...

9 files changed, 99 insertions, 12 deletions

diff --git a/include/cru/ui/render/border_render_object.hpp b/include/cru/ui/render/border_render_object.hpp
index 5c147df5..22e8ab58 100644
--- a/include/cru/ui/render/border_render_object.hpp
+++ b/include/cru/ui/render/border_render_object.hpp
@@ -77,8 +77,6 @@ class BorderRenderObject : public RenderObject {
   RenderObject* HitTest(const Point& point) override;
 
  protected:
-  void OnAddChild(RenderObject* new_child, int position) override;
-
   void OnSizeChanged(const Size& old_size, const Size& new_size) override;
 
   void OnMeasureCore(const Size& available_size) override;
diff --git a/include/cru/ui/render/flex_layout_render_object.hpp b/include/cru/ui/render/flex_layout_render_object.hpp
index 1234b920..68ffc89e 100644
--- a/include/cru/ui/render/flex_layout_render_object.hpp
+++ b/include/cru/ui/render/flex_layout_render_object.hpp
@@ -41,7 +41,7 @@ struct FlexChildLayoutData {
 
 class FlexLayoutRenderObject : public RenderObject {
  public:
-  FlexLayoutRenderObject() = default;
+  FlexLayoutRenderObject();
   FlexLayoutRenderObject(const FlexLayoutRenderObject& other) = delete;
   FlexLayoutRenderObject& operator=(const FlexLayoutRenderObject& other) =
       delete;
diff --git a/include/cru/ui/render/render_object.hpp b/include/cru/ui/render/render_object.hpp
index dca254cc..8ea7ca79 100644
--- a/include/cru/ui/render/render_object.hpp
+++ b/include/cru/ui/render/render_object.hpp
@@ -15,6 +15,18 @@ class Painter;
 }
 
 namespace cru::ui::render {
+struct IRenderHost : Interface {
+  // Mark the layout as invalid, and arrange a re-layout later.
+  // Note this method might be called more than one times in a message cycle. So
+  // implementation should merge multiple request into once.
+  virtual void InvalidateLayout() = 0;
+
+  // Mark the paint as invalid, and arrange a re-paint later.
+  // Note this method might be called more than one times in a message cycle. So
+  // implementation should merge multiple request into once.
+  virtual void InvalidatePaint() = 0;
+};
+
 class RenderObject : public Object {
  protected:
   RenderObject() = default;
@@ -29,6 +41,9 @@ class RenderObject : public Object {
   Control* GetAttachedControl() const { return control_; }
   void SetAttachedControl(Control* new_control) { control_ = new_control; }
 
+  IRenderHost* GetRenderHost() const { return render_host_; }
+  void SetRenderHost(IRenderHost* render_host) { render_host_ = render_host; }
+
   RenderObject* GetParent() const { return parent_; }
 
   const std::vector<RenderObject*>& GetChildren() const { return children_; }
@@ -63,10 +78,29 @@ class RenderObject : public Object {
   virtual RenderObject* HitTest(const Point& point) = 0;
 
  protected:
+  enum class ChildMode {
+    None,
+    Single,
+    Multiple,
+  };
+
+  void SetChildMode(ChildMode mode) { child_mode_ = mode; }
+
+  void InvalidateLayout() const {
+    if (render_host_ != nullptr) render_host_->InvalidateLayout();
+  }
+
+  void InvalidatePaint() const {
+    if (render_host_ != nullptr) render_host_->InvalidatePaint();
+  }
+
+ protected:
   virtual void OnParentChanged(RenderObject* old_parent,
                                RenderObject* new_parent);
 
+  // default is to invalidate both layout and paint
   virtual void OnAddChild(RenderObject* new_child, int position);
+  // default is to invalidate both layout and paint
   virtual void OnRemoveChild(RenderObject* removed_child, int position);
 
   virtual void OnSizeChanged(const Size& old_size, const Size& new_size);
@@ -83,10 +117,13 @@ class RenderObject : public Object {
 
  private:
   Control* control_ = nullptr;
+  IRenderHost* render_host_ = nullptr;
 
