From 3b9e1e8a9491c8db305320951c58360622f57846 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Wed, 24 May 2023 19:16:51 +0900
Subject: [PATCH] Ensure editor selection buttons remain on screen when
 selection is near edge

Addresses https://github.com/ppy/osu/discussions/23599.
---
 .../Edit/Compose/Components/SelectionBox.cs   | 40 +++++++++++++++++--
 1 file changed, 37 insertions(+), 3 deletions(-)

diff --git a/osu.Game/Screens/Edit/Compose/Components/SelectionBox.cs b/osu.Game/Screens/Edit/Compose/Components/SelectionBox.cs
index 17790547ed..677b0cd76e 100644
--- a/osu.Game/Screens/Edit/Compose/Components/SelectionBox.cs
+++ b/osu.Game/Screens/Edit/Compose/Components/SelectionBox.cs
@@ -22,6 +22,8 @@ namespace osu.Game.Screens.Edit.Compose.Components
     {
         public const float BORDER_RADIUS = 3;
 
+        private const float button_padding = 5;
+
         public Func<float, bool> OnRotation;
         public Func<Vector2, Anchor, bool> OnScale;
         public Func<Direction, bool, bool> OnFlip;
@@ -182,6 +184,13 @@ namespace osu.Game.Screens.Edit.Compose.Components
             return base.OnKeyDown(e);
         }
 
+        protected override void Update()
+        {
+            base.Update();
+
+            ensureButtonsOnScreen();
+        }
+
         private void recreate()
         {
             if (LoadState < LoadState.Loading)
@@ -234,11 +243,12 @@ namespace osu.Game.Screens.Edit.Compose.Components
                 },
                 buttons = new FillFlowContainer
                 {
-                    Y = 20,
-                    AutoSizeAxes = Axes.Both,
+                    AutoSizeAxes = Axes.X,
+                    Height = 30,
                     Direction = FillDirection.Horizontal,
+                    Margin = new MarginPadding(button_padding),
                     Anchor = Anchor.BottomCentre,
-                    Origin = Anchor.Centre
+                    Origin = Anchor.TopCentre
                 }
             };
 
@@ -352,5 +362,29 @@ namespace osu.Game.Screens.Edit.Compose.Components
             if (activeOperations++ == 0)
                 OperationStarted?.Invoke();
         }
+
+        private void ensureButtonsOnScreen()
+        {
+            buttons.Position = Vector2.Zero;
+
+            var buttonsQuad = buttons.ScreenSpaceDrawQuad;
+            var thisQuad = ScreenSpaceDrawQuad;
+
+            // Shrink the parent quad to give a bit of padding so the buttons don't stick *right* on the border.
+            // AABBFloat assumes no rotation. one would hope the whole editor is not being rotated.
+            var parentQuad = Parent.ScreenSpaceDrawQuad.AABBFloat.Shrink(ToLocalSpace(thisQuad.TopLeft + new Vector2(button_padding * 2)));
+
+            float leftExcess = buttonsQuad.TopLeft.X - parentQuad.TopLeft.X;
+            float rightExcess = parentQuad.TopRight.X - buttonsQuad.TopRight.X;
+            float bottomExcess = thisQuad.BottomLeft.Y + buttonsQuad.Height - parentQuad.BottomLeft.Y;
+
+            if (leftExcess < 0)
+                buttons.X += ToLocalSpace(thisQuad.TopLeft - new Vector2(leftExcess)).X;
+            else if (rightExcess < 0)
+                buttons.X -= ToLocalSpace(thisQuad.TopLeft - new Vector2(rightExcess)).X;
+
+            if (bottomExcess > 0)
+                buttons.Y += ToLocalSpace(thisQuad.TopLeft - new Vector2(bottomExcess)).X;
+        }
     }
 }