Add picker date time unit test (#4213)

Author: shai-almog

maven/core-unittests/src/test/java/com/codename1/ui/spinner/PickerDateTimeTest.java

@@ -0,0 +1,59 @@
+package com.codename1.ui.spinner;
+
+import com.codename1.junit.FormTest;
+import com.codename1.junit.UITestBase;
+import com.codename1.testing.TestCodenameOneImplementation;
+import com.codename1.ui.Display;
+import com.codename1.ui.Form;
+import com.codename1.ui.Dialog;
+import com.codename1.ui.layouts.BoxLayout;
+
+import java.util.Calendar;
+import java.util.Date;
+import java.util.TimeZone;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class PickerDateTimeTest extends UITestBase {
+
+    @FormTest
+    void pickerRetainsDateAndTimeAfterProgrammaticSelection() {
+        Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
+        calendar.set(Calendar.YEAR, 2020);
+        calendar.set(Calendar.MONTH, Calendar.APRIL);
+        calendar.set(Calendar.DAY_OF_MONTH, 3);
+        calendar.set(Calendar.HOUR_OF_DAY, 22);
+        calendar.set(Calendar.MINUTE, 30);
+        calendar.set(Calendar.SECOND, 0);
+        calendar.set(Calendar.MILLISECOND, 0);
+        Date target = calendar.getTime();
+
+        Picker picker = new Picker();
+        picker.setType(Display.PICKER_TYPE_DATE_AND_TIME);
+        picker.setUseLightweightPopup(true);
+        picker.setDate(target);
+
+        Form form = new Form(BoxLayout.y());
+        form.add(picker);
+        form.show();
+
+        TestCodenameOneImplementation impl = TestCodenameOneImplementation.getInstance();
+        impl.tapComponent(picker);
+
+        if (Display.getInstance().getCurrent() instanceof Dialog) {
+            ((Dialog) Display.getInstance().getCurrent()).dispose();
+        }
+
+        Date chosen = picker.getDate();
+        assertNotNull(chosen, "Picker should expose a selected date");
+
+        Calendar picked = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
+        picked.setTime(chosen);
+
+        assertEquals(calendar.get(Calendar.YEAR), picked.get(Calendar.YEAR));
+        assertEquals(calendar.get(Calendar.MONTH), picked.get(Calendar.MONTH));
+        assertEquals(calendar.get(Calendar.DAY_OF_MONTH), picked.get(Calendar.DAY_OF_MONTH));
+        assertEquals(calendar.get(Calendar.HOUR_OF_DAY), picked.get(Calendar.HOUR_OF_DAY));
+        assertEquals(calendar.get(Calendar.MINUTE), picked.get(Calendar.MINUTE));
+    }
+}