Write layout logic at half way.

9 files changed, 415 insertions, 328 deletions

diff --git a/src/ui/render/BorderRenderObject.cpp b/src/ui/render/BorderRenderObject.cpp
index ad0c6455..74e50561 100644
--- a/src/ui/render/BorderRenderObject.cpp
+++ b/src/ui/render/BorderRenderObject.cpp
@@ -73,9 +73,10 @@ RenderObject* BorderRenderObject::HitTest(const Point& point) {
   }
 }
 
-Size BorderRenderObject::OnMeasureCore(const MeasureRequirement& requirement) {
+Size BorderRenderObject::OnMeasureCore(const MeasureRequirement& requirement,
+                                       const MeasureSize& preferred_size) {
   if (!is_border_enabled_) {
-    return RenderObject::OnMeasureCore(requirement);
+    return RenderObject::OnMeasureCore(requirement, preferred_size);
   }
 
   const auto margin = GetMargin();
@@ -90,36 +91,51 @@ Size BorderRenderObject::OnMeasureCore(const MeasureRequirement& requirement) {
 
   MeasureRequirement content_requirement = requirement;
 
-  if (!requirement.max_width.IsNotSpecify()) {
-    const auto max_width = requirement.max_width.GetLength();
+  if (!requirement.max.width.IsNotSpecified()) {
+    const auto max_width = requirement.max.width.GetLengthOrMax();
     if (coerced_space_size.width > max_width) {
       log::Warn(
-          "Measure: horizontal length of padding and margin is bigger than "
-          "available length.");
+          "BorderRenderObject: During measure, horizontal length of padding, "
+          "border and margin is bigger than required max length.");
       coerced_space_size.width = max_width;
     }
-    content_requirement.max_width = max_width - coerced_space_size.width;
+    content_requirement.max.width = max_width - coerced_space_size.width;
   }
 
-  if (!requirement.max_height.IsNotSpecify()) {
-    const auto max_height = requirement.max_height.GetLength();
+  if (!requirement.min.width.IsNotSpecified()) {
+    const auto min_width = requirement.min.width.GetLengthOr0();
+    content_requirement.min.width = std::max(0.f, min_width - space_size.width);
+  }
+
+  if (!requirement.max.height.IsNotSpecified()) {
+    const auto max_height = requirement.max.height.GetLengthOrMax();
     if (coerced_space_size.height > max_height) {
       log::Warn(
-          "Measure: horizontal length of padding and margin is bigger than "
-          "available length.");
+          "BorderRenderObject: During measure, vertical length of padding, "
+          "border and margin is bigger than required max length.");
       coerced_space_size.height = max_height;
     }
-    content_requirement.max_height = max_height - coerced_space_size.height;
+    content_requirement.max.height = max_height - coerced_space_size.height;
   }
 
-  const auto content_size = OnMeasureContent(content_requirement);
+  if (!requirement.min.height.IsNotSpecified()) {
+    const auto min_height = requirement.min.height.GetLengthOr0();
+    content_requirement.min.height =
+        std::max(0.f, min_height - space_size.height);
+  }
+
+  MeasureSize content_preferred_size =
+      content_requirement.Coerce(preferred_size.Minus(space_size));
+
+  const auto content_size =
+      OnMeasureContent(content_requirement, content_preferred_size);
 
   return coerced_space_size + content_size;
-}  // namespace cru::ui::render
+}
 
-void BorderRenderObject::OnLayoutCore(const Size& size) {
+void BorderRenderObject::OnLayoutCore() {
   if (!is_border_enabled_) {
-    return RenderObject::OnLayoutCore(size);
+    return RenderObject::OnLayoutCore();
   }
 
   const auto margin = GetMargin();
@@ -129,18 +145,20 @@ void BorderRenderObject::OnLayoutCore(const Size& size) {
                   margin.GetVerticalTotal() + padding.GetVerticalTotal() +
                       border_thickness_.GetVerticalTotal()};
 
+  const auto size = GetSize();
+
   auto content_size = size - space_size;
 
   if (content_size.width < 0) {
     log::Warn(
-        "Layout: horizontal length of padding, border and margin is bigger "
-        "than available length.");
+        "BorderRenderObject: During layout, horizontal length of padding, "
+        "border and margin is bigger than available length.");
     content_size.width = 0;
   }
   if (content_size.height < 0) {
     log::Warn(
-        "Layout: vertical length of padding, border and margin is bigger "
-        "than available length.");
+        "BorderRenderObject: During layout, vertical length of padding, "
+        "border and margin is bigger than available length.");
     content_size.height = 0;
   }
 
@@ -158,12 +176,12 @@ void BorderRenderObject::OnLayoutCore(const Size& size) {
   OnLayoutContent(content_rect);
 }
 
