Rename GameModes namespace to Screens.

osu.Game/Screens/Menu/FlowContainerWithOrigin.cs

@@ -0,0 +1,31 @@
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using OpenTK;
+
+namespace osu.Game.Screens.Menu
+{
+    /// <summary>
+    /// A flow container with an origin based on one of its contained drawables.
+    /// </summary>
+    public class FlowContainerWithOrigin : FlowContainer
+    {
+        /// <summary>
+        /// A target drawable which this flowcontainer should be centered around.
+        /// This target should be a direct child of this FlowContainer.
+        /// </summary>
+        public Drawable CentreTarget;
+
+        public override Anchor Origin => Anchor.Custom;
+
+        public override Vector2 OriginPosition
+        {
+            get
+            {
+                if (CentreTarget == null)
+                    return base.OriginPosition;
+
+                return CentreTarget.DrawPosition + CentreTarget.DrawSize / 2;
+            }
+        }
+    }
+}