Element.setPointerCapture()
The setPointerCapture()
method of the
Element
interface is used to designate a specific element as the
capture target of future pointer events. Subsequent events for the pointer will
be targeted at the capture element until capture is released (via
Element.releasePointerCapture()
or the
pointerup
event is fired).
Note: When pointer capture is set,
pointerover
,
pointerout
,
pointerenter
, and
pointerleave
events are only generated
when crossing the boundary of the capture target. This has the effect of suppressing
these events on all other elements.
Overview of pointer capture
Pointer capture allows events for a particular pointer event
(PointerEvent
) to be re-targeted to a particular element instead of the
normal (or hit test) target at a pointer's location. This can be used to ensure
that an element continues to receive pointer events even if the pointer device's contact
moves off the element (such as by scrolling or panning).
Syntax
targetElement.setPointerCapture(pointerId);
Parameters
pointerId
-
The
pointerId
of aPointerEvent
object.
Return value
This method returns undefined
.
Exceptions
NotFoundError
DOMException
-
Thrown if
pointerId
does not match any active pointer.
Example
This example sets pointer capture on a <div>
when you press down on
it. This lets you slide the element horizontally, even when you pointer moves outside of
its boundaries.
HTML
<div id="slider">SLIDE ME</div>
CSS
div {
width: 140px;
height: 50px;
display: flex;
align-items: center;
justify-content: center;
background: #fbe;
}
JavaScript
function beginSliding(e) {
slider.onpointermove = slide;
slider.setPointerCapture(e.pointerId);
}
function stopSliding(e) {
slider.onpointermove = null;
slider.releasePointerCapture(e.pointerId);
}
function slide(e) {
slider.style.transform = `translate(${e.clientX - 70}px)`;
}
const slider = document.getElementById('slider');
slider.onpointerdown = beginSliding;
slider.onpointerup = stopSliding;
Result
Specifications
Specification |
---|
Pointer Events # dom-element-setpointercapture |
Browser compatibility
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