Callback function that is triggered when event is fired.
Optional info: unknownOptional options: LCJSAddEventListenerOptionsOptional extra configuration options.
Remove event listener added using addEventListener.
The expected argument should be the exact same callback function that was supplied using addEventListener:
// Basic example syntax
const listener = () => {}
obj.addEventListener('click', listener)
obj.removeEventListener('click', listener)
// Basic boilerplate of custom interaction when user drags on an object
obj.addEventListener('pointerdown', (eventDown) => {
let prevCoord = eventDown
const handlePointerMove: LCJSInteractionEventListener<'pointermove'> = (eventMove) => {
const delta = { x: eventMove.clientX - prevCoord.clientX, y: eventMove.clientY - prevCoord.clientY }
prevCoord = eventMove
console.log(delta, eventMove.clientX, eventMove.clientY)
}
const handlePointerUp: LCJSInteractionEventListener<'pointerup'> = (eventUp) => {
window.removeEventListener('pointermove', handlePointerMove)
window.removeEventListener('pointerup', handlePointerUp)
}
window.addEventListener('pointermove', handlePointerMove)
window.addEventListener('pointerup', handlePointerUp)
})
Listener that was added using addEventListener.
Optional info: unknown
Add callback function to be triggered when specified event is fired.
Some classes also report extra information about the interacted object with the second parameter:
Optional third parameter allows registering event handlers that will automatically remove themselves after first trigger:
Each class has its own list of supported events. Some events are from HTML standard (
click,pointerdown, etc.), while others are own events from LightningChart JS (dispose,resize, etc.)To find what events are available, you can try following:
TypeScriptenabled, just writeaddEventListenerand see what possible event types the IDE suggests. These APIs are strongly typed, and even the callback event will be correctly typed.Ktype parameter extends.