...

7 files changed, 102 insertions, 86 deletions

diff --git a/src/ui/UiHost.cpp b/src/ui/UiHost.cpp
index 56ce1eb9..9bde06ad 100644
--- a/src/ui/UiHost.cpp
+++ b/src/ui/UiHost.cpp
@@ -231,6 +231,7 @@ void UiHost::OnNativeDestroy(INativeWindow* window, std::nullptr_t) {
 
 void UiHost::OnNativePaint(INativeWindow* window, std::nullptr_t) {
   auto painter = window->BeginPaint();
+  painter->Clear(colors::white);
   root_render_object_->Draw(painter.get());
   painter->EndDraw();
 }
diff --git a/src/ui/render/BorderRenderObject.cpp b/src/ui/render/BorderRenderObject.cpp
index 74e50561..6513c4c4 100644
--- a/src/ui/render/BorderRenderObject.cpp
+++ b/src/ui/render/BorderRenderObject.cpp
@@ -16,28 +16,6 @@ BorderRenderObject::BorderRenderObject() {
 
 BorderRenderObject::~BorderRenderObject() {}
 
-void BorderRenderObject::Draw(platform::graph::IPainter* painter) {
-  if (background_brush_ != nullptr)
-    painter->FillGeometry(border_inner_geometry_.get(),
-                          background_brush_.get());
-  if (is_border_enabled_) {
-    if (border_brush_ == nullptr) {
-      log::Warn("Border is enabled but brush is null");
-    } else {
-      painter->FillGeometry(geometry_.get(), border_brush_.get());
-    }
-  }
-  if (const auto child = GetSingleChild()) {
-    auto offset = child->GetOffset();
-    platform::graph::util::WithTransform(
-        painter, platform::Matrix::Translation(offset.x, offset.y),
-        [child](auto p) { child->Draw(p); });
-  }
-  if (foreground_brush_ != nullptr)
-    painter->FillGeometry(border_inner_geometry_.get(),
-                          foreground_brush_.get());
-}
-
 void BorderRenderObject::SetBorderStyle(const BorderStyle& style) {
   border_brush_ = style.border_brush;
   border_thickness_ = style.border_thickness;
@@ -73,6 +51,27 @@ RenderObject* BorderRenderObject::HitTest(const Point& point) {
   }
 }
 
+void BorderRenderObject::OnDrawCore(platform::graph::IPainter* painter) {
+  if (background_brush_ != nullptr)
+    painter->FillGeometry(border_inner_geometry_.get(),
+                          background_brush_.get());
+  if (is_border_enabled_) {
+    if (border_brush_ == nullptr) {
+      log::Warn("Border is enabled but brush is null");
+    } else {
+      painter->FillGeometry(geometry_.get(), border_brush_.get());
+    }
+  }
+
+  DefaultDrawContent(painter);
+
+  if (foreground_brush_ != nullptr)
+    painter->FillGeometry(border_inner_geometry_.get(),
+                          foreground_brush_.get());
+
+  DefaultDrawChildren(painter);
+}
+
 Size BorderRenderObject::OnMeasureCore(const MeasureRequirement& requirement,
                                        const MeasureSize& preferred_size) {
   if (!is_border_enabled_) {
diff --git a/src/ui/render/CanvasRenderObject.cpp b/src/ui/render/CanvasRenderObject.cpp
index 211d1fce..967fdcec 100644
--- a/src/ui/render/CanvasRenderObject.cpp
+++ b/src/ui/render/CanvasRenderObject.cpp
@@ -5,17 +5,17 @@ CanvasRenderObject::CanvasRenderObject() : RenderObject(ChildMode::None) {}
 
 CanvasRenderObject::~CanvasRenderObject() = default;
 
-void CanvasRenderObject::Draw(platform::graph::IPainter* painter) {
-  const auto rect = GetContentRect();
-  CanvasPaintEventArgs args{painter, rect};
-  paint_event_.Raise(args);
-}
-
 RenderObject* CanvasRenderObject::HitTest(const Point& point) {
   const auto padding_rect = GetPaddingRect();
   return padding_rect.IsPointInside(point) ? this : nullptr;
 }
 
