Extract HardwareState conversion into a class and test it

Putting the conversion logic into its own class makes it more obvious
which variables are used for HardwareState conversion, and also provides
a clean public API to write tests against.

Bug: 251196347
Test: m inputflinger_tests && \
    $ANDROID_HOST_OUT/nativetest64/inputflinger_tests/inputflinger_tests \
    --gtest_filter='*HardwareStateConverterTest*'
Test: atest inputflinger_tests
Change-Id: I26771887b6b2eae46c9cec7190499da0016fdb1f
diff --git a/services/inputflinger/reader/Android.bp b/services/inputflinger/reader/Android.bp
index f37f0fa..1535df3 100644
--- a/services/inputflinger/reader/Android.bp
+++ b/services/inputflinger/reader/Android.bp
@@ -29,6 +29,7 @@
         "include",
         "mapper",
         "mapper/accumulator",
+        "mapper/gestures",
     ],
 }
 
@@ -61,6 +62,7 @@
         "mapper/accumulator/SingleTouchMotionAccumulator.cpp",
         "mapper/accumulator/TouchButtonAccumulator.cpp",
         "mapper/gestures/GesturesLogging.cpp",
+        "mapper/gestures/HardwareStateConverter.cpp",
     ],
 }
 
diff --git a/services/inputflinger/reader/mapper/TouchpadInputMapper.cpp b/services/inputflinger/reader/mapper/TouchpadInputMapper.cpp
index 956a7aa..f535ab4 100644
--- a/services/inputflinger/reader/mapper/TouchpadInputMapper.cpp
+++ b/services/inputflinger/reader/mapper/TouchpadInputMapper.cpp
@@ -16,8 +16,6 @@
 
 #include "../Macros.h"
 
-#include <chrono>
-
 #include <android/input.h>
 #include <log/log_main.h>
 #include "TouchCursorInputMapperCommon.h"
@@ -106,7 +104,7 @@
       : InputMapper(deviceContext),
         mGestureInterpreter(NewGestureInterpreter(), DeleteGestureInterpreter),
         mPointerController(getContext()->getPointerController(getDeviceId())),
-        mTouchButtonAccumulator(deviceContext) {
+        mStateConverter(deviceContext) {
     mGestureInterpreter->Initialize(GESTURES_DEVCLASS_TOUCHPAD);
     mGestureInterpreter->SetHardwareProperties(createHardwareProperties(deviceContext));
     // Even though we don't explicitly delete copy/move semantics, it's safe to
@@ -116,16 +114,6 @@
     mGestureInterpreter->SetCallback(gestureInterpreterCallback, this);
     // TODO(b/251196347): set a property provider, so we can change gesture properties.
     // TODO(b/251196347): set a timer provider, so the library can use timers.
-
-    RawAbsoluteAxisInfo slotAxisInfo;
-    getAbsoluteAxisInfo(ABS_MT_SLOT, &slotAxisInfo);
-    if (!slotAxisInfo.valid || slotAxisInfo.maxValue <= 0) {
-        ALOGW("Touchpad \"%s\" doesn't have a valid ABS_MT_SLOT axis, and probably won't work "
-              "properly.",
-              getDeviceName().c_str());
-    }
-    mMotionAccumulator.configure(getDeviceContext(), slotAxisInfo.maxValue + 1, true);
-    mTouchButtonAccumulator.configure();
 }
 
 TouchpadInputMapper::~TouchpadInputMapper() {
@@ -139,82 +127,28 @@
 }
 
 std::list<NotifyArgs> TouchpadInputMapper::reset(nsecs_t when) {
-    mCursorButtonAccumulator.reset(getDeviceContext());
-    mTouchButtonAccumulator.reset();
-    mMscTimestamp = 0;
+    mStateConverter.reset();
 
     mButtonState = 0;
     return InputMapper::reset(when);
 }
 
 std::list<NotifyArgs> TouchpadInputMapper::process(const RawEvent* rawEvent) {
-    std::list<NotifyArgs> out = {};
-    if (rawEvent->type == EV_SYN && rawEvent->code == SYN_REPORT) {
-        out = sync(rawEvent->when, rawEvent->readTime);
+    std::optional<SelfContainedHardwareState> state = mStateConverter.processRawEvent(rawEvent);
+    if (state) {
+        return sendHardwareState(rawEvent->when, rawEvent->readTime, *state);
+    } else {
+        return {};
     }
-    if (rawEvent->type == EV_MSC && rawEvent->code == MSC_TIMESTAMP) {
-        mMscTimestamp = rawEvent->value;
-    }
-    mCursorButtonAccumulator.process(rawEvent);
-    mMotionAccumulator.process(rawEvent);
-    mTouchButtonAccumulator.process(rawEvent);
-    return out;
 }
 