-Size BorderRenderObject::OnMeasureContent(
-    const MeasureRequirement& requirement) {
+Size BorderRenderObject::OnMeasureContent(const MeasureRequirement& requirement,
+                                          const MeasureSize& preferred_size) {
   const auto child = GetSingleChild();
   if (child) {
-    child->Measure(requirement);
-    return child->GetMeasuredSize();
+    child->Measure(requirement, preferred_size);
+    return child->GetSize();
   } else {
     return Size{};
   }
@@ -172,7 +190,7 @@ Size BorderRenderObject::OnMeasureContent(
 void BorderRenderObject::OnLayoutContent(const Rect& content_rect) {
   const auto child = GetSingleChild();
   if (child) {
-    child->Layout(content_rect);
+    child->Layout(content_rect.GetLeftTop());
   }
 }
 
diff --git a/src/ui/render/CanvasRenderObject.cpp b/src/ui/render/CanvasRenderObject.cpp
index 72eb3570..211d1fce 100644
--- a/src/ui/render/CanvasRenderObject.cpp
+++ b/src/ui/render/CanvasRenderObject.cpp
@@ -1,7 +1,5 @@
 #include "cru/ui/render/CanvasRenderObject.hpp"
 
-#include "cru/ui/render/LayoutUtility.hpp"
-
 namespace cru::ui::render {
 CanvasRenderObject::CanvasRenderObject() : RenderObject(ChildMode::None) {}
 
@@ -18,9 +16,10 @@ RenderObject* CanvasRenderObject::HitTest(const Point& point) {
   return padding_rect.IsPointInside(point) ? this : nullptr;
 }
 
-Size CanvasRenderObject::OnMeasureContent(
-    const MeasureRequirement& requirement) {
-  return Min(requirement.GetMaxSize(), GetDesiredSize());
+Size CanvasRenderObject::OnMeasureContent(const MeasureRequirement& requirement,
+                                          const MeasureSize& preferred_size) {
+  return requirement.Coerce(Size{preferred_size.width.GetLengthOr(100),
+                                 preferred_size.height.GetLengthOr(100)});
 }
 
 void CanvasRenderObject::OnLayoutContent(const Rect& content_rect) {
diff --git a/src/ui/render/FlexLayoutRenderObject.cpp b/src/ui/render/FlexLayoutRenderObject.cpp
index 72341a64..fcaf6f9a 100644
--- a/src/ui/render/FlexLayoutRenderObject.cpp
+++ b/src/ui/render/FlexLayoutRenderObject.cpp
@@ -7,194 +7,207 @@
 
