osu/osu.Game/Graphics/UserInterface/OsuDropDownMenu.cs

// Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE

using osu.Framework.Graphics.Transforms;
using osu.Framework.Graphics.UserInterface;
using OpenTK;
using OpenTK.Graphics;
using osu.Framework.Extensions.Color4Extensions;

namespace osu.Game.Graphics.UserInterface
{
    public class OsuDropDownMenu<U> : DropDownMenu<U>
    {
        protected override BasicDropDownHeader CreateHeader() => new OsuDropDownHeader();

        public OsuDropDownMenu()
        {
            ContentContainer.CornerRadius = 4;
            ContentBackground.Colour = Color4.Black.Opacity(0.5f);
        }

        protected override void AnimateOpen()
        {
            ContentContainer.FadeIn(300, EasingTypes.OutQuint);
        }

        protected override void AnimateClose()
        {
            ContentContainer.FadeOut(300, EasingTypes.OutQuint);
        }

        protected override void UpdateContentHeight()
        {
            ContentContainer.ResizeTo(State == DropDownMenuState.Opened ? new Vector2(1, ContentHeight) : new Vector2(1, 0), 300, EasingTypes.OutQuint);
        }

        protected override DropDownMenuItem<U> CreateDropDownItem(string key, U value) => new OsuDropDownMenuItem<U>(key, value);
    }
}