feat: Scrollbar auto collapse.

2 files changed, 12 insertions, 0 deletions

diff --git a/include/cru/platform/gui/UiApplication.hpp b/include/cru/platform/gui/UiApplication.hpp
index ba85020a..5a5b0b13 100644
--- a/include/cru/platform/gui/UiApplication.hpp
+++ b/include/cru/platform/gui/UiApplication.hpp
@@ -79,6 +79,9 @@ class TimerAutoCanceler {
   }
 
   TimerAutoCanceler& operator=(TimerAutoCanceler&& other) {
+    if (&other == this) {
+      return *this;
+    }
     Reset(other.id_);
     other.id_ = 0;
     return *this;
@@ -101,6 +104,8 @@ class TimerAutoCanceler {
     id_ = id;
   }
 
+  explicit operator bool() const { return id_; }
+
  private:
   long long id_;
 };
diff --git a/include/cru/ui/render/ScrollBar.hpp b/include/cru/ui/render/ScrollBar.hpp
index fc2910c4..7cfd2576 100644
--- a/include/cru/ui/render/ScrollBar.hpp
+++ b/include/cru/ui/render/ScrollBar.hpp
@@ -94,6 +94,11 @@ class ScrollBar : public Object {
   void SetCursor();
   void RestoreCursor();
 
+  void BeginAutoCollapseTimer();
+  void StopAutoCollapseTimer();
+
+  void OnMouseLeave();
+
  protected:
   gsl::not_null<ScrollRenderObject*> render_object_;
 
@@ -118,6 +123,8 @@ class ScrollBar : public Object {
   Event<Scroll> scroll_attempt_event_;
 
   std::optional<std::shared_ptr<platform::gui::ICursor>> old_cursor_;
+
+  platform::gui::TimerAutoCanceler auto_collapse_timer_canceler_;
 };
 
 class HorizontalScrollBar : public ScrollBar {