quasar/src/utils/event/event.js

Build high-performance VueJS user interfaces (SPA, PWA, SSR, Mobile and Desktop) in record time

export const listenOpts = {
  hasPassive: false,
  passiveCapture: true,
  notPassiveCapture: true
}

try {
  const opts = Object.defineProperty({}, 'passive', {
    get () {
      Object.assign(listenOpts, {
        hasPassive: true,
        passive: { passive: true },
        notPassive: { passive: false },
        passiveCapture: { passive: true, capture: true },
        notPassiveCapture: { passive: false, capture: true }
      })
    }
  })
  window.addEventListener('qtest', null, opts)
  window.removeEventListener('qtest', null, opts)
}
catch (_) {}

export function noop () {}

export function leftClick (e) {
  return e.button === 0
}

export function middleClick (e) {
  return e.button === 1
}

export function rightClick (e) {
  return e.button === 2
}

export function position (e) {
  if (e.touches && e.touches[ 0 ]) {
    e = e.touches[ 0 ]
  }
  else if (e.changedTouches && e.changedTouches[ 0 ]) {
    e = e.changedTouches[ 0 ]
  }
  else if (e.targetTouches && e.targetTouches[ 0 ]) {
    e = e.targetTouches[ 0 ]
  }

  return {
    top: e.clientY,
    left: e.clientX
  }
}

export function getEventPath (e) {
  if (e.path) {
    return e.path
  }
  if (e.composedPath) {
    return e.composedPath()
  }

  const path = []
  let el = e.target

  while (el) {
    path.push(el)

    if (el.tagName === 'HTML') {
      path.push(document)
      path.push(window)
      return path
    }

    el = el.parentElement
  }
}

// Reasonable defaults
const
  LINE_HEIGHT = 40,
  PAGE_HEIGHT = 800

export function getMouseWheelDistance (e) {
  let x = e.deltaX, y = e.deltaY

  if ((x || y) && e.deltaMode) {
    const multiplier = e.deltaMode === 1 ? LINE_HEIGHT : PAGE_HEIGHT
    x *= multiplier
    y *= multiplier
  }

  if (e.shiftKey && !x) {
    [ y, x ] = [ x, y ]
  }

  return { x, y }
}

export function stop (e) {
  e.stopPropagation()
}

export function prevent (e) {
  e.cancelable !== false && e.preventDefault()
}

export function stopAndPrevent (e) {
  e.cancelable !== false && e.preventDefault()
  e.stopPropagation()
}

export function preventDraggable (el, status) {
  if (el === void 0 || (status === true && el.__dragPrevented === true)) {
    return
  }

  const fn = status === true
    ? el => {
      el.__dragPrevented = true
      el.addEventListener('dragstart', prevent, listenOpts.notPassiveCapture)
    }
    : el => {
      delete el.__dragPrevented
      el.removeEventListener('dragstart', prevent, listenOpts.notPassiveCapture)
    }

  el.querySelectorAll('a, img').forEach(fn)
}

export function addEvt (ctx, targetName, events) {
  const name = `__q_${ targetName }_evt`

  ctx[ name ] = ctx[ name ] !== void 0
    ? ctx[ name ].concat(events)
    : events

  events.forEach(evt => {
    evt[ 0 ].addEventListener(evt[ 1 ], ctx[ evt[ 2 ] ], listenOpts[ evt[ 3 ] ])
  })
}

export function cleanEvt (ctx, targetName) {
  const name = `__q_${ targetName }_evt`

  if (ctx[ name ] !== void 0) {
    ctx[ name ].forEach(evt => {
      evt[ 0 ].removeEventListener(evt[ 1 ], ctx[ evt[ 2 ] ], listenOpts[ evt[ 3 ] ])
    })
    ctx[ name ] = void 0
  }
}

/*
 * also update /types/utils/event.d.ts
 */

export default {
  listenOpts,
  leftClick,
  middleClick,
  rightClick,
  position,
  getEventPath,
  getMouseWheelDistance,
  stop,
  prevent,
  stopAndPrevent,
  preventDraggable
}