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#pragma once
#include "nes/common/types.hh"
#include "nes/app/graphics/renderer.hh"
#include "nes/app/graphics/color.hh"
namespace nes::app
{
/// A selection menu managing a fixed number of items and pagination.
template<typename Item, u32 PageSize>
class selection
{
Item items_[PageSize];
u32 count_{ 0 };
u32 page_count_{ 0 };
i32 x_{};
i32 y_{};
u32 width_{};
i32 selected_{ -1 };
i32 current_page_{ -1 };
public:
explicit selection(i32 const x, i32 const y, u32 const width)
: x_{ x }
, y_{ y }
, width_{ width }
{
}
virtual ~selection() = default;
selection(selection const&) = delete;
selection(selection&&) = delete;
auto operator=(selection const&) -> selection& = delete;
auto operator=(selection&&) -> selection& = delete;
auto set_page_count(u32 const page_count) -> void
{
page_count_ = page_count;
set_page(page_count_ > 0 ? 0 : -1);
}
auto get_page_count() const -> u32 { return page_count_; }
auto get_current_page() const -> i32 { return current_page_; }
auto get_selected() const -> Item const* { return selected_ >= 0 ? &items_[selected_] : nullptr; }
auto render(renderer& renderer) const -> void
{
for (auto i = u32{ 0 }; i < count_; ++i)
{
auto const y = y_ + static_cast<i32>(3 * i);
auto const is_selected = static_cast<i32>(i) == selected_;
auto const color = is_selected ? color::accent_primary : color::foreground_primary;
if (is_selected)
{
renderer.render_text(x_, y, ">", color);
}
render_item(renderer, items_[i], x_ + 2, y, width_ - 2, color);
}
}
auto go_next() -> void
{
if (selected_ < 0) { return; }
selected_ += 1;
if (selected_ == static_cast<i32>(count_)) { selected_ = 0; }
}
auto go_up() -> void
{
if (selected_ <= 0)
{
if (current_page_ <= 0) { return; }
set_page(current_page_ - 1, true);
return;
}
selected_ -= 1;
}
auto go_down() -> void
{
if (selected_ < 0 || selected_ + 1 == static_cast<i32>(count_))
{
if (current_page_ < 0 || current_page_ + 1 == static_cast<i32>(page_count_)) { return; }
set_page(current_page_ + 1, false);
return;
}
selected_ += 1;
}
protected:
/// Render an item's caption at the given position and width.
virtual auto render_item(renderer&, Item const&, i32 x, i32 y, u32 width, color) const -> void = 0;
/// Load the items for a page (max. PageSize items) and return the number of loaded items.
virtual auto load_page(Item(&)[PageSize], u32 page) -> u32 = 0;
private:
auto set_page(i32 const page, bool const select_last = false) -> void
{
if (page < 0)
{
current_page_ = -1;
count_ = 0;
selected_ = -1;
return;
}
current_page_ = page;
count_ = load_page(items_, static_cast<u32>(page));
if (count_ > 0)
{
selected_ = select_last ? static_cast<i32>(count_) - 1 : 0;
}
else
{
selected_ = -1;
}
}
};
} // namespace nes::app
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