osu/osu.Game/Overlays/Mods/NestedVerticalScrollContain...

49 lines
1.8 KiB
C#

// 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.
#nullable enable
using osu.Framework.Graphics;
using osu.Framework.Input.Events;
using osu.Game.Graphics.Containers;
namespace osu.Game.Overlays.Mods
{
/// <summary>
/// A scroll container that handles the case of vertically scrolling content inside a larger horizontally scrolling parent container.
/// </summary>
public class NestedVerticalScrollContainer : OsuScrollContainer
{
private OsuScrollContainer? parentScrollContainer;
protected override void LoadComplete()
{
base.LoadComplete();
parentScrollContainer = this.FindClosestParent<OsuScrollContainer>();
}
protected override bool OnScroll(ScrollEvent e)
{
if (parentScrollContainer == null)
return base.OnScroll(e);
bool topRightInView = parentScrollContainer.ScreenSpaceDrawQuad.Contains(ScreenSpaceDrawQuad.TopRight);
bool bottomLeftInView = parentScrollContainer.ScreenSpaceDrawQuad.Contains(ScreenSpaceDrawQuad.BottomLeft);
// If not completely on-screen, handle scroll but also allow parent to scroll at the same time (to hopefully bring our content into full view).
if (!topRightInView || !bottomLeftInView)
return false;
bool scrollingPastEnd = e.ScrollDelta.Y < 0 && IsScrolledToEnd();
bool scrollingPastStart = e.ScrollDelta.Y > 0 && Target <= 0;
// If at either of our extents, delegate scroll to the horizontal parent container.
if (scrollingPastStart || scrollingPastEnd)
return false;
return base.OnScroll(e);
}
}
}