Slight code re-org.

Updated Prime.


Former-commit-id: ba0bda0

Nu/Nu/Nu/Nu.fsproj

@@ -89,7 +89,6 @@
     <Compile Include="WorldGroup.fs" />
     <Compile Include="WorldScreen.fs" />
     <Compile Include="WorldGame.fs" />
-    <Compile Include="WorldSimulant.fs" />
     <Compile Include="WorldInput.fs" />
     <Compile Include="WorldClipboard.fs" />
     <Compile Include="WorldPhysics.fs" />

Nu/Nu/Nu/WorldDispatchers.fs

@@ -366,7 +366,7 @@ module GuiDispatcherModule =
             let gui = evt.Subscriber : Entity
             let data = evt.Data : MouseButtonData
             let handling =
-                if World.isSimulantSelected gui world && gui.GetVisible world then
+                if World.isEntitySelected gui world && gui.GetVisible world then
                     let mousePositionWorld = World.getCameraBy (Camera.mouseToWorld (gui.GetViewType world) data.Position) world
                     if data.Down &&
                        gui.GetSwallowMouseLeft world &&
@@ -407,7 +407,7 @@ module ButtonDispatcherModule =
         let handleMouseLeftDown evt world =
             let button = evt.Subscriber : Entity
             let data = evt.Data : MouseButtonData
-            if World.isSimulantSelected button world then
+            if World.isEntitySelected button world then
                 let mousePositionWorld = World.getCameraBy (Camera.mouseToWorld (button.GetViewType world) data.Position) world
                 if  button.GetVisible world &&
                     Math.isPointInBounds mousePositionWorld (button.GetBounds world) then
@@ -423,7 +423,7 @@ module ButtonDispatcherModule =
         let handleMouseLeftUp evt world =
             let button = evt.Subscriber : Entity
             let data = evt.Data : MouseButtonData
-            if World.isSimulantSelected button world then
+            if World.isEntitySelected button world then
                 let wasDown = button.GetDown world
                 let world = button.SetDown false world
                 let mousePositionWorld = World.getCameraBy (Camera.mouseToWorld (button.GetViewType world) data.Position) world
@@ -595,7 +595,7 @@ module ToggleDispatcherModule =
         let handleMouseLeftDown evt world =
             let toggle = evt.Subscriber : Entity
             let data = evt.Data : MouseButtonData
-            if World.isSimulantSelected toggle world then
+            if World.isEntitySelected toggle world then
                 let mousePositionWorld = World.getCameraBy (Camera.mouseToWorld (toggle.GetViewType world) data.Position) world
                 if  toggle.GetVisible world &&
                     Math.isPointInBounds mousePositionWorld (toggle.GetBounds world) then
@@ -609,7 +609,7 @@ module ToggleDispatcherModule =
         let handleMouseLeftUp evt world =
             let toggle = evt.Subscriber : Entity
             let data = evt.Data : MouseButtonData
-            if World.isSimulantSelected toggle world then
+            if World.isEntitySelected toggle world then
                 let wasPressed = toggle.GetPressed world
                 let world = toggle.SetPressed false world
                 let mousePositionWorld = World.getCameraBy (Camera.mouseToWorld (toggle.GetViewType world) data.Position) world
@@ -678,7 +678,7 @@ module FeelerDispatcherModule =
         let handleMouseLeftDown evt world =
             let feeler = evt.Subscriber : Entity
             let data = evt.Data : MouseButtonData
-            if World.isSimulantSelected feeler world then
+            if World.isEntitySelected feeler world then
                 let mousePositionWorld = World.getCameraBy (Camera.mouseToWorld (feeler.GetViewType world) data.Position) world
                 if  feeler.GetVisible world &&
                     Math.isPointInBounds mousePositionWorld (feeler.GetBounds world) then
@@ -694,7 +694,7 @@ module FeelerDispatcherModule =
         let handleMouseLeftUp evt world =
             let feeler = evt.Subscriber : Entity
             let data = evt.Data : MouseButtonData
-            if World.isSimulantSelected feeler world && feeler.GetVisible world then
+            if World.isEntitySelected feeler world && feeler.GetVisible world then
                 if feeler.GetEnabled world then
                     let world = feeler.SetTouched false world
                     let eventTrace = EventTrace.record "FeelerDispatcher" "handleMouseLeftDown" EventTrace.empty

Nu/Nu/Nu/WorldEvents.fs

@@ -23,10 +23,6 @@ type [<StructuralEquality; NoComparison>] KeyboardKeyData =
       Repeated : bool
       Down : bool }
 
-/// The data for a change in a simulant.
-type SimulantChangeData<'s, 'w when 's :> Simulant and 'w :> 'w Eventable> =
-    ParticipantChangeData<'s, 'w>
-
 /// The data for a collision event.
 type [<StructuralEquality; NoComparison>] CollisionData =
     { Normal : Vector2
@@ -35,7 +31,7 @@ type [<StructuralEquality; NoComparison>] CollisionData =
 
