 560px;
height: 360px;
}
JavaScript
// When true, moving the mouse draws on the canvas
let isDrawing = false;
let x = 0;
let y = 0;
const myPics = document.getElementById("myPics");
const context = myPics.getContext("2d");
// event.offsetX, event.offsetY gives the (x,y) offset from the edge of the canvas.
// Add the event listeners for mousedown, mousemove, and mouseup
myPics.addEventListener("mousedown", (e) => {
x = e.offsetX;
y = e.offsetY;
isDrawing = true;
});
myPics.addEventListener("mousemove", (e) => {
if (isDrawing) {
drawLine(context, x, y, e.offsetX, e.offsetY);
x = e.offsetX;
y = e.offsetY;
}
});
window.addEventListener("mouseup", (e) => {
if (isDrawing) {
drawLine(context, x, y, e.offsetX, e.offsetY);
x = 0;
y = 0;
isDrawing = false;
}
});
function drawLine(context, x1, y1, x2, y2) {
context.beginPath();
context.strokeStyle = "black";
context.lineWidth = 1;
context.moveTo(x1, y1);
context.lineTo(x2, y2);
context.stroke();
context.closePath();
}
Result
Specifications
Specification |
---|
UI Events # event-type-mousemove |
HTML Standard # handler-onmousemove |
Browser compatibility
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