Move selection hotkeys out of world interaction widget

- Split SelectionUtils for selecting actors in the world to a static class
- Split selection hotkeys into their own logic classes

OpenRA.Mods.Common/Widgets/SelectionUtils.cs

@@ -0,0 +1,83 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2021 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using OpenRA.Graphics;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Widgets
+{
+	public static class SelectionUtils
+	{
+		public static IEnumerable<Actor> SelectActorsOnScreen(World world, WorldRenderer wr, IEnumerable<string> selectionClasses, IEnumerable<Player> players)
+		{
+			var actors = world.ScreenMap.ActorsInMouseBox(wr.Viewport.TopLeft, wr.Viewport.BottomRight).Select(a => a.Actor);
+			return SelectActorsByOwnerAndSelectionClass(actors, players, selectionClasses);
+		}
+
+		public static IEnumerable<Actor> SelectActorsInWorld(World world, IEnumerable<string> selectionClasses, IEnumerable<Player> players)
+		{
+			return SelectActorsByOwnerAndSelectionClass(world.Actors.Where(a => a.IsInWorld), players, selectionClasses);
+		}
+
+		public static IEnumerable<Actor> SelectActorsByOwnerAndSelectionClass(IEnumerable<Actor> actors, IEnumerable<Player> owners, IEnumerable<string> selectionClasses)
+		{
+			return actors.Where(a =>
+			{
+				if (!owners.Contains(a.Owner))
+					return false;
+
+				var s = a.TraitOrDefault<ISelectable>();
+
+				// selectionClasses == null means that units, that meet all other criteria, get selected
+				return s != null && (selectionClasses == null || selectionClasses.Contains(s.Class));
+			});
+		}
+
+		public static IEnumerable<Actor> SelectHighestPriorityActorAtPoint(World world, int2 a, Modifiers modifiers)
+		{
+			var selected = world.ScreenMap.ActorsAtMouse(a)
+				.Where(x => x.Actor.Info.HasTraitInfo<ISelectableInfo>() && (x.Actor.Owner.IsAlliedWith(world.RenderPlayer) || !world.FogObscures(x.Actor)))
+				.WithHighestSelectionPriority(a, modifiers);
+
+			if (selected != null)
+				yield return selected;
+		}
+
+		public static IEnumerable<Actor> SelectActorsInBoxWithDeadzone(World world, int2 a, int2 b, Modifiers modifiers)
+		{
+			// For dragboxes that are too small, shrink the dragbox to a single point (point b)
+			if ((a - b).Length <= Game.Settings.Game.SelectionDeadzone)
+				a = b;
+
+			if (a == b)
+				return SelectHighestPriorityActorAtPoint(world, a, modifiers);
+
+			return world.ScreenMap.ActorsInMouseBox(a, b)
+				.Select(x => x.Actor)
+				.Where(x => x.Info.HasTraitInfo<ISelectableInfo>() && (x.Owner.IsAlliedWith(world.RenderPlayer) || !world.FogObscures(x)))
+				.SubsetWithHighestSelectionPriority(modifiers);
+		}
+
+		public static Player[] GetPlayersToIncludeInSelection(World world)
+		{
+			// Players to be included in the selection (the viewer or all players in "Disable shroud" / "All players" mode)
+			var viewer = world.RenderPlayer ?? world.LocalPlayer;
+			var isShroudDisabled = viewer == null || (world.RenderPlayer == null && world.LocalPlayer.Spectating);
+			var isEveryone = viewer != null && viewer.NonCombatant && viewer.Spectating;
+
+			return isShroudDisabled || isEveryone ? world.Players : new[] { viewer };
+		}
+	}
+}