Implement OverlayScrollContainer component

osu.Game.Tests/Visual/UserInterface/TestSceneOverlayScrollContainer.cs

@@ -0,0 +1,90 @@
+// 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 osu.Framework.Graphics.Containers;
+using osu.Game.Overlays;
+using System;
+using System.Collections.Generic;
+using osu.Framework.Graphics;
+using osu.Framework.Allocation;
+using osu.Framework.Graphics.Shapes;
+using osuTK.Graphics;
+using NUnit.Framework;
+using osu.Framework.Utils;
+using osuTK.Input;
+
+namespace osu.Game.Tests.Visual.UserInterface
+{
+    public class TestSceneOverlayScrollContainer : OsuManualInputManagerTestScene
+    {
+        public override IReadOnlyList<Type> RequiredTypes => new[]
+        {
+            typeof(OverlayScrollContainer)
+        };
+
+        [Cached]
+        private readonly OverlayColourProvider colourProvider = new OverlayColourProvider(OverlayColourScheme.Blue);
+
+        private OverlayScrollContainer scroll;
+
+        private int invocationCount;
+
+        [SetUp]
+        public void SetUp() => Schedule(() =>
+        {
+            Add(scroll = new OverlayScrollContainer
+            {
+                RelativeSizeAxes = Axes.Both,
+                Child = new Container
+                {
+                    Height = 3000,
+                    RelativeSizeAxes = Axes.X,
+                    Child = new Box
+                    {
+                        RelativeSizeAxes = Axes.Both,
+                        Colour = Color4.Gray
+                    }
+                }
+            });
+
+            invocationCount = 0;
+
+            scroll.Button.Action += () => invocationCount++;
+        });
+
+        [Test]
+        public void TestButtonVisibility()
+        {
+            AddAssert("button is hidden", () => scroll.Button.State.Value == Visibility.Hidden);
+
+            AddStep("scroll to end", () => scroll.ScrollToEnd(false));
+            AddAssert("button is visible", () => scroll.Button.State.Value == Visibility.Visible);
+
+            AddStep("scroll to start", () => scroll.ScrollToStart(false));
+            AddAssert("button is hidden", () => scroll.Button.State.Value == Visibility.Hidden);
+        }
+
+        [Test]
+        public void TestButtonAction()
+        {
+            AddStep("scroll to end", () => scroll.ScrollToEnd(false));
+
+            AddStep("invoke action", () => scroll.Button.Action.Invoke());
+
+            AddUntilStep("scrolled back to start", () => Precision.AlmostEquals(scroll.Current, 0, 0.1f));
+        }
+
+        [Test]
+        public void TestMultipleClicks()
+        {
+            AddStep("scroll to end", () => scroll.ScrollToEnd(false));
+
+            AddAssert("invocation count is 0", () => invocationCount == 0);
+
+            AddStep("hover button", () => InputManager.MoveMouseTo(scroll.Button));
+            AddRepeatStep("click button", () => InputManager.Click(MouseButton.Left), 3);
+
+            AddAssert("invocation count is 1", () => invocationCount == 1);
+        }
+    }
+}

