ebd1f5ddb0
1. Run the tests in both an environment without PointerEvent and one with PointerEvent. 2. Improve test coverage to include both mouse and touch pointers. 3. Change 'Press' so that it only listens to either pointer events or fallbacks events.
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 Responders attach to 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.
The core API is documented below. Documentation for individual Event Responders can be found here.
Event Responder Interface
An Event Responder Interface is defined using an object. Each responder can define DOM events to listen to, handle the synthetic responder events, dispatch custom events, and implement a state machine.
// types
type ResponderEventType = string;
type ResponderEvent = {|
nativeEvent: any,
responderTarget: Element | Document,
target: Element | Document,
pointerType: string,
type: string,
passive: boolean,
passiveSupported: boolean,
|};
type CustomEvent = {
type: string,
target: Element,
...
}
getInitialState?: (props: null | Object) => Object
The initial state of that the Event Responder is created with.
onEvent?: (event: ResponderEvent, context: ResponderContext, props, state)
Called during the bubble phase of the targetEventTypes dispatched on DOM
elements within the Event Responder.
onMount?: (context: ResponderContext, props, state)
Called after an Event Responder in mounted.
onOwnershipChange?: (context: ResponderContext, props, state)
Called when ownership is granted or terminated (either globally or for the responder) for an Event Responder instance.
onRootEvent?: (event: ResponderEvent, context: ResponderContext, props, state)
Called when any of the rootEventTypes are dispatched on the root of the app.
onUnmount?: (context: ResponderContext, props, state)
Called before an Event Responder in unmounted.
rootEventTypes?: Array
Defines the DOM events to listen to on the root of the app.
targetEventTypes?: Array
Defines the DOM events to listen to within the Event Responder subtree.
ResponderContext
The Event Responder Context is exposed via the context argument for certain methods
on the EventResponder object.
addRootEventTypes(eventTypes: Array)
This can be used to dynamically listen to events on the root of the app only when it is necessary to do so.
clearTimeout(id: Symbol): void
Clear a timeout defined using context.setTimeout.
dispatchEvent(propName: string, event: CustomEvent, { discrete: boolean })
Dispatches a custom synthetic event. The type and target are required
fields if the event is an object, but any other fields can be defined on the event that will be passed
to the listener. You can also pass a value that is not an object, but a boolean. For example:
const event = { type: 'press', target, pointerType, x, y };
context.dispatchEvent('onPress', event, DiscreteEvent);
getFocusableElementsInScope(): Array
Returns every DOM element that can be focused within the scope of the Event Responder instance.
hasOwnership(): boolean
Returns true if the instance has taken ownership of the responder.
isTargetWithinNode(target: Element, element: Element): boolean
Returns true if target is a child of element.
isTargetWithinResponder(target: Element): boolean
Returns true is the target element is within the subtree of the Event Responder.
isTargetWithinResponderScope(target: Element): boolean
Returns true is the target element is within the current Event Responder's scope. If the target element
is within the scope of the same responder, but owned by another Event Responder instance, this will return false.
releaseOwnership(): boolean
Returns true if the instance released ownership of the Event Responder instance.
removeRootEventTypes(eventTypes: Array)
Remove the root event types added with addRootEventTypes.
requestGlobalOwnership(): boolean
The current Event Responder instance can request global ownership of the event system. When an Event Responder instance
has global ownership, only that instance and its responder are active. To release ownership to other event responders,
either releaseOwnership() must be called or the Event Responder instance that had global ownership must be
unmounted. Calling requestGlobalOwnership also returns true/false if the request was successful.
setTimeout(func: () => void, delay: number): Symbol
This can be used to dispatch async events, e.g., those that fire after a delay.