InputDevice: return std::optional from getAbsoluteAxisInfo

This also allows us to remove the valid field from RawAbsoluteAxisInfo,
since we can represent "invalid" axes (which usually just meant absent
ones) using std::nullopt.

Test: atest inputflinger_tests
Test: m checkinput
Test: Check "Raw Touch Axes" section of touch input mapper info in
      dumpsys input
Bug: 245989146
Flag: EXEMPT refactor
Change-Id: I045a2e0b61a84657f2f8171c1fee3cc3e331ac86
diff --git a/services/inputflinger/reader/mapper/MultiTouchInputMapper.cpp b/services/inputflinger/reader/mapper/MultiTouchInputMapper.cpp
index 1986fe2..3ea3c20 100644
--- a/services/inputflinger/reader/mapper/MultiTouchInputMapper.cpp
+++ b/services/inputflinger/reader/mapper/MultiTouchInputMapper.cpp
@@ -133,7 +133,7 @@
 
         bool isHovering = mTouchButtonAccumulator.getToolType() != ToolType::MOUSE &&
                 (mTouchButtonAccumulator.isHovering() ||
-                 (mRawPointerAxes.pressure.valid && inSlot.getPressure() <= 0));
+                 (mRawPointerAxes.pressure && inSlot.getPressure() <= 0));
         outPointer.isHovering = isHovering;
 
         // Assign pointer id using tracking id if available.
@@ -189,21 +189,23 @@
 void MultiTouchInputMapper::configureRawPointerAxes() {
     TouchInputMapper::configureRawPointerAxes();
 
-    getAbsoluteAxisInfo(ABS_MT_POSITION_X, &mRawPointerAxes.x);
-    getAbsoluteAxisInfo(ABS_MT_POSITION_Y, &mRawPointerAxes.y);
-    getAbsoluteAxisInfo(ABS_MT_TOUCH_MAJOR, &mRawPointerAxes.touchMajor);
-    getAbsoluteAxisInfo(ABS_MT_TOUCH_MINOR, &mRawPointerAxes.touchMinor);
-    getAbsoluteAxisInfo(ABS_MT_WIDTH_MAJOR, &mRawPointerAxes.toolMajor);
-    getAbsoluteAxisInfo(ABS_MT_WIDTH_MINOR, &mRawPointerAxes.toolMinor);
-    getAbsoluteAxisInfo(ABS_MT_ORIENTATION, &mRawPointerAxes.orientation);
-    getAbsoluteAxisInfo(ABS_MT_PRESSURE, &mRawPointerAxes.pressure);
-    getAbsoluteAxisInfo(ABS_MT_DISTANCE, &mRawPointerAxes.distance);
-    getAbsoluteAxisInfo(ABS_MT_TRACKING_ID, &mRawPointerAxes.trackingId);
-    getAbsoluteAxisInfo(ABS_MT_SLOT, &mRawPointerAxes.slot);
+    // We can safely assume that ABS_MT_POSITION_X and _Y axes will be available, as EventHub won't
+    // classify a device as multitouch if they're not present.
+    mRawPointerAxes.x = getAbsoluteAxisInfo(ABS_MT_POSITION_X).value();
+    mRawPointerAxes.y = getAbsoluteAxisInfo(ABS_MT_POSITION_Y).value();
+    mRawPointerAxes.touchMajor = getAbsoluteAxisInfo(ABS_MT_TOUCH_MAJOR);
+    mRawPointerAxes.touchMinor = getAbsoluteAxisInfo(ABS_MT_TOUCH_MINOR);
+    mRawPointerAxes.toolMajor = getAbsoluteAxisInfo(ABS_MT_WIDTH_MAJOR);
+    mRawPointerAxes.toolMinor = getAbsoluteAxisInfo(ABS_MT_WIDTH_MINOR);
+    mRawPointerAxes.orientation = getAbsoluteAxisInfo(ABS_MT_ORIENTATION);
+    mRawPointerAxes.pressure = getAbsoluteAxisInfo(ABS_MT_PRESSURE);
+    mRawPointerAxes.distance = getAbsoluteAxisInfo(ABS_MT_DISTANCE);
+    mRawPointerAxes.trackingId = getAbsoluteAxisInfo(ABS_MT_TRACKING_ID);
+    mRawPointerAxes.slot = getAbsoluteAxisInfo(ABS_MT_SLOT);
 
-    if (mRawPointerAxes.trackingId.valid && mRawPointerAxes.slot.valid &&
-        mRawPointerAxes.slot.minValue == 0 && mRawPointerAxes.slot.maxValue > 0) {
-        size_t slotCount = mRawPointerAxes.slot.maxValue + 1;
+    if (mRawPointerAxes.trackingId && mRawPointerAxes.slot && mRawPointerAxes.slot->minValue == 0 &&
+        mRawPointerAxes.slot->maxValue > 0) {
+        size_t slotCount = mRawPointerAxes.slot->maxValue + 1;
         if (slotCount > MAX_SLOTS) {
             ALOGW("MultiTouch Device %s reported %zu slots but the framework "
                   "only supports a maximum of %zu slots at this time.",