Feature/custom presentation

src/main/java/com/flowingcode/vaadin/addons/localecombobox/LocaleComboBox.java

@@ -42,18 +42,77 @@ public class LocaleComboBox extends ComboBox<Locale> {
   private static final String ITEM_LAYOUT_CLASS_NAME = "fc-locale-combo-box-item-layout";
   private static final String ITEM_FLAG_CLASS_NAME = "fc-locale-combo-box-item-flag";
 
+  /**
+   * Display mode representing the built-in display modes in LocaleComboBox
+   * <p>
+   * These enums can be used in {@link #setDisplayMode(DisplayMode)} to easily switch between the
+   * built-in display modes.
+   */
+  public enum DisplayMode {
+
+    /**
+     * Default display mode.
+     * <p>
+     * In this mode, the Locale names are displayed using the default locale's display format.
+     */
+    DEFAULT,
+
+    /**
+     * Selected display mode.
+     * <p>
+     * In this mode, the Locale names are displayed using the formatting of the currently selected
+     * locale.
+     */
+    SELECTED,
+
+    /**
+     * Custom display mode.
+     * <p>
+     * In this mode, the Locale names are displayed using the formatting of the specific locale set
+     * by {@link #setDisplayLocale(Locale)}.
+     */
+    CUSTOM;
+  }
+  private DisplayMode displayMode = DisplayMode.DEFAULT;
+  private Locale customDisplayLocale = Locale.getDefault();
+
   /**
    * Creates a new instance of LocaleComboBox with all the installed locales.
    */
   public LocaleComboBox() {
-    setItemLabelGenerator(Locale::getDisplayName);
+    setItemLabelGenerator(item -> item.getDisplayName(getLocaleForDisplay()));
     setRenderer(getLocaleRenderer());
     addValueChangeListener(this::onValueChange);
     setItems(
         Arrays.stream(Locale.getAvailableLocales()).filter(loc -> loc.getCountry().length() == 2)
             .sorted((l1, l2) -> l1.getDisplayName().compareTo(l2.getDisplayName())).toList());
   }
 
+  /**
+   * Sets the display mode of the LocaleComboBox.
+   * 
+   * @param displayMode the display mode to use
+   * 
+   * @see DisplayMode
+   */
+  public void setDisplayMode(DisplayMode displayMode) {
+    this.displayMode = displayMode;
+  }
+
+  /**
+   * Sets the locale used for formatting Locale names when {@link DisplayMode#CUSTOM} mode is
+   * active.
+   * <p>
+   * This locale determines how Locale names are formatted when {@link DisplayMode#CUSTOM} is
+   * selected as the display mode. If the display mode is any other than {@link DisplayMode#CUSTOM},
+   * this setting is ignored.
+   * 
+   * @param displayLocale the locale to use for formatting.
+   */
+  public void setDisplayLocale(Locale displayLocale) {
+    this.customDisplayLocale = displayLocale == null ? Locale.getDefault() : displayLocale;
+  }
+
   private LitRenderer<Locale> getLocaleRenderer() {
     return LitRenderer
         .<Locale>of(
@@ -65,8 +124,23 @@ private LitRenderer<Locale> getLocaleRenderer() {
         .withProperty("layoutClass", loc -> ITEM_LAYOUT_CLASS_NAME)
         .withProperty("flagClass", loc -> ITEM_FLAG_CLASS_NAME)
         .withProperty("countryCode", loc -> loc.getCountry().toLowerCase())
-        .withProperty("countryName", loc -> loc.getDisplayCountry())
-        .withProperty("displayName", loc -> loc.getDisplayName());
+        .withProperty("countryName", loc -> loc.getDisplayCountry(getLocaleForDisplay()))
+        .withProperty("displayName", loc -> loc.getDisplayName(getLocaleForDisplay()));
+  }
+
+  private Locale getLocaleForDisplay() {
+
+    switch (displayMode) {
+
+      case CUSTOM:
+        return customDisplayLocale;
+
+      case SELECTED:
+        return this.getValue() == null ? Locale.getDefault() : this.getValue();
+
+      default:
+        return Locale.getDefault();
+    }
   }
 
   private void onValueChange(ComponentValueChangeEvent<ComboBox<Locale>, Locale> event) {

src/test/java/com/flowingcode/vaadin/addons/localecombobox/LocaleComboBoxDemo.java

@@ -21,17 +21,59 @@
 package com.flowingcode.vaadin.addons.localecombobox;
 
 import com.flowingcode.vaadin.addons.demo.DemoSource;
+import com.vaadin.flow.component.Text;
 import com.vaadin.flow.component.html.Div;
+import com.vaadin.flow.component.html.Span;
+import com.vaadin.flow.component.orderedlayout.FlexComponent.Alignment;
+import com.vaadin.flow.component.orderedlayout.FlexComponent.JustifyContentMode;
+import com.vaadin.flow.component.orderedlayout.HorizontalLayout;
 import com.vaadin.flow.router.PageTitle;
 import com.vaadin.flow.router.Route;
+import java.util.Locale;
 
 @DemoSource
-@PageTitle("LocaleComboBox Add-on Demo")
+@PageTitle("Display modes")
 @SuppressWarnings("serial")
 @Route(value = "demo", layout = LocaleComboBoxDemoView.class)
 public class LocaleComboBoxDemo extends Div {
 
   public LocaleComboBoxDemo() {
-    add(new LocaleComboBox());
+
+    LocaleComboBox defaultDisplayLocale = new LocaleComboBox();
+    LocaleComboBox koreanLocaleCombo = new LocaleComboBox();
+    LocaleComboBox selectedLocaleCombo = new LocaleComboBox();
+
+    defaultDisplayLocale.setValue(Locale.ITALY);
+
+    koreanLocaleCombo.setDisplayLocale(Locale.KOREA);
+    koreanLocaleCombo.setDisplayMode(LocaleComboBox.DisplayMode.CUSTOM);
+    koreanLocaleCombo.setValue(Locale.ITALY);
+
+    selectedLocaleCombo.setDisplayMode(LocaleComboBox.DisplayMode.SELECTED);
+    selectedLocaleCombo.setValue(Locale.ITALY);
+
+    // #if vaadin eq 0
+    add(createHorizontalContainer("Default display mode (uses default locale):", defaultDisplayLocale),
+        createHorizontalContainer("Display locales with Korean locale:", koreanLocaleCombo),
+        createHorizontalContainer("Display locales with selected locale:", selectedLocaleCombo));
+    // #endif
+    // show-source add(defaultDisplayLocale);
+    // show-source add(koreanLocaleCombo);
+    // show-source add(selectedLocaleCombo);
   }
+
+  // #if vaadin eq 0
+  private HorizontalLayout createHorizontalContainer(String title, LocaleComboBox combo) {
+    Span titleSpan = new Span(new Text(title));
+    titleSpan.setWidth("300px");
+    HorizontalLayout container = new HorizontalLayout();
+    container.setWidthFull();
+    container.setAlignItems(Alignment.CENTER);
+    container.setJustifyContentMode(JustifyContentMode.BETWEEN);
+    container.add(titleSpan, combo);
+    container.expand(combo);
+    return container;
+  }
+  // #endif
+
 }