1 /*
2  * Copyright (C) 2022 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #pragma once
18 
19 #include <map>
20 #include <set>
21 
22 #include <android-base/thread_annotations.h>
23 #include "include/UnwantedInteractionBlockerInterface.h"
24 #include "ui/events/ozone/evdev/touch_filter/neural_stylus_palm_detection_filter_util.h"
25 #include "ui/events/ozone/evdev/touch_filter/palm_detection_filter.h"
26 
27 #include "PreferStylusOverTouchBlocker.h"
28 
29 namespace android {
30 
31 // --- Functions for manipulation of event streams
32 
33 struct AndroidPalmFilterDeviceInfo : ::ui::PalmFilterDeviceInfo {
34     // Additional fields from 'TouchEventConverterEvdev', added here for convenience
35     int32_t touch_major_res = 1; // info.GetAbsInfoByCode(ABS_MT_TOUCH_MAJOR).resolution;
36     int32_t touch_minor_res = 1; // info.GetAbsInfoByCode(ABS_MT_TOUCH_MINOR).resolution;
37 
38     auto operator<=>(const AndroidPalmFilterDeviceInfo&) const = default;
39 };
40 
41 std::optional<AndroidPalmFilterDeviceInfo> createPalmFilterDeviceInfo(
42         const InputDeviceInfo& deviceInfo);
43 
44 static constexpr int32_t ACTION_UNKNOWN = -1;
45 
46 /**
47  * Remove the data for the provided pointers from the args. The pointers are identified by their
48  * pointerId, not by the index inside the array.
49  * Return the new NotifyMotionArgs struct that has the remaining pointers.
50  * The only fields that may be different in the returned args from the provided args are:
51  *     - action
52  *     - pointerCount
53  *     - pointerProperties
54  *     - pointerCoords
55  * Action might change because it contains a pointer index. If another pointer is removed, the
56  * active pointer index would be shifted.
57  *
58  * If the active pointer id is removed (for example, for events like
59  * POINTER_UP or POINTER_DOWN), then the action is set to ACTION_UNKNOWN. It is up to the caller
60  * to set the action appropriately after the call.
61  *
62  * @param args the args from which the pointers should be removed
63  * @param pointerIds the pointer ids of the pointers that should be removed
64  */
65 NotifyMotionArgs removePointerIds(const NotifyMotionArgs& args,
66                                   const std::set<int32_t>& pointerIds);
67 
68 std::vector<NotifyMotionArgs> cancelSuppressedPointers(
69         const NotifyMotionArgs& args, const std::set<int32_t>& oldSuppressedPointerIds,
70         const std::set<int32_t>& newSuppressedPointerIds);
71 
72 std::string toString(const ::ui::InProgressTouchEvdev& touch);
73 
74 // --- Main classes and interfaces ---
75 
76 class PalmRejector;
77 
78 // --- Implementations ---
79 
80 /**
81  * Implementation of the UnwantedInteractionBlockerInterface.
82  * Represents a separate stage of input processing. All of the input events go through this stage.
83  * Acts as a passthrough for all input events except for motion events.
84  *
85  * The events of motion type are sent to PalmRejectors. PalmRejectors detect unwanted touches,
86  * and emit input streams with the bad pointers removed.
87  */
88 class UnwantedInteractionBlocker : public UnwantedInteractionBlockerInterface {
89 public:
90     explicit UnwantedInteractionBlocker(InputListenerInterface& listener);
91     explicit UnwantedInteractionBlocker(InputListenerInterface& listener, bool enablePalmRejection);
92 
93     void notifyInputDevicesChanged(const NotifyInputDevicesChangedArgs& args) override;
94     void notifyConfigurationChanged(const NotifyConfigurationChangedArgs& args) override;
95     void notifyKey(const NotifyKeyArgs& args) override;
96     void notifyMotion(const NotifyMotionArgs& args) override;
97     void notifySwitch(const NotifySwitchArgs& args) override;
98     void notifySensor(const NotifySensorArgs& args) override;
99     void notifyVibratorState(const NotifyVibratorStateArgs& args) override;
100     void notifyDeviceReset(const NotifyDeviceResetArgs& args) override;
101     void notifyPointerCaptureChanged(const NotifyPointerCaptureChangedArgs& args) override;
102 
103     void dump(std::string& dump) override;
104     void monitor() override;
105 
106     ~UnwantedInteractionBlocker();
107 
108 private:
109     std::mutex mLock;
110     // The next stage to pass input events to
111 
112     QueuedInputListener mQueuedListener;
113     const bool mEnablePalmRejection;
114 
115     // When stylus is down, ignore touch
116     PreferStylusOverTouchBlocker mPreferStylusOverTouchBlocker GUARDED_BY(mLock);
117 
118     // Detect and reject unwanted palms on screen
119     // Use a separate palm rejector for every touch device.