+void CanvasRenderObject::OnDrawContent(platform::graph::IPainter* painter) {
+  const auto rect = GetContentRect();
+  CanvasPaintEventArgs args{painter, rect.GetSize()};
+  paint_event_.Raise(args);
+}
+
 Size CanvasRenderObject::OnMeasureContent(const MeasureRequirement& requirement,
                                           const MeasureSize& preferred_size) {
   return requirement.Coerce(Size{preferred_size.width.GetLengthOr(100),
diff --git a/src/ui/render/RenderObject.cpp b/src/ui/render/RenderObject.cpp
index ac38c6b5..d9977f2a 100644
--- a/src/ui/render/RenderObject.cpp
+++ b/src/ui/render/RenderObject.cpp
@@ -1,6 +1,7 @@
 #include "cru/ui/render/RenderObject.hpp"
 
 #include "cru/common/Logger.hpp"
+#include "cru/platform/graph/util/Painter.hpp"
 #include "cru/ui/UiHost.hpp"
 
 #include <algorithm>
@@ -76,6 +77,10 @@ void RenderObject::Layout(const Point& offset) {
   OnLayoutCore();
 }
 
+void RenderObject::Draw(platform::graph::IPainter* painter) {
+  OnDrawCore(painter);
+}
+
 RenderObject* RenderObject::GetSingleChild() const {
   Expects(child_mode_ == ChildMode::Single);
   const auto& children = GetChildren();
@@ -107,6 +112,32 @@ void RenderObject::OnRemoveChild(RenderObject* removed_child, Index position) {
   InvalidatePaint();
 }
 
+void RenderObject::DefaultDrawChildren(platform::graph::IPainter* painter) {
+  for (const auto child : GetChildren()) {
+    auto offset = child->GetOffset();
+    platform::graph::util::WithTransform(
+        painter, platform::Matrix::Translation(offset.x, offset.y),
+        [child](auto p) { child->Draw(p); });
+  }
+}
+
+void RenderObject::DefaultDrawContent(platform::graph::IPainter* painter) {
+  const auto content_rect = GetContentRect();
+
+  platform::graph::util::WithTransform(
+      painter, Matrix::Translation(content_rect.left, content_rect.top),
+      [this](auto p) { this->OnDrawContent(p); });
+}
+
+void RenderObject::OnDrawCore(platform::graph::IPainter* painter) {
+  DefaultDrawContent(painter);
+  DefaultDrawChildren(painter);
+}
+
+void RenderObject::OnDrawContent(platform::graph::IPainter* painter) {
+  CRU_UNUSED(painter);
+}
+
 Size RenderObject::OnMeasureCore(const MeasureRequirement& requirement,
                                  const MeasureSize& preferred_size) {
   const Size space_size{
diff --git a/src/ui/render/ScrollRenderObject.cpp b/src/ui/render/ScrollRenderObject.cpp
index e4cc27f3..aab8c003 100644
--- a/src/ui/render/ScrollRenderObject.cpp
+++ b/src/ui/render/ScrollRenderObject.cpp
@@ -31,17 +31,6 @@ Point CoerceScroll(const Point& scroll_offset, const Size& content_size,
 }
 }  // namespace
 
-void ScrollRenderObject::Draw(platform::graph::IPainter* painter) {
-  if (const auto child = GetSingleChild()) {
-    painter->PushLayer(this->GetPaddingRect());
-    const auto offset = child->GetOffset();
-    platform::graph::util::WithTransform(
-        painter, Matrix::Translation(offset.x, offset.y),
-        [child](platform::graph::IPainter* p) { child->Draw(p); });
-    painter->PopLayer();
-  }
-}
-
 RenderObject* ScrollRenderObject::HitTest(const Point& point) {
   if (const auto child = GetSingleChild()) {
     const auto offset = child->GetOffset();
@@ -53,6 +42,18 @@ RenderObject* ScrollRenderObject::HitTest(const Point& point) {
   return rect.IsPointInside(point) ? this : nullptr;
 }  // namespace cru::ui::render
 
+void ScrollRenderObject::OnDrawCore(platform::graph::IPainter* painter) {
+  DefaultDrawContent(painter);
+  if (const auto child = GetSingleChild()) {
+    painter->PushLayer(this->GetPaddingRect());
+    const auto offset = child->GetOffset();
+    platform::graph::util::WithTransform(
+        painter, Matrix::Translation(offset.x, offset.y),
+        [child](platform::graph::IPainter* p) { child->Draw(p); });
+    painter->PopLayer();
+  }
+}
+
 Point ScrollRenderObject::GetScrollOffset() {
   if (const auto child = GetSingleChild())
     return CoerceScroll(scroll_offset_, GetContentRect().GetSize(),
diff --git a/src/ui/render/TextRenderObject.cpp b/src/ui/render/TextRenderObject.cpp
index e0c68683..7efffafb 100644
--- a/src/ui/render/TextRenderObject.cpp
+++ b/src/ui/render/TextRenderObject.cpp
@@ -118,48 +118,42 @@ void TextRenderObject::SetCaretWidth(const float width) {
   }
 }
 
