Improve simple pointer protocol state query (#43)

* Fix pointer tests
* Use an Option to prevent future issues

Author: HadrienG2

src/proto/console/pointer/mod.rs

@@ -27,13 +27,18 @@ impl Pointer {
 
     /// Retrieves the pointer device's current state.
     ///
+    /// Will return None if the state has not changed since the last query.
+    ///
     /// # Errors
-    /// - `NotReady` is returned if the state hasn't changed since the last call.
     /// - `DeviceError` if there was an issue with the pointer device.
-    pub fn state(&self) -> Result<PointerState> {
+    pub fn state(&self) -> Result<Option<PointerState>> {
         let mut pointer_state = unsafe { mem::uninitialized() };
 
-        (self.get_state)(self, &mut pointer_state).into_with(|| pointer_state)
+        match (self.get_state)(self, &mut pointer_state) {
+            Status::Success => Ok(Some(pointer_state)),
+            Status::NotReady => Ok(None),
+            error => Err(error)
+        }
     }
 
     /// Returns a reference to the pointer device information.

uefi-test-runner/src/proto/console/pointer.rs

@@ -12,10 +12,11 @@ pub fn test(bt: &BootServices) {
             .reset(false)
             .expect("Failed to reset pointer device");
 
-        if let Ok(state) = pointer.state() {
-            info!("Pointer State: {:#?}", state);
+        let state = pointer.state().expect("Failed to retrieve pointer state");
+        if let Some(state) = state {
+            info!("New pointer State: {:#?}", state);
         } else {
-            error!("Failed to retrieve pointer state");
+            info!("Pointer state has not changed since the last query");
         }
     } else {
         warn!("No pointer device found");