fix: libinput dwt support (#196)

src/device.rs

@@ -4,7 +4,7 @@ extern crate nix;
 use anyhow::bail;
 use derive_where::derive_where;
 use evdev::uinput::{VirtualDevice, VirtualDeviceBuilder};
-use evdev::{AttributeSet, Device, FetchEventsSynced, Key, RelativeAxisType};
+use evdev::{AttributeSet, BusType, Device, FetchEventsSynced, InputId, Key, RelativeAxisType};
 use nix::sys::inotify::{AddWatchFlags, InitFlags, Inotify};
 use std::collections::HashMap;
 use std::error::Error;
@@ -38,7 +38,7 @@ static MOUSE_BTNS: [&str; 20] = [
 ];
 
 // Credit: https://github.com/mooz/xkeysnail/blob/bf3c93b4fe6efd42893db4e6588e5ef1c4909cfb/xkeysnail/output.py#L10-L32
-pub fn output_device() -> Result<VirtualDevice, Box<dyn Error>> {
+pub fn output_device(bus_type: Option<BusType>) -> Result<VirtualDevice, Box<dyn Error>> {
     let mut keys: AttributeSet<Key> = AttributeSet::new();
     for code in Key::KEY_RESERVED.code()..Key::BTN_TRIGGER_HAPPY40.code() {
         let key = Key::new(code);
@@ -56,6 +56,8 @@ pub fn output_device() -> Result<VirtualDevice, Box<dyn Error>> {
     relative_axes.insert(RelativeAxisType::REL_MISC);
 
     let device = VirtualDeviceBuilder::new()?
+        // These are taken from https://docs.rs/evdev/0.12.0/src/evdev/uinput.rs.html#183-188
+        .input_id(InputId::new(bus_type.unwrap_or(BusType::BUS_USB), 0x1234, 0x5678, 0x111))
         .name(&InputDevice::current_name())
         .with_keys(&keys)?
         .with_relative_axes(&relative_axes)?
@@ -190,6 +192,10 @@ impl InputDevice {
     fn device_name(&self) -> &str {
         self.device.name().unwrap_or("<Unnamed device>")
     }
+
+    pub fn bus_type(&self) -> BusType {
+        self.device.input_id().bus_type()
+    }
 }
 
 impl InputDevice {

src/main.rs

@@ -105,14 +105,9 @@ fn main() -> anyhow::Result<()> {
     let watch_config = watch.contains(&WatchTargets::Config);
 
     // Event listeners
-    let output_device = match output_device() {
-        Ok(output_device) => output_device,
-        Err(e) => bail!("Failed to prepare an output device: {}", e),
-    };
     let timer = TimerFd::new(ClockId::CLOCK_MONOTONIC, TimerFlags::empty())?;
     let timer_fd = timer.as_raw_fd();
     let delay = Duration::from_millis(config.keypress_delay_ms);
-    let mut handler = EventHandler::new(output_device, timer, &config.default_mode, delay);
     let mut input_devices = match get_input_devices(&device_filter, &ignore_filter, mouse, watch_devices) {
         Ok(input_devices) => input_devices,
         Err(e) => bail!("Failed to prepare input devices: {}", e),
@@ -120,6 +115,11 @@ fn main() -> anyhow::Result<()> {
     let device_watcher = device_watcher(watch_devices).context("Setting up device watcher")?;
     let config_watcher = config_watcher(watch_config, &config_path).context("Setting up config watcher")?;
     let watchers: Vec<_> = device_watcher.iter().chain(config_watcher.iter()).collect();
+    let output_device = match output_device(input_devices.values().next().map(InputDevice::bus_type)) {
+        Ok(output_device) => output_device,
+        Err(e) => bail!("Failed to prepare an output device: {}", e),
+    };
+    let mut handler = EventHandler::new(output_device, timer, &config.default_mode, delay);
 
     // Main loop
     loop {