From 72238143825361b7d5e3a7d4446d1694d6948af7 Mon Sep 17 00:00:00 2001
From: Larry Davis <lazdnet@gmail.com>
Date: Mon, 6 Jan 2020 15:45:14 -0800
Subject: [PATCH] Behave like a touchscreen, properly

* except dragging to select, which times out after 14ms and screws up your selection
---
 .../VoodooI2CGoodixEventDriver.cpp            | 40 +++++++++++++++++++
 .../VoodooI2CGoodixEventDriver.hpp            | 14 ++++++-
 2 files changed, 52 insertions(+), 2 deletions(-)

diff --git a/VoodooI2CGoodix/VoodooI2CGoodixEventDriver.cpp b/VoodooI2CGoodix/VoodooI2CGoodixEventDriver.cpp
index 394348e..d2b362b 100644
--- a/VoodooI2CGoodix/VoodooI2CGoodixEventDriver.cpp
+++ b/VoodooI2CGoodix/VoodooI2CGoodixEventDriver.cpp
@@ -30,13 +30,32 @@ void VoodooI2CGoodixEventDriver::dispatchDigitizerEvent(int logicalX, int logica
 
     // Dispatch the actual event
     dispatchDigitizerEventWithTiltOrientation(timestamp, 0, kDigitiserTransducerFinger, 0x1, click ? 0x1 : 0x0, x, y);
+
+    last_x = x;
+    last_y = y;
+    last_id = 0;
+}
+
+void VoodooI2CGoodixEventDriver::scheduleLift() {
+    this->timer_source->setTimeoutMS(14);
+}
+
+void VoodooI2CGoodixEventDriver::fingerLift() {
+    AbsoluteTime timestamp;
+    clock_get_uptime(&timestamp);
+
+    dispatchDigitizerEventWithTiltOrientation(timestamp, last_id, kDigitiserTransducerFinger, 0x1, 0x0, last_x, last_y);
 }
 
+
 void VoodooI2CGoodixEventDriver::reportTouches(struct Touch touches[], int numTouches) {
     if (numTouches == 1) {
         // Initial mouse down event
         Touch touch = touches[0];
         dispatchDigitizerEvent(touch.x, touch.y, true);
+
+        // Lift a bit later
+        scheduleLift();
     }
     else {
         // Move the cursor to the location of the first finger, but don't click
@@ -87,6 +106,15 @@ bool VoodooI2CGoodixEventDriver::handleStart(IOService* provider) {
         return false;
     }
 
+    this->work_loop = getWorkLoop();
+    if (!this->work_loop) {
+        IOLog("%s::Unable to get workloop\n", getName());
+        stop(provider);
+        return false;
+    }
+
+    work_loop->retain();
+
     name = getProductName();
 
     publishMultitouchInterface();
@@ -105,6 +133,13 @@ bool VoodooI2CGoodixEventDriver::handleStart(IOService* provider) {
 
     multitouch_interface->registerService();
 
+    timer_source = IOTimerEventSource::timerEventSource(this, OSMemberFunctionCast(IOTimerEventSource::Action, this, &VoodooI2CGoodixEventDriver::fingerLift));
+
+    if (!timer_source || work_loop->addEventSource(timer_source) != kIOReturnSuccess) {
+        IOLog("%s::Could not add timer source to work loop\n", getName());
+        return false;
+    }
+
     return true;
 }
 
@@ -121,6 +156,11 @@ void VoodooI2CGoodixEventDriver::handleStop(IOService* provider) {
         OSSafeReleaseNULL(transducers);
     }
 
+    if (timer_source) {
+        work_loop->removeEventSource(timer_source);
+        OSSafeReleaseNULL(timer_source);
+    }
+
     super::handleStop(provider);
 }
 
diff --git a/VoodooI2CGoodix/VoodooI2CGoodixEventDriver.hpp b/VoodooI2CGoodix/VoodooI2CGoodixEventDriver.hpp
index 89d7d71..92664f9 100644
--- a/VoodooI2CGoodix/VoodooI2CGoodixEventDriver.hpp
+++ b/VoodooI2CGoodix/VoodooI2CGoodixEventDriver.hpp
@@ -18,6 +18,7 @@
 
 #include <IOKit/IOLib.h>
 #include <IOKit/IOService.h>
+#include <IOKit/IOTimerEventSource.h>
 
 #include <IOKit/hidevent/IOHIDEventService.h>
 #include <IOKit/hidsystem/IOHIDTypes.h>
@@ -105,14 +106,23 @@ class EXPORT VoodooI2CGoodixEventDriver : public IOHIDEventService {
  protected:
     const char* name;
     bool awake = true;
-//    IOHIDInterface* hid_interface;
     VoodooI2CMultitouchInterface* multitouch_interface;
     OSArray* transducers;
 
  private:
-    OSSet* attached_hid_pointer_devices;
+    IOWorkLoop *work_loop;
+    IOTimerEventSource *timer_source;
+
+    UInt32 buttons = 0;
+    IOFixed last_x = 0;
+    IOFixed last_y = 0;
+    SInt32 last_id = 0;
+
+    int click_tick = 0;
 
     void dispatchDigitizerEvent(int logicalX, int logicalY, bool click);
+    void fingerLift();
+    void scheduleLift();
 };