Support for InputDevice ViewBehavior

This change creates a struct within InputDeviceInfo to hold View related
behaviors of an input device. Currently, a single behavior is supported:
device.viewBehavior_smoothScroll. This can be specified in an IDC file
to hint clients of the InputDevice that they should animate scrolls for
motion events generated by the InputDevice.

Bug: 246946631
Test: add property in IDC, check API returns expected value
Test: atest frameworks/native/services/inputflinger/tests/InputReader_test.cpp
Change-Id: Ibe373cadc40d2a08116e787b744dd30812638edb

6 files changed, 58 insertions, 4 deletions

diff --git a/include/input/InputDevice.h b/include/input/InputDevice.h
index b7751f704a..57b659d9ee 100644
--- a/include/input/InputDevice.h
+++ b/include/input/InputDevice.h
@@ -75,6 +75,17 @@ struct InputDeviceIdentifier {
     bool operator!=(const InputDeviceIdentifier&) const = default;
 };
 
+/**
+ * Holds View related behaviors for an InputDevice.
+ */
+struct InputDeviceViewBehavior {
+    /**
+     * The smooth scroll behavior that applies for all source/axis, if defined by the device.
+     * Empty optional if the device has not specified the default smooth scroll behavior.
+     */
+    std::optional<bool> shouldSmoothScroll;
+};
+
 /* Types of input device sensors. Keep sync with core/java/android/hardware/Sensor.java */
 enum class InputDeviceSensorType : int32_t {
     ACCELEROMETER = ASENSOR_TYPE_ACCELEROMETER,
@@ -266,7 +277,8 @@ public:
 
     void initialize(int32_t id, int32_t generation, int32_t controllerNumber,
                     const InputDeviceIdentifier& identifier, const std::string& alias,
-                    bool isExternal, bool hasMic, int32_t associatedDisplayId);
+                    bool isExternal, bool hasMic, int32_t associatedDisplayId,
+                    InputDeviceViewBehavior viewBehavior = {{}});
 
     inline int32_t getId() const { return mId; }
     inline int32_t getControllerNumber() const { return mControllerNumber; }
@@ -298,6 +310,8 @@ public:
         return mKeyboardLayoutInfo;
     }
 
+    inline const InputDeviceViewBehavior& getViewBehavior() const { return mViewBehavior; }
+
     inline void setKeyCharacterMap(const std::shared_ptr<KeyCharacterMap> value) {
         mKeyCharacterMap = value;
     }
@@ -359,6 +373,8 @@ private:
     std::unordered_map<int32_t, InputDeviceLightInfo> mLights;
     /* Map from battery ID to battery info */
     std::unordered_map<int32_t, InputDeviceBatteryInfo> mBatteries;
+    /** The View related behaviors for the device. */
+    InputDeviceViewBehavior mViewBehavior;
 };
 
 /* Types of input device configuration files. */
diff --git a/libs/input/InputDevice.cpp b/libs/input/InputDevice.cpp
index 9c7c0c19ed..d4dbc45090 100644
--- a/libs/input/InputDevice.cpp
+++ b/libs/input/InputDevice.cpp
@@ -190,14 +190,16 @@ InputDeviceInfo::InputDeviceInfo(const InputDeviceInfo& other)
         mHasSensor(other.mHasSensor),
         mMotionRanges(other.mMotionRanges),
         mSensors(other.mSensors),
-        mLights(other.mLights) {}
+        mLights(other.mLights),
+        mViewBehavior(other.mViewBehavior) {}
 
 InputDeviceInfo::~InputDeviceInfo() {
 }
 
 void InputDeviceInfo::initialize(int32_t id, int32_t generation, int32_t controllerNumber,
                                  const InputDeviceIdentifier& identifier, const std::string& alias,
-                                 bool isExternal, bool hasMic, int32_t associatedDisplayId) {
+                                 bool isExternal, bool hasMic, int32_t associatedDisplayId,
+                                 InputDeviceViewBehavior viewBehavior) {
     mId = id;
     mGeneration = generation;
     mControllerNumber = controllerNumber;
@@ -212,6 +214,7 @@ void InputDeviceInfo::initialize(int32_t id, int32_t generation, int32_t control
     mHasBattery = false;
     mHasButtonUnderPad = false;
     mHasSensor = false;
+    mViewBehavior = viewBehavior;
     mUsiVersion.reset();
     mMotionRanges.clear();
     mSensors.clear();
diff --git a/libs/input/input_flags.aconfig b/libs/input/input_flags.aconfig
index 174464d86f..ec7a2849ea 100644
--- a/libs/input/input_flags.aconfig
+++ b/libs/input/input_flags.aconfig
@@ -111,3 +111,10 @@ flag {
   description: "Move user-activity poke rate-limiting from PowerManagerService to InputDispatcher."
   bug: "320499729"
 }
+
+flag {
+  name: "input_device_view_behavior_api"
+  namespace: "input"
+  description: "Controls the API to provide InputDevice view behavior."
+  bug: "246946631"
+}
diff --git a/services/inputflinger/reader/InputDevice.cpp b/services/inputflinger/reader/InputDevice.cpp
index a41064b361..f3f15df151 100644
--- a/services/inputflinger/reader/InputDevice.cpp
+++ b/services/inputflinger/reader/InputDevice.cpp
@@ -251,6 +251,7 @@ std::list<NotifyArgs> InputDevice::configureInternal(nsecs_t when,
             mAssociatedDeviceType =
                     getValueByKey(readerConfig.deviceTypeAssociations, mIdentifier.location);
             mIsWaking = mConfiguration.getBool("device.wake").value_or(false);
+            mShouldSmoothScroll = mConfiguration.getBool("device.viewBehavior_smoothScroll");
         }
 
