Use depth to arrange buttons.

osu.Game/Screens/Select/EditSongSelect.cs

@@ -1,10 +1,7 @@
 // Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
-using OpenTK.Input;
-using osu.Framework.Allocation;
 using osu.Game.Beatmaps;
-using osu.Game.Graphics;
 using osu.Game.Screens.Edit;
 
 namespace osu.Game.Screens.Select
@@ -12,13 +9,5 @@ namespace osu.Game.Screens.Select
     internal class EditSongSelect : SongSelect
     {
         protected override void OnSelected(WorkingBeatmap beatmap) => Push(new Editor(beatmap));
-        [BackgroundDependencyLoader]
-        private void load(OsuColour colours)
-        {
-            Footer.AddButton(@"random", colours.Green, SelectRandom, Key.F2);
-            Footer.AddButton(@"options", colours.Blue, BeatmapOptions.ToggleVisibility, Key.F3);
-
-            BeatmapOptions.AddButton(@"Delete", @"Beatmap", FontAwesome.fa_trash, colours.Pink, PromptDelete, Key.Number4);
-        }
     }
 }

osu.Game/Screens/Select/Footer.cs

@@ -36,13 +36,18 @@ namespace osu.Game.Screens.Select
 
         public OsuLogo StartButton;
 
-        public void AddButton(string text, Color4 colour, Action action, Key? hotkey = null)
+        /// <param name="depth">
+        /// <para>Higher depth to be put on the left, and lower to be put on the right.</para>
+        /// <para>Notice this is different to <see cref="Options.BeatmapOptionsOverlay"/>!</para>
+        /// </param>
+        public void AddButton(string text, Color4 colour, Action action, Key? hotkey = null, float depth = 0)
         {
             var button = new FooterButton
             {
                 Text = text,
                 Height = play_song_select_button_height,
                 Width = play_song_select_button_width,
+                Depth = depth,
                 SelectedColour = colour,
                 DeselectedColour = colour.Opacity(0.5f),
                 Hotkey = hotkey,

osu.Game/Screens/Select/MatchSongSelect.cs

@@ -1,23 +1,12 @@
 // Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
-using OpenTK.Input;
-using osu.Framework.Allocation;
 using osu.Game.Beatmaps;
-using osu.Game.Graphics;
 
 namespace osu.Game.Screens.Select
 {
     internal class MatchSongSelect : SongSelect
     {
         protected override void OnSelected(WorkingBeatmap beatmap) => Exit();
-        [BackgroundDependencyLoader]
-        private void load(OsuColour colours)
-        {
-            Footer.AddButton(@"random", colours.Green, SelectRandom, Key.F2);
-            Footer.AddButton(@"options", colours.Blue, BeatmapOptions.ToggleVisibility, Key.F3);
-
-            BeatmapOptions.AddButton(@"Delete", @"Beatmap", FontAwesome.fa_trash, colours.Pink, PromptDelete, Key.Number4);
-        }
     }
 }

osu.Game/Screens/Select/Options/BeatmapOptionsOverlay.cs

@@ -86,7 +86,11 @@ namespace osu.Game.Screens.Select.Options
             };
         }
 
-        public void AddButton(string firstLine, string secongLine, FontAwesome icon, Color4 colour, Action action, Key? hotkey = null)
+        /// <param name="depth">
+        /// <para>Lower depth to be put on the left, and higher to be put on the right.</para>
+        /// <para>Notice this is different to <see cref="Footer"/>!</para>
+        /// </param>
+        public void AddButton(string firstLine, string secongLine, FontAwesome icon, Color4 colour, Action action, Key? hotkey = null, float depth = 0)
         {
             buttonsContainer.Add(new BeatmapOptionsButton
             {
@@ -94,6 +98,7 @@ namespace osu.Game.Screens.Select.Options
                 SecondLineText = secongLine,
                 Icon = icon,
                 ButtonColour = colour,
+                Depth = depth,
                 Action = () =>
                 {
                     Hide();

osu.Game/Screens/Select/PlaySongSelect.cs

@@ -29,14 +29,11 @@ namespace osu.Game.Screens.Select
                 Margin = new MarginPadding { Bottom = 50 }
             });
 
-            Footer.AddButton(@"mods", colours.Yellow, modSelect.ToggleVisibility, Key.F1);
+            Footer.AddButton(@"mods", colours.Yellow, modSelect.ToggleVisibility, Key.F1, float.MaxValue);
-            Footer.AddButton(@"random", colours.Green, SelectRandom, Key.F2);
-            Footer.AddButton(@"options", colours.Blue, BeatmapOptions.ToggleVisibility, Key.F3);
 
             BeatmapOptions.AddButton(@"Remove", @"from unplayed", FontAwesome.fa_times_circle_o, colours.Purple, null, Key.Number1);
             BeatmapOptions.AddButton(@"Clear", @"local scores", FontAwesome.fa_eraser, colours.Purple, null, Key.Number2);
             BeatmapOptions.AddButton(@"Edit", @"Beatmap", FontAwesome.fa_pencil, colours.Yellow, null, Key.Number3);
-            BeatmapOptions.AddButton(@"Delete", @"Beatmap", FontAwesome.fa_trash, colours.Pink, PromptDelete, Key.Number4);
         }
 
         protected override void OnBeatmapChanged(WorkingBeatmap beatmap)

osu.Game/Screens/Select/SongSelect.cs

@@ -146,6 +146,11 @@ namespace osu.Game.Screens.Select
                 },
             };
 
+            Footer.AddButton(@"random", colours.Green, SelectRandom, Key.F2);
+            Footer.AddButton(@"options", colours.Blue, BeatmapOptions.ToggleVisibility, Key.F3);
+
+            BeatmapOptions.AddButton(@"Delete", @"Beatmap", FontAwesome.fa_trash, colours.Pink, promptDelete, Key.Number4, float.MaxValue);
+
             if (osu != null)
                 playMode.BindTo(osu.PlayMode);
             playMode.ValueChanged += playMode_ValueChanged;
@@ -404,7 +409,7 @@ namespace osu.Game.Screens.Select
             }
         }
 
-        protected void PromptDelete()
+        private void promptDelete()
         {
             if (Beatmap != null)
                 dialogOverlay?.Push(new BeatmapDeleteDialog(Beatmap));
@@ -414,7 +419,7 @@ namespace osu.Game.Screens.Select
         {
             if (!args.Repeat && args.Key == Key.Delete && state.Keyboard.ShiftPressed)
             {
-                PromptDelete();
+                promptDelete();
                 return true;
             }