Merge branch 'master' of https://github.com/crupest/CruUI

1 files changed, 218 insertions, 0 deletions

diff --git a/include/cru/ui/render/ScrollBar.hpp b/include/cru/ui/render/ScrollBar.hpp
new file mode 100644
index 00000000..3293e9d0
--- /dev/null
+++ b/include/cru/ui/render/ScrollBar.hpp
@@ -0,0 +1,218 @@
+#pragma once
+#include "Base.hpp"
+#include "cru/common/Base.hpp"
+#include "cru/common/Event.hpp"
+#include "cru/platform/graphics/Base.hpp"
+#include "cru/platform/graphics/Geometry.hpp"
+#include "cru/platform/graphics/Painter.hpp"
+#include "cru/platform/gui/Cursor.hpp"
+#include "cru/platform/gui/UiApplication.hpp"
+#include "cru/ui/Base.hpp"
+#include "cru/ui/controls/Control.hpp"
+
+#include <gsl/pointers>
+#include <memory>
+#include <optional>
+
+namespace cru::ui::render {
+class ScrollRenderObject;
+
+enum class ScrollKind { Absolute, Relative, Page, Line };
+
+struct Scroll {
+  Direction direction;
+  ScrollKind kind;
+  // For absolute, the new scroll position. Otherwise, offset.
+  float value;
+};
+
+enum class ScrollBarAreaKind {
+  UpArrow,    // Line up
+  DownArrow,  // Line down
+  UpSlot,     // Page up
+  DownSlot,   // Page down
+  Thumb
+};
+
+class ScrollBar : public Object {
+ public:
+  ScrollBar(gsl::not_null<ScrollRenderObject*> render_object,
+            Direction direction);
+
+  CRU_DELETE_COPY(ScrollBar)
+  CRU_DELETE_MOVE(ScrollBar)
+
+  ~ScrollBar() override;
+
+ public:
+  Direction GetDirection() const { return direction_; }
+
+  bool IsEnabled() const { return is_enabled_; }
+  void SetEnabled(bool value);
+
+  bool IsExpanded() const { return is_expanded_; }
+  void SetExpanded(bool value);
+
+  void Draw(platform::graphics::IPainter* painter);
+
+  IEvent<Scroll>* ScrollAttemptEvent() { return &scroll_attempt_event_; }
+
+  void InstallHandlers(controls::Control* control);
+  void UninstallHandlers() { InstallHandlers(nullptr); }
+
+  gsl::not_null<std::shared_ptr<platform::graphics::IBrush>>
+  GetCollapsedThumbBrush() const;
+  gsl::not_null<std::shared_ptr<platform::graphics::IBrush>>
+  GetExpandedThumbBrush() const;
+  gsl::not_null<std::shared_ptr<platform::graphics::IBrush>>
+  GetExpandedSlotBrush() const;
+  gsl::not_null<std::shared_ptr<platform::graphics::IBrush>>
+  GetExpandedArrowBrush() const;
+  gsl::not_null<std::shared_ptr<platform::graphics::IBrush>>
+  GetExpandedArrowBackgroundBrush() const;
+
+ protected:
+  void OnDraw(platform::graphics::IPainter* painter, bool expand);
+
+  virtual void DrawUpArrow(platform::graphics::IPainter* painter,
+                           const Rect& area) = 0;
+  virtual void DrawDownArrow(platform::graphics::IPainter* painter,
+                             const Rect& area) = 0;
+
+  std::optional<ScrollBarAreaKind> ExpandedHitTest(const Point& point);
+
+  virtual bool IsShowBar() = 0;
+
+  virtual std::optional<Rect> GetExpandedAreaRect(
+      ScrollBarAreaKind area_kind) = 0;
+  virtual std::optional<Rect> GetCollapsedTriggerExpandAreaRect() = 0;
+  virtual std::optional<Rect> GetCollapsedThumbRect() = 0;
+
+  virtual float CalculateNewScrollPosition(const Rect& thumb_original_rect,
+                                           const Point& mouse_offset) = 0;
+
+ private:
+  void SetCursor();
+  void RestoreCursor();
+
+  void BeginAutoCollapseTimer();
+  void StopAutoCollapseTimer();
+
+  void OnMouseLeave();
+
+ protected:
+  gsl::not_null<ScrollRenderObject*> render_object_;
+
+  std::unique_ptr<platform::graphics::IGeometry> arrow_geometry_;
+
+ private:
