sort by location

src/arch/InputHandler/LinuxInputManager.cpp

@@ -13,8 +13,16 @@
 #include <dirent.h>
 #endif
 
+#if defined(HAVE_FCNTL_H)
+#include <fcntl.h>
+#endif
+
+#include <linux/input.h>
+
 #include <errno.h>
 
+Preference<bool> g_bInputLinuxOrderByLocation( "InputLinuxOrderByLocation", false );
+
 RString getDevice(RString inputDir, RString type)
 {
 	RString result = "";
@@ -78,13 +86,73 @@ LinuxInputManager::LinuxInputManager()
 			LOG->Info("LinuxInputManager: %s seems to have no eventNN or jsNN.", dName.c_str() );
 	}
 
-	// Sort devices for more consistent numbering.
-	std::sort(m_vsPendingEventDevices.begin(), m_vsPendingEventDevices.end(), cmpDevices);
-	std::sort(m_vsPendingJoystickDevices.begin(), m_vsPendingJoystickDevices.end(), cmpDevices);
+	if(g_bInputLinuxOrderByLocation)
+	{
+		// use Presort to sort the devices by unique location (like USB port/hub number.)
+		PresortPhysical(m_vsPendingEventDevices, "event");
+		PresortPhysical(m_vsPendingJoystickDevices, "js");
+	}
+	else
+	{
+		// Sort devices for more consistent numbering.
+		std::sort(m_vsPendingEventDevices.begin(), m_vsPendingEventDevices.end(), cmpDevices);
+		std::sort(m_vsPendingJoystickDevices.begin(), m_vsPendingJoystickDevices.end(), cmpDevices);
+	}
 
 	closedir(sysClassInput);
 }
 
+
+static bool presort_cmpDevices(LinuxInputSort a, LinuxInputSort b)
+{
+	return a.UniqueString < b.UniqueString;
+}
+
+void LinuxInputManager::PresortPhysical(std::vector<RString>& sortingArray, RString sortBy)
+{
+	m_vPreSort.clear();
+
+	for (RString &dev : sortingArray)
+	{
+		LinuxInputSort entry;
+
+		entry.DeviceName = dev;
+		entry.UniqueString = "";
+
+		int m_iFD = open(getDevice(dev, sortBy.c_str()).c_str(), O_RDWR);
+
+		if(m_iFD >= 0)
+		{
+			char szLocation[1024];
+
+			// EVIOCGPHYS can return values like "usb-0000:0d:00.3-4"
+			// telling us where the device is located physically on the computer.
+			if(ioctl(m_iFD, EVIOCGPHYS(sizeof(szLocation)), szLocation) != -1)
+			{
+				entry.UniqueString += szLocation;
+			}
+
+			close(m_iFD);
+		}
+
+		// in the event we didn't get a unique location from ioctl
+		// default to the name so that sorting by number still works as intended.
+		entry.UniqueString += entry.DeviceName;
+
+		m_vPreSort.push_back(entry);
+	}
+
+	std::sort(m_vPreSort.begin(), m_vPreSort.end(), presort_cmpDevices);
+
+	sortingArray.clear();
+
+	for (LinuxInputSort &dev : m_vPreSort)
+	{
+		// LOG->Info("%s -> %s", dev.DeviceName.c_str(), dev.UniqueString.c_str());
+		sortingArray.push_back(dev.DeviceName);
+	}
+}
+
 void LinuxInputManager::InitDriver(InputHandler_Linux_Event* driver)
 {
 	m_EventDriver = driver;

src/arch/InputHandler/LinuxInputManager.h

@@ -10,6 +10,13 @@ class InputHandler_Linux_Event;
 // Enumerates the input devices on the system and dispatches them to
 // IH_Linux_Event and IH_Linux_Joystick as appropriate.
 
+// Helper struct for keeping track of inputs.
+struct LinuxInputSort
+{
+    RString DeviceName;
+    RString UniqueString;
+};
+
 class LinuxInputManager
 {
 public:
@@ -18,6 +25,9 @@ public:
 	void InitDriver(InputHandler_Linux_Event* drv);
 	~LinuxInputManager();
 private:
+	std::vector<LinuxInputSort> m_vPreSort;
+	void PresortPhysical(std::vector<RString>& sortingArray, RString sortBy);
+
 	bool m_bEventEnabled;
 	InputHandler_Linux_Event* m_EventDriver;
 	std::vector<RString> m_vsPendingEventDevices;