Add configuration for disabling stylus button motion events

This adds an option for disabling stylus buttons from being reported as
part of a motion gesture. When disabled, all reported motion events'
button state will not include any stylus buttons. Key events are
unaffected.

This configuration is toggled through PhoneWindowManager based on
user-facing settings. Since this configuration does not affect KeyEvents
generated from stylus buttons, this gives a chance for the policy to
react to stylus button presses even when motion events are disabled.
For example, the policy can still be notified of stylus button presses
just as with any other key press, allowing the policy to make decisions
such as whether or not the device should be woken up. The policy can
also choose to ignore key presses and prevent them from being sent to
apps.

DD: go/android-stylus-buttons

Bug: 263256832
Test: atest inputflinger_tests
Change-Id: I68edaef5e6228aadf645586fbc1c4afcd499f712

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

@@ -206,4 +206,11 @@ public abstract class InputManagerInternal {
      * @param inputPort The port of the input device.
      */
     public abstract void removeKeyboardLayoutAssociation(@NonNull String inputPort);
+
+    /**
+     * Set whether stylus button reporting through motion events should be enabled.
+     *
+     * @param enabled When true, stylus buttons will not be reported through motion events.
+     */
+    public abstract void setStylusButtonMotionEventsEnabled(boolean enabled);
 }

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

@@ -3364,6 +3364,11 @@ public class InputManagerService extends IInputManager.Stub
         public void removeKeyboardLayoutAssociation(@NonNull String inputPort) {
             InputManagerService.this.removeKeyboardLayoutAssociation(inputPort);
         }
+
+        @Override
+        public void setStylusButtonMotionEventsEnabled(boolean enabled) {
+            mNative.setStylusButtonMotionEventsEnabled(enabled);
+        }
     }
 
     @Override

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

@@ -213,6 +213,9 @@ interface NativeInputManagerService {
     /** Get the bluetooth address of an input device if known, otherwise return null. */
     String getBluetoothAddress(int deviceId);
 
+    /** Set whether stylus button reporting through motion events should be enabled. */
+    void setStylusButtonMotionEventsEnabled(boolean enabled);
+
     /** The native implementation of InputManagerService methods. */
     class NativeImpl implements NativeInputManagerService {
         /** Pointer to native input manager service object, used by native code. */
@@ -439,5 +442,8 @@ interface NativeInputManagerService {
 
         @Override
         public native String getBluetoothAddress(int deviceId);
+
+        @Override
+        public native void setStylusButtonMotionEventsEnabled(boolean enabled);
     }
 }

services/core/java/com/android/server/policy/PhoneWindowManager.java

@@ -2577,6 +2577,7 @@ public class PhoneWindowManager implements WindowManagerPolicy {
 
             mStylusButtonsDisabled = Settings.Secure.getIntForUser(resolver,
                     Secure.STYLUS_BUTTONS_DISABLED, 0, UserHandle.USER_CURRENT) == 1;
+            mInputManagerInternal.setStylusButtonMotionEventsEnabled(!mStylusButtonsDisabled);
         }
         if (updateRotation) {
             updateRotation(true);

services/core/jni/com_android_server_input_InputManagerService.cpp

@@ -302,6 +302,7 @@ public:
     void setCustomPointerIcon(const SpriteIcon& icon);
     void setMotionClassifierEnabled(bool enabled);
     std::optional<std::string> getBluetoothAddress(int32_t deviceId);
+    void setStylusButtonMotionEventsEnabled(bool enabled);
 
     /* --- InputReaderPolicyInterface implementation --- */
 
@@ -405,6 +406,9 @@ private:
 
         // Associated Pointer controller display.
         int32_t pointerDisplayId{ADISPLAY_ID_DEFAULT};
+
+        // True if stylus button reporting through motion events is enabled.
+        bool stylusButtonMotionEventsEnabled{true};
     } mLocked GUARDED_BY(mLock);
 
     std::atomic<bool> mInteractive;
@@ -654,6 +658,8 @@ void NativeInputManager::getReaderConfiguration(InputReaderConfiguration* outCon
         outConfig->defaultPointerDisplayId = mLocked.pointerDisplayId;
 
         outConfig->disabledDevices = mLocked.disabledInputDevices;
+
+        outConfig->stylusButtonMotionEventsEnabled = mLocked.stylusButtonMotionEventsEnabled;
     } // release lock
 }
 
@@ -1524,6 +1530,21 @@ std::optional<std::string> NativeInputManager::getBluetoothAddress(int32_t devic
     return mInputManager->getReader().getBluetoothAddress(deviceId);
 }
 
+void NativeInputManager::setStylusButtonMotionEventsEnabled(bool enabled) {
+    { // acquire lock
+        AutoMutex _l(mLock);
+
+        if (mLocked.stylusButtonMotionEventsEnabled == enabled) {
+            return;
+        }
+
+        mLocked.stylusButtonMotionEventsEnabled = enabled;
+    } // release lock
+
+    mInputManager->getReader().requestRefreshConfiguration(
+            InputReaderConfiguration::CHANGE_STYLUS_BUTTON_REPORTING);
+}
+
 bool NativeInputManager::isPerDisplayTouchModeEnabled() {
     JNIEnv* env = jniEnv();
     jboolean enabled =
@@ -2393,6 +2414,12 @@ static jstring nativeGetBluetoothAddress(JNIEnv* env, jobject nativeImplObj, jin
     return address ? env->NewStringUTF(address->c_str()) : nullptr;
 }
 
+static void nativeSetStylusButtonMotionEventsEnabled(JNIEnv* env, jobject nativeImplObj,
+                                                     jboolean enabled) {
+    NativeInputManager* im = getNativeInputManager(env, nativeImplObj);
+    im->setStylusButtonMotionEventsEnabled(enabled);
+}
+
 // ----------------------------------------------------------------------------
 
 static const JNINativeMethod gInputManagerMethods[] = {
@@ -2479,6 +2506,8 @@ static const JNINativeMethod gInputManagerMethods[] = {
         {"cancelCurrentTouch", "()V", (void*)nativeCancelCurrentTouch},
         {"setPointerDisplayId", "(I)V", (void*)nativeSetPointerDisplayId},
         {"getBluetoothAddress", "(I)Ljava/lang/String;", (void*)nativeGetBluetoothAddress},
+        {"setStylusButtonMotionEventsEnabled", "(Z)V",
+         (void*)nativeSetStylusButtonMotionEventsEnabled},
 };
 
 #define FIND_CLASS(var, className) \