Plumb IME subtype change from IMMS to IMS (again)

This CL introduces

  onInputMethodSubtypeChangedForKeyboardLayoutMapping()

to

  InputManagerInternal

in a way that is similar to our previous attempt [1].

The two major differences are

 A. It also provides InputMethodSubtypeHandle so that
    InputManagerService can use it as look up keys, and

 B. Subtypes that return false from
      isSuitableForPhysicalKeyboardLayoutMapping() [2]
    are mapped to null.

Other than those two differences, this CL is the same as our previous
CL [1].

See also another previous CL [3] about how this callback can be used.

 [1]: I58e71ffce9ac9131551a00dd35e24235dadfef87
      b097b8262b
 [2]: Ifc0247041a43ef64f8a76a23832da2ee058c6958
      6980a434cd
 [3]: Ie88ce1ab77dbfe03ab51d89c1dc9e0a7ddbb3216
      d5f7ed9fe9

Bug: 252816846
Test: manually verified
Change-Id: I087f02d06dc5575d2e657c25614d0361ef2ff443

services/core/java/com/android/server/input/InputManagerInternal.java

@@ -17,10 +17,15 @@
 package com.android.server.input;
 
 import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.annotation.UserIdInt;
 import android.graphics.PointF;
 import android.hardware.display.DisplayViewport;
 import android.os.IBinder;
 import android.view.InputChannel;
+import android.view.inputmethod.InputMethodSubtype;
+
+import com.android.internal.inputmethod.InputMethodSubtypeHandle;
 
 import java.util.List;
 
@@ -135,6 +140,26 @@ public abstract class InputManagerInternal {
     /** Create an {@link InputChannel} that is registered to InputDispatcher. */
     public abstract InputChannel createInputChannel(String inputChannelName);
 
+    /**
+     * Pilfer pointers from the input channel with the given token so that ongoing gestures are
+     * canceled for all other channels.
+     */
+    public abstract void pilferPointers(IBinder token);
+
+    /**
+     * Called when the current input method and/or {@link InputMethodSubtype} is updated.
+     *
+     * @param userId User ID to be notified about.
+     * @param subtypeHandle A {@link InputMethodSubtypeHandle} corresponds to {@code subtype}.
+     * @param subtype A {@link InputMethodSubtype} object, or {@code null} when the current
+     *                {@link InputMethodSubtype} is not suitable for the physical keyboard layout
+     *                mapping.
+     * @see InputMethodSubtype#isSuitableForPhysicalKeyboardLayoutMapping()
+     */
+    public abstract void onInputMethodSubtypeChangedForKeyboardLayoutMapping(@UserIdInt int userId,
+            @Nullable InputMethodSubtypeHandle subtypeHandle,
+            @Nullable InputMethodSubtype subtype);
+
     /**
      * Increments keyboard backlight level if the device has an associated keyboard backlight
      * {@see Light.LIGHT_TYPE_KEYBOARD_BACKLIGHT}

services/core/java/com/android/server/input/InputManagerService.java

@@ -23,6 +23,7 @@ import android.Manifest;
 import android.annotation.EnforcePermission;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
+import android.annotation.UserIdInt;
 import android.app.ActivityManagerInternal;
 import android.app.Notification;
 import android.app.NotificationManager;
@@ -110,11 +111,13 @@ import android.view.Surface;
 import android.view.SurfaceControl;
 import android.view.VerifiedInputEvent;
 import android.view.ViewConfiguration;
+import android.view.inputmethod.InputMethodSubtype;
 import android.widget.Toast;
 
 import com.android.internal.R;
 import com.android.internal.annotations.GuardedBy;
 import com.android.internal.annotations.VisibleForTesting;
+import com.android.internal.inputmethod.InputMethodSubtypeHandle;
 import com.android.internal.messages.nano.SystemMessageProto.SystemMessage;
 import com.android.internal.notification.SystemNotificationChannels;
 import com.android.internal.os.SomeArgs;
@@ -3781,6 +3784,21 @@ public class InputManagerService extends IInputManager.Stub
             return InputManagerService.this.createInputChannel(inputChannelName);
         }
 
