app/assets/openlayers/SimpleLayerSwitcher.js

   1 var SimpleLayerSwitcher = OpenLayers.Class(OpenLayers.Control, {
   2     layerStates: null,
   3     layersDiv: null,
   4     ascending: true,
   5
   6     initialize: function(options) {
   7         OpenLayers.Control.prototype.initialize.apply(this, arguments);
   8         this.layerStates = [];
   9     },
  10
  11     destroy: function() {
  12         OpenLayers.Event.stopObservingElement(this.div);
  13
  14         //clear out layers info and unregister their events
  15         this.map.events.un({
  16             "addlayer": this.redraw,
  17             "changelayer": this.redraw,
  18             "removelayer": this.redraw,
  19             "changebaselayer": this.redraw,
  20             scope: this
  21         });
  22         OpenLayers.Control.prototype.destroy.apply(this, arguments);
  23     },
  24
  25     setMap: function(map) {
  26         OpenLayers.Control.prototype.setMap.apply(this, arguments);
  27
  28         this.map.events.on({
  29             "addlayer": this.redraw,
  30             "changelayer": this.redraw,
  31             "removelayer": this.redraw,
  32             "changebaselayer": this.redraw,
  33             scope: this
  34         });
  35     },
  36
  37     draw: function() {
  38         OpenLayers.Control.prototype.draw.apply(this);
  39         this.loadContents();
  40         this.redraw();
  41         return this.div;
  42     },
  43
  44     checkRedraw: function() {
  45         var redraw = false;
  46         if ( !this.layerStates.length ||
  47              (this.map.layers.length != this.layerStates.length) ) {
  48             redraw = true;
  49         } else {
  50             for (var i=0, len=this.layerStates.length; i<len; i++) {
  51                 var layerState = this.layerStates[i];
  52                 var layer = this.map.layers[i];
  53                 if ( (layerState.name != layer.name) ||
  54                      (layerState.inRange != layer.inRange) ||
  55                      (layerState.id != layer.id) ||
  56                      (layerState.visibility != layer.visibility) ) {
  57                     redraw = true;
  58                     break;
  59                 }
  60             }
  61         }
  62         return redraw;
  63     },
  64
  65     redraw: function() {
  66         if (!this.checkRedraw()) {
  67             return this.div;
  68         }
  69
  70         this.div.innerHTML = '';
  71         var len = this.map.layers.length;
  72         this.layerStates = [];
  73         for (var i = 0; i < this.map.layers.length; i++) {
  74             var layer = this.map.layers[i];
  75             this.layerStates[i] = {
  76                 'name': layer.name,
  77                 'visibility': layer.visibility,
  78                 'inRange': layer.inRange,
  79                 'id': layer.id
  80             };
  81         }
  82
  83         var layers = this.map.layers.slice();
  84         if (!this.ascending) { layers.reverse(); }
  85         for (var i = 0; i < layers.length; i++) {
  86             var layer = layers[i];
  87             var baseLayer = layer.isBaseLayer;
  88
  89             if (layer.displayInLayerSwitcher && baseLayer) {
  90                 var on = (baseLayer) ? (layer == this.map.baseLayer)
  91                           : layer.getVisibility();
  92                 var layerElem = document.createElement('a');
  93                 layerElem.id = this.id + '_input_' + layer.name;
  94                 layerElem.innerHTML = layer.name;
  95                 layerElem.href = '#';
  96
  97                 OpenLayers.Element.addClass(layerElem, 'basey');
  98                 OpenLayers.Element.addClass(layerElem,
  99                     'basey-' + (on ? 'on' : 'off'));
 100
 101                 if (!baseLayer && !layer.inRange) {
 102                     layerElem.disabled = true;
 103                 }
 104                 var context = {
 105                     'layer': layer
 106                 };
 107                 OpenLayers.Event.observe(layerElem, 'mouseup',
 108                     OpenLayers.Function.bindAsEventListener(
 109                         this.onInputClick,
 110                         context)
 111                 );
 112
 113                 this.div.appendChild(layerElem);
 114             }
 115         }
 116
 117         return this.div;
 118     },
 119
 120     onInputClick: function(e) {
 121         if (this.layer.isBaseLayer) {
 122             this.layer.map.setBaseLayer(this.layer);
 123         } else {
 124             this.layer.setVisibility(!this.layer.getVisibility());
 125         }
 126         OpenLayers.Event.stop(e);
 127     },
 128
 129     updateMap: function() {
 130
 131         // set the newly selected base layer
 132         for(var i=0, len=this.baseLayers.length; i<len; i++) {
 133             var layerEntry = this.baseLayers[i];
 134             if (layerEntry.inputElem.checked) {
 135                 this.map.setBaseLayer(layerEntry.layer, false);
 136             }
 137         }
 138
 139         // set the correct visibilities for the overlays
 140         for(var i=0, len=this.dataLayers.length; i<len; i++) {
 141             var layerEntry = this.dataLayers[i];
 142             layerEntry.layer.setVisibility(layerEntry.inputElem.checked);
 143         }
 144
 145     },
 146
 147     loadContents: function() {
 148         //configure main div
 149         OpenLayers.Event.observe(this.div, 'mouseup',
 150             OpenLayers.Function.bindAsEventListener(this.mouseUp, this));
 151         OpenLayers.Event.observe(this.div, 'click',
 152                       this.ignoreEvent);
 153         OpenLayers.Event.observe(this.div, 'mousedown',
 154             OpenLayers.Function.bindAsEventListener(this.mouseDown, this));
 155         OpenLayers.Event.observe(this.div, 'dblclick', this.ignoreEvent);
 156     },
 157
 158     ignoreEvent: function(evt) {
 159         OpenLayers.Event.stop(evt);
 160     },
 161
 162     mouseDown: function(evt) {
 163         this.isMouseDown = true;
 164         this.ignoreEvent(evt);
 165     },
 166
 167     mouseUp: function(evt) {
 168         if (this.isMouseDown) {
 169             this.isMouseDown = false;
 170             this.ignoreEvent(evt);
 171         }
 172     },
 173
 174     CLASS_NAME: "SimpleLayerSwitcher"
 175 });