   RenderObject* parent_ = nullptr;
   std::vector<RenderObject*> children_{};
 
+  ChildMode child_mode_ = ChildMode::None;
+
   Point offset_{};
   Size size_{};
 
diff --git a/include/cru/ui/render/window_render_object.hpp b/include/cru/ui/render/window_render_object.hpp
index dfeae487..e73a6bfe 100644
--- a/include/cru/ui/render/window_render_object.hpp
+++ b/include/cru/ui/render/window_render_object.hpp
@@ -1,6 +1,8 @@
 #pragma once
 #include "render_object.hpp"
 
+#include <memory>
+
 namespace cru::ui {
 class Window;
 }
@@ -8,7 +10,7 @@ class Window;
 namespace cru::ui::render {
 class WindowRenderObject : public RenderObject {
  public:
-  WindowRenderObject(Window* window) : window_(window) {}
+  WindowRenderObject(Window* window);
   WindowRenderObject(const WindowRenderObject& other) = delete;
   WindowRenderObject(WindowRenderObject&& other) = delete;
   WindowRenderObject& operator=(const WindowRenderObject& other) = delete;
@@ -23,6 +25,7 @@ class WindowRenderObject : public RenderObject {
 
  protected:
   void OnAddChild(RenderObject* new_child, int position) override;
+  void OnRemoveChild(RenderObject* new_child, int position) override;
 
   Size OnMeasureContent(const Size& available_size) override;
   void OnLayoutContent(const Rect& content_rect) override;
@@ -34,5 +37,7 @@ class WindowRenderObject : public RenderObject {
 
  private:
   Window* window_;
+
+  std::unique_ptr<IRenderHost> render_host_;
 };
 }  // namespace cru::ui::render
diff --git a/src/ui/render/border_render_object.cpp b/src/ui/render/border_render_object.cpp
index 68e74740..6af76b32 100644
--- a/src/ui/render/border_render_object.cpp
+++ b/src/ui/render/border_render_object.cpp
@@ -9,7 +9,10 @@
 #include <cassert>
 
 namespace cru::ui::render {
-BorderRenderObject::BorderRenderObject() { RecreateGeometry(); }
+BorderRenderObject::BorderRenderObject() {
+  SetChildMode(ChildMode::Single);
+  RecreateGeometry();
+}
 
 BorderRenderObject::~BorderRenderObject() {}
 
@@ -61,10 +64,6 @@ RenderObject* BorderRenderObject::HitTest(const Point& point) {
   }
 }
 
-void BorderRenderObject::OnAddChild(RenderObject* new_child, int position) {
-  assert(GetChildren().size() == 1);
-}
-
 void BorderRenderObject::OnSizeChanged(const Size& old_size,
                                        const Size& new_size) {
   RecreateGeometry();
diff --git a/src/ui/render/flex_layout_render_object.cpp b/src/ui/render/flex_layout_render_object.cpp
index c4bdd874..416f39bd 100644
--- a/src/ui/render/flex_layout_render_object.cpp
+++ b/src/ui/render/flex_layout_render_object.cpp
@@ -7,6 +7,10 @@
 #include <functional>
 
 namespace cru::ui::render {
+FlexLayoutRenderObject::FlexLayoutRenderObject() {
+  SetChildMode(ChildMode::Multiple);
+}
+
 FlexChildLayoutData* FlexLayoutRenderObject::GetChildLayoutData(int position) {
   assert(position >= 0 &&
          position < child_layout_data_.size());  // Position out of bound.
diff --git a/src/ui/render/render_object.cpp b/src/ui/render/render_object.cpp
index a083403b..dcd2f0b9 100644
--- a/src/ui/render/render_object.cpp
+++ b/src/ui/render/render_object.cpp
@@ -7,6 +7,9 @@
 
