Configurable capture backend (#150)

capture backend can now be configured via the `capture_backend` cli argument / config entry

src/capture.rs

@@ -4,9 +4,14 @@ use futures_core::Stream;
 
 use crate::{
     client::{ClientEvent, ClientHandle},
+    config::CaptureBackend,
     event::Event,
 };
 
+use self::error::CaptureCreationError;
+
+pub mod error;
+
 #[cfg(all(unix, feature = "libei", not(target_os = "macos")))]
 pub mod libei;
 
@@ -25,24 +30,42 @@ pub mod x11;
 /// fallback input capture (does not produce events)
 pub mod dummy;
 
-pub async fn create() -> Box<dyn InputCapture<Item = io::Result<(ClientHandle, Event)>>> {
+#[allow(unreachable_code)]
+pub async fn create(
+    backend: Option<CaptureBackend>,
+) -> Result<Box<dyn InputCapture<Item = io::Result<(ClientHandle, Event)>>>, CaptureCreationError> {
+    if let Some(backend) = backend {
+        return match backend {
+            #[cfg(all(unix, feature = "libei", not(target_os = "macos")))]
+            CaptureBackend::InputCapturePortal => {
+                Ok(Box::new(libei::LibeiInputCapture::new().await?))
+            }
+            #[cfg(all(unix, feature = "wayland", not(target_os = "macos")))]
+            CaptureBackend::LayerShell => Ok(Box::new(wayland::WaylandInputCapture::new()?)),
+            #[cfg(all(unix, feature = "x11", not(target_os = "macos")))]
+            CaptureBackend::X11 => Ok(Box::new(x11::X11InputCapture::new()?)),
+            #[cfg(windows)]
+            CaptureBackend::Windows => Ok(Box::new(windows::WindowsInputCapture::new())),
+            #[cfg(target_os = "macos")]
+            CaptureBackend::MacOs => Ok(Box::new(macos::MacOSInputCapture::new()?)),
+            CaptureBackend::Dummy => Ok(Box::new(dummy::DummyInputCapture::new())),
+        };
+    }
+
     #[cfg(target_os = "macos")]
     match macos::MacOSInputCapture::new() {
-        Ok(p) => return Box::new(p),
+        Ok(p) => return Ok(Box::new(p)),
         Err(e) => log::info!("macos input capture not available: {e}"),
     }
 
     #[cfg(windows)]
-    match windows::WindowsInputCapture::new() {
-        Ok(p) => return Box::new(p),
-        Err(e) => log::info!("windows input capture not available: {e}"),
-    }
+    return Ok(Box::new(windows::WindowsInputCapture::new()));
 
     #[cfg(all(unix, feature = "libei", not(target_os = "macos")))]
     match libei::LibeiInputCapture::new().await {
         Ok(p) => {
             log::info!("using libei input capture");
-            return Box::new(p);
+            return Ok(Box::new(p));
         }
         Err(e) => log::info!("libei input capture not available: {e}"),
     }
@@ -51,7 +74,7 @@ pub async fn create() -> Box<dyn InputCapture<Item = io::Result<(ClientHandle, E
     match wayland::WaylandInputCapture::new() {
         Ok(p) => {
             log::info!("using layer-shell input capture");
-            return Box::new(p);
+            return Ok(Box::new(p));
         }
         Err(e) => log::info!("layer_shell input capture not available: {e}"),
     }
@@ -60,13 +83,13 @@ pub async fn create() -> Box<dyn InputCapture<Item = io::Result<(ClientHandle, E
     match x11::X11InputCapture::new() {
         Ok(p) => {
             log::info!("using x11 input capture");
-            return Box::new(p);
+            return Ok(Box::new(p));
         }
         Err(e) => log::info!("x11 input capture not available: {e}"),
     }
 
     log::error!("falling back to dummy input capture");
-    Box::new(dummy::DummyInputCapture::new())
+    Ok(Box::new(dummy::DummyInputCapture::new()))
 }
 
 pub trait InputCapture: Stream<Item = io::Result<(ClientHandle, Event)>> + Unpin {