PTBAS-737: Fix inconsistent locale usage in some DatePickers

Author: MomdAli

src/main/java/de/doubleslash/keeptime/common/DateFormatter.java

@@ -31,7 +31,7 @@ public class DateFormatter {
    private static DateTimeFormatter dayDateFormatter = DateTimeFormatter.ofPattern("eeee dd.MM.yyyy");
    private static DateTimeFormatter timeFormatter = DateTimeFormatter.ofPattern("HH:mm:ss");
 
-   private static Locale systemLocale = Locale.GERMAN;
+   private static Locale systemLocale = Locale.getDefault();
 
    private DateFormatter() {
       throw new IllegalStateException("Utility class: DateFormatter");

src/main/java/de/doubleslash/keeptime/view/ExternalProjectsSyncController.java

@@ -124,7 +124,9 @@ public class ExternalProjectsSyncController {
    private final Color colorLoadingSuccess = Color.valueOf("#74a317");
    private final Color colorLoadingFailure = Color.valueOf("#c63329");
 
-   private final LocalTimeStringConverter localTimeStringConverter = new LocalTimeStringConverter(FormatStyle.MEDIUM);
+   private final LocalTimeStringConverter localTimeStringConverter = new LocalTimeStringConverter(
+         FormatStyle.MEDIUM,
+         DateFormatter.getSystemLocale());
    private ObservableList<TableRow> items;
 
    private LocalDate currentReportDate;
@@ -579,8 +581,10 @@ private void showErrorDialog(List<String> errorMessages) {
    }
 
    private void setUpTimeSpinner(final Spinner<LocalTime> spinner) {
+      final LocalTimeStringConverter stringConverter = new LocalTimeStringConverter(
+            FormatStyle.MEDIUM,
+            DateFormatter.getSystemLocale());
       spinner.focusedProperty().addListener(e -> {
-         final LocalTimeStringConverter stringConverter = new LocalTimeStringConverter(FormatStyle.MEDIUM);
          final StringProperty text = spinner.getEditor().textProperty();
          try {
             stringConverter.fromString(text.get());
@@ -621,7 +625,7 @@ public void increment(final int steps) {
 
       });
 
-      spinner.getValueFactory().setConverter(new LocalTimeStringConverter(FormatStyle.MEDIUM));
+      spinner.getValueFactory().setConverter(stringConverter);
    }
 
    public static LocalTime decrementToLastFullQuarter(LocalTime time) {

src/test/java/de/doubleslash/keeptime/common/DateFormatterTest.java

@@ -18,12 +18,17 @@
 
 import static org.hamcrest.MatcherAssert.assertThat;
 
+import java.time.LocalDate;
 import java.time.LocalDateTime;
+import java.util.Locale;
 
+import javafx.scene.control.DatePicker;
 import org.hamcrest.Matchers;
 import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
 @Disabled
 class DateFormatterTest {
 
@@ -38,4 +43,21 @@ void zeroSecondsBetweenTest() {
       final long secondsBewtweenSwitched = DateFormatter.getSecondsBewtween(endDate, startDate);
       assertThat(secondsBewtweenSwitched, Matchers.is(0l)); // why??
    }
+
+   @Test
+   void applySystemLocaleShouldSetDatePickerLocale() {
+      // GIVEN
+      Locale.setDefault(Locale.ENGLISH);
+      DateFormatter.setSystemLocale(Locale.GERMAN);
+      DatePicker datePicker = new DatePicker();
+      LocalDate date = LocalDate.of(2024, 6, 3);
+
+      // WHEN
+      DateFormatter.applySystemLocaleOnDate(datePicker);
+      datePicker.setValue(date);
+
+      // THEN
+      String shown = datePicker.getEditor().getText();
+      assertTrue(shown.contains("Montag") || shown.contains("06.2024") || shown.contains("06"));
+   }
 }