-std::list<NotifyArgs> TouchpadInputMapper::sync(nsecs_t when, nsecs_t readTime) {
-    HardwareState hwState;
-    // The gestures library uses doubles to represent timestamps in seconds.
-    hwState.timestamp = std::chrono::duration<stime_t>(std::chrono::nanoseconds(when)).count();
-    hwState.msc_timestamp =
-            std::chrono::duration<stime_t>(std::chrono::microseconds(mMscTimestamp)).count();
-
-    hwState.buttons_down = 0;
-    if (mCursorButtonAccumulator.isLeftPressed()) {
-        hwState.buttons_down |= GESTURES_BUTTON_LEFT;
-    }
-    if (mCursorButtonAccumulator.isMiddlePressed()) {
-        hwState.buttons_down |= GESTURES_BUTTON_MIDDLE;
-    }
-    if (mCursorButtonAccumulator.isRightPressed()) {
-        hwState.buttons_down |= GESTURES_BUTTON_RIGHT;
-    }
-    if (mCursorButtonAccumulator.isBackPressed() || mCursorButtonAccumulator.isSidePressed()) {
-        hwState.buttons_down |= GESTURES_BUTTON_BACK;
-    }
-    if (mCursorButtonAccumulator.isForwardPressed() || mCursorButtonAccumulator.isExtraPressed()) {
-        hwState.buttons_down |= GESTURES_BUTTON_FORWARD;
-    }
-
-    std::vector<FingerState> fingers;
-    for (size_t i = 0; i < mMotionAccumulator.getSlotCount(); i++) {
-        MultiTouchMotionAccumulator::Slot slot = mMotionAccumulator.getSlot(i);
-        if (slot.isInUse()) {
-            FingerState& fingerState = fingers.emplace_back();
-            fingerState = {};
-            fingerState.touch_major = slot.getTouchMajor();
-            fingerState.touch_minor = slot.getTouchMinor();
-            fingerState.width_major = slot.getToolMajor();
-            fingerState.width_minor = slot.getToolMinor();
-            fingerState.pressure = slot.getPressure();
-            fingerState.orientation = slot.getOrientation();
-            fingerState.position_x = slot.getX();
-            fingerState.position_y = slot.getY();
-            fingerState.tracking_id = slot.getTrackingId();
-        }
-    }
-    hwState.fingers = fingers.data();
-    hwState.finger_cnt = fingers.size();
-    hwState.touch_cnt = mTouchButtonAccumulator.getTouchCount();
-
+std::list<NotifyArgs> TouchpadInputMapper::sendHardwareState(nsecs_t when, nsecs_t readTime,
+                                                             SelfContainedHardwareState schs) {
     mProcessing = true;
-    mGestureInterpreter->PushHardwareState(&hwState);
+    mGestureInterpreter->PushHardwareState(&schs.state);
     mProcessing = false;
 
-    std::list<NotifyArgs> out = processGestures(when, readTime);
-
-    mMotionAccumulator.finishSync();
-    mMscTimestamp = 0;
-    return out;
+    return processGestures(when, readTime);
 }
 
 void TouchpadInputMapper::consumeGesture(const Gesture* gesture) {
diff --git a/services/inputflinger/reader/mapper/TouchpadInputMapper.h b/services/inputflinger/reader/mapper/TouchpadInputMapper.h
index fe6b1fe..c6863f5 100644
--- a/services/inputflinger/reader/mapper/TouchpadInputMapper.h
+++ b/services/inputflinger/reader/mapper/TouchpadInputMapper.h
@@ -17,6 +17,7 @@
 #pragma once
 