 namespace cru::ui::render {
 Size FlexLayoutRenderObject::OnMeasureContent(
-    const MeasureRequirement& requirement) {
-  const bool horizontal = (direction_ == FlexDirection::Horizontal ||
-                           direction_ == FlexDirection::HorizontalReverse);
-
-  const auto main_max_length =
-      horizontal ? requirement.max_width : requirement.max_height;
-  const auto cross_max_length =
-      horizontal ? requirement.max_height : requirement.max_width;
-
-  std::function<float(const Size&)> get_main_length;
-  std::function<float(const Size&)> get_cross_length;
-  std::function<void(Size&, const Size&)> calculate_result_size;
-  std::function<MeasureRequirement(MeasureLength main, MeasureLength cross)>
-      create_requirement;
-
-  if (horizontal) {
-    get_main_length = [](const Size& size) { return size.width; };
-    get_cross_length = [](const Size& size) { return size.height; };
-    calculate_result_size = [](Size& result, const Size& child_size) {
-      result.width += child_size.width;
-      result.height = std::max(result.height, child_size.height);
-    };
-    create_requirement = [](MeasureLength main, MeasureLength cross) {
-      return MeasureRequirement{main, cross};
-    };
-  } else {
-    get_main_length = [](const Size& size) { return size.height; };
-    get_cross_length = [](const Size& size) { return size.width; };
-    calculate_result_size = [](Size& result, const Size& child_size) {
-      result.height += child_size.height;
-      result.width = std::max(result.width, child_size.width);
-    };
-    create_requirement = [](MeasureLength main, MeasureLength cross) {
-      return MeasureRequirement{cross, main};
-    };
-  }
-
-  const auto& children = GetChildren();
-  Index children_count = children.size();
-
-  if (!main_max_length.IsNotSpecify()) {
-    float remain_main_length = main_max_length.GetLength();
-
-    for (Index i = 0; i < children_count; i++) {
-      const auto child = children[i];
-      child->Measure(create_requirement(remain_main_length, cross_max_length));
-      const auto measure_result = child->GetMeasuredSize();
-      remain_main_length -= get_main_length(measure_result);
-    }
-
-    if (remain_main_length > 0) {
-      std::vector<Index> expand_children;
-      float total_expand_factor = 0;
-
-      for (Index i = 0; i < children_count; i++) {
-        const auto factor = GetChildLayoutData(i)->expand_factor;
-        if (factor > 0) {
-          expand_children.push_back(i);
-          total_expand_factor += factor;
-        }
-      }
-
-      for (const Index i : expand_children) {
-        const float distributed_grow_length =
-            remain_main_length *
-            (GetChildLayoutData(i)->expand_factor / total_expand_factor);
-        const auto child = children[i];
-        const float new_main_length =
-            get_main_length(child->GetMeasuredSize()) + distributed_grow_length;
-        child->Measure(create_requirement(new_main_length, cross_max_length));
-      }
-    } else if (remain_main_length < 0) {
-      std::vector<Index> shrink_children;
-      float total_shrink_factor = 0;
-
-      for (Index i = 0; i < children_count; i++) {
-        const auto factor = GetChildLayoutData(i)->shrink_factor;
-        if (factor > 0) {
-          shrink_children.push_back(i);
-          total_shrink_factor += factor;
-        }
-      }
-
-      for (const Index i : shrink_children) {
-        const float distributed_shrink_length =  // negative
-            remain_main_length *
-            (GetChildLayoutData(i)->shrink_factor / total_shrink_factor);
-        const auto child = children[i];
-        float new_main_length = get_main_length(child->GetMeasuredSize()) +
-                                distributed_shrink_length;
-        new_main_length = new_main_length > 0 ? new_main_length : 0;
-        child->Measure(create_requirement(new_main_length, cross_max_length));
-      }
-    }
-  } else {
-    for (Index i = 0; i < children_count; i++) {
-      const auto child = children[i];
-      child->Measure(requirement);
-    }
-  }
-
-  Size result;
-  for (auto child : children) {
-    calculate_result_size(result, child->GetMeasuredSize());
-  }
-
-  return result;
+    const MeasureRequirement& requirement, const MeasureSize& preferred_size) {
+  // TODO: Rewrite this.
+  CRU_UNUSED(requirement);
+  CRU_UNUSED(preferred_size);
+  throw std::runtime_error("Not implemented.");
+
+  // const bool horizontal = (direction_ == FlexDirection::Horizontal ||
+  //                          direction_ == FlexDirection::HorizontalReverse);
+
+  // const auto main_max_length =
+  //     horizontal ? requirement.max_width : requirement.max_height;
+  // const auto cross_max_length =
+  //     horizontal ? requirement.max_height : requirement.max_width;
+
+  // std::function<float(const Size&)> get_main_length;
+  // std::function<float(const Size&)> get_cross_length;
+  // std::function<void(Size&, const Size&)> calculate_result_size;
+  // std::function<MeasureRequirement(MeasureLength main, MeasureLength cross)>
+  //     create_requirement;
+
+  // if (horizontal) {
+  //   get_main_length = [](const Size& size) { return size.width; };
+  //   get_cross_length = [](const Size& size) { return size.height; };
+  //   calculate_result_size = [](Size& result, const Size& child_size) {
+  //     result.width += child_size.width;
+  //     result.height = std::max(result.height, child_size.height);
+  //   };
+  //   create_requirement = [](MeasureLength main, MeasureLength cross) {
+  //     return MeasureRequirement{main, cross};
+  //   };
+  // } else {
+  //   get_main_length = [](const Size& size) { return size.height; };
+  //   get_cross_length = [](const Size& size) { return size.width; };
+  //   calculate_result_size = [](Size& result, const Size& child_size) {
+  //     result.height += child_size.height;
+  //     result.width = std::max(result.width, child_size.width);
+  //   };
+  //   create_requirement = [](MeasureLength main, MeasureLength cross) {
+  //     return MeasureRequirement{cross, main};
+  //   };
+  // }
+
+  // const auto& children = GetChildren();
+  // Index children_count = children.size();
+
+  // if (!main_max_length.IsNotSpecify()) {
+  //   float remain_main_length = main_max_length.GetLengthOrMax();
+
+  //   for (Index i = 0; i < children_count; i++) {
+  //     const auto child = children[i];
+  //     child->Measure(create_requirement(remain_main_length,
+  //     cross_max_length)); const auto measure_result =
+  //     child->GetMeasuredSize(); remain_main_length -=
+  //     get_main_length(measure_result);
+  //   }
+
+  //   if (remain_main_length > 0) {
+  //     std::vector<Index> expand_children;
+  //     float total_expand_factor = 0;
+
+  //     for (Index i = 0; i < children_count; i++) {
+  //       const auto factor = GetChildLayoutData(i)->expand_factor;
+  //       if (factor > 0) {
+  //         expand_children.push_back(i);
+  //         total_expand_factor += factor;
+  //       }
+  //     }
+
+  //     for (const Index i : expand_children) {
+  //       const float distributed_grow_length =
+  //           remain_main_length *
+  //           (GetChildLayoutData(i)->expand_factor / total_expand_factor);
+  //       const auto child = children[i];
+  //       const float new_main_length =
+  //           get_main_length(child->GetMeasuredSize()) +
+  //           distributed_grow_length;
+  //       child->Measure(create_requirement(new_main_length,
+  //       cross_max_length));
+  //     }
+  //   } else if (remain_main_length < 0) {
+  //     std::vector<Index> shrink_children;
+  //     float total_shrink_factor = 0;
+
+  //     for (Index i = 0; i < children_count; i++) {
+  //       const auto factor = GetChildLayoutData(i)->shrink_factor;
+  //       if (factor > 0) {
+  //         shrink_children.push_back(i);
+  //         total_shrink_factor += factor;
+  //       }
+  //     }
+
+  //     for (const Index i : shrink_children) {
+  //       const float distributed_shrink_length =  // negative
+  //           remain_main_length *
+  //           (GetChildLayoutData(i)->shrink_factor / total_shrink_factor);
+  //       const auto child = children[i];
+  //       float new_main_length = get_main_length(child->GetMeasuredSize()) +
+  //                               distributed_shrink_length;
+  //       new_main_length = new_main_length > 0 ? new_main_length : 0;
+  //       child->Measure(create_requirement(new_main_length,
+  //       cross_max_length));
+  //     }
+  //   }
+  // } else {
+  //   for (Index i = 0; i < children_count; i++) {
+  //     const auto child = children[i];
+  //     child->Measure(requirement);
+  //   }
+  // }
+
+  // Size result;
+  // for (auto child : children) {
+  //   calculate_result_size(result, child->GetMeasuredSize());
+  // }
+
+  // return result;
 }
 
