[ADD] web : add isMobile attribute directly in config.js

It is frequently needed whenever we want to make something responsive
Also, we refactor the code to the new coding guidelines (this part was
done by ged)

addons/web/static/src/js/services/config.js

@@ -1,7 +1,47 @@
 odoo.define('web.config', function (require) {
 "use strict";
 
-var bus = require('web.core').bus;
+/**
+ * This module contains all the (mostly) static 'environmental' information.
+ * This is often necessary to allow the rest of the web client to properly
+ * render itself.
+ *
+ * Note that many informations currently stored in session should be moved to
+ * this file someday.
+ */
+
+var core = require('web.core');
+
+var config = {
+    /**
+     * debug is a boolean flag.  It is only considered true if the flag is set
+     * in the url
+     */
+    debug: ($.deparam($.param.querystring()).debug !== undefined),
+    device: {
+        /**
+         * touch is a boolean, true if the device supports touch interaction
+         */
+        touch: 'ontouchstart' in window || 'onmsgesturechange' in window,
+        /**
+         * size_class is an integer: 0, 1, 2 or 3, depending on the (current)
+         * size of the device.  This is a dynamic property, updated whenever the
+         * browser is resized
+         */
+        size_class: null,
+        /**
+         * A frequent use case is to have a different render in 'mobile' mode,
+         * meaning when the screen is small.  This flag (boolean) is true when
+         * the size is not 3.  It is also updated dynamically.
+         */
+        isMobile: null,
+        /**
+         * Mapping between the numbers 0,1,2,3 and some descriptions
+         */
+        SIZES: { XS: 0, SM: 1, MD: 2, LG: 3 },
+    },
+};
+
 
 var medias = [
     window.matchMedia('(max-width: 767px)'),
@@ -9,34 +49,35 @@ var medias = [
     window.matchMedia('(min-width: 992px) and (max-width: 1199px)'),
     window.matchMedia('(min-width: 1200px)')
 ];
-_.each(medias, function(m) {
-    m.addListener(set_size_class);
-});
 
-var config = {
-    debug: ($.deparam($.param.querystring()).debug !== undefined),
-    device: {
-        touch: 'ontouchstart' in window || 'onmsgesturechange' in window,
-        size_class: size_class(),
-        SIZES: { XS: 0, SM: 1, MD: 2, LG: 3 },
-    },
-};
-
-function size_class() {
+/**
+ * Return the current size class
+ *
+ * @returns {integer} a number between 0 and 3, included
+ */
+function _getSizeClass() {
     for(var i = 0 ; i < medias.length ; i++) {
         if(medias[i].matches) {
             return i;
         }
     }
 }
-function set_size_class() {
-    var sc = size_class();
+/**
+ * Update the size dependant properties in the config object.  This method
+ * should be called every time the size class changes.
+ */
+function _updateSizeProps() {
+    var sc = _getSizeClass();
     if (sc !== config.device.size_class) {
         config.device.size_class = sc;
-        bus.trigger('size_class', sc);
+        config.isMobile = config.device.size_class <= config.device.SIZES.XS;
+        core.bus.trigger('size_class', sc);
     }
 }
 
+_.invoke(medias, 'addListener', _updateSizeProps);
+_updateSizeProps();
+
 return config;
 
 });