Source: js/models/Map.js

/*global define */
define(['jquery', 'underscore', 'backbone', 'gmaps'],
	function($, _, Backbone, gmaps) {
	'use strict';

	// Map Model
	// ------------------
	var Map = Backbone.Model.extend(
    /** @lends Map.prototype */{
		// This model contains all of the map settings used for searching datasets
		defaults: function(){
			var model = this;
			return {
				map: null,

				//The options for the map using the Google Maps API MapOptions syntax
				mapOptions:
					(gmaps)?
						{   zoom: 3,
							minZoom: 3,
							maxZoom: 16,
						    center: new google.maps.LatLng(44, -103),
							disableDefaultUI: true,
						    zoomControl: true,
						    zoomControlOptions: {
							          style: google.maps.ZoomControlStyle.LARGE,
							          position: google.maps.ControlPosition.LEFT_CENTER
							        },
							panControl: false,
							scaleControl: true,
							streetViewControl: false,
							mapTypeControl: true,
							mapTypeControlOptions:{
									style: google.maps.MapTypeControlStyle.HORIZONTAL_BAR,
									mapTypeIds: [google.maps.MapTypeId.SATELLITE, google.maps.MapTypeId.TERRAIN],
									position: google.maps.ControlPosition.LEFT_BOTTOM
							},
						    mapTypeId: google.maps.MapTypeId.TERRAIN,
						    styles: [{"featureType":"water","stylers":[{"visibility":"on"},{"color":"#b5cbe4"}]},{"featureType":"landscape","stylers":[{"color":"#efefef"}]},{"featureType":"road.highway","elementType":"geometry","stylers":[{"color":"#83a5b0"}]},{"featureType":"road.arterial","elementType":"geometry","stylers":[{"color":"#bdcdd3"}]},{"featureType":"road.local","elementType":"geometry","stylers":[{"color":"#ffffff"}]},{"featureType":"poi.park","elementType":"geometry","stylers":[{"color":"#e3eed3"}]},{"featureType":"administrative","stylers":[{"visibility":"on"},{"lightness":33}]},{"featureType":"road"},{"featureType":"poi.park","elementType":"labels","stylers":[{"visibility":"on"},{"lightness":20}]},{},{"featureType":"road","stylers":[{"lightness":20}]}]
						}
					: null,

				//Set to true to draw markers where tile counts are equal to 1. If set to false, a tile with the count "1" will be drawn instead.
				drawMarkers: false,

				//If this theme doesn't have an image in this location, Google maps will use their default marker image
				markerImage: "./js/themes/" + MetacatUI.theme + "/img/map-marker.png",

				//Keep track of the geohash level used to draw tiles on this map
				tileGeohashLevel: 1,

				///****** MAP TILE OPTIONS **********//
				//The options for the tiles. Using Google Maps Web API
				tileOptions: {
				      fillOpacity: 0.2,
				      strokeWeight: 1,
				      strokePosition: (typeof google != "undefined")? google.maps.StrokePosition.INSIDE : "",
				      strokeOpacity: 1
				},

				//The options for the tiles when they are hovered on. Using Google Maps Web API
				tileOnHover: {
						fillOpacity: 0.8,
						strokeColor: "#FFFF00",
						strokePosition: (typeof google != "undefined")? google.maps.StrokePosition.INSIDE : "",
						strokeWeight: 1,
						strokeOpacity: 1,
						fillColor: "#FFFF66"
				},

				//The options for the tile text
				tileLabelColorOnHover: '#000000',
				tileLabelColor: '#444444',

				//The tile hue - the number of the hue that will be used to color tiles
				//Tile lightness - percent range of lightness/brightness of this tile hue
				tileHue: model.tileHue || "192",
				tileLightnessMax: 100,
				tileLightnessMin: 30
			}
		},

		initialize: function(options){
			if(typeof options == "object"){
				if(options.tileHue) this.tileHue = options.tileHue;
			}
		},

		isMaxZoom: function(map){
			var zoom = map.getZoom(),
				type = map.getMapTypeId();

			if(zoom >= this.get("mapOptions").maxZoom) return true;
			else return false;
		},

		/**
		 * This function will return the appropriate geohash level to use for mapping geohash tiles on the map at the specified zoom level.
		 */
		determineGeohashLevel: function(zoom){
			var geohashLevel;

			switch(zoom){
				case 0: // The whole world zoom level
					geohashLevel = 2;
					break;
				case 1:
					geohashLevel = 2;
					break;
				case 2:
					geohashLevel = 2;
					break;
				case 3:
					geohashLevel = 2;
					break;
				case 4:
					geohashLevel = 2;
					break;
				case 5:
					geohashLevel = 3;
					break;
				case 6:
					geohashLevel = 3;
					break;
				case 7:
					geohashLevel = 4;
					break;
				case 8:
					geohashLevel = 4;
					break;
				case 9:
					geohashLevel = 4;
					break;
				case 10:
					geohashLevel = 5;
					break;
				case 11:
					geohashLevel = 5;
					break;
				case 12:
					geohashLevel = 6;
					break;
				case 13:
					geohashLevel = 6;
					break;
				case 14:
					geohashLevel = 7;
					break;
				case 15:
					geohashLevel = 7;
					break;
				case 16:
					geohashLevel = 7;
					break;
				case 17:
					geohashLevel = 8;
					break;
				case 18:
					geohashLevel = 9;
					break;
				case 19:
					geohashLevel = 9;
					break;
				case 20:
					geohashLevel = 9;
					break;
				default:  //Anything over (Gmaps goes up to 19)
					geohashLevel = 9;
			}

			return geohashLevel;
		},

		getSearchPrecision: function(zoom){
			if(zoom <= 5) return 2;
			else if(zoom <= 7) return 3;
			else if (zoom <= 11) return 4;
			else if (zoom <= 13) return 5;
			else if (zoom <= 15) return 6;
			else return 7;
		},

		/*
		* Creates a LatLng Google Maps object based on the given latitude and longitude
		*/
		createLatLng: function(lat, long){
			return new google.maps.LatLng(parseFloat(lat), parseFloat(long));
		},

		clear: function() {
		    return this.set(_.clone(this.defaults()));
		  }

	});
	return Map;
});