feat: add MouseEventKind::get_button() (#1111)

* feat: add `MouseEventKind::get_button()`

* style: fix formatting

Co-authored-by: Orhun Parmaksız <orhunparmaksiz@gmail.com>

* docs: Document `get_button` method for `MouseEventKind`

* Rename get_button to button in MouseEventKind

---------

Co-authored-by: Bishops-exe <Bishops-exe@users.noreply.github.com>
Co-authored-by: Orhun Parmaksız <orhunparmaksiz@gmail.com>

Author: Bishops-exe

src/event.rs

@@ -799,6 +799,21 @@ pub enum MouseEventKind {
     ScrollRight,
 }
 
+impl MouseEventKind {
+    /// Returns the mouse button connected with the event.
+    ///
+    /// This will return `Some(MouseButton)` for `Down`, `Up`, and `Drag` events.
+    /// For other events, like `Moved` or `Scroll...`, it returns `None`.
+    pub fn button(&self) -> Option<MouseButton> {
+        match self {
+            MouseEventKind::Down(button)
+            | MouseEventKind::Up(button)
+            | MouseEventKind::Drag(button) => Some(*button),
+            _ => None,
+        }
+    }
+}
+
 /// Represents a mouse button.
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 #[cfg_attr(feature = "derive-more", derive(IsVariant))]
@@ -1708,4 +1723,19 @@ mod tests {
             assert_eq!(event.as_key_event(), None);
         }
     }
+
+    #[test]
+    fn event_button() {
+        let event = MouseEventKind::Down(MouseButton::Left);
+        assert_eq!(event.button(), Some(MouseButton::Left));
+
+        let event = MouseEventKind::Up(MouseButton::Right);
+        assert_eq!(event.button(), Some(MouseButton::Right));
+
+        let event = MouseEventKind::Drag(MouseButton::Middle);
+        assert_eq!(event.button(), Some(MouseButton::Middle));
+
+        let event = MouseEventKind::Moved;
+        assert_eq!(event.button(), None);
+    }
 }