ScrollBarNode.h

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#pragma once
 
#include "UI/Layout/RectNode.h"
 
#include <functional>
 
namespace z8::ui {
 
enum class ScrollBarOrientation { Horizontal, Vertical };
 
class ScrollBarNode : public RectNode {
private:
  float ViewportExtent = 0.0f;
  float ContentExtent = 0.0f;
  float Value = 0.0f;
  float Maximum = 0.0f;
  float DragScale = 0.0f;
  bool DraggingThumb = false;
 
public:
  RectNode *ThumbNode;
  ScrollBarOrientation Orientation;
  std::function<void(float)> ValueChanged;
 
  explicit ScrollBarNode(
      ScrollBarOrientation orientation = ScrollBarOrientation::Vertical);
 
  const char *TypeName() const override { return "ScrollBar"; }
  EventReply OnMouseDown(MouseMovArgs args) override;
  EventReply OnMouseDrag(MouseMovArgs args) override;
  EventReply OnMouseUp(MouseMovArgs args) override;
  void OnPointerCaptureLost() override { DraggingThumb = false; }
  void OnAfterLayout() override;
 
  void SetMetrics(float viewportExtent, float contentExtent);
  void SetValue(float value, bool notify = true);
 
private:
  void OnVisualStateChanged() override;
};
 
} // namespace z8::ui