index.js

/* global AFRAME */

if (typeof AFRAME === 'undefined') {
  throw new Error('Component attempted to register before AFRAME was available.')
}

require('./systems/super-hands-system.js')
require('./reaction_components/hoverable.js')
require('./reaction_components/grabbable.js')
require('./reaction_components/stretchable.js')
require('./reaction_components/drag-droppable.js')
require('./reaction_components/draggable.js')
require('./reaction_components/droppable.js')
require('./reaction_components/clickable.js')

/**
 * Super Hands component for A-Frame.
 */
AFRAME.registerComponent('super-hands', {
  schema: {
    colliderEvent: { default: 'hit' },
    colliderEventProperty: { default: 'el' },
    colliderEndEvent: { default: 'hitend' },
    colliderEndEventProperty: { default: 'el' },
    grabStartButtons: {
      default: ['gripdown', 'trackpaddown', 'triggerdown', 'gripclose',
        'abuttondown', 'bbuttondown', 'xbuttondown', 'ybuttondown',
        'pointup', 'thumbup', 'pointingstart', 'pistolstart',
        'thumbstickdown', 'mousedown', 'touchstart']
    },
    grabEndButtons: {
      default: ['gripup', 'trackpadup', 'triggerup', 'gripopen',
        'abuttonup', 'bbuttonup', 'xbuttonup', 'ybuttonup',
        'pointdown', 'thumbdown', 'pointingend', 'pistolend',
        'thumbstickup', 'mouseup', 'touchend']
    },
    stretchStartButtons: {
      default: ['gripdown', 'trackpaddown', 'triggerdown', 'gripclose',
        'abuttondown', 'bbuttondown', 'xbuttondown', 'ybuttondown',
        'pointup', 'thumbup', 'pointingstart', 'pistolstart',
        'thumbstickdown', 'mousedown', 'touchstart']
    },
    stretchEndButtons: {
      default: ['gripup', 'trackpadup', 'triggerup', 'gripopen',
        'abuttonup', 'bbuttonup', 'xbuttonup', 'ybuttonup',
        'pointdown', 'thumbdown', 'pointingend', 'pistolend',
        'thumbstickup', 'mouseup', 'touchend']
    },
    dragDropStartButtons: {
      default: ['gripdown', 'trackpaddown', 'triggerdown', 'gripclose',
        'abuttondown', 'bbuttondown', 'xbuttondown', 'ybuttondown',
        'pointup', 'thumbup', 'pointingstart', 'pistolstart',
        'thumbstickdown', 'mousedown', 'touchstart']
    },
    dragDropEndButtons: {
      default: ['gripup', 'trackpadup', 'triggerup', 'gripopen',
        'abuttonup', 'bbuttonup', 'xbuttonup', 'ybuttonup',
        'pointdown', 'thumbdown', 'pointingend', 'pistolend',
        'thumbstickup', 'mouseup', 'touchend']
    },
    interval: { default: 0 }
  },

  /**
   * Set if component needs multiple instancing.
   */
  multiple: false,

  /**
   * Called once when component is attached. Generally for initial setup.
   */
  init: function () {
    // constants
    this.HOVER_EVENT = 'hover-start'
    this.UNHOVER_EVENT = 'hover-end'
    this.GRAB_EVENT = 'grab-start'
    this.UNGRAB_EVENT = 'grab-end'
    this.STRETCH_EVENT = 'stretch-start'
    this.UNSTRETCH_EVENT = 'stretch-end'
    this.DRAG_EVENT = 'drag-start'
    this.UNDRAG_EVENT = 'drag-end'
    this.DRAGOVER_EVENT = 'dragover-start'
    this.UNDRAGOVER_EVENT = 'dragover-end'
    this.DRAGDROP_EVENT = 'drag-drop'

    // links to other systems/components
    this.otherSuperHand = null

    // state tracking - global event handlers (GEH)
    this.gehDragged = new Set()
    this.gehClicking = new Set()

