Function RadioButtonsAt

Siv3D/src/Siv3D/SimpleGUI/SivSimpleGUI.cpp:532–597

		}

		bool RadioButtonsAt(size_t& index, const Array<String>& options, const Vec2& center, const Optional<double>& _width, bool enabled)
		{
			const Font& font = GetFont();
			const RectF region = RadioButtonsRegionAt(options, center, _width);
			const bool onClient = Cursor::OnClientRect();

			bool hasChanged = false;
			const int32 labelPosX = static_cast<int32>(region.x + RadioButtonPadding * 2 + RadioButtonSize);
			const double baseY = (center.y - (options.size() * CellSize - (CellSize - UnitSize)) / 2.0 + 18);

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

				for (size_t row = 0; row < options.size(); ++row)
				{
					const RectF radioButtonBox{ Arg::leftCenter(region.x + RadioButtonPadding, baseY + row * CellSize), RadioButtonSize };
					const Circle radioButton{ radioButtonBox.center(), RadioButtonSize / 2.0 };
					const bool mouseOver = (enabled && radioButtonBox.mouseOver());
					const bool checked = (index == row);

					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);
					}

					if (enabled && onClient && radioButtonBox.leftClicked())
					{
						if (index != row)
						{
							index = row;
							hasChanged = true;
						}
					}
				}
			}

			{
				const int32 fontHeight = font.height();
				const ColorF textColor = GetTextColor(enabled);
				size_t row = 0;

				for (const auto& option : options)
				{
					const RectF radioButtonBox{ Arg::leftCenter(region.x + RadioButtonPadding, baseY + row * CellSize), RadioButtonSize };
					const Circle radioButton{ radioButtonBox.center(), RadioButtonSize / 2.0 };
					const Vec2 labelPos{ labelPosX, (radioButton.y - fontHeight / 2.0 + FontYOffset - 0.5) };