 void FlexLayoutRenderObject::OnLayoutContent(const Rect& content_rect) {
-  auto calculate_anchor = [](int alignment, float start_point,
-                             float total_length,
-                             float content_length) -> float {
-    switch (alignment) {
-      case internal::align_start:
-        return start_point;
-      case internal::align_center:
-        return start_point + (total_length - content_length) / 2.0f;
-      case internal::align_end:
-        return start_point + total_length - content_length;
-      default:
-        return start_point;
-    }
-  };
-
-  const auto& children = GetChildren();
-  if (direction_ == FlexDirection::Horizontal ||
-      direction_ == FlexDirection::HorizontalReverse) {
-    float actual_content_width = 0;
-    for (const auto child : children) {
-      actual_content_width += child->GetMeasuredSize().width;
-    }
-
-    const float content_anchor_x =
-        calculate_anchor(static_cast<int>(content_main_align_), 0,
-                         content_rect.width, actual_content_width);
-
-    float anchor_x = 0;
-    for (int i = 0; i < static_cast<int>(children.size()); i++) {
-      const auto child = children[i];
-      const auto size = child->GetMeasuredSize();
-
-      float real_anchor_x = anchor_x + content_anchor_x;
-      if (direction_ == FlexDirection::Horizontal)
-        real_anchor_x = content_rect.left + real_anchor_x;
-      else
-        real_anchor_x = content_rect.GetRight() - real_anchor_x;
-      child->Layout(Rect{
-          real_anchor_x,
-          calculate_anchor(
-              static_cast<int>(GetChildLayoutData(i)->cross_alignment.value_or(
-                  this->item_cross_align_)),
-              content_rect.top, content_rect.height, size.height),
-          size.width, size.height});
-
-      anchor_x += size.width;
-    }
-  } else {
-    float actual_content_height = 0;
-    for (const auto child : children) {
-      actual_content_height = child->GetMeasuredSize().height;
-    }
-
-    const float content_anchor_y =
-        calculate_anchor(static_cast<int>(content_main_align_), 0,
-                         content_rect.height, actual_content_height);
-
-    float anchor_y = 0;
-    for (int i = 0; i < static_cast<int>(children.size()); i++) {
-      const auto child = children[i];
-      const auto size = child->GetMeasuredSize();
-
-      float real_anchor_y = anchor_y + content_anchor_y;
-      if (direction_ == FlexDirection::Vertical) {
-        real_anchor_y = content_rect.top + real_anchor_y;
-      } else {
-        real_anchor_y = content_rect.GetBottom() - real_anchor_y;
-      }
-      child->Layout(Rect{
-          real_anchor_y,
-          calculate_anchor(
-              static_cast<int>(GetChildLayoutData(i)->cross_alignment.value_or(
-                  this->item_cross_align_)),
-              content_rect.left, content_rect.width, size.width),
-          size.width, size.height});
-
-      anchor_y += size.height;
-    }
-  }
+  // TODO: Rewrite this.
+  CRU_UNUSED(content_rect);
+  throw std::runtime_error("Not implemented.");
+
+  // auto calculate_anchor = [](int alignment, float start_point,
+  //                            float total_length,
+  //                            float content_length) -> float {
+  //   switch (alignment) {
+  //     case internal::align_start:
+  //       return start_point;
+  //     case internal::align_center:
+  //       return start_point + (total_length - content_length) / 2.0f;
+  //     case internal::align_end:
+  //       return start_point + total_length - content_length;
+  //     default:
+  //       return start_point;
+  //   }
+  // };
+
+  // const auto& children = GetChildren();
+  // if (direction_ == FlexDirection::Horizontal ||
+  //     direction_ == FlexDirection::HorizontalReverse) {
+  //   float actual_content_width = 0;
+  //   for (const auto child : children) {
+  //     actual_content_width += child->GetMeasuredSize().width;
+  //   }
+
+  //   const float content_anchor_x =
+  //       calculate_anchor(static_cast<int>(content_main_align_), 0,
+  //                        content_rect.width, actual_content_width);
+
+  //   float anchor_x = 0;
+  //   for (int i = 0; i < static_cast<int>(children.size()); i++) {
+  //     const auto child = children[i];
+  //     const auto size = child->GetMeasuredSize();
+
+  //     float real_anchor_x = anchor_x + content_anchor_x;
+  //     if (direction_ == FlexDirection::Horizontal)
+  //       real_anchor_x = content_rect.left + real_anchor_x;
+  //     else
+  //       real_anchor_x = content_rect.GetRight() - real_anchor_x;
+  //     child->Layout(Rect{
+  //         real_anchor_x,
+  //         calculate_anchor(
+  //             static_cast<int>(GetChildLayoutData(i)->cross_alignment.value_or(
+  //                 this->item_cross_align_)),
+  //             content_rect.top, content_rect.height, size.height),
+  //         size.width, size.height});
+
+  //     anchor_x += size.width;
+  //   }
+  // } else {
+  //   float actual_content_height = 0;
+  //   for (const auto child : children) {
+  //     actual_content_height = child->GetMeasuredSize().height;
+  //   }
+
+  //   const float content_anchor_y =
+  //       calculate_anchor(static_cast<int>(content_main_align_), 0,
+  //                        content_rect.height, actual_content_height);
+
+  //   float anchor_y = 0;
+  //   for (int i = 0; i < static_cast<int>(children.size()); i++) {
+  //     const auto child = children[i];
+  //     const auto size = child->GetMeasuredSize();
+
+  //     float real_anchor_y = anchor_y + content_anchor_y;
+  //     if (direction_ == FlexDirection::Vertical) {
+  //       real_anchor_y = content_rect.top + real_anchor_y;
+  //     } else {
+  //       real_anchor_y = content_rect.GetBottom() - real_anchor_y;
+  //     }
+  //     child->Layout(Rect{
+  //         real_anchor_y,
+  //         calculate_anchor(
+  //             static_cast<int>(GetChildLayoutData(i)->cross_alignment.value_or(
+  //                 this->item_cross_align_)),
+  //             content_rect.left, content_rect.width, size.width),
+  //         size.width, size.height});
+
+  //     anchor_y += size.height;
+  //   }
+  // }
 }
 }  // namespace cru::ui::render
diff --git a/src/ui/render/LayoutUtility.cpp b/src/ui/render/LayoutUtility.cpp
deleted file mode 100644
index 03252f1c..00000000
--- a/src/ui/render/LayoutUtility.cpp
+++ /dev/null
@@ -1,15 +0,0 @@
-#include "cru/ui/render/LayoutUtility.hpp"
-
-#include <algorithm>
-
-namespace cru::ui::render {
-Size Min(const Size& left, const Size& right) {
-  return Size{std::min(left.width, right.width),
-              std::min(left.height, right.height)};
-}
-
-Size Max(const Size& left, const Size& right) {
-  return Size{std::max(left.width, right.width),
-              std::max(left.height, right.height)};
-}
-}  // namespace cru::ui::render
diff --git a/src/ui/render/RenderObject.cpp b/src/ui/render/RenderObject.cpp
index abd5e1c4..ac38c6b5 100644
--- a/src/ui/render/RenderObject.cpp
+++ b/src/ui/render/RenderObject.cpp
@@ -57,20 +57,23 @@ Point RenderObject::FromRootToContent(const Point& point) const {
                point.y - (offset.y + rect.top)};
 }
 