 /// The data for a change in the world's ambient state.
 /// NOTE: I couldn't give its field the more normal name of 'OldWorld' due to field name conflicts with the more
-/// pervasive SimulantChangeData type below.
+/// pervasive ParticipantChangeData type.
 type [<StructuralEquality; NoComparison>] AmbientStateChangeData = 
     { OldWorldWithOldState : World }
 
@@ -90,16 +86,16 @@ module Events =
     let AmbientState = ntoa<obj> !!"AmbientState"
     let AmbientStateChange = AmbientState -<- ntoa<AmbientStateChangeData> !!"Change"
     let Game = ntoa<obj> !!"Game"
-    let GameChange = Game -<- ntoa<SimulantChangeData<Game, World>> !!"Change"
+    let GameChange = Game -<- ntoa<ParticipantChangeData<Game, World>> !!"Change"
     let Screen = ntoa<obj> !!"Screen"
     let ScreenAdd = Screen -<- ntoa<unit> !!"Add"
     let ScreenRemoving = Screen -<- ntoa<unit> !!"Removing"
-    let ScreenChange = Screen -<- ntoa<SimulantChangeData<Screen, World>> !!"Change"
+    let ScreenChange = Screen -<- ntoa<ParticipantChangeData<Screen, World>> !!"Change"
     let Group = ntoa<obj> !!"Group"
     let GroupAdd = Group -<- ntoa<unit> !!"Add"
     let GroupRemoving = Group -<- ntoa<unit> !!"Removing"
-    let GroupChange = Group -<- ntoa<SimulantChangeData<Group, World>> !!"Change"
+    let GroupChange = Group -<- ntoa<ParticipantChangeData<Group, World>> !!"Change"
     let Entity = ntoa<obj> !!"Entity"
     let EntityAdd = Entity -<- ntoa<unit> !!"Add"
     let EntityRemoving = Entity -<- ntoa<unit> !!"Removing"
-    let EntityChange = Entity -<- ntoa<SimulantChangeData<Entity, World>> !!"Change"
+    let EntityChange = Entity -<- ntoa<ParticipantChangeData<Entity, World>> !!"Change"

Nu/Nu/Nu/WorldGame.fs

@@ -88,6 +88,34 @@ module WorldGameModule =
         static member setSelectedScreen screen world =
             World.setOptSelectedScreen (Some screen) world
 
+        /// Determine if an entity is selected by being in a group of the currently selected screeen.
+        static member isEntitySelected entity world =
+            let screenName = Address.head entity.EntityAddress
+            match World.getOptSelectedScreen world with
+            | Some selectedScreen -> screenName = selectedScreen.ScreenName
+            | None -> false
+
+        /// Determine if a group is selected by being in the currently selected screeen.
+        static member isGroupSelected group world =
+            let screenName = Address.head group.GroupAddress
+            match World.getOptSelectedScreen world with
+            | Some selectedScreen -> screenName = selectedScreen.ScreenName
+            | None -> false
+
+        /// Determine if a screen is the currently selected screeen.
+        static member isScreenSelected screen world =
+            World.getOptSelectedScreen world = Some screen
+
+        /// Determine if a simulant is contained by, or is the same as, the currently selected screen.
+        /// Game is always considered 'selected' as well.
+        static member isSimulantSelected (simulant : Simulant) world =
+            match Address.getNames simulant.SimulantAddress with
+            | [] -> true
+            | screenName :: _ ->
+                match World.getOptSelectedScreen world with
+                | Some screen -> screen.ScreenName = screenName
+                | None -> false
+
         /// Write a game to an xml writer.
         static member writeGame (writer : XmlWriter) world =
             let gameState = World.getGameState world

Nu/Nu/Nu/WorldObservation.fs

@@ -18,11 +18,13 @@ module Observation =
         observation |> organize (fun _ world -> World.getUpdateCount world) |> toFst |> choose
 
     /// Take events from an observation only while World.isTicking evaluates to true.
-    let [<DebuggerHidden; DebuggerStepThrough>] isTicking _ world = World.isTicking world
+    let [<DebuggerHidden; DebuggerStepThrough>] isTicking _ world =
+        World.isTicking world
 
-    /// Take events from an observation only when the observer is selected in the world (see
-    /// documentation for World.isAddressSelected for what this means (it's very useful!)).
-    let [<DebuggerHidden; DebuggerStepThrough>] isObserverSelected evt world = World.isSimulantSelected evt.Subscriber world
+    /// Take events from an observation only when the observer is contained by, or is the same as,
+    /// the currently selected screen. Game is always considered 'selected' as well.
+    let [<DebuggerHidden; DebuggerStepThrough>] isObserverSelected evt world =
+        World.isSimulantSelected evt.Subscriber world
 
     /// Take events from an observation only when the currently selected screen is idling (that
     /// is, there is no screen transition in progress).