120     std::map<int32_t /*deviceId*/, PalmRejector> mPalmRejectors GUARDED_BY(mLock);
121     // TODO(b/210159205): delete this when simultaneous stylus and touch is supported
122     void notifyMotionLocked(const NotifyMotionArgs& args) REQUIRES(mLock);
123 
124     // Call this function for outbound events so that they can be logged when logging is enabled.
125     void enqueueOutboundMotionLocked(const NotifyMotionArgs& args) REQUIRES(mLock);
126 
127     void onInputDevicesChanged(const std::vector<InputDeviceInfo>& inputDevices);
128 };
129 
130 class SlotState {
131 public:
132     /**
133      * Update the state using the new information provided in the NotifyMotionArgs
134      */
135     void update(const NotifyMotionArgs& args);
136     std::optional<size_t> getSlotForPointerId(int32_t pointerId) const;
137     std::string dump() const;
138 
139 private:
140     // Process a pointer with the provided action, and return the slot associated with it
141     void processPointerId(int32_t pointerId, int32_t action);
142     // The map from tracking id to slot state. Since the PalmRejectionFilter works close to the
143     // evdev level, the only way to tell it about UP or CANCEL events is by sending tracking id = -1
144     // to the appropriate touch slot. So we need to reconstruct the original slot.
145     // The two collections below must always be in-sync.
146     // Use std::map instead of std::unordered_map because we rely on these collections being
147     // ordered. It also has better space efficiency than unordered_map because we only have a few
148     // pointers most of the time.
149     std::map<int32_t /*pointerId*/, size_t /*slot*/> mSlotsByPointerId;
150     std::map<size_t /*slot*/, int32_t /*pointerId */> mPointerIdsBySlot;
151 
152     size_t findUnusedSlot() const;
153 };
154 
155 /**
156  * Convert an Android event to a linux-like 'InProgressTouchEvdev'. The provided SlotState's
157  * are used to figure out which slot does each pointer belong to.
158  */
159 std::vector<::ui::InProgressTouchEvdev> getTouches(const NotifyMotionArgs& args,
160                                                    const AndroidPalmFilterDeviceInfo& deviceInfo,
161                                                    const SlotState& oldSlotState,
162                                                    const SlotState& newSlotState);
163 
164 class PalmRejector {
165 public:
166     explicit PalmRejector(const AndroidPalmFilterDeviceInfo& info,
167                           std::unique_ptr<::ui::PalmDetectionFilter> filter = nullptr);
168     std::vector<NotifyMotionArgs> processMotion(const NotifyMotionArgs& args);
169 
170     // Get the device info of this device, for comparison purposes
171     const AndroidPalmFilterDeviceInfo& getPalmFilterDeviceInfo() const;
172     std::string dump() const;
173 
174 private:
175     PalmRejector(const PalmRejector&) = delete;
176     PalmRejector& operator=(const PalmRejector&) = delete;
177 
178     /**
179      * Update the slot state and send this event to the palm rejection model for palm detection.
180      * Return the pointer ids that should be suppressed.
181      *
182      * This function is not const because it has side-effects. It will update the slot state using
183      * the incoming args! Also, it will call Filter(..), which has side-effects.
184      */
185     std::set<int32_t> detectPalmPointers(const NotifyMotionArgs& args);
186     std::unique_ptr<::ui::SharedPalmDetectionFilterState> mSharedPalmState;
187     AndroidPalmFilterDeviceInfo mDeviceInfo;
188     std::unique_ptr<::ui::PalmDetectionFilter> mPalmDetectionFilter;
189     std::set<int32_t> mSuppressedPointerIds;
190 
191     // Used to help convert an Android touch stream to Linux input stream.
192     SlotState mSlotState;
193 };
194 
195 } // namespace android
196