Merge "Allow the skeleton of "jmma" in DateFormat.getBestDateTimePattern()"

core/java/android/text/format/DateFormat.java

@@ -17,10 +17,14 @@
 package android.text.format;
 
 import android.annotation.NonNull;
+import android.app.compat.CompatChanges;
+import android.compat.annotation.ChangeId;
+import android.compat.annotation.EnabledAfter;
 import android.compat.annotation.UnsupportedAppUsage;
 import android.content.Context;
 import android.icu.text.DateFormatSymbols;
 import android.icu.text.DateTimePatternGenerator;
+import android.os.Build;
 import android.provider.Settings;
 import android.text.SpannableStringBuilder;
 import android.text.Spanned;
@@ -158,6 +162,16 @@ public class DateFormat {
     private static Locale sIs24HourLocale;
     private static boolean sIs24Hour;
 
+    /**
+     * {@link #getBestDateTimePattern(Locale, String)} does not allow non-consecutive repeated
+     * symbol in the skeleton. For example, please use a skeleton of {@code "jmm"} or
+     * {@code "hmma"} instead of {@code "ahmma"} or {@code "jmma"}, because the field 'j' could
+     * mean using 12-hour in some locales and, in this case, is duplicated as the 'a' field.
+     */
+    @ChangeId
+    @EnabledAfter(targetSdkVersion = Build.VERSION_CODES.R)
+    static final long DISALLOW_DUPLICATE_FIELD_IN_SKELETON = 170233598L;
+
     /**
      * Returns true if times should be formatted as 24 hour times, false if times should be
      * formatted as 12 hour (AM/PM) times. Based on the user's chosen locale and other preferences.
@@ -251,7 +265,9 @@ public class DateFormat {
      */
     public static String getBestDateTimePattern(Locale locale, String skeleton) {
         DateTimePatternGenerator dtpg = DateTimePatternGenerator.getInstance(locale);
-        return dtpg.getBestPattern(skeleton);
+        boolean allowDuplicateFields = !CompatChanges.isChangeEnabled(
+                DISALLOW_DUPLICATE_FIELD_IN_SKELETON);
+        return dtpg.getBestPattern(skeleton, allowDuplicateFields);
     }
 
     /**

core/tests/coretests/src/android/text/format/DateFormatTest.java

@@ -21,13 +21,19 @@ import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
+import android.compat.testing.PlatformCompatChangeRule;
 import android.icu.text.DateFormatSymbols;
 import android.platform.test.annotations.Presubmit;
 
 import androidx.test.filters.SmallTest;
 import androidx.test.runner.AndroidJUnit4;
 
+import libcore.junit.util.compat.CoreCompatChangeRule.DisableCompatChanges;
+import libcore.junit.util.compat.CoreCompatChangeRule.EnableCompatChanges;
+
+import org.junit.Rule;
 import org.junit.Test;
+import org.junit.rules.TestRule;
 import org.junit.runner.RunWith;
 
 import java.util.Arrays;
@@ -38,6 +44,9 @@ import java.util.Locale;
 @RunWith(AndroidJUnit4.class)
 public class DateFormatTest {
 
+    @Rule
+    public TestRule compatChangeRule = new PlatformCompatChangeRule();
+
     @Test
     public void testHasDesignator() {
         assertTrue(DateFormat.hasDesignator("hh:mm:ss", DateFormat.MINUTE));
@@ -135,4 +144,29 @@ public class DateFormatTest {
     private static String best(Locale l, String skeleton) {
         return DateFormat.getBestDateTimePattern(l, skeleton);
     }
+
+    @Test
+    @EnableCompatChanges({DateFormat.DISALLOW_DUPLICATE_FIELD_IN_SKELETON})
+    public void testGetBestDateTimePattern_disableDuplicateField() {
+        assertIllegalArgumentException(Locale.US, "jmma");
+        assertIllegalArgumentException(Locale.US, "ahmma");
+    }
+
+    @Test
+    @DisableCompatChanges({DateFormat.DISALLOW_DUPLICATE_FIELD_IN_SKELETON})
+    public void testGetBestDateTimePattern_enableDuplicateField() {
+        // en-US uses 12-hour format by default.
+        assertEquals("h:mm a", DateFormat.getBestDateTimePattern(Locale.US, "jmma"));
+        assertEquals("h:mm a", DateFormat.getBestDateTimePattern(Locale.US, "ahmma"));
+    }
+
+    private static void assertIllegalArgumentException(Locale l, String skeleton) {
+        try {
+            DateFormat.getBestDateTimePattern(l, skeleton);
+            fail("getBestDateTimePattern() does not fail with Locale: " + l
+                    + " skeleton: " + skeleton);
+        } catch (IllegalArgumentException expected) {
+            // ignored
+        }
+    }
 }