Convert almost all IActivate instances that open UIs to ActivatableUI (#7028)

* Chem master

* Drone support for handhelds

* Vending machines, scanners

* Cloners, R&D computers

* make research a little less sussy

* Unfuck wires

* PA control computer

* Unfuck merge

* Clean up git gore for good

* Disposals

* Microwaves

* paper

* Magic mirror

* More vendors for drones

* Solar computer whitelist

* EFR review updates

Content.Server/UserInterface/ActivatableUISystem.cs

@@ -112,13 +112,23 @@ namespace Content.Server.UserInterface
             // If we've gotten this far, fire a cancellable event that indicates someone is about to activate this.
             // This is so that stuff can require further conditions (like power).
             var oae = new ActivatableUIOpenAttemptEvent(user);
-            var uae = new UserOpenActivatableUIAttemptEvent(user);
+            var uae = new UserOpenActivatableUIAttemptEvent(user, aui.Owner);
             RaiseLocalEvent(user, uae, false);
             RaiseLocalEvent((aui).Owner, oae, false);
             if (oae.Cancelled || uae.Cancelled) return false;
 
+            // Give the UI an opportunity to prepare itself if it needs to do anything
+            // before opening
+            var bae = new BeforeActivatableUIOpenEvent(user);
+            RaiseLocalEvent((aui).Owner, bae, false);
+
             SetCurrentSingleUser((aui).Owner, actor.PlayerSession, aui);
             ui.Toggle(actor.PlayerSession);
+
+            //Let the component know a user opened it so it can do whatever it needs to do
+            var aae = new AfterActivatableUIOpenEvent(user);
+            RaiseLocalEvent((aui).Owner, aae, false);
+
             return true;
         }
 
@@ -153,11 +163,37 @@ namespace Content.Server.UserInterface
     public sealed class UserOpenActivatableUIAttemptEvent : CancellableEntityEventArgs //have to one-up the already stroke-inducing name
     {
         public EntityUid User { get; }
-        public UserOpenActivatableUIAttemptEvent(EntityUid who)
+        public EntityUid Target { get; }
+        public UserOpenActivatableUIAttemptEvent(EntityUid who, EntityUid target)
+        {
+            User = who;
+            Target = target;
+        }
+    }
+
+    public sealed class AfterActivatableUIOpenEvent : EntityEventArgs
+    {
+        public EntityUid User { get; }
+        public AfterActivatableUIOpenEvent(EntityUid who)
         {
             User = who;
         }
     }
+
+    /// <summary>
+    /// This is after it's decided the user can open the UI,
+    /// but before the UI actually opens.
+    /// Use this if you need to prepare the UI itself
+    /// </summary>
+    public sealed class BeforeActivatableUIOpenEvent : EntityEventArgs
+    {
+        public EntityUid User { get; }
+        public BeforeActivatableUIOpenEvent(EntityUid who)
+        {
+            User = who;
+        }
+    }
+
     public sealed class ActivatableUIPlayerChangedEvent : EntityEventArgs
     {
     }