Allow relative mouse movement to be negative

src/backend/input.rs

@@ -239,22 +239,22 @@ impl PointerAxisEvent for UnusedEvent {
 /// Trait for pointer events generated by relative device movement.
 pub trait PointerMotionEvent: Event {
     /// Delta between the last and new pointer device position interpreted as pixel movement
-    fn delta(&self) -> (u32, u32) {
+    fn delta(&self) -> (i32, i32) {
         (self.delta_x(), self.delta_y())
     }
 
     /// Delta on the x axis between the last and new pointer device position interpreted as pixel movement
-    fn delta_x(&self) -> u32;
+    fn delta_x(&self) -> i32;
     /// Delta on the y axis between the last and new pointer device position interpreted as pixel movement
-    fn delta_y(&self) -> u32;
+    fn delta_y(&self) -> i32;
 }
 
 impl PointerMotionEvent for UnusedEvent {
-    fn delta_x(&self) -> u32 {
+    fn delta_x(&self) -> i32 {
         match *self {}
     }
 
-    fn delta_y(&self) -> u32 {
+    fn delta_y(&self) -> i32 {
         match *self {}
     }
 }

src/backend/libinput.rs

@@ -133,11 +133,11 @@ impl backend::Event for event::pointer::PointerMotionEvent {
 }
 
 impl backend::PointerMotionEvent for event::pointer::PointerMotionEvent {
-    fn delta_x(&self) -> u32 {
-        self.dx() as u32
+    fn delta_x(&self) -> i32 {
+        self.dx() as i32
     }
-    fn delta_y(&self) -> u32 {
-        self.dy() as u32
+    fn delta_y(&self) -> i32 {
+        self.dy() as i32
     }
 }