TypeScript is.func方法代码示例

function collectDrops ({ interactables }, draggableElement) {
  const drops = []

  // collect all dropzones and their elements which qualify for a drop
  for (const dropzone of interactables.list) {
    if (!dropzone.options.drop.enabled) { continue }

    const accept = dropzone.options.drop.accept

    // test the draggable draggableElement against the dropzone's accept setting
    if ((utils.is.element(accept) && accept !== draggableElement) ||
        (utils.is.string(accept) &&
        !utils.dom.matchesSelector(draggableElement, accept)) ||
        (utils.is.func(accept) && !accept({ dropzone, draggableElement }))) {
      continue
    }

    // query for new elements if necessary
    const dropElements = utils.is.string(dropzone.target)
      ? dropzone._context.querySelectorAll(dropzone.target)
      : utils.is.array(dropzone.target) ? dropzone.target : [dropzone.target]

    for (const dropzoneElement of dropElements) {
      if (dropzoneElement !== draggableElement) {
        drops.push({
          dropzone,
          element: dropzoneElement,
        })
      }
    }
  }

  return drops
}

function dropzoneMethod (interactable: Interact.Interactable, options?: Interact.DropzoneOptions | boolean) {
  if (utils.is.object(options)) {
    interactable.options.drop.enabled = options.enabled !== false

    if (options.listeners) {
      const normalized = utils.normalizeListeners(options.listeners)
      // rename 'drop' to '' as it will be prefixed with 'drop'
      const corrected = Object.keys(normalized).reduce((acc, type) => {
        const correctedType = /^(enter|leave)/.test(type)
          ? `drag${type}`
          : /^(activate|deactivate|move)/.test(type)
            ? `drop${type}`
            : type

        acc[correctedType] = normalized[type]

        return acc
      }, {})

      interactable.off(interactable.options.drop.listeners)
      interactable.on(corrected)
      interactable.options.drop.listeners = corrected
    }

    if (utils.is.func(options.ondrop)) { interactable.on('drop', options.ondrop) }
    if (utils.is.func(options.ondropactivate)) { interactable.on('dropactivate', options.ondropactivate) }
    if (utils.is.func(options.ondropdeactivate)) { interactable.on('dropdeactivate', options.ondropdeactivate) }
    if (utils.is.func(options.ondragenter)) { interactable.on('dragenter', options.ondragenter) }
    if (utils.is.func(options.ondragleave)) { interactable.on('dragleave', options.ondragleave) }
    if (utils.is.func(options.ondropmove)) { interactable.on('dropmove', options.ondropmove) }

    if (/^(pointer|center)$/.test(options.overlap as string)) {
      interactable.options.drop.overlap = options.overlap
    }
    else if (utils.is.number(options.overlap)) {
      interactable.options.drop.overlap = Math.max(Math.min(1, options.overlap), 0)
    }
    if ('accept' in options) {
      interactable.options.drop.accept = options.accept
    }
    if ('checker' in options) {
      interactable.options.drop.checker = options.checker
    }

    return interactable
  }

  if (utils.is.bool(options)) {
    interactable.options.drop.enabled = options

    return interactable
  }

  return interactable.options.drop
}

function set (arg: Interact.SignalArg) {
  const { interaction, coords, state } = arg
  const { options, offsets } = state

  const origin = utils.getOriginXY(interaction.interactable, interaction.element, interaction.prepared.name)
  const page = utils.extend({}, coords)
  const targets = []
  let target

  if (!options.offsetWithOrigin) {
    page.x -= origin.x
    page.y -= origin.y
  }

  state.realX = page.x
  state.realY = page.y

  for (const offset of offsets) {
    const relativeX = page.x - offset.x
    const relativeY = page.y - offset.y

    for (let index = 0, len = options.targets.length; index < len; index++) {
      const snapTarget = options.targets[index]
      if (utils.is.func(snapTarget)) {
        target = snapTarget(relativeX, relativeY, interaction, offset, index)
      }
      else {
        target = snapTarget
      }

      if (!target) { continue }

      targets.push({
        x: (utils.is.number(target.x) ? target.x : relativeX) + offset.x,
        y: (utils.is.number(target.y) ? target.y : relativeY) + offset.y,

        range: utils.is.number(target.range) ? target.range : options.range,
      })
    }
  }

  const closest = {
    target: null,
    inRange: false,
    distance: 0,
    range: 0,
    dx: 0,
    dy: 0,
  }

  for (let i = 0, len = targets.length; i < len; i++) {
    target = targets[i]

    const range = target.range
    const dx = target.x - page.x
    const dy = target.y - page.y
    const distance = utils.hypot(dx, dy)
    let inRange = distance <= range

    // Infinite targets count as being out of range
    // compared to non infinite ones that are in range
    if (range === Infinity && closest.inRange && closest.range !== Infinity) {
      inRange = false
    }

    if (!closest.target || (inRange
      // is the closest target in range?
      ? (closest.inRange && range !== Infinity
        // the pointer is relatively deeper in this target
        ? distance / range < closest.distance / closest.range
        // this target has Infinite range and the closest doesn't
        : (range === Infinity && closest.range !== Infinity) ||
          // OR this target is closer that the previous closest
          distance < closest.distance)
      // The other is not in range and the pointer is closer to this target
      : (!closest.inRange && distance < closest.distance))) {
      closest.target = target
      closest.distance = distance
      closest.range = range
      closest.inRange = inRange
      closest.dx = dx
      closest.dy = dy

      state.range = range
    }
  }

  if (closest.inRange) {
    coords.x = closest.target.x
    coords.y = closest.target.y
  }

  state.closest = closest
}