Add callback function to be triggered when specified event is fired.
// Example syntax
object.addEventListener('click', (event) => {
console.log(event)
})
Some classes also report extra information about the interacted object with the second parameter:
// Most series share information about interacted data point
series.addEventListener('click', (event, info) => {
console.log(info)
})
Optional third parameter allows registering event handlers that will automatically remove themselves after first trigger:
// Example this listener will only fire once
object.addEventListener('click', (event) => {})
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:
TypeScript enabled, just write addEventListener and see what possible event types the IDE suggests. These APIs are strongly typed, and even the callback event will be correctly typed.K type parameter extends.Callback function that is triggered when event is fired.
Optional info: unknownOptional options: LCJSAddEventListenerOptionsOptional extra configuration options.
Get elements Background object
Type of Background is generic, see UIBackground for minimum interface.
Background object
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: unknownMethod for mutating Background of object.
Type of Background is generic, see UIBackground for minimum interface.
Object itself for fluent interface
Mutator function for Background
Set state of component highlighting.
// Example usage
component.setHighlight(true)
Object itself
Boolean or number between 0 and 1, where 1 is fully highlighted.
Set padding around object in pixels. Padding is empty space between the UiElements content and Background
Object itself
Number with pixel margins for all sides or datastructure with individual pixel paddings for each side. Any side can be omitted, only passed values will be overridden.
Interface for an object that has stylable background.