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#include "cru/ui/render/FlexLayoutRenderObject.hpp"
#include "cru/platform/graph/util/Painter.hpp"
#include <algorithm>
#include <functional>
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.IsInfinate()) {
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 int 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 int 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;
}
}
}
} // namespace cru::ui::render
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