From 3a10dd47d5c8fdc7d01d1f32f8d53691aef7a16f Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Fri, 4 Jan 2019 15:28:35 +0900
Subject: [PATCH] Add preview for gameplay region

---
 .../Graphics/Containers/ScalingContainer.cs   | 15 +++----
 .../Sections/Graphics/LayoutSettings.cs       | 41 +++++++++++++++++--
 2 files changed, 45 insertions(+), 11 deletions(-)

diff --git a/osu.Game/Graphics/Containers/ScalingContainer.cs b/osu.Game/Graphics/Containers/ScalingContainer.cs
index 6686e6057e..0fba88bb28 100644
--- a/osu.Game/Graphics/Containers/ScalingContainer.cs
+++ b/osu.Game/Graphics/Containers/ScalingContainer.cs
@@ -23,7 +23,7 @@ namespace osu.Game.Graphics.Containers
         private Bindable<float> posX;
         private Bindable<float> posY;
 
-        private readonly ScalingMode targetMode;
+        private readonly ScalingMode? targetMode;
 
         private Bindable<ScalingMode> scalingMode;
 
@@ -37,8 +37,8 @@ namespace osu.Game.Graphics.Containers
         /// <summary>
         /// Create a new instance.
         /// </summary>
-        /// <param name="targetMode">The mode which this container should be handling.</param>
-        public ScalingContainer(ScalingMode targetMode)
+        /// <param name="targetMode">The mode which this container should be handling. Handles all modes if null.</param>
+        public ScalingContainer(ScalingMode? targetMode = null)
         {
             this.targetMode = targetMode;
             RelativeSizeAxes = Axes.Both;
@@ -47,6 +47,7 @@ namespace osu.Game.Graphics.Containers
             {
                 RelativeSizeAxes = Axes.Both,
                 RelativePositionAxes = Axes.Both,
+                Masking = true,
                 CornerRadius = 10,
                 Child = content = new DrawSizePreservingFillContainer()
             };
@@ -76,7 +77,7 @@ namespace osu.Game.Graphics.Containers
             base.LoadComplete();
 
             updateSize();
-            content.FinishTransforms();
+            sizableContainer.FinishTransforms();
         }
 
         private bool requiresBackgroundVisible => (scalingMode == ScalingMode.Everything || scalingMode == ScalingMode.ExcludeOverlays) && (sizeX.Value != 1 || sizeY.Value != 1);
@@ -106,10 +107,10 @@ namespace osu.Game.Graphics.Containers
                     backgroundLayer?.FadeOut(500);
             }
 
-            bool letterbox = scalingMode.Value == targetMode;
+            bool scaling = targetMode == null || scalingMode.Value == targetMode;
 
-            var targetSize = letterbox ? new Vector2(sizeX, sizeY) : Vector2.One;
-            var targetPosition = letterbox ? new Vector2(posX, posY) * (Vector2.One - targetSize) : Vector2.Zero;
+            var targetSize = scaling ? new Vector2(sizeX, sizeY) : Vector2.One;
+            var targetPosition = scaling ? new Vector2(posX, posY) * (Vector2.One - targetSize) : Vector2.Zero;
             bool requiresMasking = targetSize != Vector2.One;
 
             if (requiresMasking)
diff --git a/osu.Game/Overlays/Settings/Sections/Graphics/LayoutSettings.cs b/osu.Game/Overlays/Settings/Sections/Graphics/LayoutSettings.cs
index 3b0de5db10..9a55e97452 100644
--- a/osu.Game/Overlays/Settings/Sections/Graphics/LayoutSettings.cs
+++ b/osu.Game/Overlays/Settings/Sections/Graphics/LayoutSettings.cs
@@ -9,9 +9,12 @@ using osu.Framework.Allocation;
 using osu.Framework.Configuration;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Shapes;
 using osu.Framework.Threading;
 using osu.Game.Configuration;
+using osu.Game.Graphics.Containers;
 using osu.Game.Graphics.UserInterface;
+using osuTK.Graphics;
 using osuTK.Input;
 
 namespace osu.Game.Overlays.Settings.Sections.Graphics
@@ -151,15 +154,32 @@ namespace osu.Game.Overlays.Settings.Sections.Graphics
             configBindable.BindValueChanged(v => delayed.Value = v, true);
             delayed.ValueChanged += v =>
             {
-                if (scalingMode == ScalingMode.Everything)
-                    applyWithDelay(() => configBindable.Value = v);
-                else
-                    configBindable.Value = v;
+                switch (scalingMode.Value)
+                {
+                    case ScalingMode.Everything:
+                        applyWithDelay(() => configBindable.Value = v);
+                        return;
+                    case ScalingMode.Gameplay:
+                        showPreview();
+                        break;
+                }
+
+                configBindable.Value = v;
             };
 
             return delayed;
         }
 
+        private Drawable preview;
+        private void showPreview()
+        {
+            if (preview?.IsAlive != true)
+                game.Add(preview = new ScalingPreview());
+
+            preview.FadeOutFromOne(1500);
+            preview.Expire();
+        }
+
         private ScheduledDelegate delayedApplication;
 
         private void applyWithDelay(Action func, bool firstRun = true)
@@ -191,6 +211,19 @@ namespace osu.Game.Overlays.Settings.Sections.Graphics
             return resolutions;
         }
 
+        private class ScalingPreview : ScalingContainer
+        {
+            public ScalingPreview()
+            {
+                Child = new Box
+                {
+                    Colour = Color4.White,
+                    RelativeSizeAxes = Axes.Both,
+                    Alpha = 0.5f,
+                };
+            }
+        }
+
         private class ResolutionSettingsDropdown : SettingsDropdown<Size>
         {
             protected override OsuDropdown<Size> CreateDropdown() => new ResolutionDropdownControl { Items = Items };