Function HorizontalRadioButtonsAt

Siv3D/src/Siv3D/SimpleGUI/SivSimpleGUI.cpp:655–741

		}

		bool HorizontalRadioButtonsAt(size_t& index, const Array<String>& options, const Vec2& center, const Optional<double>& _itemWidth, bool enabled)
		{
			const Font& font = GetFont();

			double itemWidth = 0.0;
			{
				if (_itemWidth)
				{
					itemWidth = *_itemWidth;
				}
				else
				{
					for (const auto& option : options)
					{
						itemWidth = Max<double>(itemWidth, RadioButtonPadding * 3 + RadioButtonSize + font(option).region().w);
					}

					itemWidth = Math::Ceil(itemWidth);
				}
			}

			const double width = (itemWidth * options.size());
			const RectF region{ Arg::center = center, width, UnitSize };
			const bool onClient = Cursor::OnClientRect();

			bool hasChanged = false;
			const double baseY = (center.y - UnitSize / 2 + 18);
			const int32 fontHeight = font.height();

			region.draw(BackgroundColor);
			{
				const ColorF checkedCircleColor = (enabled ? RadioButtonFillColor : RadioButtonDisabledBaseColor);
				const ColorF uncheckedCircleColor = (enabled ? RadioButtonBaseColor : RadioButtonDisabledBaseColor);

				for (size_t itemIndex = 0; itemIndex < options.size(); ++itemIndex)
				{
					const double posX = (region.x + itemWidth * itemIndex);
					const RectF radioButtonBox{ Arg::leftCenter(posX + RadioButtonPadding, baseY), RadioButtonSize };
					const Circle radioButton{ radioButtonBox.center(), (RadioButtonSize / 2.0) };
					const Vec2 labelPos{ (posX + RadioButtonPadding * 2 + RadioButtonSize), (radioButton.y - fontHeight / 2.0 + FontYOffset - 0.5) };
					const bool mouseOver = (enabled && radioButtonBox.mouseOver());
					const bool checked = (index == itemIndex);

					if (checked)
					{
						radioButton.drawFrame(2, 0.5, checkedCircleColor);
						radioButton.stretched(-5).draw(checkedCircleColor);
					}
					else
					{
						radioButton.drawFrame(2, 0.5, uncheckedCircleColor);
					}

					if (mouseOver && onClient)
					{
						Cursor::RequestStyle(CursorStyle::Hand);
					}