useHover
Opens the floating element while hovering over the reference
element, like CSS :hover
.
import {useHover} from '@floating-ui/react';
import {useHover} from '@floating-ui/react';
Usage
This hook is an interaction hook that returns event handler props.
To use it, pass it the context
context
object returned from
useFloating()
useFloating()
, and then feed its result into the
useInteractions()
useInteractions()
array. The returned prop getters are
then spread onto the elements for rendering.
function App() {
const [isOpen, setIsOpen] = useState(false);
const {refs, floatingStyles, context} = useFloating({
open: isOpen,
onOpenChange: setIsOpen,
});
const hover = useHover(context);
const {getReferenceProps, getFloatingProps} = useInteractions([
hover,
]);
return (
<>
<div ref={refs.setReference} {...getReferenceProps()}>
Reference element
</div>
{isOpen && (
<div
ref={refs.setFloating}
style={floatingStyles}
{...getFloatingProps()}
>
Floating element
</div>
)}
</>
);
}
function App() {
const [isOpen, setIsOpen] = useState(false);
const {refs, floatingStyles, context} = useFloating({
open: isOpen,
onOpenChange: setIsOpen,
});
const hover = useHover(context);
const {getReferenceProps, getFloatingProps} = useInteractions([
hover,
]);
return (
<>
<div ref={refs.setReference} {...getReferenceProps()}>
Reference element
</div>
{isOpen && (
<div
ref={refs.setFloating}
style={floatingStyles}
{...getFloatingProps()}
>
Floating element
</div>
)}
</>
);
}
Examples
Props
interface Props {
enabled?: boolean;
mouseOnly?: boolean;
delay?: number | Partial<{open: number; close: number}>;
restMs?: number;
move?: boolean;
handleClose?: null | HandleCloseFn;
}
interface Props {
enabled?: boolean;
mouseOnly?: boolean;
delay?: number | Partial<{open: number; close: number}>;
restMs?: number;
move?: boolean;
handleClose?: null | HandleCloseFn;
}
enabled
default: true
true
Conditionally enable/disable the hook.
useHover(context, {
enabled: false,
});
useHover(context, {
enabled: false,
});
mouseOnly
default: false
false
Whether the logic only runs for mouse input, ignoring both touch and pen pointer inputs.
useHover(context, {
mouseOnly: true,
});
useHover(context, {
mouseOnly: true,
});
delay
default: 0
0
Waits for the specified time when the event listener runs before
changing the open
open
state.
useHover(context, {
// both open and close in ms
delay: 500,
// configure them individually
delay: {
open: 500,
close: 0,
},
});
useHover(context, {
// both open and close in ms
delay: 500,
// configure them individually
delay: {
open: 500,
close: 0,
},
});
restMs
default: 0
0
(off)
Waits until the user’s cursor is at “rest” over the reference element before changing the open state.
useHover(context, {
// waits 150 ms once the user's cursor is at rest
restMs: 150,
});
useHover(context, {
// waits 150 ms once the user's cursor is at rest
restMs: 150,
});
You can also use a fallback delay if the user’s cursor never rests, to ensure the floating element will eventually open:
useHover(context, {
restMs: 150,
// if their cursor never rests, open it after 1000 ms (fallback)
delay: {open: 1000},
});
useHover(context, {
restMs: 150,
// if their cursor never rests, open it after 1000 ms (fallback)
delay: {open: 1000},
});
move
default: true
true
Whether moving the cursor over the floating element will open it, without a regular hover event required.
For example, if it was resting over the reference element when it
closed. Uses the 'mousemove'
'mousemove'
event.
useHover(context, {
move: false,
});
useHover(context, {
move: false,
});
handleClose
default: null
null
Instead of closing the floating element when the cursor leaves its reference, we can leave it open until a certain condition is satisfied.
The package exports a safePolygon()
safePolygon()
handler which will
only close the floating element if the pointer is outside a
dynamically computed polygon area.
This allows the user to move the cursor off the reference element and towards the floating element without it closing (e.g. it has interactive content inside).
import {useHover, safePolygon} from '@floating-ui/react';
// ...
useHover(context, {
handleClose: safePolygon(),
});
import {useHover, safePolygon} from '@floating-ui/react';
// ...
useHover(context, {
handleClose: safePolygon(),
});
This handler runs on mousemove
mousemove
.
For a simpler alternative, depending on the type of floating element, you can use a short close delay instead.
safePolygon
A “safe” polygon is one that a pointer is safe to traverse as it moves off the reference element and toward the floating element after hovering it. If the pointer moves outside of this safe area, the floating element closes.
It is a dynamic polygon (either a rect or a triangle) originating from the cursor once it leaves a reference element. The triangle looks like this:
This function takes options.
requireIntent
default: true
true
Determines whether intent is required for the triangle polygon to
be generated (that is, the cursor is moving quickly enough toward
the floating element). false
false
will keep the triangle active
no matter the intent.
useHover(context, {
handleClose: safePolygon({
requireIntent: false,
}),
});
useHover(context, {
handleClose: safePolygon({
requireIntent: false,
}),
});
When reference elements are placed near each other and they each
have a hoverable floating element attached, true
true
ensures
that hover events for the other nearby references aren’t too
aggressively blocked.
buffer
default: 0.5
0.5
Determines the amount of buffer (in pixels) there is around the polygon.
While the default value should handle the vast majority of cases correctly, if you find your floating element is closing unexpectedly as the pointer tries to move toward the floating element, try increasing this value.
useHover(context, {
handleClose: safePolygon({
buffer: 1,
}),
});
useHover(context, {
handleClose: safePolygon({
buffer: 1,
}),
});
Ignoring the triangle
If you only want the offset portion (rectangle bridge) between
the reference and floating elements to be considered, you can set
the value to -Infinity
-Infinity
.
useHover(context, {
handleClose: safePolygon({
// Don't generate a triangle polygon, only consider the
// rectangular bridge between the elements.
buffer: -Infinity,
}),
});
useHover(context, {
handleClose: safePolygon({
// Don't generate a triangle polygon, only consider the
// rectangular bridge between the elements.
buffer: -Infinity,
}),
});
blockPointerEvents
default: false
false
Whether CSS pointer-events
behind the polygon, reference, and
floating elements are blocked. This ensures the user does not
fire hover events over other elements unintentionally while they
traverse the polygon.
useHover(context, {
handleClose: safePolygon({
blockPointerEvents: true,
}),
});
useHover(context, {
handleClose: safePolygon({
blockPointerEvents: true,
}),
});
This has some side-effects:
- While hovering over the reference element, if it’s inside a scrolling container, it cannot be scrolled (the main window is unaffected).
- Container elements that listen for
mouseleave
events may fire unexpectedly.
For the first two points, a
[data-floating-ui-safe-polygon]
[data-floating-ui-safe-polygon]
selector is
available as a parent, so scrolling containers can negate the
pointer-events
pointer-events
style:
[data-floating-ui-safe-polygon] .scroll {
pointer-events: auto;
}
[data-floating-ui-safe-polygon] .scroll > div {
pointer-events: none;
}
[data-floating-ui-safe-polygon] .scroll {
pointer-events: auto;
}
[data-floating-ui-safe-polygon] .scroll > div {
pointer-events: none;
}
<div className="scroll">
<div>
Content inside here will remain blocked without affecting the
scrolling parent.
</div>
</div>
<div className="scroll">
<div>
Content inside here will remain blocked without affecting the
scrolling parent.
</div>
</div>