 #include <memory>
+#include <vector>
 
 #include <PointerControllerInterface.h>
 
@@ -24,9 +25,7 @@
 #include "InputDevice.h"
 #include "InputMapper.h"
 #include "NotifyArgs.h"
-#include "accumulator/CursorButtonAccumulator.h"
-#include "accumulator/MultiTouchMotionAccumulator.h"
-#include "accumulator/TouchButtonAccumulator.h"
+#include "gestures/HardwareStateConverter.h"
 
 #include "include/gestures.h"
 
@@ -44,7 +43,8 @@
     void consumeGesture(const Gesture* gesture);
 
 private:
-    [[nodiscard]] std::list<NotifyArgs> sync(nsecs_t when, nsecs_t readTime);
+    [[nodiscard]] std::list<NotifyArgs> sendHardwareState(nsecs_t when, nsecs_t readTime,
+                                                          SelfContainedHardwareState schs);
     [[nodiscard]] std::list<NotifyArgs> processGestures(nsecs_t when, nsecs_t readTime);
     NotifyArgs handleMove(nsecs_t when, nsecs_t readTime, const Gesture& gesture);
     [[nodiscard]] std::list<NotifyArgs> handleButtonsChange(nsecs_t when, nsecs_t readTime,
@@ -61,10 +61,7 @@
             mGestureInterpreter;
     std::shared_ptr<PointerControllerInterface> mPointerController;
 
-    CursorButtonAccumulator mCursorButtonAccumulator;
-    MultiTouchMotionAccumulator mMotionAccumulator;
-    TouchButtonAccumulator mTouchButtonAccumulator;
-    int32_t mMscTimestamp = 0;
+    HardwareStateConverter mStateConverter;
 
