react-events
This package is experimental. It is intended for use with the experimental React
events API that is not available in open source builds.
Event components do not render a host node. They listen to native browser events
dispatched on the host node of their child and transform those events into
high-level events for applications.
Focus
The Focus
module responds to focus and blur events on the element it wraps.
Focus events are dispatched for mouse
, pen
, touch
, and keyboard
pointer types.
const TextField = (props) => (
<Focus
onBlur={props.onBlur}
onFocus={props.onFocus}
>
<textarea></textarea>
</Focus>
);
type FocusEvent = {
target: Element,
type: 'blur' | 'focus' | 'focuschange'
}
disabled: boolean
Disables all Focus
events.
onBlur: (e: FocusEvent) => void
Called when the element loses focus.
onFocus: (e: FocusEvent) => void
Called when the element gains focus.
onFocusChange: boolean => void
Called when the element changes hover state (i.e., after onBlur
and
onFocus
).
Hover
The Hover
module responds to hover events on the element it wraps. Hover
events are only dispatched for mouse
pointer types. Hover begins when the
pointer enters the element's bounds and ends when the pointer leaves.
const Link = (props) => (
const [ hovered, setHovered ] = useState(false);
return (
<Hover onHoverChange={setHovered}>
<a
{...props}
href={props.href}
style={{
...props.style,
textDecoration: hovered ? 'underline': 'none'
}}
/>
</Hover>
);
);
type HoverEvent = {
pointerType: 'mouse',
target: Element,
type: 'hoverstart' | 'hoverend' | 'hovermove' | 'hoverchange'
}
delayHoverEnd: number
The duration of the delay between when hover ends and when onHoverEnd
is
called.
delayHoverStart: number
The duration of the delay between when hover starts and when onHoverStart
is
called.
disabled: boolean
Disables all Hover
events.
onHoverChange: boolean => void
Called when the element changes hover state (i.e., after onHoverStart
and
onHoverEnd
).
onHoverEnd: (e: HoverEvent) => void
Called once the element is no longer hovered. It will be cancelled if the
pointer leaves the element before the delayHoverStart
threshold is exceeded.
onHoverMove: (e: HoverEvent) => void
Called when the pointer moves within the hit bounds of the element. onHoverMove
is
called immediately and doesn't wait for delayed onHoverStart
.
onHoverStart: (e: HoverEvent) => void
Called once the element is hovered. It will not be called if the pointer leaves
the element before the delayHoverStart
threshold is exceeded. And it will not
be called more than once before onHoverEnd
is called.
preventDefault: boolean = true
Whether to preventDefault()
native events.
Press
The Press
module responds to press events on the element it wraps. Press
events are dispatched for mouse
, pen
, touch
, and keyboard
pointer types.
Press events are only dispatched for keyboards when pressing the Enter or
Spacebar keys. If neither onPress
nor onLongPress
are called, this signifies
that the press ended outside of the element hit bounds (i.e., the user aborted
the press).
const Button = (props) => (
const [ pressed, setPressed ] = useState(false);
return (
<Press
onPress={props.onPress}
onPressChange={setPressed}
onLongPress={props.onLongPress}
>
<div
{...props}
role="button"
tabIndex={0}
style={
...buttonStyles,
...(pressed && pressedStyles)
}}
/>
</Press>
);
);
type PressEvent = {
pointerType: 'mouse' | 'touch' | 'pen' | 'keyboard',
target: Element,
type: 'press' | 'pressstart' | 'pressend' | 'presschange' | 'pressmove' | 'longpress' | 'longpresschange'
}
type PressOffset = {
top: number,
right: number,
bottom: number,
right: number
};
delayLongPress: number = 500ms
The duration of a press before onLongPress
and onLongPressChange
are called.
delayPressEnd: number
The duration of the delay between when the press ends and when onPressEnd
is
called.
delayPressStart: number
The duration of a delay between when the press starts and when onPressStart
is
called. This delay is cut short (and onPressStart
is called) if the press is
released before the threshold is exceeded.
disabled: boolean
Disables all Press
events.
onLongPress: (e: PressEvent) => void
Called once the element has been pressed for the length of delayLongPress
. If
the press point moves more than 10px onLongPress
is cancelled.
onLongPressChange: boolean => void
Called when the element changes long-press state.
onLongPressShouldCancelPress: () => boolean
Determines whether calling onPress
should be cancelled if onLongPress
or
onLongPressChange
have already been called. Default is false
.
onPress: (e: PressEvent) => void
Called immediately after a press is released, unless either 1) the press is
released outside the hit bounds of the element (accounting for
pressRetentionOffset
and TouchHitTarget
), or 2) the press was a long press,
and onLongPress
or onLongPressChange
props are provided, and
onLongPressCancelsPress()
is true
.
onPressChange: boolean => void
Called when the element changes press state (i.e., after onPressStart
and
onPressEnd
).
onPressEnd: (e: PressEvent) => void
Called once the element is no longer pressed (because it was released, or moved
beyond the hit bounds). If the press starts again before the delayPressEnd
threshold is exceeded then the delay is reset to prevent onPressEnd
being
called during a press.
onPressMove: (e: PressEvent) => void
Called when a press moves within the hit bounds of the element. onPressMove
is
called immediately and doesn't wait for delayed onPressStart
. Never called for
keyboard-initiated press events.
onPressStart: (e: PressEvent) => void
Called once the element is pressed down. If the press is released before the
delayPressStart
threshold is exceeded then the delay is cut short and
onPressStart
is called immediately.
pressRetentionOffset: PressOffset
Defines how far the pointer (while held down) may move outside the bounds of the
element before it is deactivated. Once deactivated, the pointer (still held
down) can be moved back within the bounds of the element to reactivate it.
Ensure you pass in a constant to reduce memory allocations.
preventDefault: boolean = true
Whether to preventDefault()
native events. Native behavior is prevented by
default. If an anchor is the child of Press
, internal and external navigation
should be performed in onPress
/onLongPress
. To rely on native behavior
instead, set preventDefault
to false
, but be aware that native behavior will
take place immediately after interaction without respect for delays or long
press.