Register keys for keypress only when needed

there seems to be an issue that with too many registered events some window
manager cannot recognize the device as input device with systemd 247.

PixlOne#166

src/logid/InputDevice.cpp

@@ -43,12 +43,7 @@ InputDevice::InputDevice(const char* name)
     device = libevdev_new();
     libevdev_set_name(device, name);
 
-    ///TODO: Is it really a good idea to enable all events?
     libevdev_enable_event_type(device, EV_KEY);
-    // KEY_ROTATE_LOCK_TOGGLE is the highest key mapped by
-    // /usr/share/X11/xkb/keycodes/evdev
-    for(unsigned int i = 0; i <= KEY_ROTATE_LOCK_TOGGLE; i++)
-        libevdev_enable_event_code(device, EV_KEY, i, nullptr);
     libevdev_enable_event_type(device, EV_REL);
     for(unsigned int i = 0; i < REL_CNT; i++)
         libevdev_enable_event_code(device, EV_REL, i, nullptr);
@@ -68,6 +63,18 @@ InputDevice::~InputDevice()
     libevdev_free(device);
 }
 
+void InputDevice::registerKey(uint 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);
+        throw std::system_error(-err, std::generic_category());
+    }
+}
+
 void InputDevice::moveAxis(uint axis, int movement)
 {
     _sendEvent(EV_REL, axis, movement);
@@ -123,4 +130,4 @@ void InputDevice::_sendEvent(uint type, uint code, int value)
 {
     libevdev_uinput_write_event(ui_device, type, code, value);
     libevdev_uinput_write_event(ui_device, EV_SYN, SYN_REPORT, 0);
-}
+}

src/logid/InputDevice.h

@@ -44,6 +44,7 @@ namespace logid
         explicit InputDevice(const char *name);
         ~InputDevice();
 
+        void registerKey(uint code);
         void moveAxis(uint axis, int movement);
         void pressKey(uint code);
         void releaseKey(uint code);

src/logid/actions/KeypressAction.cpp

@@ -64,9 +64,11 @@ KeypressAction::Config::Config(Device* device, libconfig::Setting& config) :
                 auto& key = keys[i];
                 if(key.isNumber()) {
                     _keys.push_back(key);
+                    virtual_input->registerKey(key);
                 } else if(key.getType() == libconfig::Setting::TypeString) {
                     try {
                         _keys.push_back(virtual_input->toKeyCode(key));
+                        virtual_input->registerKey(virtual_input->toKeyCode(key));
                     } catch(InputDevice::InvalidEventCode& e) {
                         logPrintf(WARN, "Line %d: Invalid keycode %s, skipping."
                             , key.getSourceLine(), key.c_str());