     bool mProcessing = false;
     std::vector<Gesture> mGesturesToProcess;
diff --git a/services/inputflinger/reader/mapper/gestures/HardwareStateConverter.cpp b/services/inputflinger/reader/mapper/gestures/HardwareStateConverter.cpp
new file mode 100644
index 0000000..49c13ca
--- /dev/null
+++ b/services/inputflinger/reader/mapper/gestures/HardwareStateConverter.cpp
@@ -0,0 +1,109 @@
+/*
+ * Copyright 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.
+ */
+
+#include "gestures/HardwareStateConverter.h"
+
+#include <chrono>
+#include <vector>
+
+#include <linux/input-event-codes.h>
+
+namespace android {
+
+HardwareStateConverter::HardwareStateConverter(InputDeviceContext& deviceContext)
+      : mDeviceContext(deviceContext), mTouchButtonAccumulator(deviceContext) {
+    RawAbsoluteAxisInfo slotAxisInfo;
+    deviceContext.getAbsoluteAxisInfo(ABS_MT_SLOT, &slotAxisInfo);
+    if (!slotAxisInfo.valid || slotAxisInfo.maxValue <= 0) {
+        ALOGW("Touchpad \"%s\" doesn't have a valid ABS_MT_SLOT axis, and probably won't work "
+              "properly.",
+              deviceContext.getName().c_str());
+    }
+    mMotionAccumulator.configure(deviceContext, slotAxisInfo.maxValue + 1, true);
+    mTouchButtonAccumulator.configure();
+}
+
+std::optional<SelfContainedHardwareState> HardwareStateConverter::processRawEvent(
+        const RawEvent* rawEvent) {
+    std::optional<SelfContainedHardwareState> out;
+    if (rawEvent->type == EV_SYN && rawEvent->code == SYN_REPORT) {
+        out = produceHardwareState(rawEvent->when);
+        mMotionAccumulator.finishSync();
+        mMscTimestamp = 0;
+    }
+    if (rawEvent->type == EV_MSC && rawEvent->code == MSC_TIMESTAMP) {
+        mMscTimestamp = rawEvent->value;
+    }
+    mCursorButtonAccumulator.process(rawEvent);
+    mMotionAccumulator.process(rawEvent);
+    mTouchButtonAccumulator.process(rawEvent);
+    return out;
+}
+
+SelfContainedHardwareState HardwareStateConverter::produceHardwareState(nsecs_t when) {
+    SelfContainedHardwareState schs;
+    // The gestures library uses doubles to represent timestamps in seconds.
+    schs.state.timestamp = std::chrono::duration<stime_t>(std::chrono::nanoseconds(when)).count();
+    schs.state.msc_timestamp =
+            std::chrono::duration<stime_t>(std::chrono::microseconds(mMscTimestamp)).count();
+
+    schs.state.buttons_down = 0;
+    if (mCursorButtonAccumulator.isLeftPressed()) {
+        schs.state.buttons_down |= GESTURES_BUTTON_LEFT;
+    }
+    if (mCursorButtonAccumulator.isMiddlePressed()) {
+        schs.state.buttons_down |= GESTURES_BUTTON_MIDDLE;
+    }
+    if (mCursorButtonAccumulator.isRightPressed()) {
+        schs.state.buttons_down |= GESTURES_BUTTON_RIGHT;
+    }
+    if (mCursorButtonAccumulator.isBackPressed() || mCursorButtonAccumulator.isSidePressed()) {
+        schs.state.buttons_down |= GESTURES_BUTTON_BACK;
+    }
+    if (mCursorButtonAccumulator.isForwardPressed() || mCursorButtonAccumulator.isExtraPressed()) {
+        schs.state.buttons_down |= GESTURES_BUTTON_FORWARD;
+    }
+
+    schs.fingers.clear();
+    for (size_t i = 0; i < mMotionAccumulator.getSlotCount(); i++) {
+        MultiTouchMotionAccumulator::Slot slot = mMotionAccumulator.getSlot(i);
+        if (slot.isInUse()) {
+            FingerState& fingerState = schs.fingers.emplace_back();
+            fingerState = {};
+            fingerState.touch_major = slot.getTouchMajor();
+            fingerState.touch_minor = slot.getTouchMinor();
+            fingerState.width_major = slot.getToolMajor();
+            fingerState.width_minor = slot.getToolMinor();
+            fingerState.pressure = slot.getPressure();
+            fingerState.orientation = slot.getOrientation();
+            fingerState.position_x = slot.getX();
+            fingerState.position_y = slot.getY();
+            fingerState.tracking_id = slot.getTrackingId();
+        }
+    }
+    schs.state.fingers = schs.fingers.data();
+    schs.state.finger_cnt = schs.fingers.size();
+    schs.state.touch_cnt = mTouchButtonAccumulator.getTouchCount();
+    return schs;
+}
+
+void HardwareStateConverter::reset() {
+    mCursorButtonAccumulator.reset(mDeviceContext);
+    mTouchButtonAccumulator.reset();
+    mMscTimestamp = 0;
+}
+
+} // namespace android
diff --git a/services/inputflinger/reader/mapper/gestures/HardwareStateConverter.h b/services/inputflinger/reader/mapper/gestures/HardwareStateConverter.h
new file mode 100644
index 0000000..fd63c05
--- /dev/null
+++ b/services/inputflinger/reader/mapper/gestures/HardwareStateConverter.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright 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 <optional>
+
+#include <utils/Timers.h>
+
+#include "EventHub.h"
+#include "InputDevice.h"
+#include "accumulator/CursorButtonAccumulator.h"
+#include "accumulator/MultiTouchMotionAccumulator.h"
+#include "accumulator/TouchButtonAccumulator.h"
+
+#include "include/gestures.h"
+
+namespace android {
+
+// A HardwareState struct, but bundled with a vector to contain its FingerStates, so you don't have
+// to worry about where that memory is allocated.
+struct SelfContainedHardwareState {
+    HardwareState state;
+    std::vector<FingerState> fingers;
+};
+
+// Converts RawEvents into the HardwareState structs used by the gestures library.
+class HardwareStateConverter {
+public:
+    HardwareStateConverter(InputDeviceContext& deviceContext);
+
+    std::optional<SelfContainedHardwareState> processRawEvent(const RawEvent* event);
+    void reset();
+
+private:
+    SelfContainedHardwareState produceHardwareState(nsecs_t when);
+
+    InputDeviceContext& mDeviceContext;
+    CursorButtonAccumulator mCursorButtonAccumulator;
+    MultiTouchMotionAccumulator mMotionAccumulator;
+    TouchButtonAccumulator mTouchButtonAccumulator;
+    int32_t mMscTimestamp = 0;
+};
+
+} // namespace android