-void RenderObject::Measure(const MeasureRequirement& requirement) {
-  measured_size_ = OnMeasureCore(requirement);
+void RenderObject::Measure(const MeasureRequirement& requirement,
+                           const MeasureSize& preferred_size) {
+  MeasureRequirement merged_requirement =
+      MeasureRequirement::Merge(requirement, custom_measure_requirement_)
+          .Normalize();
+  MeasureSize merged_preferred_size =
+      preferred_size.OverrideBy(preferred_size_);
 
-  Ensures(measured_size_.width >= 0);
-  Ensures(measured_size_.height >= 0);
-  Ensures(requirement.Satisfy(measured_size_));
+  size_ = OnMeasureCore(merged_requirement, merged_preferred_size);
+  Ensures(size_.width >= 0);
+  Ensures(size_.height >= 0);
+  Ensures(requirement.Satisfy(size_));
 }
 
-void RenderObject::Layout(const Rect& rect) {
-  Expects(rect.width >= 0);
-  Expects(rect.height >= 0);
-  offset_ = rect.GetLeftTop();
-  size_ = rect.GetSize();
-  OnLayoutCore(rect.GetSize());
+void RenderObject::Layout(const Point& offset) {
+  offset_ = offset;
+  OnLayoutCore();
 }
 
 RenderObject* RenderObject::GetSingleChild() const {
@@ -104,7 +107,8 @@ void RenderObject::OnRemoveChild(RenderObject* removed_child, Index position) {
   InvalidatePaint();
 }
 
