Refactor out WorldSelector element (#1316)

Author: Jamie Brynes

CHANGELOG.md

@@ -14,6 +14,7 @@
 - Added the ability to select a specific cluster for deployments in the [Deployment Launcher](https://documentation.improbable.io/gdk-for-unity/docs/deployment-launcher). [#1357](https://github.com/spatialos/gdk-for-unity/pull/1357)
     - You can select _either_ a region or a cluster, but not both!
 - Added non-generic overloads for the `EntityTemplate` class which allow you to use `ISpatialComponentSnapshot`s directly. [#1360](https://github.com/spatialos/gdk-for-unity/pull/1360)
+- Extracted the world selection UI element from the Network Analyzer window to a `WorldSelector` element. [#1316](https://github.com/spatialos/gdk-for-unity/pull/1316)
 
 ### Changed
 
@@ -26,6 +27,7 @@
 - The Mobile Launcher will no longer break if Android build support is not installed. [#1354](https://github.com/spatialos/gdk-for-unity/pull/1354)
 - Fixed a bug in the `EntityTemplate` class where calling `AddComponent` with an `EntityAcl.Snapshot` would incorrectly apply its write access [#1360](https://github.com/spatialos/gdk-for-unity/pull/1360)
 - The Deployment Launcher will now generate Dev Auth Tokens using the environment specified in the GDK Tools Configuration. [#1366](https://github.com/spatialos/gdk-for-unity/pull/1366)
+- Fixed a bug where the Network Analyzer window would throw exceptions after being opened. [#1316](https://github.com/spatialos/gdk-for-unity/pull/1316)
 
 ### Internal
 

workers/unity/Packages/io.improbable.gdk.core/Editor/Improbable.Gdk.Core.Editor.asmdef

@@ -1,6 +1,9 @@
 {
     "name": "Improbable.Gdk.Core.Editor",
-    "references": [],
+    "references": [
+        "GUID:734d92eba21c94caba915361bd5ac177",
+        "GUID:edb3612c44ad0d24988d387581fd5fbe"
+    ],
     "includePlatforms": [
         "Editor"
     ],

workers/unity/Packages/io.improbable.gdk.core/Editor/UIElements.meta

@@ -0,0 +1,78 @@
+using System.Collections.Generic;
+using System.Linq;
+using Unity.Entities;
+using UnityEditor;
+using UnityEditor.UIElements;
+using UnityEngine.UIElements;
+
+namespace Improbable.Gdk.Core.Editor.UIElements
+{
+    public class WorldSelector : VisualElement
+    {
+        public delegate void WorldChanged(World world);
+
+        private const string UxmlPath = "Packages/io.improbable.gdk.core/Editor/UIElements/WorldSelector.uxml";
+
+        public World ActiveWorld { get; private set; }
+        public WorldChanged OnWorldChanged;
+
+        private readonly ToolbarMenu menuElement;
+
+        public WorldSelector()
+        {
+            var template = AssetDatabase.LoadAssetAtPath<VisualTreeAsset>(UxmlPath);
+            template.CloneTree(this);
+            menuElement = this.Q<ToolbarMenu>("worldSelector");
+        }
+
+        public void UpdateWorldSelection()
+        {
+            var worldMenu = menuElement.menu;
+
+            var spatialWorlds = new List<World>();
+
+            foreach (var world in World.All)
+            {
+                if (world.GetExistingSystem<WorkerSystem>() != null)
+                {
+                    spatialWorlds.Add(world);
+                }
+            }
+
+            for (var i = 0; i < spatialWorlds.Count; i++)
+            {
+                var spatialWorld = spatialWorlds[i];
+                worldMenu.InsertAction(i, spatialWorld.Name,
+                    action => SelectWorld((World) action.userData),
+                    action => ActiveWorld == (World) action.userData
+                        ? DropdownMenuAction.Status.Checked
+                        : DropdownMenuAction.Status.Normal,
+                    spatialWorld);
+            }
+
+            // Trim excess items
+            var menuSize = worldMenu.MenuItems().Count;
+            for (var i = spatialWorlds.Count; i < menuSize; i++)
+            {
+                worldMenu.RemoveItemAt(spatialWorlds.Count);
+            }
+
+            // Update selected item if needed
+            if (ActiveWorld == null || !ActiveWorld.IsCreated)
+            {
+                SelectWorld(spatialWorlds.FirstOrDefault());
+            }
+        }
+
+        private void SelectWorld(World world)
+        {
+            ActiveWorld = world;
+            menuElement.text = ActiveWorld?.Name ?? "No SpatialOS worlds active";
+            OnWorldChanged?.Invoke(world);
+        }
+
+        public new class UxmlFactory : UxmlFactory<WorldSelector>
+        {
+        }
+    }
+}

workers/unity/Packages/io.improbable.gdk.core/Editor/UIElements/WorldSelector.cs

@@ -0,0 +1,5 @@
+.world-selector {
+    height: 15px;
+    flex-shrink: 0;
+    white-space: nowrap;
+}

workers/unity/Packages/io.improbable.gdk.core/Editor/UIElements/WorldSelector.cs.meta

@@ -0,0 +1,5 @@
+<UXML xmlns="UnityEngine.UIElements" xmlns:uie="UnityEditor.UIElements">
+    <uie:ToolbarMenu name="worldSelector" class="world-selector">
+        <Style path="Packages/io.improbable.gdk.core/Editor/UIElements/WorldSelector.uss" />
+    </uie:ToolbarMenu>
+</UXML>