Merge pull request #185 from aragon999/feature/only-register-axes-if-used

Enable axis in virtual_input device only when needed

src/logid/InputDevice.cpp

@@ -77,26 +77,28 @@ InputDevice::~InputDevice()
 
 void InputDevice::registerKey(uint code)
 {
-    if (registered_keys[code]) {
+    // TODO: Maybe print error message, if wrong code is passed?
+    if(registered_keys[code] || code > KEY_CNT) {
         return;
     }
 
-    libevdev_uinput_destroy(ui_device);
+    _enableEvent(EV_KEY, code);
-
-    libevdev_enable_event_code(device, EV_KEY, code, nullptr);
-    int err = libevdev_uinput_create_from_device(device,
-            LIBEVDEV_UINPUT_OPEN_MANAGED, &ui_device);
-
-    if(err != 0) {
-        libevdev_free(device);
-        device = nullptr;
-        ui_device = nullptr;
-        throw std::system_error(-err, std::generic_category());
-    }
 
     registered_keys[code] = true;
 }
 
+void InputDevice::registerAxis(uint axis)
+{
+    // TODO: Maybe print error message, if wrong code is passed?
+    if(registered_axis[axis] || axis > REL_CNT) {
+        return;
+    }
+
+    _enableEvent(EV_REL, axis);
+
+    registered_axis[axis] = true;
+}
+
 void InputDevice::moveAxis(uint axis, int movement)
 {
     _sendEvent(EV_REL, axis, movement);
@@ -148,6 +150,23 @@ uint InputDevice::_toEventCode(uint type, const std::string& name)
     return code;
 }
 
+void InputDevice::_enableEvent(const uint type, const uint code)
+{
+    libevdev_uinput_destroy(ui_device);
+
+    libevdev_enable_event_code(device, type, code, nullptr);
+
+    int err = libevdev_uinput_create_from_device(device,
+            LIBEVDEV_UINPUT_OPEN_MANAGED, &ui_device);
+
+    if(err != 0) {
+        libevdev_free(device);
+        device = nullptr;
+        ui_device = nullptr;
+        throw std::system_error(-err, std::generic_category());
+    }
+}
+
 void InputDevice::_sendEvent(uint type, uint code, int value)
 {
     libevdev_uinput_write_event(ui_device, type, code, value);

src/logid/InputDevice.h

@@ -45,6 +45,7 @@ namespace logid
         ~InputDevice();
 
         void registerKey(uint code);
+        void registerAxis(uint axis);
         void moveAxis(uint axis, int movement);
         void pressKey(uint code);
         void releaseKey(uint code);
@@ -55,10 +56,12 @@ namespace logid
 
     private:
         void _sendEvent(uint type, uint code, int value);
+        void _enableEvent(uint type, uint name);
 
         static uint _toEventCode(uint type, const std::string& name);
 
         bool registered_keys[KEY_CNT];
+        bool registered_axis[REL_CNT];
         libevdev* device;
         libevdev_uinput* ui_device{};
     };

src/logid/actions/gesture/AxisGesture.cpp

@@ -104,9 +104,11 @@ AxisGesture::Config::Config(Device *device, libconfig::Setting &setting) :
         auto& axis = setting.lookup("axis");
         if(axis.isNumber()) {
             _axis = axis;
+            virtual_input->registerAxis(_axis);
         } else if(axis.getType() == libconfig::Setting::TypeString) {
             try {
                 _axis = virtual_input->toAxisCode(axis);
+                virtual_input->registerAxis(_axis);
             } catch(InputDevice::InvalidEventCode& e) {
                 logPrintf(WARN, "Line %d: Invalid axis %s, skipping."
                         , axis.getSourceLine(), axis.c_str());
@@ -138,8 +140,11 @@ AxisGesture::Config::Config(Device *device, libconfig::Setting &setting) :
         // Ignore
     }
 
-    if(InputDevice::getLowResAxis(_axis) != -1)
+    int low_res_axis = InputDevice::getLowResAxis(_axis);
+    if(low_res_axis != -1) {
         _multiplier *= 120;
+        virtual_input->registerAxis(low_res_axis);
+    }
 }
 
 unsigned int AxisGesture::Config::axis() const
@@ -168,4 +173,4 @@ void AxisGesture::Config::setHiresMultiplier(double multiplier)
     }
 
     _hires_multiplier = multiplier;
-}
+}