         if (!changes.any() || changes.test(Change::DEVICE_ALIAS)) {
@@ -401,7 +402,8 @@ std::list<NotifyArgs> InputDevice::updateExternalStylusState(const StylusState&
 InputDeviceInfo InputDevice::getDeviceInfo() {
     InputDeviceInfo outDeviceInfo;
     outDeviceInfo.initialize(mId, mGeneration, mControllerNumber, mIdentifier, mAlias, mIsExternal,
-                             mHasMic, getAssociatedDisplayId().value_or(ADISPLAY_ID_NONE));
+                             mHasMic, getAssociatedDisplayId().value_or(ADISPLAY_ID_NONE),
+                             {mShouldSmoothScroll});
 
     for_each_mapper(
             [&outDeviceInfo](InputMapper& mapper) { mapper.populateDeviceInfo(outDeviceInfo); });
diff --git a/services/inputflinger/reader/include/InputDevice.h b/services/inputflinger/reader/include/InputDevice.h
index ba7234b3e1..0719b0ce3c 100644
--- a/services/inputflinger/reader/include/InputDevice.h
+++ b/services/inputflinger/reader/include/InputDevice.h
@@ -199,6 +199,7 @@ private:
     std::optional<DisplayViewport> mAssociatedViewport;
     bool mHasMic;
     bool mDropUntilNextSync;
+    std::optional<bool> mShouldSmoothScroll;
 
     typedef int32_t (InputMapper::*GetStateFunc)(uint32_t sourceMask, int32_t code);
     int32_t getState(uint32_t sourceMask, int32_t code, GetStateFunc getStateFunc);
diff --git a/services/inputflinger/tests/InputReader_test.cpp b/services/inputflinger/tests/InputReader_test.cpp
index 460a7b185d..c1dc7ffcfb 100644
--- a/services/inputflinger/tests/InputReader_test.cpp
+++ b/services/inputflinger/tests/InputReader_test.cpp
@@ -2706,6 +2706,31 @@ TEST_F(InputDeviceTest, WhenMappersAreRegistered_DeviceIsNotIgnoredAndForwardsRe
     ASSERT_NO_FATAL_FAILURE(mapper2.assertProcessWasCalled());
 }
 
+TEST_F(InputDeviceTest, Configure_SmoothScrollViewBehaviorNotSet) {
+    // Set some behavior to force the configuration to be update.
+    mFakeEventHub->addConfigurationProperty(EVENTHUB_ID, "device.wake", "1");
+    mDevice->addMapper<FakeInputMapper>(EVENTHUB_ID, mFakePolicy->getReaderConfiguration(),
+                                        AINPUT_SOURCE_KEYBOARD);
+
+    std::list<NotifyArgs> unused =
+            mDevice->configure(ARBITRARY_TIME, mFakePolicy->getReaderConfiguration(),
+                               /*changes=*/{});
+
+    ASSERT_FALSE(mDevice->getDeviceInfo().getViewBehavior().shouldSmoothScroll.has_value());
+}
+
+TEST_F(InputDeviceTest, Configure_SmoothScrollViewBehaviorEnabled) {
+    mFakeEventHub->addConfigurationProperty(EVENTHUB_ID, "device.viewBehavior_smoothScroll", "1");
+    mDevice->addMapper<FakeInputMapper>(EVENTHUB_ID, mFakePolicy->getReaderConfiguration(),
+                                        AINPUT_SOURCE_KEYBOARD);
+
+    std::list<NotifyArgs> unused =
+            mDevice->configure(ARBITRARY_TIME, mFakePolicy->getReaderConfiguration(),
+                               /*changes=*/{});
+
+    ASSERT_TRUE(mDevice->getDeviceInfo().getViewBehavior().shouldSmoothScroll.value_or(false));
+}
+
 TEST_F(InputDeviceTest, WakeDevice_AddsWakeFlagToProcessNotifyArgs) {
     mFakeEventHub->addConfigurationProperty(EVENTHUB_ID, "device.wake", "1");
     FakeInputMapper& mapper =