@antv/x6/src/common/dom/event/special.ts

JavaScript diagramming library that uses SVG and HTML for rendering

import { register } from './hook'
import { contains } from './util'

// Prevent triggered image.load events from bubbling to window.load
register('load', {
  noBubble: true,
})

// Support: Chrome <=73+
// Chrome doesn't alert on `event.preventDefault()`
// as the standard mandates.
register('beforeunload', {
  postDispatch(elem, event) {
    if (event.result !== undefined && event.originalEvent) {
      event.originalEvent.returnValue = event.result
    }
  },
})

// For mouseenter/leave call the handler if related is outside the target.
// NB: No relatedTarget if the mouse left/entered the browser window
register('mouseenter', {
  delegateType: 'mouseover',
  bindType: 'mouseover',
  handle(target, event) {
    let ret
    const related = event.relatedTarget
    const handleObj = event.handleObj
    if (!related || (related !== target && !contains(target, related))) {
      event.type = handleObj.originType
      ret = handleObj.handler.call(target, event)
      event.type = 'mouseover'
    }
    return ret
  },
})
register('mouseleave', {
  delegateType: 'mouseout',
  bindType: 'mouseout',
  handle(target, event) {
    let ret
    const related = event.relatedTarget
    const handleObj = event.handleObj
    if (!related || (related !== target && !contains(target, related))) {
      event.type = handleObj.originType
      ret = handleObj.handler.call(target, event)
      event.type = 'mouseout'
    }
    return ret
  },
})