widget.js

window.utils = window.utils || {};

utils.Grid = function() {
  // Defaults
  var that = this;
  this.idealColumnWidth = 320;
  this.marginHoriz = 15;
    
  // Public Interface
  this.setupGrid = function(opts) {
    this.containerWidth = opts.containerWidth;
    this.calculateColumnCount();
    this.calculateColumnWidth();
    this.calculateScaleFactor();
  };
  
  // Private Interface
  this.calculateColumnCount = function() {
   
    var columns = Math.floor( this.containerWidth / this.idealColumnWidth );
    if (columns < 1) {
      columns = 1;
    };
    this.numberOfColumns = columns;
  };
  
  this.calculateScaleFactor = function() {
    this.scaleFactor = this.columnWidth / this.idealColumnWidth
  };
  
  this.calculateColumnWidth = function() {
    this.columnWidth = Math.floor(
      (this.containerWidth / this.numberOfColumns) - this.marginHoriz/2
    );
  }
  
  var exports = { 
    setupGrid: this.setupGrid,
    numberOfColumns: this.numberOfColumns,
    scaleFactor: this.scaleFactor
  }
  return exports;
}