add locale service to GUI. minor cleanup of controller.

gui/scripts/syncthing/core/services/localeService.js

@@ -0,0 +1,83 @@
+angular.module('syncthing.core')
+    .provider('LocaleService', function () {
+
+        var _defaultLocale,
+            _availableLocales;
+
+        this.setDefaultLocale = function (locale) {
+            _defaultLocale = locale;
+        };
+
+        this.setAvailableLocales = function (locales) {
+            _availableLocales = locales;
+        };
+
+        this.$get = ['$http', '$translate', function ($http, $translate) {
+
+            /**
+             * Requests the server in order to get the browser's requested locale strings.
+             *
+             * @returns promise which on success resolves with a locales array
+             */
+            function readBrowserLocales() {
+                // @TODO: check if there is nice way to utilize window.navigator.languages or similiar api.
+
+                return $http.get(urlbase + "/lang");
+            }
+
+            function autoConfigLocale() {
+
+                return readBrowserLocales().success(function (langs) {
+                    // Find the first language in the list provided by the user's browser
+                    // that is a prefix of a language we have available. That is, "en"
+                    // sent by the browser will match "en" or "en-US", while "zh-TW" will
+                    // match only "zh-TW" and not "zh-CN".
+
+                    var i,
+                        lang,
+                        matching;
+
+                    for (i = 0; i < langs.length; i++) {
+                        lang = langs[i];
+
+                        if (lang.length < 2) {
+                            continue;
+                        }
+
+                        matching = _availableLocales.filter(function (possibleLang) {
+                            // The langs returned by the /rest/langs call will be in lower
+                            // case. We compare to the lowercase version of the language
+                            // code we have as well.
+                            possibleLang = possibleLang.toLowerCase();
+                            if (possibleLang.length > lang.length) {
+                                return possibleLang.indexOf(lang) === 0;
+                            } else {
+                                return lang.indexOf(possibleLang) === 0;
+                            }
+                        });
+
+                        if (matching.length >= 1) {
+                            $translate.use(matching[0]);
+                            return;
+                        }
+                    }
+                    // Fallback if nothing matched
+                    $translate.use(_defaultLocale);
+                });
+
+            }
+
+            function useLocale(language) {
+                // @TODO: eventually check for valid locale format
+                if (language) {
+                    $translate.use(language);
+                }
+            }
+
+            return {
+                autoConfigLocale: autoConfigLocale,
+                useLocale: useLocale
+            }
+        }];
+
+    });