show language selection dialog if gui.properties does not exist

gui/griffon-app/lifecycle/Initialize.groovy

@@ -1,4 +1,5 @@
 import griffon.core.GriffonApplication
+import groovy.swing.SwingBuilder
 import groovy.util.logging.Log
 import net.i2p.util.SystemVersion
 
@@ -12,22 +13,26 @@ import com.muwire.gui.UISettings
 import javax.annotation.Nonnull
 import javax.inject.Inject
 import javax.swing.ImageIcon
+import javax.swing.JFrame
 import javax.swing.JLabel
 import javax.swing.JPopupMenu
 import javax.swing.JTable
 import javax.swing.LookAndFeel
+import javax.swing.SwingUtilities
 import javax.swing.UIManager
 import javax.swing.plaf.FontUIResource
 
 import static griffon.util.GriffonApplicationUtils.isMacOSX
 import static groovy.swing.SwingBuilder.lookAndFeel
 
+import java.awt.BorderLayout
 import java.awt.Font
 import java.awt.MenuItem
 import java.awt.PopupMenu
 import java.awt.SystemTray
 import java.awt.Toolkit
 import java.awt.TrayIcon
+import java.util.concurrent.CountDownLatch
 import java.util.logging.Level
 import java.util.logging.LogManager
 
@@ -119,6 +124,8 @@ class Initialize extends AbstractLifecycleHandler {
             uiSettings.fontSize = defaultFont.getSize()
             uiSettings.fontStyle = defaultFont.getStyle()
             rowHeight = uiSettings.fontSize + 3
+            
+            uiSettings.locale = showLanguageDialog()
         }
 
         application.context.put("row-height", rowHeight)
@@ -196,5 +203,37 @@ class Initialize extends AbstractLifecycleHandler {
         }
         defaultHome.getAbsolutePath()
     }
+
+    private String showLanguageDialog() {
+        def builder = new SwingBuilder()
+        def languageComboBox
+        def chooseButton
+        def frame = builder.frame (visible : true, locationRelativeTo: null,
+        defaultCloseOperation : JFrame.EXIT_ON_CLOSE,
+        iconImage : builder.imageIcon("/MuWire-48x48.png").image) {
+            borderLayout()
+            panel(constraints : BorderLayout.NORTH) {
+                label("Select Language")
+            }
+            
+            languageComboBox = comboBox (editable: false, items : Translator.LOCALE_WRAPPERS, constraints : BorderLayout.CENTER)
+            
+            panel (constraints : BorderLayout.SOUTH) {
+                chooseButton = button(text : "Choose")
+            }
+        }
+        
+        CountDownLatch latch = new CountDownLatch(1)
+        chooseButton.addActionListener({
+            frame.setVisible(false)
+            latch.countDown()
+        })
+        SwingUtilities.invokeAndWait({
+            frame.pack()
+            frame.setVisible(true)
+        })
+        latch.await()
+        languageComboBox.getSelectedItem().locale.toLanguageTag()
+    }
 }
 

gui/src/main/java/com/muwire/gui/Translator.java

@@ -1,11 +1,29 @@
 package com.muwire.gui;
 
+import java.util.ArrayList;
+import java.util.LinkedHashSet;
+import java.util.List;
 import java.util.Locale;
 import java.util.MissingResourceException;
 import java.util.ResourceBundle;
+import java.util.Set;
 
 public class Translator {
 
+    
+    public static final Set<Locale> SUPPORTED_LOCALES = new LinkedHashSet<>();
+    static {
+        SUPPORTED_LOCALES.add(Locale.US);
+        SUPPORTED_LOCALES.add(Locale.forLanguageTag("bg"));
+        // add more as they get translated
+    }
+    
+    public static final List<LocaleWrapper> LOCALE_WRAPPERS = new ArrayList<>();
+    static {
+        for (Locale l : SUPPORTED_LOCALES)
+            LOCALE_WRAPPERS.add(new LocaleWrapper(l));
+    }
+    
     private static Locale locale = Locale.US;
     private static ResourceBundle usBundle = ResourceBundle.getBundle("messages");
     private static ResourceBundle localeBundle;
@@ -25,4 +43,15 @@ public class Translator {
         }
     }
     
+    public static class LocaleWrapper {
+        private final Locale locale;
+        LocaleWrapper(Locale locale) {
+            this.locale = locale;
+        }
+        
+        public String toString() {
+            return locale.getDisplayLanguage();
+        }
+    }
+
 }