-Size RenderObject::OnMeasureCore(const MeasureRequirement& requirement) {
+Size RenderObject::OnMeasureCore(const MeasureRequirement& requirement,
+                                 const MeasureSize& preferred_size) {
   const Size space_size{
       margin_.GetHorizontalTotal() + padding_.GetHorizontalTotal(),
       margin_.GetVerticalTotal() + padding_.GetVerticalTotal()};
@@ -113,58 +117,74 @@ Size RenderObject::OnMeasureCore(const MeasureRequirement& requirement) {
 
   MeasureRequirement content_requirement = requirement;
 
-  if (!requirement.max_width.IsNotSpecify()) {
-    const auto max_width = requirement.max_width.GetLength();
+  if (!requirement.max.width.IsNotSpecified()) {
+    const auto max_width = requirement.max.width.GetLengthOrMax();
     if (coerced_space_size.width > max_width) {
       log::Warn(
-          "Measure: horizontal length of padding and margin is bigger than "
-          "available length.");
+          "RenderObject: During measure, horizontal length of padding and "
+          "margin is bigger than required max length.");
       coerced_space_size.width = max_width;
     }
-    content_requirement.max_width = max_width - coerced_space_size.width;
+    content_requirement.max.width = max_width - coerced_space_size.width;
   }
 
-  if (!requirement.max_height.IsNotSpecify()) {
-    const auto max_height = requirement.max_height.GetLength();
+  if (!requirement.min.width.IsNotSpecified()) {
+    const auto min_width = requirement.min.width.GetLengthOr0();
+    content_requirement.min.width = std::max(0.f, min_width - space_size.width);
+  }
+
+  if (!requirement.max.height.IsNotSpecified()) {
+    const auto max_height = requirement.max.height.GetLengthOrMax();
     if (coerced_space_size.height > max_height) {
       log::Warn(
-          "Measure: horizontal length of padding and margin is bigger than "
-          "available length.");
+          "RenderObject: During measure, vertical length of padding and "
+          "margin is bigger than required max length.");
       coerced_space_size.height = max_height;
     }
-    content_requirement.max_height = max_height - coerced_space_size.height;
+    content_requirement.max.height = max_height - coerced_space_size.height;
   }
 
-  const auto content_size = OnMeasureContent(content_requirement);
+  if (!requirement.min.height.IsNotSpecified()) {
+    const auto min_height = requirement.min.height.GetLengthOr0();
+    content_requirement.min.height =
+        std::max(0.f, min_height - space_size.height);
+  }
+
+  MeasureSize content_preferred_size =
+      content_requirement.Coerce(preferred_size.Minus(space_size));
+
+  const auto content_size =
+      OnMeasureContent(content_requirement, content_preferred_size);
 
   return coerced_space_size + content_size;
 }
 
-void RenderObject::OnLayoutCore(const Size& size) {
+void RenderObject::OnLayoutCore() {
+  Size total_size = GetSize();
   Size space_size{margin_.GetHorizontalTotal() + padding_.GetHorizontalTotal(),
                   margin_.GetVerticalTotal() + padding_.GetVerticalTotal()};
 
-  auto content_size = size - space_size;
+  auto content_size = total_size - space_size;
 
   if (content_size.width < 0) {
     log::Warn(
-        "Layout: horizontal length of padding and margin is bigger than "
-        "available length.");
+        "RenderObject: During layout, horizontal length of padding and margin "
+        "is bigger than available length.");
     content_size.width = 0;
   }
   if (content_size.height < 0) {
     log::Warn(
-        "Layout: vertical length of padding and margin is bigger than "
-        "available length.");
+        "RenderObject: During layout, vertical length of padding and margin "
+        "is bigger than available length.");
     content_size.height = 0;
   }
 
   Point lefttop{margin_.left + padding_.left, margin_.top + padding_.top};
-  if (lefttop.x > size.width) {
-    lefttop.x = size.width;
+  if (lefttop.x > total_size.width) {
+    lefttop.x = total_size.width;
   }
-  if (lefttop.y > size.height) {
-    lefttop.y = size.height;
+  if (lefttop.y > total_size.height) {
+    lefttop.y = total_size.height;
   }
 
   const Rect content_rect{lefttop, content_size};
diff --git a/src/ui/render/ScrollRenderObject.cpp b/src/ui/render/ScrollRenderObject.cpp
index 98254690..e4cc27f3 100644
--- a/src/ui/render/ScrollRenderObject.cpp
+++ b/src/ui/render/ScrollRenderObject.cpp
@@ -2,7 +2,6 @@
 
 #include "cru/platform/graph/Painter.hpp"
 #include "cru/platform/graph/util/Painter.hpp"
-#include "cru/ui/render/LayoutUtility.hpp"
 
 #include <algorithm>
 
@@ -67,23 +66,32 @@ void ScrollRenderObject::SetScrollOffset(const Point& offset) {
   InvalidateLayout();
 }
 