    // state tracking - reaction components
    this.hoverEls = []
    this.hoverElsIntersections = []
    this.prevCheckTime = null
    this.state = new Map()
    this.dragging = false

    this.unHover = this.unHover.bind(this)
    this.unWatch = this.unWatch.bind(this)
    this.onHit = this.onHit.bind(this)
    this.onGrabStartButton = this.onGrabStartButton.bind(this)
    this.onGrabEndButton = this.onGrabEndButton.bind(this)
    this.onStretchStartButton = this.onStretchStartButton.bind(this)
    this.onStretchEndButton = this.onStretchEndButton.bind(this)
    this.onDragDropStartButton = this.onDragDropStartButton.bind(this)
    this.onDragDropEndButton = this.onDragDropEndButton.bind(this)
    this.system.registerMe(this)
  },

  /**
   * Called when component is attached and when component data changes.
   * Generally modifies the entity based on the data.
   */
  update: function (oldData) {
    this.unRegisterListeners(oldData)
    this.registerListeners()
  },

  /**
   * Called when a component is removed (e.g., via removeAttribute).
   * Generally undoes all modifications to the entity.
   */
  remove: function () {
    this.system.unregisterMe(this)
    this.unRegisterListeners()
    this.hoverEls.length = 0
    if (this.state.get(this.HOVER_EVENT)) {
      this._unHover(this.state.get(this.HOVER_EVENT))
    }
    this.onGrabEndButton()
    this.onStretchEndButton()
    this.onDragDropEndButton()
  },
  tick: (function () {
    // closer objects and objects with no distance come later in list
    function sorter (a, b) {
      const aDist = a.distance == null ? -1 : a.distance
      const bDist = b.distance == null ? -1 : b.distance
      if (aDist < bDist) {
        return 1
      }
      if (bDist < aDist) {
        return -1
      }
      return 0
    }
    return function (time) {
      const data = this.data
      const prevCheckTime = this.prevCheckTime
      if (prevCheckTime && (time - prevCheckTime < data.interval)) { return }
      this.prevCheckTime = time

