1 files changed, 145 insertions, 0 deletions
diff --git a/src/ui/render/ScrollBarDelegate.cpp b/src/ui/render/ScrollBarDelegate.cpp
new file mode 100644
index 00000000..2814c567
--- /dev/null
+++ b/src/ui/render/ScrollBarDelegate.cpp
@@ -0,0 +1,145 @@
+#include "cru/ui/render/ScrollBarDelegate.hpp"
+
+#include "../Helper.hpp"
+#include "cru/common/Base.hpp"
+#include "cru/platform/GraphBase.hpp"
+#include "cru/platform/graphics/Factory.hpp"
+#include "cru/platform/graphics/Painter.hpp"
+#include "cru/ui/render/ScrollRenderObject.hpp"
+
+#include <gsl/pointers>
+#include <optional>
+
+namespace cru::ui::render {
+constexpr float kScrollBarCollapseThumbWidth = 2;
+
+ScrollBar::ScrollBar(gsl::not_null<ScrollRenderObject*> render_object)
+    : render_object_(render_object) {
+  // TODO: Use theme resource and delete this.
+  auto collapse_thumb_brush = GetUiApplication()
+                                  ->GetInstance()
+                                  ->GetGraphFactory()
+                                  ->CreateSolidColorBrush();
+  collapse_thumb_brush->SetColor(colors::gray.WithAlpha(128));
+  collapse_thumb_brush_ = std::move(collapse_thumb_brush);
+}
+
+void ScrollBar::SetEnabled(bool value) {
+  CRU_UNUSED(value)
+  // TODO: Implement this.
+}
+
+void ScrollBar::Draw(platform::graphics::IPainter* painter) {
+  if (is_enabled_) {
+    OnDraw(painter, is_expanded_);
+  }
+}
+
+void ScrollBar::InstallHandlers(controls::Control* control) {
+  CRU_UNUSED(control);
+  // TODO: Implement this.
+}
+
+gsl::not_null<std::shared_ptr<platform::graphics::IBrush>>
+ScrollBar::GetCollapseThumbBrush() const {
+  // TODO: Read theme resource.
+  return collapse_thumb_brush_;
+}
+
+HorizontalScrollBar::HorizontalScrollBar(
+    gsl::not_null<ScrollRenderObject*> render_object)
+    : ScrollBar(render_object) {}
+
+std::optional<ScrollBarAreaKind> HorizontalScrollBar::HitTest(
+    const Point& point) {
+  // TODO: Implement this.
+  CRU_UNUSED(point);
+  return std::nullopt;
+}
+
+void HorizontalScrollBar::OnDraw(platform::graphics::IPainter* painter,
+                                 bool expand) {
+  const auto child = render_object_->GetFirstChild();
+  if (child == nullptr) return;
+
+  const auto view_rect = render_object_->GetViewRect();
+  const auto padding_rect = render_object_->GetPaddingRect();
+  const auto child_size = child->GetSize();
+
+  if (view_rect.width >= child_size.width) return;
+
+  const float start_percentage = view_rect.left / child_size.width;
+  const float length_percentage = view_rect.width / child_size.width;
+  // const float end_percentage = start_percentage + length_percentage;
+
+  if (expand) {
+    // TODO: Implement this.
+  } else {
+    Rect thumb_rect{padding_rect.left + padding_rect.width * start_percentage,
+                    padding_rect.GetBottom() - kScrollBarCollapseThumbWidth,
+                    padding_rect.width * length_percentage,
+                    kScrollBarCollapseThumbWidth};
+    painter->FillRectangle(thumb_rect, GetCollapseThumbBrush().get().get());
+  }
+}
+
+VerticalScrollBar::VerticalScrollBar(
+    gsl::not_null<ScrollRenderObject*> render_object)
+    : ScrollBar(render_object) {}
+
+std::optional<ScrollBarAreaKind> VerticalScrollBar::HitTest(
+    const Point& point) {
+  // TODO: Implement this.
+  CRU_UNUSED(point);
+  return std::nullopt;
+}
+
+void VerticalScrollBar::OnDraw(platform::graphics::IPainter* painter,
+                               bool expand) {
+  const auto child = render_object_->GetFirstChild();
+  if (child == nullptr) return;
+
+  const auto view_rect = render_object_->GetViewRect();
+  const auto padding_rect = render_object_->GetPaddingRect();
+  const auto child_size = child->GetSize();
+
+  if (view_rect.height >= child_size.height) return;
+
+  const float start_percentage = view_rect.top / child_size.height;
+  const float length_percentage = view_rect.height / child_size.height;
+  // const float end_percentage = start_percentage + length_percentage;
+
+  if (expand) {
+    // TODO: Implement this.
+  } else {
+    Rect thumb_rect{padding_rect.GetRight() - kScrollBarCollapseThumbWidth,
+                    padding_rect.top + padding_rect.height * start_percentage,
+                    kScrollBarCollapseThumbWidth,
+                    padding_rect.height * length_percentage};
+    painter->FillRectangle(thumb_rect, GetCollapseThumbBrush().get().get());
+  }
+}
+
+ScrollBarDelegate::ScrollBarDelegate(
+    gsl::not_null<ScrollRenderObject*> render_object)
+    : render_object_(render_object),
+      horizontal_bar_(render_object),
+      vertical_bar_(render_object) {
+  horizontal_bar_.ScrollAttemptEvent()->AddHandler([this](float offset) {
+    this->scroll_attempt_event_.Raise({offset, 0});
+  });
+  vertical_bar_.ScrollAttemptEvent()->AddHandler([this](float offset) {
+    this->scroll_attempt_event_.Raise({0, offset});
+  });
+}
+
+void ScrollBarDelegate::DrawScrollBar(platform::graphics::IPainter* painter) {
+  horizontal_bar_.Draw(painter);
+  vertical_bar_.Draw(painter);
+}
+
+void ScrollBarDelegate::InstallHandlers(controls::Control* control) {
+  horizontal_bar_.InstallHandlers(control);
+  vertical_bar_.InstallHandlers(control);
+}
+}  // namespace cru::ui::render