Change the structure of project.

1 files changed, 178 insertions, 0 deletions

diff --git a/src/ui/controls/linear_layout.cpp b/src/ui/controls/linear_layout.cpp
new file mode 100644
index 00000000..8f537ea8
--- /dev/null
+++ b/src/ui/controls/linear_layout.cpp
@@ -0,0 +1,178 @@
+#include "linear_layout.h"
+
+namespace cru::ui::controls
+{
+    LinearLayout::LinearLayout(const Orientation orientation)
+        : Control(true), orientation_(orientation)
+    {
+
+    }
+
+    inline float AtLeast0(const float value)
+    {
+        return value < 0 ? 0 : value;
+    }
+
+    inline Size AtLeast0(const Size& size)
+    {
+        return Size(AtLeast0(size.width), AtLeast0(size.height));
+    }
+
+    Size LinearLayout::OnMeasure(const Size& available_size)
+    {
+        const auto layout_params = GetLayoutParams();
+
+        if (!layout_params->Validate())
+            throw std::runtime_error("LayoutParams is not valid. Please check it.");
+
+        auto&& get_available_length_for_child = [](const LayoutSideParams& layout_length, const float available_length) -> float
+        {
+            switch (layout_length.mode)
+            {
+            case MeasureMode::Exactly:
+            {
+                return std::min(layout_length.length, available_length);
+            }
+            case MeasureMode::Stretch:
+            case MeasureMode::Content:
+            {
+                return available_length;
+            }
+            default:
+                UnreachableCode();
+            }
+        };
+
+        Size total_available_size_for_children(
+            get_available_length_for_child(layout_params->width, available_size.width),
+            get_available_length_for_child(layout_params->height, available_size.height)
+        );
+
+        auto rest_available_size_for_children = total_available_size_for_children;
+
+        float secondary_side_child_max_length = 0;
+
+        std::list<Control*> stretch_control_list;
+
+        // First measure Content and Exactly and count Stretch.
+        if (orientation_ == Orientation::Horizontal)
+            ForeachChild([&](Control* const control)
+        {
+            const auto mode = control->GetLayoutParams()->width.mode;
+            if (mode == MeasureMode::Content || mode == MeasureMode::Exactly)
+            {
+                control->Measure(AtLeast0(rest_available_size_for_children));
+                const auto size = control->GetDesiredSize();
+                rest_available_size_for_children.width -= size.width;
+                secondary_side_child_max_length = std::max(size.height, secondary_side_child_max_length);
+            }
+            else
+                stretch_control_list.push_back(control);
+        });
+        else
+            ForeachChild([&](Control* const control)
+        {
+            const auto mode = control->GetLayoutParams()->height.mode;
+            if (mode == MeasureMode::Content || mode == MeasureMode::Exactly)
+            {
+                control->Measure(AtLeast0(rest_available_size_for_children));
+                const auto size = control->GetDesiredSize();
+                rest_available_size_for_children.height -= size.height;
+                secondary_side_child_max_length = std::max(size.width, secondary_side_child_max_length);
+            }
+            else
+                stretch_control_list.push_back(control);
+        });
+
+        if (orientation_ == Orientation::Horizontal)
+        {
+            const auto available_width = rest_available_size_for_children.width / stretch_control_list.size();
+            for (const auto control : stretch_control_list)
+            {
+                control->Measure(Size(AtLeast0(available_width), rest_available_size_for_children.height));
+                const auto size = control->GetDesiredSize();
+                rest_available_size_for_children.width -= size.width;
+                secondary_side_child_max_length = std::max(size.height, secondary_side_child_max_length);
+            }
+        }
+        else
+        {
+            const auto available_height = rest_available_size_for_children.height / stretch_control_list.size();
+            for (const auto control : stretch_control_list)
+            {
+                control->Measure(Size(rest_available_size_for_children.width, AtLeast0(available_height)));
+                const auto size = control->GetDesiredSize();
+                rest_available_size_for_children.height -= size.height;
+                secondary_side_child_max_length = std::max(size.width, secondary_side_child_max_length);
+            }
+        }
+
+        auto actual_size_for_children = total_available_size_for_children;
+        if (orientation_ == Orientation::Horizontal)
+        {
+            actual_size_for_children.width -= rest_available_size_for_children.width;
+            actual_size_for_children.height = secondary_side_child_max_length;
+        }
+        else
+        {
+            actual_size_for_children.width = secondary_side_child_max_length;
+            actual_size_for_children.height -= rest_available_size_for_children.height;
+        }
+
+        auto&& calculate_final_length = [](const LayoutSideParams& layout_length, const float length_for_children, const float max_child_length) -> float
+        {
+            switch (layout_length.mode)
+            {
+            case MeasureMode::Exactly:
+            case MeasureMode::Stretch:
+                return length_for_children;
+            case MeasureMode::Content:
+                return max_child_length;
+            default:
+                UnreachableCode();
+            }
+        };
+
+        return Size(
+            calculate_final_length(layout_params->width, total_available_size_for_children.width, actual_size_for_children.width),
+            calculate_final_length(layout_params->height, total_available_size_for_children.height, actual_size_for_children.height)
+        );
+    }
+
+    void LinearLayout::OnLayout(const Rect& rect)
+    {
+        float current_anchor_length = 0;
+        ForeachChild([this, &current_anchor_length, rect](Control* control)
+        {
+            const auto layout_params = control->GetLayoutParams();
+            const auto size = control->GetDesiredSize();
+            const auto alignment = orientation_ == Orientation::Horizontal ? layout_params->height.alignment : layout_params->width.alignment;
+
+            auto&& calculate_anchor = [alignment](const float layout_length, const float control_length) -> float
+            {
+                switch (alignment)
+                {
+                case Alignment::Center:
+                    return (layout_length - control_length) / 2;
+                case Alignment::Start:
+                    return 0;
+                case Alignment::End:
+                    return layout_length - control_length;
+                default:
+                    UnreachableCode();
+                }
+            };
+
+            if (orientation_ == Orientation::Horizontal)
+            {
+                control->Layout(Rect(Point(current_anchor_length, calculate_anchor(rect.height, size.height)), size));
+                current_anchor_length += size.width;
+            }
+            else
+            {
+                control->Layout(Rect(Point(calculate_anchor(rect.width, size.width), current_anchor_length), size));
+                current_anchor_length += size.height;
+            }
+        });
+    }
+}