-Size ScrollRenderObject::OnMeasureContent(
-    const MeasureRequirement& requirement) {
-  if (const auto child = GetSingleChild()) {
-    child->Measure(MeasureRequirement::Infinate());
-    const auto preferred_size = child->GetMeasuredSize();
-    return Min(preferred_size, requirement.GetMaxSize());
-  } else {
-    return Size{};
-  }
+Size ScrollRenderObject::OnMeasureContent(const MeasureRequirement& requirement,
+                                          const MeasureSize& preferred_size) {
+  // TODO: Rewrite this.
+  CRU_UNUSED(requirement);
+  CRU_UNUSED(preferred_size);
+  throw std::runtime_error("Not implemented.");
+
+  // if (const auto child = GetSingleChild()) {
+  //   child->Measure(MeasureRequirement::Infinate());
+  //   const auto preferred_size = child->GetMeasuredSize();
+  //   return Min(preferred_size, requirement.GetMaxSize());
+  // } else {
+  //   return Size{};
+  // }
 }  // namespace cru::ui::render
 
 void ScrollRenderObject::OnLayoutContent(const Rect& content_rect) {
-  if (const auto child = GetSingleChild()) {
-    const auto child_size = child->GetMeasuredSize();
-    const auto true_scroll =
-        CoerceScroll(scroll_offset_, content_rect.GetSize(), child_size);
-    child->Layout(Rect{content_rect.GetLeftTop() - true_scroll, child_size});
-  }
+  // TODO: Rewrite this.
+  CRU_UNUSED(content_rect);
+  throw std::runtime_error("Not implemented.");
+
+  // if (const auto child = GetSingleChild()) {
+  //   const auto child_size = child->GetMeasuredSize();
+  //   const auto true_scroll =
+  //       CoerceScroll(scroll_offset_, content_rect.GetSize(), child_size);
+  //   child->Layout(Rect{content_rect.GetLeftTop() - true_scroll, child_size});
+  // }
 }
 }  // namespace cru::ui::render
diff --git a/src/ui/render/StackLayoutRenderObject.cpp b/src/ui/render/StackLayoutRenderObject.cpp
index 7dce1a83..b953ae7e 100644
--- a/src/ui/render/StackLayoutRenderObject.cpp
+++ b/src/ui/render/StackLayoutRenderObject.cpp
@@ -4,47 +4,57 @@
 
 namespace cru::ui::render {
 Size StackLayoutRenderObject::OnMeasureContent(
-    const MeasureRequirement& requirement) {
-  auto size = Size{};
-  for (const auto child : GetChildren()) {
-    child->Measure(requirement);
-    const auto& measure_result = child->GetMeasuredSize();
-    size.width = std::max(size.width, measure_result.width);
-    size.height = std::max(size.height, measure_result.height);
-  }
-  return size;
+    const MeasureRequirement& requirement, const MeasureSize& preferred_size) {
+  // TODO: Rewrite this.
+  CRU_UNUSED(requirement);
+  CRU_UNUSED(preferred_size);
+  throw std::runtime_error("Not implemented.");
+
+  // throw std::runtime_error("Not implemented.");
+  // auto size = Size{};
+  // for (const auto child : GetChildren()) {
+  //   child->Measure(requirement);
+  //   const auto& measure_result = child->GetMeasuredSize();
+  //   size.width = std::max(size.width, measure_result.width);
+  //   size.height = std::max(size.height, measure_result.height);
+  // }
+  // return size;
 }
 
-void StackLayoutRenderObject::OnLayoutContent(const Rect& rect) {
-  auto calculate_anchor = [](int alignment, float start_point,
-                             float total_length,
-                             float content_length) -> float {
-    switch (alignment) {
-      case internal::align_start:
-        return start_point;
-      case internal::align_center:
-        return start_point + (total_length - content_length) / 2.0f;
-      case internal::align_end:
-        return start_point + total_length - content_length;
-      default:
-        return start_point;
-    }
-  };
+void StackLayoutRenderObject::OnLayoutContent(const Rect& content_rect) {
+  // TODO: Rewrite this.
+  CRU_UNUSED(content_rect);
+  throw std::runtime_error("Not implemented.");
 
-  const auto count = GetChildCount();
-  const auto& children = GetChildren();
+  // auto calculate_anchor = [](int alignment, float start_point,
+  //                            float total_length,
+  //                            float content_length) -> float {
+  //   switch (alignment) {
+  //     case internal::align_start:
+  //       return start_point;
+  //     case internal::align_center:
+  //       return start_point + (total_length - content_length) / 2.0f;
+  //     case internal::align_end:
+  //       return start_point + total_length - content_length;
+  //     default:
+  //       return start_point;
+  //   }
+  // };
 
-  for (int i = 0; i < count; i++) {
-    const auto layout_data = GetChildLayoutData(i);
-    const auto child = children[i];
-    const auto& size = child->GetMeasuredSize();
-    child->Layout(
-        Rect{calculate_anchor(static_cast<int>(layout_data->horizontal),
-                              rect.left, rect.width, size.width),
-             calculate_anchor(static_cast<int>(layout_data->vertical), rect.top,
-                              rect.height, size.height),
-             size.width, size.height});
-  }
-}
+  // const auto count = GetChildCount();
+  // const auto& children = GetChildren();
 
