Add IEntity.IsWeightless extension method (#2255)

Checking manually every time wasn't that cool

Content.Shared/GameObjects/Components/Movement/MovementIgnoreGravityComponent.cs

@@ -1,4 +1,8 @@
+#nullable enable
 using Robust.Shared.GameObjects;
+using Robust.Shared.Interfaces.GameObjects;
+using Robust.Shared.Interfaces.Physics;
+using Robust.Shared.IoC;
 
 namespace Content.Shared.GameObjects.Components.Movement
 {
@@ -7,4 +11,15 @@ namespace Content.Shared.GameObjects.Components.Movement
     {
         public override string Name => "MovementIgnoreGravity";
     }
+
+    public static class GravityExtensions
+    {
+        public static bool IsWeightless(this IEntity entity, IPhysicsManager? physicsManager = null)
+        {
+            physicsManager ??= IoCManager.Resolve<IPhysicsManager>();
+
+            return !entity.HasComponent<MovementIgnoreGravityComponent>() &&
+                   physicsManager.IsWeightless(entity.Transform.Coordinates);
+        }
+    }
 }

Content.Shared/GameObjects/EntitySystems/SharedMoverSystem.cs

@@ -56,8 +56,7 @@ namespace Content.Shared.GameObjects.EntitySystems
         {
             physics.EnsureController<MoverController>();
 
-            var weightless = !transform.Owner.HasComponent<MovementIgnoreGravityComponent>() &&
+            var weightless = !transform.Owner.IsWeightless();
-                             _physicsManager.IsWeightless(transform.Coordinates);
 
             if (weightless)
             {

Content.Shared/Physics/ConveyedController.cs

@@ -14,8 +14,7 @@ namespace Content.Shared.Physics
 
         public void Move(Vector2 velocityDirection, float speed)
         {
-            if (ControlledComponent?.Owner.HasComponent<MovementIgnoreGravityComponent>() == false &&
+            if (ControlledComponent?.Owner.IsWeightless() ?? false)
-                IoCManager.Resolve<IPhysicsManager>().IsWeightless(ControlledComponent.Owner.Transform.Coordinates))
             {
                 return;
             }

Content.Shared/Physics/MoverController.cs

@@ -1,8 +1,6 @@
 #nullable enable
 using Content.Shared.GameObjects.Components.Movement;
 using Robust.Shared.GameObjects.Components;
-using Robust.Shared.Interfaces.Physics;
-using Robust.Shared.IoC;
 using Robust.Shared.Maths;
 using Robust.Shared.Physics;
 
@@ -10,14 +8,11 @@ namespace Content.Shared.Physics
 {
     public class MoverController : VirtualController
     {
-        [Dependency] private readonly IPhysicsManager _physicsManager = default!;
-
         public override IPhysicsComponent? ControlledComponent { protected get; set; }
 
         public void Move(Vector2 velocityDirection, float speed)
         {
-            if (ControlledComponent?.Owner.HasComponent<MovementIgnoreGravityComponent>() == false
+            if (ControlledComponent?.Owner.IsWeightless() ?? false)
-                && _physicsManager.IsWeightless(ControlledComponent.Owner.Transform.Coordinates))
             {
                 return;
             }