      let orderChanged = false
      this.hoverElsIntersections.sort(sorter)
      for (let i = 0; i < this.hoverElsIntersections.length; i++) {
        if (this.hoverEls[i] !== this.hoverElsIntersections[i].object.el) {
          orderChanged = true
          this.hoverEls[i] = this.hoverElsIntersections[i].object.el
        }
      }
      if (orderChanged) {
        this.hover()
      }
    }
  })(),
  onGrabStartButton: function (evt) {
    let carried = this.state.get(this.GRAB_EVENT)
    this.dispatchMouseEventAll('mousedown', this.el)
    this.gehClicking = new Set(this.hoverEls)
    if (!carried) {
      carried = this.findTarget(this.GRAB_EVENT, {
        hand: this.el,
        buttonEvent: evt
      })
      if (carried) {
        this.state.set(this.GRAB_EVENT, carried)
        this._unHover(carried)
      }
    }
  },
  onGrabEndButton: function (evt) {
    const clickables = this.hoverEls.filter(h => this.gehClicking.has(h))
    const grabbed = this.state.get(this.GRAB_EVENT)
    const endEvt = { hand: this.el, buttonEvent: evt }
    this.dispatchMouseEventAll('mouseup', this.el)
    for (let i = 0; i < clickables.length; i++) {
      this.dispatchMouseEvent(clickables[i], 'click', this.el)
    }
    this.gehClicking.clear()
    // check if grabbed entity accepts ungrab event
    if (grabbed && !this.emitCancelable(grabbed, this.UNGRAB_EVENT, endEvt)) {
      /* push to top of stack so a drop followed by re-grab gets the same
         target */
      this.promoteHoveredEl(this.state.get(this.GRAB_EVENT))
      this.state.delete(this.GRAB_EVENT)
      this.hover()
    }
  },
  onStretchStartButton: function (evt) {
    let stretched = this.state.get(this.STRETCH_EVENT)
    if (!stretched) {
      stretched = this.findTarget(this.STRETCH_EVENT, {
        hand: this.el,
        buttonEvent: evt
      })
      if (stretched) {
        this.state.set(this.STRETCH_EVENT, stretched)
        this._unHover(stretched)
      }
    }
  },
  onStretchEndButton: function (evt) {
    const stretched = this.state.get(this.STRETCH_EVENT)
    const endEvt = { hand: this.el, buttonEvent: evt }
    // check if end event accepted
    if (stretched &&
        !this.emitCancelable(stretched, this.UNSTRETCH_EVENT, endEvt)) {
      this.promoteHoveredEl(stretched)
      this.state.delete(this.STRETCH_EVENT)
      this.hover()
    }
  },
  onDragDropStartButton: function (evt) {
    let dragged = this.state.get(this.DRAG_EVENT)
    this.dragging = true
    if (this.hoverEls.length) {
      this.gehDragged = new Set(this.hoverEls)
      this.dispatchMouseEventAll('dragstart', this.el)
    }
    if (!dragged) {
      /* prefer carried so that a drag started after a grab will work
       with carried element rather than a currently intersected drop target.
       fall back to queue in case a drag is initiated independent
       of a grab */
      if (this.state.get(this.GRAB_EVENT) &&
          !this.emitCancelable(this.state.get(this.GRAB_EVENT), this.DRAG_EVENT,
            { hand: this.el, buttonEvent: evt })) {
        dragged = this.state.get(this.GRAB_EVENT)
      } else {
        dragged = this.findTarget(this.DRAG_EVENT, {
          hand: this.el,
          buttonEvent: evt
        })
      }
      if (dragged) {
        this.state.set(this.DRAG_EVENT, dragged)
        this._unHover(dragged)
      }
    }
  },
  onDragDropEndButton: function (evt) {
    const carried = this.state.get(this.DRAG_EVENT)
    this.dragging = false // keep _unHover() from activating another droptarget
    this.gehDragged.forEach(carried => {
      this.dispatchMouseEvent(carried, 'dragend', this.el)
      // fire event both ways for all intersected targets
      this.dispatchMouseEventAll('drop', carried, true, true)
      this.dispatchMouseEventAll('dragleave', carried, true, true)
    })
    this.gehDragged.clear()
    if (carried) {
      const ddEvt = {
        hand: this.el,
        dropped: carried,
        on: null,
        buttonEvent: evt
      }
      const endEvt = { hand: this.el, buttonEvent: evt }
      const dropTarget = this.findTarget(this.DRAGDROP_EVENT, ddEvt, true)
      if (dropTarget) {
        ddEvt.on = dropTarget
        this.emitCancelable(carried, this.DRAGDROP_EVENT, ddEvt)
        this._unHover(dropTarget)
      }
      // check if end event accepted
      if (!this.emitCancelable(carried, this.UNDRAG_EVENT, endEvt)) {
        this.promoteHoveredEl(carried)
        this.state.delete(this.DRAG_EVENT)
        this.hover()
      }
    }
  },
  processHitEl: function (hitEl, intersection) {
    const dist = intersection && intersection.distance
    const sects = this.hoverElsIntersections
    const hoverEls = this.hoverEls