+  // for (int i = 0; i < count; i++) {
+  //   const auto layout_data = GetChildLayoutData(i);
+  //   const auto child = children[i];
+  //   const auto& size = child->GetMeasuredSize();
+  //   child->Layout(
+  //       Rect{calculate_anchor(static_cast<int>(layout_data->horizontal),
+  //                             rect.left, rect.width, size.width),
+  //            calculate_anchor(static_cast<int>(layout_data->vertical),
+  //            rect.top,
+  //                             rect.height, size.height),
+  //            size.width, size.height});
+  // }
+}
 }  // namespace cru::ui::render
diff --git a/src/ui/render/TextRenderObject.cpp b/src/ui/render/TextRenderObject.cpp
index ececfbc2..9cae65d6 100644
--- a/src/ui/render/TextRenderObject.cpp
+++ b/src/ui/render/TextRenderObject.cpp
@@ -1,10 +1,10 @@
 #include "cru/ui/render/TextRenderObject.hpp"
 
 #include "../Helper.hpp"
+#include "cru/common/Logger.hpp"
 #include "cru/platform/graph/Factory.hpp"
 #include "cru/platform/graph/TextLayout.hpp"
 #include "cru/platform/graph/util/Painter.hpp"
-#include "cru/ui/render/LayoutUtility.hpp"
 
 #include <algorithm>
 #include <limits>
@@ -160,10 +160,44 @@ RenderObject* TextRenderObject::HitTest(const Point& point) {
   return padding_rect.IsPointInside(point) ? this : nullptr;
 }
 
-Size TextRenderObject::OnMeasureContent(const MeasureRequirement& requirement) {
-  text_layout_->SetMaxWidth(requirement.max_height.GetLength());
-  text_layout_->SetMaxHeight(requirement.max_height.GetLength());
-  return Min(text_layout_->GetTextBounds().GetSize(), requirement.GetMaxSize());
+Size TextRenderObject::OnMeasureContent(const MeasureRequirement& requirement,
+                                        const MeasureSize& preferred_size) {
+  float measure_width;
+  if (preferred_size.width.IsSpecified())
+    measure_width = preferred_size.width.GetLengthOrUndefined();
+  else
+    measure_width = preferred_size.width.GetLengthOrMax();
+
+  text_layout_->SetMaxWidth(measure_width);
+  text_layout_->SetMaxHeight(std::numeric_limits<float>::max());
+
+  const auto text_size = text_layout_->GetTextBounds().GetSize();
+  auto result = text_size;
+
+  if (requirement.max.width.IsSpecified() &&
+      text_size.width > requirement.max.width.GetLengthOrUndefined()) {
+    log::Warn(
+        "TextRenderObject: Text actual width exceeds the required max width.");
+    result.width = requirement.max.width.GetLengthOrUndefined();
+  } else {
+    result.width = std::max(result.width, preferred_size.width.GetLengthOr0());
+    result.width = std::max(result.width, requirement.min.width.GetLengthOr0());
+  }
+
+  if (requirement.max.height.IsSpecified() &&
+      text_size.height > requirement.max.height.GetLengthOrUndefined()) {
+    log::Warn(
+        "TextRenderObject: Text actual height exceeds the required max "
+        "height.");
+    result.width = requirement.max.width.GetLengthOrUndefined();
+  } else {
+    result.height =
+        std::max(result.height, preferred_size.height.GetLengthOr0());
+    result.width =
+        std::max(result.height, requirement.min.height.GetLengthOr0());
+  }
+
+  return result;
 }
 
 void TextRenderObject::OnLayoutContent(const Rect& content_rect) {
diff --git a/src/ui/render/WindowRenderObject.cpp b/src/ui/render/WindowRenderObject.cpp
index 28afe01d..a2c7ae4d 100644
--- a/src/ui/render/WindowRenderObject.cpp
+++ b/src/ui/render/WindowRenderObject.cpp
@@ -34,17 +34,17 @@ RenderObject* WindowRenderObject::HitTest(const Point& point) {
   return Rect{Point{}, GetSize()}.IsPointInside(point) ? this : nullptr;
 }
 
-Size WindowRenderObject::OnMeasureContent(
-    const MeasureRequirement& requirement) {
+Size WindowRenderObject::OnMeasureContent(const MeasureRequirement& requirement,
+                                          const MeasureSize& preferred_size) {
   if (const auto child = GetChild()) {
-    child->Measure(requirement);
-    return child->GetMeasuredSize();
+    child->Measure(requirement, preferred_size);
+    return child->GetSize();
   } else {
     return Size{};
   }
 }
 
 void WindowRenderObject::OnLayoutContent(const Rect& content_rect) {
-  if (const auto child = GetChild()) child->Layout(content_rect);
+  if (const auto child = GetChild()) child->Layout(content_rect.GetLeftTop());
 }
 }  // namespace cru::ui::render