GlobalEventHandlers.onmousedown
The onmousedown
property of the
GlobalEventHandlers
mixin is an event handler that
processes mousedown
events.
The mousedown
event fires when the user depresses the mouse button.
Note: The opposite of onmousedown
is
onmouseup
.
Syntax
target.onmousedown = functionRef;
Value
functionRef
is a function name or a function
expression. The function receives a MouseEvent
object as its sole
argument.
Example
This example reveals part of an image when you press and hold a mouse button. It uses
the onmousedown
, onmouseup
,
and onmousemove
event handlers.
HTML
<div class="container">
<div class="view" hidden></div>
<img src="rhino.jpg">
</div>
CSS
.container {
width: 300px;
height: 227px;
background: black;
}
.view {
position: absolute;
width: 100px;
height: 100px;
background: white;
border-radius: 50%;
}
img {
mix-blend-mode: darken;
}
JavaScript
function showView(event) {
view.removeAttribute('hidden');
view.style.left = event.clientX - 50 + 'px';
view.style.top = event.clientY - 50 + 'px';
event.preventDefault();
}
function moveView(event) {
view.style.left = event.clientX - 50 + 'px';
view.style.top = event.clientY - 50 + 'px';
}
function hideView(event) {
view.setAttribute('hidden', '');
}
const container = document.querySelector('.container');
const view = document.querySelector('.view');
container.onmousedown = showView;
container.onmousemove = moveView;
document.onmouseup = hideView;
Result
Specifications
Specification |
---|
HTML Standard # handler-onmousedown |
Browser compatibility
BCD tables only load in the browser
See also
mousedown
event