+  Direction direction_;
+
+  bool is_enabled_ = true;
+
+  bool is_expanded_ = false;
+
+  std::shared_ptr<platform::graphics::IBrush> collapsed_thumb_brush_;
+  std::shared_ptr<platform::graphics::IBrush> expanded_thumb_brush_;
+  std::shared_ptr<platform::graphics::IBrush> expanded_slot_brush_;
+  std::shared_ptr<platform::graphics::IBrush> expanded_arrow_brush_;
+  std::shared_ptr<platform::graphics::IBrush> expanded_arrow_background_brush_;
+
+  Rect move_thumb_thumb_original_rect_;
+  std::optional<Point> move_thumb_start_;
+
+  EventRevokerListGuard event_guard_;
+
+  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 {
+ public:
+  explicit HorizontalScrollBar(
+      gsl::not_null<ScrollRenderObject*> render_object);
+
+  CRU_DELETE_COPY(HorizontalScrollBar)
+  CRU_DELETE_MOVE(HorizontalScrollBar)
+
+  ~HorizontalScrollBar() override = default;
+
+ protected:
+  void DrawUpArrow(platform::graphics::IPainter* painter,
+                   const Rect& area) override;
+  void DrawDownArrow(platform::graphics::IPainter* painter,
+                     const Rect& area) override;
+
+  bool IsShowBar() override;
+
+  std::optional<Rect> GetExpandedAreaRect(ScrollBarAreaKind area_kind) override;
+  std::optional<Rect> GetCollapsedTriggerExpandAreaRect() override;
+  std::optional<Rect> GetCollapsedThumbRect() override;
+
+  float CalculateNewScrollPosition(const Rect& thumb_original_rect,
+                                   const Point& mouse_offset) override;
+};
+
+class VerticalScrollBar : public ScrollBar {
+ public:
+  explicit VerticalScrollBar(gsl::not_null<ScrollRenderObject*> render_object);
+
+  CRU_DELETE_COPY(VerticalScrollBar)
+  CRU_DELETE_MOVE(VerticalScrollBar)
+
+  ~VerticalScrollBar() override = default;
+
+ protected:
+  void DrawUpArrow(platform::graphics::IPainter* painter,
+                   const Rect& area) override;
+  void DrawDownArrow(platform::graphics::IPainter* painter,
+                     const Rect& area) override;
+
+  bool IsShowBar() override;
+
+  std::optional<Rect> GetExpandedAreaRect(ScrollBarAreaKind area_kind) override;
+  std::optional<Rect> GetCollapsedTriggerExpandAreaRect() override;
+  std::optional<Rect> GetCollapsedThumbRect() override;
+
+  float CalculateNewScrollPosition(const Rect& thumb_original_rect,
+                                   const Point& mouse_offset) override;
+};
+
+// A delegate to draw scrollbar and register related events.
+class ScrollBarDelegate : public Object {
+ public:
+  explicit ScrollBarDelegate(gsl::not_null<ScrollRenderObject*> render_object);
+
+  CRU_DELETE_COPY(ScrollBarDelegate)
+  CRU_DELETE_MOVE(ScrollBarDelegate)
+
+  ~ScrollBarDelegate() override = default;
+
+ public:
+  bool IsHorizontalBarEnabled() const { return horizontal_bar_.IsEnabled(); }
+  void SetHorizontalBarEnabled(bool value) {
+    horizontal_bar_.SetEnabled(value);
+  }
+
+  bool IsVerticalBarEnabled() const { return horizontal_bar_.IsEnabled(); }
+  void SetVerticalBarEnabled(bool value) { horizontal_bar_.SetEnabled(value); }
+
+  IEvent<Scroll>* ScrollAttemptEvent() { return &scroll_attempt_event_; }
+
+  void DrawScrollBar(platform::graphics::IPainter* painter);
+
+  void InstallHandlers(controls::Control* control);
+  void UninstallHandlers() { InstallHandlers(nullptr); }
+
+ private:
+  gsl::not_null<ScrollRenderObject*> render_object_;
+
+  HorizontalScrollBar horizontal_bar_;
+  VerticalScrollBar vertical_bar_;
+
+  Event<Scroll> scroll_attempt_event_;
+};
+}  // namespace cru::ui::render