HotKey.js

  define([
    'jquery'

], function (
    $
) {


  var STARTED = false;


  var keyCode2keyName = {
    9:'tab',
    32:'space',
    191:'?',
    187:'+',
    189:'-',
    13:'enter'
  }
  for(var i = 65;i<91;i++){
    keyCode2keyName[i] = String.fromCharCode(i).toLowerCase();
  }



  var KeyShortcut = {

    events:{},

    start:function(){

      if(STARTED){
        console.log('热键监听已经启动了。');
        return;
      }else{
        STARTED = true;
      }

      var _this = this;


      this.definedKeys = []; // 获取当前定义的所有键
      this.pressedKeys = [];




      $(document).on('hotkey:active',function(e,hotkey,originalEvent){
        if(hotkey in _this.events){
          _this.analytic(hotkey);
          _this.events[hotkey].call(_this,originalEvent);
        }
      });

      $(document).on('keydown',function(e){
        _this.listenKeyDown(e);
      })

      $(document).on('keyup',function(e){
        _this.listenKeyUp(e);
      })
    },



    listenKeyDown:function(e){

      var _this = this;
      var node = e.target;
      var nodeName = node.nodeName.toLowerCase();
      var type = node.getAttribute('type') || '';

      if(node.nodeType !== Node.ELEMENT_NODE){
        return;
      }

      if(nodeName == 'input' || nodeName == 'textarea' || nodeName == 'select' && type != 'submit' && type != 'reset' ){
        return;
      }

      var keyCode = e.keyCode;

      if(!(keyCode in keyCode2keyName)){
        return;
      }

      var key = '';

      if(this.pressedKeys.length){
        if(this.pressedKeys.indexOf(keyCode)>-1){
          key = keyCode2keyName[keyCode];
        }else{
          key = keyCode2keyName[this.pressedKeys[this.pressedKeys.length-1]]+'+'+keyCode2keyName[keyCode];
        }
      }else{
          if(e.shiftKey)  key = 'shift';
          if(e.ctrlKey)   key = key?key+'+ctrl':'ctrl';
          if(e.altKey)    key = key?key+'+alt':'alt';
          if(e.metaKey)   key = key?key+'+meta':'meta';
          key = key?key+'+'+keyCode2keyName[keyCode]:keyCode2keyName[keyCode];
      }

      this.pressedKeys.indexOf(keyCode)<0 && (keyCode in keyCode2keyName) && this.pressedKeys.push(keyCode);
      $(document).trigger('hotkey:active',[key,e]);
    },


    listenKeyUp:function(e){
      this.pressedKeys.indexOf(e.keyCode)>-1 && this.pressedKeys.splice(this.pressedKeys.indexOf(e.keyCode),1);
    },


    register:function(keyCombination,callback){
      if(typeof keyCombination == 'string'){
        this.registerOne(keyCombination,callback);
      }else if(typeof keyCombination == 'object'){
        for(var key in keyCombination){
          this.registerOne(key,keyCombination[key]);
        }
      }
    },

    registerOne:function(key,fn){
      if(this.definedKeys.indexOf(key)<0){
        this.definedKeys.push(key);
      }
      this.events[key] = fn;
    },


    analytic:function(key){
      // 预留用于该功能的统计，需要接口支持
      // console.log('here count once');
    }

  };


  // 对外只暴露四个接口
  return {
    // 启动，仅运行一次
    start:function(){
      KeyShortcut.start.apply(KeyShortcut,arguments);
    },

    // 注册新的快捷键
    register:function(){
      KeyShortcut.register.apply(KeyShortcut,arguments);
    }
  }

})