Order IMEs and subtype by IME name and ID only

This modifies the comparison of ImeSubtypeListItem list item to only
take into account the IME name and IME id, and thus ignoring the subtype
name, and whether this is the same as the system language or locale.

This allows the order specified by the IME app to be kept as-is.

Flag: android.view.inputmethod.ime_switcher_revamp
Test: atest InputMethodSubtypeSwitchingControllerTest
Bug: 311791923
Fix: 283046933
Change-Id: I2fba8c0ac6e756539deb433a77a8d647a30134ab

2 files changed, 116 insertions, 13 deletions

diff --git a/services/core/java/com/android/server/inputmethod/InputMethodSubtypeSwitchingController.java b/services/core/java/com/android/server/inputmethod/InputMethodSubtypeSwitchingController.java
index 8b3c718c0537..05cc5985a8cc 100644
--- a/services/core/java/com/android/server/inputmethod/InputMethodSubtypeSwitchingController.java
+++ b/services/core/java/com/android/server/inputmethod/InputMethodSubtypeSwitchingController.java
@@ -150,20 +150,25 @@ final class InputMethodSubtypeSwitchingController {
             if (result != 0) {
                 return result;
             }
-            // Subtype that has the same locale of the system's has higher priority.
-            result = (mIsSystemLocale ? -1 : 0) - (other.mIsSystemLocale ? -1 : 0);
-            if (result != 0) {
-                return result;
-            }
-            // Subtype that has the same language of the system's has higher priority.
-            result = (mIsSystemLanguage ? -1 : 0) - (other.mIsSystemLanguage ? -1 : 0);
-            if (result != 0) {
-                return result;
-            }
-            result = compareNullableCharSequences(mSubtypeName, other.mSubtypeName);
-            if (result != 0) {
-                return result;
+            if (!Flags.imeSwitcherRevamp()) {
+                // Subtype that has the same locale of the system's has higher priority.
+                result = (mIsSystemLocale ? -1 : 0) - (other.mIsSystemLocale ? -1 : 0);
+                if (result != 0) {
+                    return result;
+                }
+                // Subtype that has the same language of the system's has higher priority.
+                result = (mIsSystemLanguage ? -1 : 0) - (other.mIsSystemLanguage ? -1 : 0);
+                if (result != 0) {
+                    return result;
+                }
+                result = compareNullableCharSequences(mSubtypeName, other.mSubtypeName);
+                if (result != 0) {
+                    return result;
+                }
             }
+            // This will no longer compare by subtype name, however as {@link Collections.sort} is
+            // guaranteed to be a stable sorting, this allows sorting by the IME name (and ID),
+            // while maintaining the order of subtypes (given by each IME) at the IME level.
             return mImi.getId().compareTo(other.mImi.getId());
         }
 
diff --git a/services/tests/InputMethodSystemServerTests/src/com/android/server/inputmethod/InputMethodSubtypeSwitchingControllerTest.java b/services/tests/InputMethodSystemServerTests/src/com/android/server/inputmethod/InputMethodSubtypeSwitchingControllerTest.java
index 4186b48ab82a..dc0373239547 100644
--- a/services/tests/InputMethodSystemServerTests/src/com/android/server/inputmethod/InputMethodSubtypeSwitchingControllerTest.java
+++ b/services/tests/InputMethodSystemServerTests/src/com/android/server/inputmethod/InputMethodSubtypeSwitchingControllerTest.java
@@ -387,6 +387,7 @@ public final class InputMethodSubtypeSwitchingControllerTest {
         assertFalse(item_en_us_allcaps.mIsSystemLanguage);
     }
 
+    @RequiresFlagsDisabled(Flags.FLAG_IME_SWITCHER_REVAMP)
     @SuppressWarnings("SelfComparison")
     @Test
     public void testImeSubtypeListComparator() {
@@ -960,6 +961,103 @@ public final class InputMethodSubtypeSwitchingControllerTest {
         assertNoAction(controller, true /* forHardware */, unknownHardwareItems);
     }
 
