language selector in menu

app/src/main/java/info/nightscout/androidaps/MainActivity.java

@@ -34,6 +34,7 @@ import info.nightscout.androidaps.plugins.Treatments.TreatmentsFragment;
 import info.nightscout.androidaps.plugins.VirtualPump.VirtualPumpFragment;
 import info.nightscout.androidaps.tabs.*;
 import info.nightscout.androidaps.plugins.Objectives.ObjectivesFragment;
+import info.nightscout.utils.LocaleHelper;
 
 public class MainActivity extends AppCompatActivity {
     private static Logger log = LoggerFactory.getLogger(MainActivity.class);
@@ -118,6 +119,14 @@ public class MainActivity extends AppCompatActivity {
             case R.id.nav_resetdb:
                 MainApp.getDbHelper().resetDatabases();
                 break;
+            case R.id.en_lang: {
+                LocaleHelper.setLocale(this, "en");
+                break;
+            }
+            case R.id.cs_lang: {
+                LocaleHelper.setLocale(this, "cs");
+                break;
+            }
             case R.id.nav_exit:
                 log.debug("Exiting");
                 //chancelAlarmManager();

app/src/main/java/info/nightscout/utils/LocaleHelper.java

@@ -0,0 +1,66 @@
+package info.nightscout.utils;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.content.res.Configuration;
+import android.content.res.Resources;
+import android.preference.PreferenceManager;
+
+import java.util.Locale;
+
+/**
+ * This class is used to change your application locale and persist this change for the next time
+ * that your app is going to be used.
+ * <p/>
+ * You can also change the locale of your application on the fly by using the setLocale method.
+ * <p/>
+ * Created by gunhansancar on 07/10/15.
+ */
+public class LocaleHelper {
+
+    private static final String SELECTED_LANGUAGE = "Locale.Helper.Selected.Language";
+
+    public static void onCreate(Context context) {
+        String lang = getPersistedData(context, Locale.getDefault().getLanguage());
+        setLocale(context, lang);
+    }
+
+    public static void onCreate(Context context, String defaultLanguage) {
+        String lang = getPersistedData(context, defaultLanguage);
+        setLocale(context, lang);
+    }
+
+    public static String getLanguage(Context context) {
+        return getPersistedData(context, Locale.getDefault().getLanguage());
+    }
+
+    public static void setLocale(Context context, String language) {
+        persist(context, language);
+        updateResources(context, language);
+    }
+
+    private static String getPersistedData(Context context, String defaultLanguage) {
+        SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
+        return preferences.getString(SELECTED_LANGUAGE, defaultLanguage);
+    }
+
+    private static void persist(Context context, String language) {
+        SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
+        SharedPreferences.Editor editor = preferences.edit();
+
+        editor.putString(SELECTED_LANGUAGE, language);
+        editor.apply();
+    }
+
+    private static void updateResources(Context context, String language) {
+        Locale locale = new Locale(language);
+        Locale.setDefault(locale);
+
+        Resources resources = context.getResources();
+
+        Configuration configuration = resources.getConfiguration();
+        configuration.locale = locale;
+
+        resources.updateConfiguration(configuration, resources.getDisplayMetrics());
+    }
+}

app/src/main/res/menu/menu_main.xml

@@ -13,6 +13,12 @@
     <item
         android:id="@+id/nav_test_alarm"
         android:title="@string/nav_test_alarm" />
+    <item
+        android:id="@+id/en_lang"
+        android:title="@string/en_lang" />
+    <item
+        android:id="@+id/cs_lang"
+        android:title="@string/cs_lang" />
     <item
         android:id="@+id/nav_exit"
         android:title="@string/nav_exit" />

app/src/main/res/values/strings.xml

@@ -154,5 +154,7 @@
     <string name="pumpstatusavailableinns">Pump status available in NS</string>
     <string name="manualenacts">Manual enacts</string>
     <string name="loopdisabled">LOOP DISABLED BY CONSTRAINTS</string>
+    <string name="cs_lang">Czech language</string>
+    <string name="en_lang">English language</string>
 
 </resources>