Merge pull request #2521 from DrabWeb/screen-breadcrumbs

Screen breadcrumbs

osu.Game.Tests/Visual/TestCaseScreenBreadcrumbControl.cs

@@ -0,0 +1,145 @@
+// Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+using System.Linq;
+using NUnit.Framework;
+using osu.Framework.Allocation;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Screens;
+using osu.Game.Graphics;
+using osu.Game.Graphics.Sprites;
+using osu.Game.Graphics.UserInterface;
+using osu.Game.Screens;
+using OpenTK;
+
+namespace osu.Game.Tests.Visual
+{
+    [TestFixture]
+    public class TestCaseScreenBreadcrumbControl : OsuTestCase
+    {
+        private readonly ScreenBreadcrumbControl breadcrumbs;
+        private Screen currentScreen, changedScreen;
+
+        public TestCaseScreenBreadcrumbControl()
+        {
+            TestScreen startScreen;
+            OsuSpriteText titleText;
+
+            Children = new Drawable[]
+            {
+                currentScreen = startScreen = new TestScreenOne(),
+                new FillFlowContainer
+                {
+                    RelativeSizeAxes = Axes.X,
+                    AutoSizeAxes = Axes.Y,
+                    Direction = FillDirection.Vertical,
+                    Spacing = new Vector2(10),
+                    Children = new Drawable[]
+                    {
+                        breadcrumbs = new ScreenBreadcrumbControl(startScreen)
+                        {
+                            RelativeSizeAxes = Axes.X,
+                        },
+                        titleText = new OsuSpriteText(),
+                    },
+                },
+            };
+
+            breadcrumbs.Current.ValueChanged += s =>
+            {
+                titleText.Text = $"Changed to {s.ToString()}";
+                changedScreen = s;
+            };
+
+            breadcrumbs.Current.TriggerChange();
+
+            assertCurrent();
+            pushNext();
+            assertCurrent();
+            pushNext();
+            assertCurrent();
+
+            AddStep(@"make start current", () =>
+            {
+                startScreen.MakeCurrent();
+                currentScreen = startScreen;
+            });
+
+            assertCurrent();
+            pushNext();
+            AddAssert(@"only 2 items", () => breadcrumbs.Items.Count() == 2);
+            AddStep(@"exit current", () => changedScreen.Exit());
+            AddAssert(@"current screen is first", () => startScreen == changedScreen);
+        }
+
+        [BackgroundDependencyLoader]
+        private void load(OsuColour colours)
+        {
+            breadcrumbs.StripColour = colours.Blue;
+        }
+
+        private void pushNext() => AddStep(@"push next screen", () => currentScreen = ((TestScreen)currentScreen).PushNext());
+        private void assertCurrent() => AddAssert(@"changedScreen correct", () => currentScreen == changedScreen);
+
+        private abstract class TestScreen : OsuScreen
+        {
+            protected abstract string Title { get; }
+            protected abstract string NextTitle { get; }
+            protected abstract TestScreen CreateNextScreen();
+
+            public override string ToString() => Title;
+
+            public TestScreen PushNext()
+            {
+                TestScreen screen = CreateNextScreen();
+                Push(screen);
+
+                return screen;
+            }
+
+            protected TestScreen()
+            {
+                Child = new FillFlowContainer
+                {
+                    Anchor = Anchor.Centre,
+                    Origin = Anchor.Centre,
+                    AutoSizeAxes = Axes.Both,
+                    Direction = FillDirection.Vertical,
+                    Spacing = new Vector2(10),
+                    Children = new Drawable[]
+                    {
+                        new OsuSpriteText
+                        {
+                            Anchor = Anchor.TopCentre,
+                            Origin = Anchor.TopCentre,
+                            Text = Title,
+                        },
+                        new TriangleButton
+                        {
+                            Anchor = Anchor.TopCentre,
+                            Origin = Anchor.TopCentre,
+                            Width = 100,
+                            Text = $"Push {NextTitle}",
+                            Action = () => PushNext(),
+                        },
+                    },
+                };
+            }
+        }
+
+        private class TestScreenOne : TestScreen
+        {
+            protected override string Title => @"Screen One";
+            protected override string NextTitle => @"Two";
+            protected override TestScreen CreateNextScreen() => new TestScreenTwo();
+        }
+
+        private class TestScreenTwo : TestScreen
+        {
+            protected override string Title => @"Screen Two";
+            protected override string NextTitle => @"One";
+            protected override TestScreen CreateNextScreen() => new TestScreenOne();
+        }
+    }
+}

osu.Game/Graphics/UserInterface/ScreenBreadcrumbControl.cs

@@ -0,0 +1,54 @@
+// Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+using System.Linq;
+using osu.Framework.Extensions.IEnumerableExtensions;
+using osu.Framework.Screens;
+
+namespace osu.Game.Graphics.UserInterface
+{
+    /// <summary>
+    /// A <see cref="BreadcrumbControl"/> which follows the active screen (and allows navigation) in a <see cref="Screen"/> stack.
+    /// </summary>
+    public class ScreenBreadcrumbControl : BreadcrumbControl<Screen>
+    {
+        private Screen last;
+
+        public ScreenBreadcrumbControl(Screen initialScreen)
+        {
+            Current.ValueChanged += newScreen =>
+            {
+                if (last != newScreen && !newScreen.IsCurrentScreen)
+                    newScreen.MakeCurrent();
+            };
+
+            onPushed(initialScreen);
+        }
+
+        private void screenChanged(Screen newScreen)
+        {
+            if (newScreen == null) return;
+
+            if (last != null)
+            {
+                last.Exited -= screenChanged;
+                last.ModePushed -= onPushed;
+            }
+
+            last = newScreen;
+
+            newScreen.Exited += screenChanged;
+            newScreen.ModePushed += onPushed;
+
+            Current.Value = newScreen;
+        }
+
+        private void onPushed(Screen screen)
+        {
+            Items.ToList().SkipWhile(i => i != Current.Value).Skip(1).ForEach(RemoveItem);
+            AddItem(screen);
+
+            screenChanged(screen);
+        }
+    }
+}