+    /** Verifies that the IME name does influence the comparison order. */
+    @RequiresFlagsEnabled(Flags.FLAG_IME_SWITCHER_REVAMP)
+    @Test
+    public void testCompareImeName() {
+        final var component = new ComponentName("com.example.ime", "Ime");
+        final var imeX = createTestItem(component, "ImeX", "A", "en_US", 0);
+        final var imeY = createTestItem(component, "ImeY", "A", "en_US", 0);
+
+        assertTrue("Smaller IME name should be smaller.", imeX.compareTo(imeY) < 0);
+        assertTrue("Larger IME name should be larger.", imeY.compareTo(imeX) > 0);
+    }
+
+    /** Verifies that the IME ID does influence the comparison order. */
+    @RequiresFlagsEnabled(Flags.FLAG_IME_SWITCHER_REVAMP)
+    @Test
+    public void testCompareImeId() {
+        final var component1 = new ComponentName("com.example.ime1", "Ime");
+        final var component2 = new ComponentName("com.example.ime2", "Ime");
+        final var ime1 = createTestItem(component1, "Ime", "A", "en_US", 0);
+        final var ime2 = createTestItem(component2, "Ime", "A", "en_US", 0);
+
+        assertTrue("Smaller IME ID should be smaller.", ime1.compareTo(ime2) < 0);
+        assertTrue("Larger IME ID should be larger.", ime2.compareTo(ime1) > 0);
+    }
+
+    /** Verifies that comparison on self returns an equal order. */
+    @SuppressWarnings("SelfComparison")
+    @RequiresFlagsEnabled(Flags.FLAG_IME_SWITCHER_REVAMP)
+    @Test
+    public void testCompareSelf() {
+        final var component = new ComponentName("com.example.ime", "Ime");
+        final var item = createTestItem(component, "Ime", "A", "en_US", 0);
+
+        assertEquals("Item should have the same order to itself.", 0, item.compareTo(item));
+    }
+
+    /** Verifies that comparison on an equivalent item returns an equal order. */
+    @RequiresFlagsEnabled(Flags.FLAG_IME_SWITCHER_REVAMP)
+    @Test
+    public void testCompareEquivalent() {
+        final var component = new ComponentName("com.example.ime", "Ime");
+        final var item = createTestItem(component, "Ime", "A", "en_US", 0);
+        final var equivalent = createTestItem(component, "Ime", "A", "en_US", 0);
+
+        assertEquals("Equivalent items should have the same order.", 0, item.compareTo(equivalent));
+    }
+
+    /**
+     * Verifies that the system locale and system language do not the influence comparison order.
+     */
+    @RequiresFlagsEnabled(Flags.FLAG_IME_SWITCHER_REVAMP)
+    @Test
+    public void testCompareSystemLocaleSystemLanguage() {
+        final var component = new ComponentName("com.example.ime", "Ime");
+        final var japanese = createTestItem(component, "Ime", "A", "ja_JP", 0);
+        final var systemLanguage = createTestItem(component, "Ime", "A", "en_GB", 0);
+        final var systemLocale = createTestItem(component, "Ime", "A", "en_US", 0);
+
+        assertFalse(japanese.mIsSystemLanguage);
+        assertFalse(japanese.mIsSystemLocale);
+        assertTrue(systemLanguage.mIsSystemLanguage);
+        assertFalse(systemLanguage.mIsSystemLocale);
+        assertTrue(systemLocale.mIsSystemLanguage);
+        assertTrue(systemLocale.mIsSystemLocale);
+
+        assertEquals("System language shouldn't influence comparison over non-system language.",
+                0, japanese.compareTo(systemLanguage));
+        assertEquals("System locale shouldn't influence comparison over non-system locale.",
+                0, japanese.compareTo(systemLocale));
+        assertEquals("System locale shouldn't influence comparison over system language.",
+                0, systemLanguage.compareTo(systemLocale));
+    }
+
+    /** Verifies that the subtype name does not influence the comparison order. */
+    @RequiresFlagsEnabled(Flags.FLAG_IME_SWITCHER_REVAMP)
+    @Test
+    public void testCompareSubtypeName() {
+        final var component = new ComponentName("com.example.ime", "Ime");
+        final var subtypeA = createTestItem(component, "Ime", "A", "en_US", 0);
+        final var subtypeB = createTestItem(component, "Ime", "B", "en_US", 0);
+
+        assertEquals("Subtype name shouldn't influence comparison.",
+                0, subtypeA.compareTo(subtypeB));
+    }
+
+    /** Verifies that the subtype index does not influence the comparison order. */
+    @RequiresFlagsEnabled(Flags.FLAG_IME_SWITCHER_REVAMP)
+    @Test
+    public void testCompareSubtypeIndex() {
+        final var component = new ComponentName("com.example.ime", "Ime");
+        final var subtype0 = createTestItem(component, "Ime1", "A", "en_US", 0);
+        final var subtype1 = createTestItem(component, "Ime1", "A", "en_US", 1);
+
+        assertEquals("Subtype index shouldn't influence comparison.",
+                0, subtype0.compareTo(subtype1));
+    }
+
     /**
      * Verifies that the controller's next item order matches the given one, and cycles back at
      * the end, both across all IMEs, and also per each IME. If a single item is given, verifies