 namespace cru::ui::render {
 void RenderObject::AddChild(RenderObject* render_object, const int position) {
+  assert(child_mode_ == ChildMode::None);
+  assert(child_mode_ == ChildMode::Single && children_.size() > 0);
+
   assert(render_object->GetParent() ==
          nullptr);                       // Render object already has a parent.
   assert(position >= 0);                 // Position index is less than 0.
@@ -41,9 +44,15 @@ void RenderObject::Layout(const Rect& rect) {
 void RenderObject::OnParentChanged(RenderObject* old_parent,
                                    RenderObject* new_parent) {}
 
-void RenderObject::OnAddChild(RenderObject* new_child, int position) {}
+void RenderObject::OnAddChild(RenderObject* new_child, int position) {
+  InvalidateLayout();
+  InvalidatePaint();
+}
 
-void RenderObject::OnRemoveChild(RenderObject* removed_child, int position) {}
+void RenderObject::OnRemoveChild(RenderObject* removed_child, int position) {
+  InvalidateLayout();
+  InvalidatePaint();
+}
 
 void RenderObject::OnSizeChanged(const Size& old_size, const Size& new_size) {}
 
diff --git a/src/ui/render/text_render_object.cpp b/src/ui/render/text_render_object.cpp
index 64a34b6c..49d7bcb4 100644
--- a/src/ui/render/text_render_object.cpp
+++ b/src/ui/render/text_render_object.cpp
@@ -16,6 +16,8 @@ TextRenderObject::TextRenderObject(
   assert(font);
   assert(selection_brush);
 
+  SetChildMode(ChildMode::None);
+
   brush.swap(brush_);
   font.swap(font_);
   selection_brush.swap(selection_brush_);
diff --git a/src/ui/render/window_render_object.cpp b/src/ui/render/window_render_object.cpp
index 18faeee8..e61dd286 100644
--- a/src/ui/render/window_render_object.cpp
+++ b/src/ui/render/window_render_object.cpp
@@ -7,6 +7,26 @@
 #include <cassert>
 
 namespace cru::ui::render {
+class WindowRenderHost : public IRenderHost {
+ public:
+  WindowRenderHost(Window* window) : window_(window) {
+    assert(window != nullptr);
+  }
+
+  void InvalidateLayout() override { window_->InvalidateLayout(); }
+
+  void InvalidatePaint() override { window_->GetNativeWindow()->Repaint(); }
+
+ private:
+  Window* window_;
+};
+
+WindowRenderObject::WindowRenderObject(Window* window)
+    : window_(window), render_host_(new WindowRenderHost(window)) {
+  SetChildMode(ChildMode::Single);
+  SetRenderHost(render_host_.get());
+}
+
 void WindowRenderObject::MeasureAndLayout() {
   const auto client_size = window_->GetNativeWindow()->GetClientSize();
   Measure(client_size);
@@ -35,8 +55,21 @@ RenderObject* WindowRenderObject::HitTest(const Point& point) {
   return Rect{Point{}, GetSize()}.IsPointInside(point) ? this : nullptr;
 }
 
+namespace {
+void SetRenderHostRecursive(RenderObject* render_object, IRenderHost* host) {
+  render_object->SetRenderHost(host);
+  for (const auto child : render_object->GetChildren()) {
+    SetRenderHostRecursive(render_object, host);
+  }
+}
+}  // namespace
+
 void WindowRenderObject::OnAddChild(RenderObject* new_child, int position) {
-  assert(GetChildren().size() == 1);
+  SetRenderHostRecursive(new_child, render_host_.get());
+}
+
+void WindowRenderObject::OnRemoveChild(RenderObject* new_child, int position) {
+  SetRenderHostRecursive(new_child, nullptr);
 }
 
 Size WindowRenderObject::OnMeasureContent(const Size& available_size) {