    const hitElIndex = this.hoverEls.indexOf(hitEl)
    let hoverNeedsUpdate = false
    if (hitElIndex === -1) {
      hoverNeedsUpdate = true
      // insert in order of distance when available
      if (dist != null) {
        let i = 0
        while (i < sects.length && dist < sects[i].distance) { i++ }
        hoverEls.splice(i, 0, hitEl)
        sects.splice(i, 0, intersection)
      } else {
        hoverEls.push(hitEl)
        sects.push({ object: { el: hitEl } })
      }
      this.dispatchMouseEvent(hitEl, 'mouseover', this.el)
      if (this.dragging && this.gehDragged.size) {
        // events on targets and on dragged
        this.gehDragged.forEach(dragged => {
          this.dispatchMouseEventAll('dragenter', dragged, true, true)
        })
      }
    }
    return hoverNeedsUpdate
  },
  onHit: function (evt) {
    const hitEl = evt.detail[this.data.colliderEventProperty]
    let hoverNeedsUpdate = 0
    if (!hitEl) { return }
    if (Array.isArray(hitEl)) {
      for (let i = 0, sect; i < hitEl.length; i++) {
        sect = evt.detail.intersections && evt.detail.intersections[i]
        hoverNeedsUpdate += this.processHitEl(hitEl[i], sect)
      }
    } else {
      hoverNeedsUpdate += this.processHitEl(hitEl, null)
    }
    if (hoverNeedsUpdate) { this.hover() }
  },
  /* search collided entities for target to hover/dragover */
  hover: function () {
    let hvrevt, hoverEl
    // end previous hover
    if (this.state.has(this.HOVER_EVENT)) {
      this._unHover(this.state.get(this.HOVER_EVENT), true)
    }
    if (this.state.has(this.DRAGOVER_EVENT)) {
      this._unHover(this.state.get(this.DRAGOVER_EVENT), true)
    }
    if (this.dragging && this.state.get(this.DRAG_EVENT)) {
      hvrevt = {
        hand: this.el,
        hovered: hoverEl,
        carried: this.state.get(this.DRAG_EVENT)
      }
      hoverEl = this.findTarget(this.DRAGOVER_EVENT, hvrevt, true)
      if (hoverEl) {
        this.emitCancelable(this.state.get(this.DRAG_EVENT), this.DRAGOVER_EVENT, hvrevt)
        this.state.set(this.DRAGOVER_EVENT, hoverEl)
      }
    }
    // fallback to hover if not dragging or dragover wasn't successful
    if (!this.state.has(this.DRAGOVER_EVENT)) {
      hoverEl = this.findTarget(this.HOVER_EVENT, { hand: this.el }, true)
      if (hoverEl) {
        this.state.set(this.HOVER_EVENT, hoverEl)
      }
    }
  },
  /* called when controller moves out of collision range of entity */
  unHover: function (evt) {
    const clearedEls = evt.detail[this.data.colliderEndEventProperty]
    if (clearedEls) {
      if (Array.isArray(clearedEls)) {
        clearedEls.forEach(el => this._unHover(el))
      } else {
        this._unHover(clearedEls)
      }
    }
  },
  /* inner unHover steps needed regardless of cause of unHover */
  _unHover: function (el, skipNextHover) {
    let unHovered = false
    let evt
    if (el === this.state.get(this.DRAGOVER_EVENT)) {
      this.state.delete(this.DRAGOVER_EVENT)
      unHovered = true
      evt = {
        hand: this.el,
        hovered: el,
        carried: this.state.get(this.DRAG_EVENT)
      }
      this.emitCancelable(el, this.UNDRAGOVER_EVENT, evt)
      if (this.state.has(this.DRAG_EVENT)) {
        this.emitCancelable(
          this.state.get(this.DRAG_EVENT),
          this.UNDRAGOVER_EVENT,
          evt
        )
      }
    }
    if (el === this.state.get(this.HOVER_EVENT)) {
      this.state.delete(this.HOVER_EVENT)
      unHovered = true
      this.emitCancelable(el, this.UNHOVER_EVENT, { hand: this.el })
    }
    // activate next target, if present
    if (unHovered && !skipNextHover) {
      this.hover()
    }
  },
  unWatch: function (evt) {
    const clearedEls = evt.detail[this.data.colliderEndEventProperty]
    if (clearedEls) {
      if (Array.isArray(clearedEls)) {
        clearedEls.forEach(el => this._unWatch(el))
      } else {
        // deprecation path: sphere-collider
        this._unWatch(clearedEls)
      }
    }
  },
  _unWatch: function (target) {
    const hoverIndex = this.hoverEls.indexOf(target)
    if (hoverIndex !== -1) {
      this.hoverEls.splice(hoverIndex, 1)
      this.hoverElsIntersections.splice(hoverIndex, 1)
    }
    this.gehDragged.forEach(dragged => {
      this.dispatchMouseEvent(target, 'dragleave', dragged)
      this.dispatchMouseEvent(dragged, 'dragleave', target)
    })
    this.dispatchMouseEvent(target, 'mouseout', this.el)
  },
  registerListeners: function () {
    this.el.addEventListener(this.data.colliderEvent, this.onHit)
    this.el.addEventListener(this.data.colliderEndEvent, this.unWatch)
    this.el.addEventListener(this.data.colliderEndEvent, this.unHover)

