Remove duplicate getAnimation function and improve namespacing

osu.Game/Skinning/LegacySkinExtensions.cs

@@ -0,0 +1,53 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Animations;
+using osu.Framework.Graphics.Sprites;
+using osu.Framework.Graphics.Textures;
+
+namespace osu.Game.Skinning
+{
+    public static class LegacySkinExtensions
+    {
+        public static Drawable GetAnimation(this ISkin source, string componentName, bool animatable, bool looping, string animationSeparator = "-")
+        {
+            const double default_frame_time = 1000 / 60d;
+
+            Texture texture;
+
+            Texture getFrameTexture(int frame) => source.GetTexture($"{componentName}{animationSeparator}{frame}");
+
+            TextureAnimation animation = null;
+
+            if (animatable)
+            {
+                for (int i = 0;; i++)
+                {
+                    if ((texture = getFrameTexture(i)) == null)
+                        break;
+
+                    if (animation == null)
+                        animation = new TextureAnimation
+                        {
+                            DefaultFrameLength = default_frame_time,
+                            Repeat = looping
+                        };
+
+                    animation.AddFrame(texture);
+                }
+            }
+
+            if (animation != null)
+                return animation;
+
+            if ((texture = source.GetTexture(componentName)) != null)
+                return new Sprite
+                {
+                    Texture = texture
+                };
+
+            return null;
+        }
+    }
+}