-void TextRenderObject::Draw(platform::graph::IPainter* painter) {
-  platform::graph::util::WithTransform(
-      painter,
-      platform::Matrix::Translation(GetMargin().left + GetPadding().left,
-                                    GetMargin().top + GetPadding().top),
-      [this](platform::graph::IPainter* p) {
-        if (this->selection_range_.has_value()) {
-          const auto&& rects =
-              text_layout_->TextRangeRect(this->selection_range_.value());
-          for (const auto& rect : rects)
-            p->FillRectangle(rect, this->GetSelectionBrush().get());
-        }
-
-        p->DrawText(Point{}, text_layout_.get(), brush_.get());
-
-        if (this->draw_caret_ && this->caret_width_ != 0.0f) {
-          auto caret_pos = this->caret_position_;
-          gsl::index text_size = this->GetText().size();
-          if (caret_pos < 0) {
-            caret_pos = 0;
-          } else if (caret_pos > text_size) {
-            caret_pos = text_size;
-          }
-
-          const auto caret_top_center =
-              this->text_layout_->TextSinglePoint(caret_pos, false);
-
-          const auto font_height = this->font_->GetFontSize();
-          const auto caret_width = this->caret_width_;
-
-          p->FillRectangle(Rect{caret_top_center.x - caret_width / 2.0f,
-                                caret_top_center.y, caret_width, font_height},
-                           this->caret_brush_.get());
-        }
-      });
-}
-
 RenderObject* TextRenderObject::HitTest(const Point& point) {
   const auto padding_rect = GetPaddingRect();
   return padding_rect.IsPointInside(point) ? this : nullptr;
 }
 
+void TextRenderObject::OnDrawContent(platform::graph::IPainter* painter) {
+  if (this->selection_range_.has_value()) {
+    const auto&& rects =
+        text_layout_->TextRangeRect(this->selection_range_.value());
+    for (const auto& rect : rects)
+      painter->FillRectangle(rect, this->GetSelectionBrush().get());
+  }
+
+  painter->DrawText(Point{}, text_layout_.get(), brush_.get());
+
+  if (this->draw_caret_ && this->caret_width_ != 0.0f) {
+    auto caret_pos = this->caret_position_;
+    gsl::index text_size = this->GetText().size();
+    if (caret_pos < 0) {
+      caret_pos = 0;
+    } else if (caret_pos > text_size) {
+      caret_pos = text_size;
+    }
+
+    const auto caret_top_center =
+        this->text_layout_->TextSinglePoint(caret_pos, false);
+
+    const auto font_height = this->font_->GetFontSize();
+    const auto caret_width = this->caret_width_;
+
+    painter->FillRectangle(Rect{caret_top_center.x - caret_width / 2.0f,
+                                caret_top_center.y, caret_width, font_height},
+                           this->caret_brush_.get());
+  }
+}
+
 Size TextRenderObject::OnMeasureContent(const MeasureRequirement& requirement,
                                         const MeasureSize& preferred_size) {
   float measure_width;
diff --git a/src/ui/render/WindowRenderObject.cpp b/src/ui/render/WindowRenderObject.cpp
index a2c7ae4d..4adf559e 100644
--- a/src/ui/render/WindowRenderObject.cpp
+++ b/src/ui/render/WindowRenderObject.cpp
@@ -12,16 +12,6 @@ WindowRenderObject::WindowRenderObject(UiHost* host) {
       [this](auto) { NotifyAfterLayoutRecursive(this); }));
 }
 
-void WindowRenderObject::Draw(platform::graph::IPainter* painter) {
-  painter->Clear(colors::white);
-  if (const auto child = GetChild()) {
-    auto offset = child->GetOffset();
-    platform::graph::util::WithTransform(
-        painter, platform::Matrix::Translation(offset.x, offset.y),
-        [child](platform::graph::IPainter* p) { child->Draw(p); });
-  }
-}
-
 RenderObject* WindowRenderObject::HitTest(const Point& point) {
   if (const auto child = GetChild()) {
     auto offset = child->GetOffset();