osu-lazer/osu.Game/Screens/BackgroundScreenStack.cs

// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
// See the LICENCE file in the repository root for full licence text.

using System.Collections.Generic;
using osu.Framework.Graphics;
using osu.Framework.Screens;

namespace osu.Game.Screens
{
    public class BackgroundScreenStack : ScreenStack
    {
        public BackgroundScreenStack()
            : base(false)
        {
            RelativeSizeAxes = Axes.Both;
            Anchor = Anchor.Centre;
            Origin = Anchor.Centre;
        }

        public void Push(BackgroundScreen screen)
        {
            if (screen == null)
                return;

            if (EqualityComparer<BackgroundScreen>.Default.Equals((BackgroundScreen)CurrentScreen, screen))
                return;

            base.Push(screen);
        }
    }
}