forked from hotwired/stimulus
/
event_listener.ts
72 lines (61 loc) · 1.94 KB
/
event_listener.ts
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import { Binding } from "./binding"
export class EventListener implements EventListenerObject {
readonly eventTarget: EventTarget
readonly eventName: string
readonly eventOptions: AddEventListenerOptions
private unorderedBindings: Set<Binding>
constructor(eventTarget: EventTarget, eventName: string, eventOptions: AddEventListenerOptions) {
this.eventTarget = eventTarget
this.eventName = eventName
this.eventOptions = eventOptions
this.unorderedBindings = new Set()
}
connect() {
this.eventTarget.addEventListener(this.eventName, this, this.eventOptions)
}
disconnect() {
this.eventTarget.removeEventListener(this.eventName, this, this.eventOptions)
}
// Binding observer delegate
bindingConnected(binding: Binding) {
this.unorderedBindings.add(binding)
}
bindingDisconnected(binding: Binding) {
this.unorderedBindings.delete(binding)
}
handleEvent(event: Event) {
// FIXME: Determine why TS won't recognize that the extended event has immediatePropagationStopped
const extendedEvent = extendEvent(event) as any
for (const binding of this.bindings) {
if (extendedEvent.immediatePropagationStopped) {
break
} else {
binding.handleEvent(extendedEvent)
}
}
}
hasBindings() {
return this.unorderedBindings.size > 0
}
get bindings(): Binding[] {
return Array.from(this.unorderedBindings).sort((left, right) => {
const leftIndex = left.index,
rightIndex = right.index
return leftIndex < rightIndex ? -1 : leftIndex > rightIndex ? 1 : 0
})
}
}
function extendEvent(event: Event) {
if ("immediatePropagationStopped" in event) {
return event
} else {
const { stopImmediatePropagation } = event
return Object.assign(event, {
immediatePropagationStopped: false,
stopImmediatePropagation() {
this.immediatePropagationStopped = true
stopImmediatePropagation.call(this)
},
})
}
}