message: forward cursor winit leave/enter events
diff: @@ -88,6 +88,9 @@ pub trait EventHandler {
  /// and relative x and y coordinates compared to its last position.
  fn mouse_motion_event(&mut self, _ctx: &mut Context, _x: f32, _y: f32, _dx: f32, _dy: f32) {}
  + ///
  + fn mouse_enter_or_leave(&mut self, _ctx: &mut Context, _entered: bool) {}
  +
  /// The mousewheel was scrolled, vertically (y, positive away from and negative toward the user)
  /// or horizontally (x, positive to the right and negative to the left).
  fn mouse_wheel_event(&mut self, _ctx: &mut Context, _x: f32, _y: f32) {}
  @@ -249,6 +252,12 @@ where
  let delta = mouse::delta(ctx);
  state.mouse_motion_event(ctx, position.x, position.y, delta.x, delta.y);
  }
  + WindowEvent::CursorEntered { .. } => {
  + state.mouse_enter_or_leave(ctx, true);
  + }
  + WindowEvent::CursorLeft { .. } => {
  + state.mouse_enter_or_leave(ctx, false);
  + }
  _x => {
  // trace!("ignoring window event {:?}", x);
  }
  