Restore logind as a default feature

Cargo.toml

@@ -43,7 +43,7 @@ slog-term = "2.3"
 gl_generator = { version = "0.10", optional = true }
 
 [features]
-default = ["backend_winit", "backend_drm_legacy", "backend_drm_gbm", "backend_drm_egl", "backend_libinput", "backend_udev", "backend_session", "renderer_glium", "xwayland", "wayland_frontend"]
+default = ["backend_winit", "backend_drm_legacy", "backend_drm_gbm", "backend_drm_egl", "backend_libinput", "backend_udev", "backend_session_logind", "renderer_glium", "xwayland", "wayland_frontend"]
 backend_winit = ["winit", "wayland-server/dlopen", "wayland-client/dlopen", "backend_egl", "renderer_gl", "use_system_lib"]
 backend_drm = ["drm"]
 backend_drm_legacy = ["backend_drm"]

anvil/Cargo.toml

@@ -25,7 +25,7 @@ features = [ "renderer_glium", "backend_egl", "wayland_frontend" ]
 gl_generator = "0.10"
 
 [features]
-default = [ "winit", "egl", "udev" ]
+default = [ "winit", "egl", "udev", "logind" ]
 egl = [ "smithay/use_system_lib" ]
 winit = [ "smithay/backend_winit" ]
 udev = [ "smithay/backend_libinput", "smithay/backend_drm_legacy", "smithay/backend_drm_gbm", "smithay/backend_drm_egl", "smithay/backend_udev", "smithay/backend_session" ]

src/utils/signaling.rs

@@ -0,0 +1,39 @@
+use std::{rc::Rc, cell::RefCell};
+
+struct SignalerInner<E> {
+    closures: RefCell<Vec<Box<dyn FnMut(&mut E)>>>
+}
+
+impl<E> SignalerInner<E> {
+    fn new() -> SignalerInner<E> {
+        SignalerInner {
+            closures: RefCell::new(Vec::new())
+        }
+    }
+}
+
+pub struct Signaler<E> {
+    inner: Rc<SignalerInner<E>>
+}
+
+impl<E> Clone for Signaler<E> {
+    fn clone(&self) -> Signaler<E> {
+        Signaler {
+            inner: self.inner.clone()
+        }
+    }
+}
+
+impl<E> Signaler<E> {
+    pub fn new() -> Signaler<E> {
+        Signaler {
+            inner: Rc::new(SignalerInner::new())
+        }
+    }
+
+    fn register_closure<F: FnMut(&mut E) + 'static>(&self, f: F) {
+    }
+
+    fn send_event(&self, event: &mut E) {
+    }
+}