LibGUI: Implement very bad widget system :D

userspace/libraries/LibGUI/Widget/Grid.cpp

@@ -0,0 +1,53 @@
+#include <LibGUI/Widget/Grid.h>
+
+namespace LibGUI::Widget
+{
+
+	BAN::ErrorOr<BAN::RefPtr<Grid>> Grid::create(BAN::RefPtr<Widget> parent, uint32_t cols, uint32_t rows, uint32_t color, Rectangle geometry)
+	{
+		auto* grid_ptr = new Grid(parent, geometry, cols, rows);
+		if (grid_ptr == nullptr)
+			return BAN::Error::from_errno(ENOMEM);
+		auto grid = BAN::RefPtr<Grid>::adopt(grid_ptr);
+		TRY(grid->initialize(color));
+		return grid;
+	}
+
+	Widget::Rectangle Grid::grid_element_area(const GridElement& element) const
+	{
+		const uint32_t this_x = element.col * width()  / m_cols;
+		const uint32_t this_y = element.row * height() / m_rows;
+
+		const uint32_t next_x = (element.col + element.col_span) * width() / m_cols;
+		const uint32_t next_y = (element.row + element.row_span) * height() / m_rows;
+
+		return Widget::Rectangle {
+			.x = static_cast<int32_t>(this_x),
+			.y = static_cast<int32_t>(this_y),
+			.w = next_x - this_x,
+			.h = next_y - this_y,
+		};
+	}
+
+	BAN::ErrorOr<void> Grid::update_geometry_impl()
+	{
+		for (auto& grid_element : m_grid_elements)
+			TRY(grid_element.widget->set_fixed_geometry(grid_element_area(grid_element)));
+		return {};
+	}
+
+	BAN::ErrorOr<void> Grid::set_widget_position(BAN::RefPtr<Widget> widget, uint32_t col, uint32_t col_span, uint32_t row, uint32_t row_span)
+	{
+		if (col_span == 0 || row_span == 0)
+			return BAN::Error::from_errno(EINVAL);
+		if (col + col_span > m_cols)
+			return BAN::Error::from_errno(EINVAL);
+		if (row + row_span > m_rows)
+			return BAN::Error::from_errno(EINVAL);
+		ASSERT(widget->parent() == this);
+		TRY(m_grid_elements.emplace_back(widget, col, col_span, row, row_span));
+		TRY(widget->set_fixed_geometry(grid_element_area(m_grid_elements.back())));
+		return {};
+	}
+
+}