TouchpadInputMapper: support touchpad capture

This allows an app to capture the touchpad and receive "raw" touch
information from it. Since some specifics (such as how size is
calculated) aren't well-defined in documentation or tests currently,
when in doubt I tried to match the behaviour of MultiTouchInputMapper in
captured mode.

Bug: b/259547750
Test: atest inputflinger_tests
Test: use a test app to dump captured events, manually verify and
      compare with old behaviour
Change-Id: I482cce6d16ed6f947ce86e8453ddb2c9789d4d00
diff --git a/services/inputflinger/reader/mapper/CapturedTouchpadEventConverter.h b/services/inputflinger/reader/mapper/CapturedTouchpadEventConverter.h
new file mode 100644
index 0000000..d81692d
--- /dev/null
+++ b/services/inputflinger/reader/mapper/CapturedTouchpadEventConverter.h
@@ -0,0 +1,83 @@
+/*
+ * Copyright 2023 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 <bitset>
+#include <list>
+#include <map>
+#include <set>
+#include <string>
+#include <vector>
+
+#include <android/input.h>
+#include <input/Input.h>
+#include <utils/Timers.h>
+
+#include "EventHub.h"
+#include "InputDevice.h"
+#include "accumulator/CursorButtonAccumulator.h"
+#include "accumulator/MultiTouchMotionAccumulator.h"
+#include "accumulator/TouchButtonAccumulator.h"
+
+namespace android {
+
+class CapturedTouchpadEventConverter {
+public:
+    explicit CapturedTouchpadEventConverter(InputReaderContext& readerContext,
+                                            const InputDeviceContext& deviceContext,
+                                            MultiTouchMotionAccumulator& motionAccumulator,
+                                            int32_t deviceId);
+    std::string dump() const;
+    void populateMotionRanges(InputDeviceInfo& info) const;
+    void reset();
+    [[nodiscard]] std::list<NotifyArgs> process(const RawEvent& rawEvent);
+
+private:
+    void tryAddRawMotionRange(InputDeviceInfo& deviceInfo, int32_t androidAxis,
+                              int32_t evdevAxis) const;
+    [[nodiscard]] std::list<NotifyArgs> sync(nsecs_t when, nsecs_t readTime);
+    [[nodiscard]] NotifyMotionArgs makeMotionArgs(nsecs_t when, nsecs_t readTime, int32_t action,
+                                                  const std::vector<PointerCoords>& coords,
+                                                  const std::vector<PointerProperties>& properties,
+                                                  int32_t actionButton = 0);
+    PointerCoords makePointerCoordsForSlot(const MultiTouchMotionAccumulator::Slot& slot) const;
+    int32_t allocatePointerIdToSlot(size_t slotNumber);
+    void freePointerIdForSlot(size_t slotNumber);
+
+    const int32_t mDeviceId;
+    InputReaderContext& mReaderContext;
+    const InputDeviceContext& mDeviceContext;
+    CursorButtonAccumulator mCursorButtonAccumulator;
+    MultiTouchMotionAccumulator& mMotionAccumulator;
+
+    float mOrientationScale = 0;
+    float mPressureScale = 1;
+    float mSizeScale = 0;
+    bool mHasTouchMajor;
+    const bool mHasTouchMinor;
+    bool mHasToolMajor;
+    const bool mHasToolMinor;
+    nsecs_t mDownTime = 0;
+    uint32_t mButtonState = 0;
+
+    std::bitset<MAX_POINTER_ID + 1> mPointerIdsInUse;
+    std::map<size_t, int32_t> mPointerIdForSlotNumber;
+
+    static constexpr uint32_t SOURCE = AINPUT_SOURCE_TOUCHPAD;
+};
+
+} // namespace android