From 28df77e83887d2eae75454bdd6de5b3a8afca46a Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Tue, 15 May 2018 21:08:55 +0900
Subject: [PATCH] Simplify code and remove generic

---
 ....cs => TestCaseScreenBreadcrumbControl.cs} | 18 ++---
 .../UserInterface/ScreenBreadcrumbControl.cs  | 75 +++++++------------
 2 files changed, 36 insertions(+), 57 deletions(-)
 rename osu.Game.Tests/Visual/{TestCaseScreenBreadcrumbs.cs => TestCaseScreenBreadcrumbControl.cs} (89%)

diff --git a/osu.Game.Tests/Visual/TestCaseScreenBreadcrumbs.cs b/osu.Game.Tests/Visual/TestCaseScreenBreadcrumbControl.cs
similarity index 89%
rename from osu.Game.Tests/Visual/TestCaseScreenBreadcrumbs.cs
rename to osu.Game.Tests/Visual/TestCaseScreenBreadcrumbControl.cs
index f477a0b97e..a64e60dbd6 100644
--- a/osu.Game.Tests/Visual/TestCaseScreenBreadcrumbs.cs
+++ b/osu.Game.Tests/Visual/TestCaseScreenBreadcrumbControl.cs
@@ -6,6 +6,7 @@ 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;
@@ -15,18 +16,19 @@ using OpenTK;
 namespace osu.Game.Tests.Visual
 {
     [TestFixture]
-    public class TestCaseScreenBreadcrumbs : OsuTestCase
+    public class TestCaseScreenBreadcrumbControl : OsuTestCase
     {
-        private readonly ScreenBreadcrumbControl<TestScreen> breadcrumbs;
-        private TestScreen currentScreen, changedScreen;
+        private readonly ScreenBreadcrumbControl breadcrumbs;
+        private Screen currentScreen, changedScreen;
 
-        public TestCaseScreenBreadcrumbs()
+        public TestCaseScreenBreadcrumbControl()
         {
             TestScreen startScreen;
             OsuSpriteText titleText;
 
             Children = new Drawable[]
             {
+                changedScreen = currentScreen = startScreen = new TestScreenOne(),
                 new FillFlowContainer
                 {
                     RelativeSizeAxes = Axes.X,
@@ -35,23 +37,21 @@ namespace osu.Game.Tests.Visual
                     Spacing = new Vector2(10),
                     Children = new Drawable[]
                     {
-                        breadcrumbs = new ScreenBreadcrumbControl<TestScreen>
+                        breadcrumbs = new ScreenBreadcrumbControl(startScreen)
                         {
                             RelativeSizeAxes = Axes.X,
                         },
                         titleText = new OsuSpriteText(),
                     },
                 },
-                currentScreen = startScreen = new TestScreenOne(),
             };
 
-            breadcrumbs.OnScreenChanged += s =>
+            breadcrumbs.Current.ValueChanged += s =>
             {
                 titleText.Text = $"Changed to {s.ToString()}";
                 changedScreen = s;
             };
 
-            AddStep(@"make start current", () => breadcrumbs.CurrentScreen = startScreen);
             assertCurrent();
             pushNext();
             assertCurrent();
@@ -75,7 +75,7 @@ namespace osu.Game.Tests.Visual
             breadcrumbs.StripColour = colours.Blue;
         }
 
-        private void pushNext() => AddStep(@"push next screen", () => currentScreen = currentScreen.PushNext());
+        private void pushNext() => AddStep(@"push next screen", () => currentScreen = ((TestScreen)currentScreen).PushNext());
         private void assertCurrent() => AddAssert(@"assert the current screen is correct", () => currentScreen == changedScreen);
 
         private abstract class TestScreen : OsuScreen
diff --git a/osu.Game/Graphics/UserInterface/ScreenBreadcrumbControl.cs b/osu.Game/Graphics/UserInterface/ScreenBreadcrumbControl.cs
index ae03a06b4f..49d854ccd2 100644
--- a/osu.Game/Graphics/UserInterface/ScreenBreadcrumbControl.cs
+++ b/osu.Game/Graphics/UserInterface/ScreenBreadcrumbControl.cs
@@ -8,67 +8,46 @@ using osu.Framework.Screens;
 
 namespace osu.Game.Graphics.UserInterface
 {
-    public class ScreenBreadcrumbControl<T> : BreadcrumbControl<T> where T : Screen
+    /// <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 T currentScreen;
-        public T CurrentScreen
+        private Screen last;
+
+        public ScreenBreadcrumbControl(Screen initialScreen)
         {
-            get { return currentScreen; }
-            set
+            Current.ValueChanged += newScreen =>
             {
-                if (value == currentScreen) return;
-
-                if (CurrentScreen != null)
-                {
-                    CurrentScreen.Exited -= onExited;
-                    CurrentScreen.ModePushed -= onPushed;
-                }
-                else
-                {
-                    // this is the first screen in the stack, so call the initial onPushed
-                    currentScreen = value;
-                    onPushed(CurrentScreen);
-                }
-
-                currentScreen = value;
-
-                if (CurrentScreen != null)
-                {
-                    CurrentScreen.Exited += onExited;
-                    CurrentScreen.ModePushed += onPushed;
-                    Current.Value = CurrentScreen;
-                    OnScreenChanged?.Invoke(CurrentScreen);
-                }
-            }
-        }
-
-        public event Action<T> OnScreenChanged;
-
-        public ScreenBreadcrumbControl()
-        {
-            Current.ValueChanged += s =>
-            {
-                if (s != CurrentScreen)
-                {
-                    CurrentScreen = s;
-                    s.MakeCurrent();
-                }
+                if (last != newScreen && !newScreen.IsCurrentScreen)
+                    newScreen.MakeCurrent();
             };
+
+            onPushed(initialScreen);
         }
 
-        private void onExited(Screen screen)
+        private void screenChanged(Screen newScreen)
         {
-            CurrentScreen = screen as T;
+            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)
         {
-            var newScreen = screen as T;
-
             Items.ToList().SkipWhile(i => i != Current.Value).Skip(1).ForEach(RemoveItem);
-            AddItem(newScreen);
+            AddItem(screen);
 
-            CurrentScreen = newScreen;
+            screenChanged(screen);
         }
     }
 }