Native support for rotary encoder high-res scroll
Test: atest RotaryEncoderInputMapperTest
Test: atest VirtualRotaryEncoderTest
Flag: android.companion.virtualdevice.flags.high_resolution_scroll
Bug: 320328752
Change-Id: Iac9092597010582bd3f55e51ee63e9eb9c8d9433
diff --git a/libs/input/VirtualInputDevice.cpp b/libs/input/VirtualInputDevice.cpp
index 2e3e1a0..0579967 100644
--- a/libs/input/VirtualInputDevice.cpp
+++ b/libs/input/VirtualInputDevice.cpp
@@ -279,13 +279,17 @@
bool VirtualMouse::writeScrollEvent(float xAxisMovement, float yAxisMovement,
std::chrono::nanoseconds eventTime) {
if (!vd_flags::high_resolution_scroll()) {
- return writeInputEvent(EV_REL, REL_HWHEEL, xAxisMovement, eventTime) &&
- writeInputEvent(EV_REL, REL_WHEEL, yAxisMovement, eventTime) &&
+ return writeInputEvent(EV_REL, REL_HWHEEL, static_cast<int32_t>(xAxisMovement),
+ eventTime) &&
+ writeInputEvent(EV_REL, REL_WHEEL, static_cast<int32_t>(yAxisMovement),
+ eventTime) &&
writeInputEvent(EV_SYN, SYN_REPORT, 0, eventTime);
}
- const int32_t highResScrollX = xAxisMovement * kEvdevMouseHighResScrollUnitsPerDetent;
- const int32_t highResScrollY = yAxisMovement * kEvdevMouseHighResScrollUnitsPerDetent;
+ const auto highResScrollX =
+ static_cast<int32_t>(xAxisMovement * kEvdevHighResScrollUnitsPerDetent);
+ const auto highResScrollY =
+ static_cast<int32_t>(yAxisMovement * kEvdevHighResScrollUnitsPerDetent);
bool highResScrollResult =
writeInputEvent(EV_REL, REL_HWHEEL_HI_RES, highResScrollX, eventTime) &&
writeInputEvent(EV_REL, REL_WHEEL_HI_RES, highResScrollY, eventTime);
@@ -299,19 +303,19 @@
// (single mouse wheel click).
mAccumulatedHighResScrollX += highResScrollX;
mAccumulatedHighResScrollY += highResScrollY;
- const int32_t scrollX = mAccumulatedHighResScrollX / kEvdevMouseHighResScrollUnitsPerDetent;
- const int32_t scrollY = mAccumulatedHighResScrollY / kEvdevMouseHighResScrollUnitsPerDetent;
+ const int32_t scrollX = mAccumulatedHighResScrollX / kEvdevHighResScrollUnitsPerDetent;
+ const int32_t scrollY = mAccumulatedHighResScrollY / kEvdevHighResScrollUnitsPerDetent;
if (scrollX != 0) {
if (!writeInputEvent(EV_REL, REL_HWHEEL, scrollX, eventTime)) {
return false;
}
- mAccumulatedHighResScrollX %= kEvdevMouseHighResScrollUnitsPerDetent;
+ mAccumulatedHighResScrollX %= kEvdevHighResScrollUnitsPerDetent;
}
if (scrollY != 0) {
if (!writeInputEvent(EV_REL, REL_WHEEL, scrollY, eventTime)) {
return false;
}
- mAccumulatedHighResScrollY %= kEvdevMouseHighResScrollUnitsPerDetent;
+ mAccumulatedHighResScrollY %= kEvdevHighResScrollUnitsPerDetent;
}
return writeInputEvent(EV_SYN, SYN_REPORT, 0, eventTime);
@@ -550,14 +554,38 @@
}
// --- VirtualRotaryEncoder ---
-VirtualRotaryEncoder::VirtualRotaryEncoder(unique_fd fd) : VirtualInputDevice(std::move(fd)) {}
+VirtualRotaryEncoder::VirtualRotaryEncoder(unique_fd fd)
+ : VirtualInputDevice(std::move(fd)), mAccumulatedHighResScrollAmount(0) {}
VirtualRotaryEncoder::~VirtualRotaryEncoder() {}
bool VirtualRotaryEncoder::writeScrollEvent(float scrollAmount,
std::chrono::nanoseconds eventTime) {
- return writeInputEvent(EV_REL, REL_WHEEL, static_cast<int32_t>(scrollAmount), eventTime) &&
- writeInputEvent(EV_SYN, SYN_REPORT, 0, eventTime);
+ if (!vd_flags::high_resolution_scroll()) {
+ return writeInputEvent(EV_REL, REL_WHEEL, static_cast<int32_t>(scrollAmount), eventTime) &&
+ writeInputEvent(EV_SYN, SYN_REPORT, 0, eventTime);
+ }
+
+ const auto highResScrollAmount =
+ static_cast<int32_t>(scrollAmount * kEvdevHighResScrollUnitsPerDetent);
+ if (!writeInputEvent(EV_REL, REL_WHEEL_HI_RES, highResScrollAmount, eventTime)) {
+ return false;
+ }
+
+ // According to evdev spec, a high-resolution scroll device needs to emit REL_WHEEL / REL_HWHEEL
+ // events in addition to high-res scroll events. Regular scroll events can approximate high-res
+ // scroll events, so we send a regular scroll event when the accumulated scroll motion reaches a
+ // detent (single wheel click).
+ mAccumulatedHighResScrollAmount += highResScrollAmount;
+ const int32_t scroll = mAccumulatedHighResScrollAmount / kEvdevHighResScrollUnitsPerDetent;
+ if (scroll != 0) {
+ if (!writeInputEvent(EV_REL, REL_WHEEL, scroll, eventTime)) {
+ return false;
+ }
+ mAccumulatedHighResScrollAmount %= kEvdevHighResScrollUnitsPerDetent;
+ }
+
+ return writeInputEvent(EV_SYN, SYN_REPORT, 0, eventTime);
}
} // namespace android