+        @Override
+        public void pilferPointers(IBinder token) {
+            mNative.pilferPointers(token);
+        }
+
+        @Override
+        public void onInputMethodSubtypeChangedForKeyboardLayoutMapping(@UserIdInt int userId,
+                @Nullable InputMethodSubtypeHandle subtypeHandle,
+                @Nullable InputMethodSubtype subtype) {
+            if (DEBUG) {
+                Slog.i(TAG, "InputMethodSubtype changed: userId=" + userId
+                        + " subtypeHandle=" + subtypeHandle);
+            }
+        }
+
         @Override
         public void incrementKeyboardBacklight(int deviceId) {
             mKeyboardBacklightController.incrementKeyboardBacklight(deviceId);

services/core/java/com/android/server/inputmethod/InputMethodManagerService.java

@@ -162,6 +162,7 @@ import com.android.internal.inputmethod.InlineSuggestionsRequestInfo;
 import com.android.internal.inputmethod.InputBindResult;
 import com.android.internal.inputmethod.InputMethodDebug;
 import com.android.internal.inputmethod.InputMethodNavButtonFlags;
+import com.android.internal.inputmethod.InputMethodSubtypeHandle;
 import com.android.internal.inputmethod.SoftInputShowHideReason;
 import com.android.internal.inputmethod.StartInputFlags;
 import com.android.internal.inputmethod.StartInputReason;
@@ -3200,6 +3201,18 @@ public final class InputMethodManagerService extends IInputMethodManager.Stub
         sendOnNavButtonFlagsChangedLocked();
     }
 
+    @GuardedBy("ImfLock.class")
+    private void notifyInputMethodSubtypeChangedLocked(@UserIdInt int userId,
+            @NonNull InputMethodInfo imi, @Nullable InputMethodSubtype subtype) {
+        final InputMethodSubtype normalizedSubtype =
+                subtype != null && subtype.isSuitableForPhysicalKeyboardLayoutMapping()
+                        ? subtype : null;
+        final InputMethodSubtypeHandle newSubtypeHandle = normalizedSubtype != null
+                ? InputMethodSubtypeHandle.of(imi, normalizedSubtype) : null;
+        mInputManagerInternal.onInputMethodSubtypeChangedForKeyboardLayoutMapping(
+                userId, newSubtypeHandle, normalizedSubtype);
+    }
+
     @GuardedBy("ImfLock.class")
     void setInputMethodLocked(String id, int subtypeId) {
         InputMethodInfo info = mMethodMap.get(id);
@@ -3209,8 +3222,10 @@ public final class InputMethodManagerService extends IInputMethodManager.Stub
 
         // See if we need to notify a subtype change within the same IME.
         if (id.equals(getSelectedMethodIdLocked())) {
+            final int userId = mSettings.getCurrentUserId();
             final int subtypeCount = info.getSubtypeCount();
             if (subtypeCount <= 0) {
+                notifyInputMethodSubtypeChangedLocked(userId, info, null);
                 return;
             }
             final InputMethodSubtype oldSubtype = mCurrentSubtype;
@@ -3225,6 +3240,7 @@ public final class InputMethodManagerService extends IInputMethodManager.Stub
             if (newSubtype == null || oldSubtype == null) {
                 Slog.w(TAG, "Illegal subtype state: old subtype = " + oldSubtype
                         + ", new subtype = " + newSubtype);
+                notifyInputMethodSubtypeChangedLocked(userId, info, null);
                 return;
             }
             if (newSubtype != oldSubtype) {
@@ -5297,6 +5313,7 @@ public final class InputMethodManagerService extends IInputMethodManager.Stub
                 mCurrentSubtype = getCurrentInputMethodSubtypeLocked();
             }
         }
+        notifyInputMethodSubtypeChangedLocked(mSettings.getCurrentUserId(), imi, mCurrentSubtype);
 
         if (!setSubtypeOnly) {
             // Set InputMethod here