osu.Game/Overlays/OverlayScrollContainer.cs

@@ -0,0 +1,169 @@
+// 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;
+using System.Collections.Generic;
+using osu.Framework.Allocation;
+using osu.Framework.Extensions.Color4Extensions;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Effects;
+using osu.Framework.Graphics.Shapes;
+using osu.Framework.Graphics.Sprites;
+using osu.Framework.Input.Events;
+using osu.Game.Graphics.Containers;
+using osuTK;
+using osuTK.Graphics;
+
+namespace osu.Game.Overlays
+{
+    /// <summary>
+    /// <see cref="OsuScrollContainer"/> which provides <see cref="ScrollToTopButton"/>. Mostly used in <see cref="FullscreenOverlay"/>.
+    /// </summary>
+    public class OverlayScrollContainer : OsuScrollContainer
+    {
+        /// <summary>
+        /// Scroll position at which the <see cref="ScrollToTopButton"/> will be shown.
+        /// </summary>
+        private const int button_scroll_position = 200;
+
+        public ScrollToTopButton Button { get; }
+
+        private float currentTarget;
+
+        public OverlayScrollContainer()
+        {
+            AddInternal(Button = new ScrollToTopButton
+            {
+                Anchor = Anchor.BottomRight,
+                Origin = Anchor.BottomRight,
+                Margin = new MarginPadding(20),
+                Action = () =>
+                {
+                    ScrollToStart();
+                    currentTarget = Target;
+                    Button.State.Value = Visibility.Hidden;
+                }
+            });
+        }
+
+        protected override void UpdateAfterChildren()
+        {
+            base.UpdateAfterChildren();
+
+            if (ScrollContent.DrawHeight + button_scroll_position < DrawHeight)
+            {
+                Button.State.Value = Visibility.Hidden;
+                return;
+            }
+
+            if (Target == currentTarget)
+                return;
+
+            currentTarget = Target;
+            Button.State.Value = Current > button_scroll_position ? Visibility.Visible : Visibility.Hidden;
+        }
+
+        public class ScrollToTopButton : VisibilityContainer
+        {
+            private const int fade_duration = 500;
+
+            public Action Action
+            {
+                get => button.Action;
+                set => button.Action = value;
+            }
+
+            public override bool PropagatePositionalInputSubTree => true;
+
+            protected override bool StartHidden => true;
+
+            private readonly Button button;
+
+            public ScrollToTopButton()
+            {
+                Size = new Vector2(50);
+                Child = button = new Button();
+            }
+
+            protected override bool OnMouseDown(MouseDownEvent e) => true;
+
+            protected override void PopIn() => button.FadeIn(fade_duration, Easing.OutQuint);
+
+            protected override void PopOut() => button.FadeOut(fade_duration, Easing.OutQuint);
+
+            private class Button : OsuHoverContainer
+            {
+                public override bool PropagatePositionalInputSubTree => Alpha == 1;
+
+                protected override IEnumerable<Drawable> EffectTargets => new[] { background };
+
+                private Color4 flashColour;
+
+                private readonly Container content;
+                private readonly Box background;
+
+                public Button()
+                {
+                    RelativeSizeAxes = Axes.Both;
+                    Add(content = new CircularContainer
+                    {
+                        RelativeSizeAxes = Axes.Both,
+                        Anchor = Anchor.Centre,
+                        Origin = Anchor.Centre,
+                        Masking = true,
+                        EdgeEffect = new EdgeEffectParameters
+                        {
+                            Type = EdgeEffectType.Shadow,
+                            Offset = new Vector2(0f, 1f),
+                            Radius = 3f,
+                            Colour = Color4.Black.Opacity(0.25f),
+                        },
+                        Children = new Drawable[]
+                        {
+                            background = new Box
+                            {
+                                RelativeSizeAxes = Axes.Both
+                            },
+                            new SpriteIcon
+                            {
+                                Anchor = Anchor.Centre,
+                                Origin = Anchor.Centre,
+                                Size = new Vector2(15),
+                                Icon = FontAwesome.Solid.ChevronUp
+                            }
+                        }
+                    });
+
+                    TooltipText = "Scroll to top";
+                }
+
+                [BackgroundDependencyLoader]
+                private void load(OverlayColourProvider colourProvider)
+                {
+                    IdleColour = colourProvider.Background6;
+                    HoverColour = colourProvider.Background5;
+                    flashColour = colourProvider.Light1;
+                }
+
+                protected override bool OnClick(ClickEvent e)
+                {
+                    background.FlashColour(flashColour, 800, Easing.OutQuint);
+                    return base.OnClick(e);
+                }
+
+                protected override bool OnMouseDown(MouseDownEvent e)
+                {
+                    content.ScaleTo(0.75f, 2000, Easing.OutQuint);
+                    return true;
+                }
+
+                protected override void OnMouseUp(MouseUpEvent e)
+                {
+                    content.ScaleTo(1, 1000, Easing.OutElastic);
+                    base.OnMouseUp(e);
+                }
+            }
+        }
+    }
+}