bootstrap-vue/src/utils/events.js

BootstrapVue, with more than 85 custom components, over 45 plugins, several custom directives, and over 300 icons, provides one of the most comprehensive implementations of Bootstrap v4 components and grid system for Vue.js. With extensive and automated W

import { hasPassiveEventSupport } from './env'
import { isObject } from './inspect'

// --- Constants ---

export const EVENT_OPTIONS_PASSIVE = { passive: true }
export const EVENT_OPTIONS_NO_CAPTURE = { passive: true, capture: false }

// --- Utils ---

// Normalize event options based on support of passive option
// Exported only for testing purposes
export const parseEventOptions = options => {
  /* istanbul ignore else: can't test in JSDOM, as it supports passive */
  if (hasPassiveEventSupport) {
    return isObject(options) ? options : { capture: !!options || false }
  } else {
    // Need to translate to actual Boolean value
    return !!(isObject(options) ? options.capture : options)
  }
}

// Attach an event listener to an element
export const eventOn = (el, evtName, handler, options) => {
  if (el && el.addEventListener) {
    el.addEventListener(evtName, handler, parseEventOptions(options))
  }
}

// Remove an event listener from an element
export const eventOff = (el, evtName, handler, options) => {
  if (el && el.removeEventListener) {
    el.removeEventListener(evtName, handler, parseEventOptions(options))
  }
}

// Utility method to add/remove a event listener based on first argument (boolean)
// It passes all other arguments to the `eventOn()` or `eventOff` method
export const eventOnOff = (on, ...args) => {
  const method = on ? eventOn : eventOff
  method(...args)
}