use in-app layer chooser on desktop mode

code/boot.js

@@ -5,6 +5,7 @@
 
 // Used to disable on multitouch devices
 window.showZoom = true;
+window.showLayerChooser = true;
 
 window.setupLargeImagePreview = function() {
   $('#portaldetails').on('click', '.imgpreview', function() {
@@ -342,6 +343,81 @@ window.setupQRLoadLib = function() {
   @@INCLUDERAW:external/jquery.qrcode.min.js@@
 }
 
+window.setupLayerChooserApi = function() {
+  // hide layer chooser on mobile devices running desktop mode
+  if (!window.showLayerChooser) {
+    $('.leaflet-control-layers').hide();
+  }
+
+  //hook some additional code into the LayerControl so it's easy for the mobile app to interface with it
+  //WARNING: does depend on internals of the L.Control.Layers code
+  window.layerChooser.getLayers = function() {
+    var baseLayers = new Array();
+    var overlayLayers = new Array();
+
+    for (i in this._layers) {
+      var obj = this._layers[i];
+      var layerActive = window.map.hasLayer(obj.layer);
+      var info = {
+        layerId: L.stamp(obj.layer),
+        name: obj.name,
+        active: layerActive
+      }
+      if (obj.overlay) {
+        overlayLayers.push(info);
+      } else {
+        baseLayers.push(info);
+      }
+    }
+
+    var overlayLayersJSON = JSON.stringify(overlayLayers);
+    var baseLayersJSON = JSON.stringify(baseLayers);
+
+    if (typeof android !== 'undefined' && android && android.setLayers) {
+        android.setLayers(baseLayersJSON, overlayLayersJSON);
+    }
+
+    return {
+      baseLayers: baseLayers,
+      overlayLayers: overlayLayers
+    }
+  }
+
+  window.layerChooser.showLayer = function(id,show) {
+    if (show === undefined) show = true;
+    obj = this._layers[id];
+    if (!obj) return false;
+
+    if(show) {
+      if (!this._map.hasLayer(obj.layer)) {
+        //the layer to show is not currently active
+        this._map.addLayer(obj.layer);
+
+        //if it's a base layer, remove any others
+        if (!obj.overlay) {
+          for(i in this._layers) {
+            if (i != id) {
+              var other = this._layers[i];
+              if (!other.overlay && this._map.hasLayer(other.layer)) this._map.removeLayer(other.layer);
+            }
+          }
+        }
+      }
+    } else {
+      if (this._map.hasLayer(obj.layer)) {
+        this._map.removeLayer(obj.layer);
+      }
+    }
+
+    //below logic based on code in L.Control.Layers _onInputClick
+    if(!obj.overlay) {
+      this._map.setZoom(this._map.getZoom());
+      this._map.fire('baselayerchange', {layer: obj.layer});
+    }
+
+    return true;
+  }
+}
 
 // BOOTING ///////////////////////////////////////////////////////////
 
@@ -407,6 +483,7 @@ function boot() {
     });
 
   window.setMapBaseLayer();
+  window.setupLayerChooserApi();
 
   window.runOnSmartphonesAfterBoot();