Add ChromeOS palm rejection model
This model will be used to block palm presses. It takes in a stream of
evdev events, and reports back the pointers which should be considered
palm.
Bug: 198472780
Test: atest libpalmrejection_test inputflinger_tests
Test: "adb shell device_config put input_native_boot
palm_rejection_enabled 0" and make sure that "adb shell dumpsys input"
shows that there aren't any palm rejectors inside
UnwantedInteractionBlocker
Change-Id: If979d335af29cf5e93b26336fea56a3a895cc562
diff --git a/services/inputflinger/UnwantedInteractionBlocker.h b/services/inputflinger/UnwantedInteractionBlocker.h
new file mode 100644
index 0000000..14068fd
--- /dev/null
+++ b/services/inputflinger/UnwantedInteractionBlocker.h
@@ -0,0 +1,153 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <map>
+#include <set>
+
+#include "include/UnwantedInteractionBlockerInterface.h"
+#include "ui/events/ozone/evdev/touch_filter/neural_stylus_palm_detection_filter_util.h"
+#include "ui/events/ozone/evdev/touch_filter/palm_detection_filter.h"
+
+namespace android {
+
+// --- Functions for manipulation of event streams
+
+struct AndroidPalmFilterDeviceInfo : ::ui::PalmFilterDeviceInfo {
+ // Additional fields from 'TouchEventConverterEvdev', added here for convenience
+ int32_t touch_major_res = 1; // info.GetAbsInfoByCode(ABS_MT_TOUCH_MAJOR).resolution;
+ int32_t touch_minor_res = 1; // info.GetAbsInfoByCode(ABS_MT_TOUCH_MINOR).resolution;
+
+ auto operator<=>(const AndroidPalmFilterDeviceInfo&) const = default;
+};
+
+std::optional<AndroidPalmFilterDeviceInfo> createPalmFilterDeviceInfo(
+ const InputDeviceInfo& deviceInfo);
+
+static constexpr int32_t ACTION_UNKNOWN = -1;
+
+NotifyMotionArgs removePointerIds(const NotifyMotionArgs& args,
+ const std::set<int32_t>& pointerIds);
+
+std::vector<NotifyMotionArgs> cancelSuppressedPointers(
+ const NotifyMotionArgs& args, const std::set<int32_t>& oldSuppressedPointerIds,
+ const std::set<int32_t>& newSuppressedPointerIds);
+
+std::string toString(const ::ui::InProgressTouchEvdev& touch);
+
+// --- Main classes and interfaces ---
+
+class PalmRejector;
+
+// --- Implementations ---
+
+/**
+ * Implementation of the UnwantedInteractionBlockerInterface.
+ * Represents a separate stage of input processing. All of the input events go through this stage.
+ * Acts as a passthrough for all input events except for motion events.
+ *
+ * The events of motion type are sent to PalmRejectors. PalmRejectors detect unwanted touches,
+ * and emit input streams with the bad pointers removed.
+ */
+class UnwantedInteractionBlocker : public UnwantedInteractionBlockerInterface {
+public:
+ explicit UnwantedInteractionBlocker(InputListenerInterface& listener);
+ explicit UnwantedInteractionBlocker(InputListenerInterface& listener, bool enablePalmRejection);
+
+ void notifyConfigurationChanged(const NotifyConfigurationChangedArgs* args) override;
+ void notifyKey(const NotifyKeyArgs* args) override;
+ void notifyMotion(const NotifyMotionArgs* args) override;
+ void notifySwitch(const NotifySwitchArgs* args) override;
+ void notifySensor(const NotifySensorArgs* args) override;
+ void notifyVibratorState(const NotifyVibratorStateArgs* args) override;
+ void notifyDeviceReset(const NotifyDeviceResetArgs* args) override;
+ void notifyPointerCaptureChanged(const NotifyPointerCaptureChangedArgs* args) override;
+
+ void notifyInputDevicesChanged(const std::vector<InputDeviceInfo>& inputDevices) override;
+ void dump(std::string& dump) override;
+ void monitor() override;
+
+ ~UnwantedInteractionBlocker();
+
+private:
+ // The next stage to pass input events to
+ InputListenerInterface& mListener;
+ const bool mEnablePalmRejection;
+
+ // Detect and reject unwanted palms on screen
+ // Use a separate palm rejector for every touch device.
+ std::map<int32_t /*deviceId*/, PalmRejector> mPalmRejectors;
+};
+
+class SlotState {
+public:
+ /**
+ * Update the state using the new information provided in the NotifyMotionArgs
+ */
+ void update(const NotifyMotionArgs& args);
+ std::optional<size_t> getSlotForPointerId(int32_t pointerId) const;
+ std::string dump() const;
+
+private:
+ // Process a pointer with the provided action, and return the slot associated with it
+ void processPointerId(int32_t pointerId, int32_t action);
+ // The map from tracking id to slot state. Since the PalmRejectionFilter works close to the
+ // evdev level, the only way to tell it about UP or CANCEL events is by sending tracking id = -1
+ // to the appropriate touch slot. So we need to reconstruct the original slot.
+ // The two collections below must always be in-sync.
+ // Use std::map instead of std::unordered_map because we rely on these collections being
+ // ordered. It also has better space efficiency than unordered_map because we only have a few
+ // pointers most of the time.
+ std::map<int32_t /*pointerId*/, size_t /*slot*/> mSlotsByPointerId;
+ std::map<size_t /*slot*/, int32_t /*pointerId */> mPointerIdsBySlot;
+
+ size_t findUnusedSlot() const;
+};
+
+/**
+ * Convert an Android event to a linux-like 'InProgressTouchEvdev'. The provided SlotState's
+ * are used to figure out which slot does each pointer belong to.
+ */
+std::vector<::ui::InProgressTouchEvdev> getTouches(const NotifyMotionArgs& args,
+ const AndroidPalmFilterDeviceInfo& deviceInfo,
+ const SlotState& oldSlotState,
+ const SlotState& newSlotState);
+
+class PalmRejector {
+public:
+ explicit PalmRejector(const AndroidPalmFilterDeviceInfo& info,
+ std::unique_ptr<::ui::PalmDetectionFilter> filter = nullptr);
+ std::vector<NotifyMotionArgs> processMotion(const NotifyMotionArgs& args);
+
+ // Get the device info of this device, for comparison purposes
+ const AndroidPalmFilterDeviceInfo& getPalmFilterDeviceInfo();
+ std::string dump() const;
+
+private:
+ PalmRejector(const PalmRejector&) = delete;
+ PalmRejector& operator=(const PalmRejector&) = delete;
+
+ std::unique_ptr<::ui::SharedPalmDetectionFilterState> mSharedPalmState;
+ AndroidPalmFilterDeviceInfo mDeviceInfo;
+ std::unique_ptr<::ui::PalmDetectionFilter> mPalmDetectionFilter;
+ std::set<int32_t> mSuppressedPointerIds;
+
+ // Used to help convert an Android touch stream to Linux input stream.
+ SlotState mSlotState;
+};
+
+} // namespace android