1 files changed, 49 insertions, 0 deletions
diff --git a/src/ui/render/stack_layout_render_object.cpp b/src/ui/render/stack_layout_render_object.cpp
new file mode 100644
index 00000000..1cb31252
--- /dev/null
+++ b/src/ui/render/stack_layout_render_object.cpp
@@ -0,0 +1,49 @@
+#include "cru/ui/render/stack_layout_render_object.hpp"
+
+#include <algorithm>
+
+namespace cru::ui::render {
+Size StackLayoutRenderObject::OnMeasureContent(const Size& available_size) {
+  auto size = Size{};
+  for (const auto child : GetChildren()) {
+    child->Measure(available_size);
+    const auto& preferred_size = child->GetPreferredSize();
+    size.width = std::max(size.width, preferred_size.width);
+    size.height = std::max(size.height, preferred_size.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 0;
+    }
+  };
+
+  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->GetPreferredSize();
+    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