Stop supporting null IME token in IMM#setInputMethodAndSubtype()

Hopefully no one has relied on this undocumented behavior that when
the caller has WRITE_SECURE_SETTINGS then null IME token is allowed in
IMM#setInputMethodAndSubtype().

Note that if the caller had WRITE_SECURE_SETTINGS they can achieve the
same goal by directly updating the following secure settings:
  * Settings.Secure.DEFAULT_INPUT_METHOD
  * Settings.Secure.SELECTED_INPUT_METHOD_SUBTYPE

Bug: 114488811
Test: CtsInputMethodServiceHostTestCases
Change-Id: Ic5c59299ace16778fc57a4ec2639508564f416a7

2 files changed, 10 insertions, 11 deletions

diff --git a/core/java/android/view/inputmethod/InputMethodManager.java b/core/java/android/view/inputmethod/InputMethodManager.java
index e57fdffdfd1a..f4eda264c101 100644
--- a/core/java/android/view/inputmethod/InputMethodManager.java
+++ b/core/java/android/view/inputmethod/InputMethodManager.java
@@ -2091,6 +2091,12 @@ public final class InputMethodManager {
     /**
      * Force switch to a new input method and subtype. This can only be called
      * from an application or a service which has a token of the currently active input method.
+     *
+     * <p>On Android {@link Build.VERSION_CODES#Q} and later devices, {@code token} cannot be
+     * {@code null} even with {@link android.Manifest.permission#WRITE_SECURE_SETTINGS}. Instead,
+     * update {@link android.provider.Settings.Secure#DEFAULT_INPUT_METHOD} and
+     * {@link android.provider.Settings.Secure#SELECTED_INPUT_METHOD_SUBTYPE} directly.</p>
+     *
      * @param token Supplies the identifying token given to an input method
      * when it was started, which allows it to perform this operation on
      * itself.
@@ -2102,16 +2108,11 @@ public final class InputMethodManager {
      * the service. APIs in this class are intended for app developers interacting with the IME.
      */
     @Deprecated
-    public void setInputMethodAndSubtype(IBinder token, String id, InputMethodSubtype subtype) {
+    public void setInputMethodAndSubtype(@NonNull IBinder token, String id,
+            InputMethodSubtype subtype) {
         if (token == null) {
-            // Note: null token is allowed for callers that have WRITE_SECURE_SETTINGS permission.
-            // Thus we cannot always rely on InputMethodPrivilegedOperationsRegistry unfortunately.
-            // TODO(Bug 114488811): Consider deprecating null token rule.
-            try {
-                mService.setInputMethodAndSubtype(token, id, subtype);
-            } catch (RemoteException e) {
-                throw e.rethrowFromSystemServer();
-            }
+            Log.e(TAG, "setInputMethodAndSubtype() does not accept null token on Android Q "
+                    + "and later.");
             return;
         }
         InputMethodPrivilegedOperationsRegistry.get(token).setInputMethodAndSubtype(id, subtype);
diff --git a/core/java/com/android/internal/view/IInputMethodManager.aidl b/core/java/com/android/internal/view/IInputMethodManager.aidl
index f62c4402cb4e..a18f9c5082f2 100644
--- a/core/java/com/android/internal/view/IInputMethodManager.aidl
+++ b/core/java/com/android/internal/view/IInputMethodManager.aidl
@@ -70,8 +70,6 @@ interface IInputMethodManager {
     boolean isInputMethodPickerShownForTest();
     // TODO(Bug 114488811): this can be removed once we deprecate special null token rule.
     void setInputMethod(in IBinder token, String id);
-    // TODO(Bug 114488811): this can be removed once we deprecate special null token rule.
-    void setInputMethodAndSubtype(in IBinder token, String id, in InputMethodSubtype subtype);
     void registerSuggestionSpansForNotification(in SuggestionSpan[] spans);
     boolean notifySuggestionPicked(in SuggestionSpan span, String originalString, int index);
     InputMethodSubtype getCurrentInputMethodSubtype();