SimpleGUI::ListBox() で項目数が多いとスクロールバーのつまみが消える不具合

[Reputeless]

• reported by: https://twitter.com/tettyA256/status/1641452831206166529

[Reputeless]

before (v0.6.7)

after (v0.6.8)

# include <Siv3D.hpp>

void Main()
{
	Scene::SetBackground(ColorF{ 0.8, 0.9, 1.0 });

	ListBoxState listbox200;
	{
		for (int32 i = 0; i < 200; ++i)
		{
			listbox200.items.emplace_back(Format(i));
		}
	}

	ListBoxState listbox2000;
	{
		for (int32 i = 0; i < 2000; ++i)
		{
			listbox2000.items.emplace_back(Format(i));
		}
	}

	while (System::Update())
	{
		ClearPrint();

		if (listbox200.selectedItemIndex)
		{
			Print << listbox200.items[*listbox200.selectedItemIndex];
		}

		if (listbox2000.selectedItemIndex)
		{
			Print << listbox2000.items[*listbox2000.selectedItemIndex];
		}

		SimpleGUI::ListBox(listbox200, Vec2{ 80, 40 }, 120, 156);

		SimpleGUI::ListBox(listbox2000, Vec2{ 240, 40 }, 120, 156);
	}
}