MouseEvent: movementY property
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
The movementY read-only property of the MouseEvent interface provides the difference in the Y coordinate of the mouse pointer between the given event and the previous mousemove event.
In other words, the value of the property is computed like this: currentEvent.movementY = currentEvent.screenY - previousEvent.screenY.
Warning:
Browsers use different units for movementY and screenY than what the specification defines. Depending on the browser and operating system, the movementY units may be a physical pixel, a logical pixel, or a CSS pixel. You may want to avoid the movement properties, and instead calculate the delta between the current client values (screenX, screenY) and the previous client values.
Value
A number. Always zero on any MouseEvent other than mousemove.
Examples
This example logs the amount of mouse movement using movementX and movementY.
HTML
<p id="log">Move your mouse around.</p>
JavaScript
function logMovement(event) {
log.innerText = `movement: ${event.movementX}, ${event.movementY}\n${log.innerText}`;
}
const log = document.getElementById("log");
document.addEventListener("mousemove", logMovement);
Result
Specifications
| Specification |
|---|
| Pointer Lock 2.0 # dom-mouseevent-movementy |