vue-hammer.js

/*
vue2-hammer, from https://github.com/bsdfzzzy/vue2-hammer

MIT License

Copyright (c) 2018 Zhengyang Zhao

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

const gestures = ['tap', 'pan', 'pinch', 'press', 'rotate', 'swipe']
const subGestures = ['panstart', 'panend', 'panmove', 'pancancel', 'pinchstart', 'pinchmove', 'pinchend', 'pinchcancel', 'pinchin', 'pinchout', 'pressup', 'rotatestart', 'rotatemove', 'rotateend', 'rotatecancel']
const directions = ['up', 'down', 'left', 'right', 'horizontal', 'vertical', 'all']

const VueHammer = {
  config: {},
  customEvents: {},
  install(Vue) {
    Vue.directive('hammer', {
      bind: (el, binding) => {
        if (!el.hammer) {
          el.hammer = new Hammer.Manager(el)
        }
        const mc = el.hammer

        // determine event type
        const event = binding.arg
        if (!event) {
          console.warn('[vue-hammer] event type argument is required.')
        }
        el.__hammerConfig = el.__hammerConfig || {}
        el.__hammerConfig[event] = {}

        const direction = binding.modifiers
        el.__hammerConfig[event].direction = el.__hammerConfig[event].direction || []
        if (Object.keys(direction).length) {
          Object.keys(direction)
            .filter(keyName => binding.modifiers[keyName])
            .forEach(keyName => {
              const elDirectionArray = el.__hammerConfig[event].direction
              if (elDirectionArray.indexOf(keyName) === -1) {
                elDirectionArray.push(String(keyName))
              }
            })
        }

        let recognizerType,
          recognizer

        if (this.customEvents[event]) {
          // custom event
          const custom = this.customEvents[event]
          recognizerType = custom.type
          recognizer = new Hammer[this.capitalize(recognizerType)](custom)
          recognizer.recognizeWith(mc.recognizers)
          mc.add(recognizer)
        } else {
          // built-in event
          recognizerType = gestures.find(gesture => gesture === event)
          const subGesturesType = subGestures.find(gesture => gesture === event)
          if (!recognizerType && !subGesturesType) {
            console.warn('[vue-hammer] invalid event type: ' + event)
            return
          }
          if (subGesturesType && el.__hammerConfig[subGesturesType].direction.length !== 0) {
            console.warn('[vue-hammer] ' + subGesturesType + ' should not have directions')
          }
          if (!recognizerType) {
            return
          }
          if (recognizerType === 'tap' || recognizerType === 'pinch' || recognizerType === 'press' || recognizerType === 'rotate') {
            if (el.__hammerConfig[recognizerType].direction.length !== 0) {
              throw Error('[vue-hammer] ' + recognizerType + ' should not have directions')
            }
          }
          recognizer = mc.get(recognizerType)
          if (!recognizer) {
            // add recognizer
            recognizer = new Hammer[this.capitalize(recognizerType)]()
            // make sure multiple recognizers work together...
            recognizer.recognizeWith(mc.recognizers)
            mc.add(recognizer)
          }
          // apply global options
          const globalOptions = this.config[recognizerType]
          if (globalOptions) {
            this.guardDirections(globalOptions)
            recognizer.set(globalOptions)
          }
          // apply local options
          const localOptions = el.hammerOptions &&
          el.hammerOptions[recognizerType]
          if (localOptions) {
            this.guardDirections(localOptions)
            recognizer.set(localOptions)
          }
        }
      },
      inserted: (el, binding) => {
        const mc = el.hammer
        const event = binding.arg
        const eventWithDir = subGestures.find(subGes => subGes === event) ? event : this.buildEventWithDirections(event, el.__hammerConfig[event].direction)
        if (mc.handler) {
          mc.off(eventWithDir, mc.handler)
        }
        if (typeof binding.value !== 'function') {
          mc.handler = null
          console.warn(
            '[vue-hammer] invalid handler function for v-hammer: ' +
            binding.arg
          )
        } else {
          mc.on(eventWithDir, (mc.handler = binding.value))
        }
      },
      componentUpdated: (el, binding) => {
        const mc = el.hammer
        const event = binding.arg
        const eventWithDir = subGestures.find(subGes => subGes === event) ? event : this.buildEventWithDirections(event, el.__hammerConfig[event].direction)
        // teardown old handler
        if (mc.handler) {
          mc.off(eventWithDir, mc.handler)
        }
        if (typeof binding.value !== 'function') {
          mc.handler = null
          console.warn(
            '[vue-hammer] invalid handler function for v-hammer: ' +
            binding.arg
          )
        } else {
          mc.on(eventWithDir, (mc.handler = binding.value))
        }
      },
      unbind: (el, binding) => {
        const mc = el.hammer
        const event = binding.arg
        const eventWithDir = subGestures.find(subGes => subGes === event) ? event : this.buildEventWithDirections(event, el.__hammerConfig[event].direction)
        if (mc.handler) {
          el.hammer.off(eventWithDir, mc.handler)
        }
        if (!Object.keys(mc.handlers).length) {
          el.hammer.destroy()
          el.hammer = null
        }
      },
    })
  },
  guardDirections(options) {
    var dir = options.direction
    if (typeof dir === 'string') {
      var hammerDirection = 'DIRECTION_' + dir.toUpperCase()
      if (directions.indexOf(dir) > -1 && Hammer.hasOwnProperty(hammerDirection)) {
        options.direction = Hammer[hammerDirection]
      } else {
        console.warn('[vue-hammer] invalid direction: ' + dir)
      }
    }
  },
  buildEventWithDirections(eventName, directionArray) {
    const f = {}
    directionArray.forEach(dir => {
      dir = dir.toLowerCase()
      if (dir === 'horizontal') {
        f.left = 1
        f.right = 1
      } else if (dir === 'vertical') {
        f.up = 1
        f.down = 1
      } else if (dir === 'all') {
        f.left = 1
        f.right = 1
        f.up = 1
        f.down = 1
      } else {
        f[dir] = 1
      }
    })
    const _directionArray = Object.keys(f)
    if (_directionArray.length === 0) {
      return eventName
    }
    const eventWithDirArray = _directionArray.map(dir => {
      return eventName + dir
    })
    return eventWithDirArray.join(' ')
  },
  capitalize(str) {
    return str.charAt(0).toUpperCase() + str.slice(1)
  },
}