    // binding order to keep grabEnd from triggering dragover
    // again before dragDropEnd can delete its carried state
    this.data.grabStartButtons.forEach(b => {
      this.el.addEventListener(b, this.onGrabStartButton)
    })
    this.data.stretchStartButtons.forEach(b => {
      this.el.addEventListener(b, this.onStretchStartButton)
    })
    this.data.dragDropStartButtons.forEach(b => {
      this.el.addEventListener(b, this.onDragDropStartButton)
    })
    this.data.dragDropEndButtons.forEach(b => {
      this.el.addEventListener(b, this.onDragDropEndButton)
    })
    this.data.stretchEndButtons.forEach(b => {
      this.el.addEventListener(b, this.onStretchEndButton)
    })
    this.data.grabEndButtons.forEach(b => {
      this.el.addEventListener(b, this.onGrabEndButton)
    })
  },
  unRegisterListeners: function (data) {
    data = data || this.data
    if (Object.keys(data).length === 0) {
      // Empty object passed on initalization
      return
    }
    this.el.removeEventListener(data.colliderEvent, this.onHit)
    this.el.removeEventListener(data.colliderEndEvent, this.unHover)
    this.el.removeEventListener(data.colliderEndEvent, this.unWatch)

    data.grabStartButtons.forEach(b => {
      this.el.removeEventListener(b, this.onGrabStartButton)
    })
    data.grabEndButtons.forEach(b => {
      this.el.removeEventListener(b, this.onGrabEndButton)
    })
    data.stretchStartButtons.forEach(b => {
      this.el.removeEventListener(b, this.onStretchStartButton)
    })
    data.stretchEndButtons.forEach(b => {
      this.el.removeEventListener(b, this.onStretchEndButton)
    })
    data.dragDropStartButtons.forEach(b => {
      this.el.removeEventListener(b, this.onDragDropStartButton)
    })
    data.dragDropEndButtons.forEach(b => {
      this.el.removeEventListener(b, this.onDragDropEndButton)
    })
  },
  emitCancelable: function (target, name, detail) {
    detail = detail || {}
    const data = { bubbles: true, cancelable: true, detail }
    data.detail.target = data.detail.target || target
    const evt = new window.CustomEvent(name, data)
    return target.dispatchEvent(evt)
  },
  dispatchMouseEvent: function (target, name, relatedTarget) {
    const mEvt = new window.MouseEvent(name, { relatedTarget })
    target.dispatchEvent(mEvt)
  },
  dispatchMouseEventAll: function (name, relatedTarget, filterUsed, alsoReverse) {
    let els = this.hoverEls
    if (filterUsed) {
      els = els
        .filter(el => el !== this.state.get(this.GRAB_EVENT) &&
                el !== this.state.get(this.DRAG_EVENT) &&
                el !== this.state.get(this.STRETCH_EVENT) &&
                !this.gehDragged.has(el))
    }
    if (alsoReverse) {
      for (let i = 0; i < els.length; i++) {
        this.dispatchMouseEvent(els[i], name, relatedTarget)
        this.dispatchMouseEvent(relatedTarget, name, els[i])
      }
    } else {
      for (let i = 0; i < els.length; i++) {
        this.dispatchMouseEvent(els[i], name, relatedTarget)
      }
    }
  },
  findTarget: function (evType, detail, filterUsed) {
    let elIndex
    let eligibleEls = this.hoverEls
    if (filterUsed) {
      eligibleEls = eligibleEls
        .filter(el => el !== this.state.get(this.GRAB_EVENT) &&
                el !== this.state.get(this.DRAG_EVENT) &&
                el !== this.state.get(this.STRETCH_EVENT))
    }
    for (elIndex = eligibleEls.length - 1; elIndex >= 0; elIndex--) {
      if (!this.emitCancelable(eligibleEls[elIndex], evType, detail)) {
        return eligibleEls[elIndex]
      }
    }
    return null
  },
  // Helper to ensure dropping and regrabbing finds the same target for
  // for order-sorted hoverEls (grabbing; no-op for distance-sorted (pointing)
  promoteHoveredEl: function (el) {
    const hoverIndex = this.hoverEls.indexOf(el)
    if (hoverIndex !== -1 &&
        this.hoverElsIntersections[hoverIndex].distance == null) {
      this.hoverEls.splice(hoverIndex, 1)
      const sect = this.hoverElsIntersections.splice(hoverIndex, 1)
      this.hoverEls.push(el)
      this.hoverElsIntersections.push(sect[0])
    }
  }
})