annotate nodejs-server/app.js~ @ 0:89a05584e39e

initial commit of mood conductor stuff

var Application = {
  init: function() {
    this.canvas = document.getElementById('canvas');
    this.marker = document.getElementById('marker');
    this.label = document.getElementById('label');

    this.canvas.addEventListener('mousedown', this.onMouseDown.bind(this));
    this.canvas.addEventListener('mousemove', this.onMouseMove.bind(this));
    this.canvas.addEventListener('mouseup', this.onMouseUp.bind(this));
    
    this.request("/moods.csv", this.loadCSV.bind(this));
  },

  loadCSV: function(text) {
    this.moods = [];

    var lines = text.split("\n");

    for (var i = 1; i < lines.length; i++) {
      var row = lines[i].split(",");
      this.moods.push({
        label: row[1], 
        x: Number(row[3]), 
        y: Number(row[5])
      });
    }
  },
  
  request: function(url, callback) {
    var request = new XMLHttpRequest();
    request.onreadystatechange = function() {
      callback(request.responseText);
    }.bind(this);
    request.open("GET", url);
    request.send(null);
  },

  onMouseDown: function(event) {
    this.mouseDown = true;
    this.setMarker(event.pageX, event.pageY);
  },

  onMouseMove: function(event) {
    if (this.mouseDown) {
      this.setMarker(event.pageX, event.pageY);
    }
  },

  onMouseUp: function(event) {
    this.mouseDown = false;
    this.setMarker(event.pageX, event.pageY);
  },

  setMarker: function(x, y) {
    this.marker.style.left = x + 'px';
    this.marker.style.top = y + 'px';
    
    var _x = x / 480;
    var _y = y / 960;
    var match = {
      dx: 1,
      dy: 1,
      index: null
    };
    
    for (var i = 0; i < this.moods.length; i++) {
      var mood = this.moods[i];
      var dx = Math.abs(mood.x - _x);
      var dy = Math.abs(mood.y - _y);

      if (dx < match.dx && dy < match.dy) {
        match.dx = dx;
        match.dy = dy;
        match.index = i;
      }
    }

    this.label.innerHTML = this.moods[match.index].label;
  }
};