firefighters tutorial: added UI button to reposition the bucket brigade lines

EntitiesSamples/Assets/Tutorials/Firefighters/README.md

@@ -22,4 +22,4 @@ This step adds behiour to the bots, who are organized into teams. Each team form
 
 # Step 4: Animation and UI
 
-This step replaces the bot capsules with animated characters. A UI HUD element displays the total count of fires that have been doused.
+This step replaces the bot capsules with animated characters. A UI HUD element displays the total count of fires that have been doused. Clicking a HUD button triggers repositioning of the bucket brigade lines.

EntitiesSamples/Assets/Tutorials/Firefighters/Step 4/FirefightersUI.uxml

@@ -1,3 +1,4 @@
 <ui:UXML xmlns:ui="UnityEngine.UIElements" xmlns:uie="UnityEditor.UIElements" editor-extension-mode="False">
-    <ui:Label tabindex="-1" text="Number of fires doused: 0" parse-escape-sequences="true" display-tooltip-when-elided="true" name="DouseCounter" style="font-size: 28px; color: rgb(255, 255, 255);" />
+    <ui:Label tabindex="-1" text="Number of fires doused: 0" parse-escape-sequences="true" display-tooltip-when-elided="true" name="DouseCounter" style="font-size: 28px; color: rgb(0, 0, 0);" />
+    <ui:Button text="Reposition the bucket brigade lines" parse-escape-sequences="true" display-tooltip-when-elided="true" name="RepositionButton" style="font-size: 28px; -unity-text-align: middle-left; width: 30%;" />
 </ui:UXML>

EntitiesSamples/Assets/Tutorials/Firefighters/Step 4/UIController.cs

@@ -1,14 +1,33 @@
+using UnityEditor.Compilation;
 using UnityEngine;
 using UnityEngine.UIElements;
 
 public class UIController : MonoBehaviour
 {
     private Label dousedLabel;
+    private Button repositionButton;
+
+    private bool reposition = false; 
     
     private void OnEnable()
     {
         var root = GetComponent<UIDocument>().rootVisualElement;
         dousedLabel = root.Q<Label>();
+        repositionButton = root.Q<Button>();
+
+        repositionButton.clicked += OnRepositionButton;
+    }
+
+    private void OnRepositionButton()
+    {
+        reposition = true;
+    }
+
+    public bool ShouldReposition()
+    {
+        var temp = reposition;
+        reposition = false;
+        return temp;
     }
 
     public void SetNumFiresDoused(int numFiresDoused)

EntitiesSamples/Assets/Tutorials/Firefighters/Step 4/UISystem.cs

@@ -4,6 +4,7 @@ using UnityEngine;
 
 namespace Tutorials.Firefighters
 {
+    [UpdateBefore(typeof(LineSystem))]
     public partial struct UISystem : ISystem
     {
         private bool initialized;
@@ -29,10 +30,19 @@ namespace Tutorials.Firefighters
                 configManaged.UIController = GameObject.FindObjectOfType<UIController>();
             }
 
+            var shouldReposition = configManaged.UIController.ShouldReposition();
             var totalFiresDoused = 0;
-            foreach (var team in SystemAPI.Query<RefRO<Team>>())
+            
+            foreach (var (team, entity) in 
+                     SystemAPI.Query<RefRO<Team>>()
+                         .WithEntityAccess())
             {
                 totalFiresDoused += team.ValueRO.NumFiresDoused;
+                
+                if (shouldReposition)
+                {
+                    SystemAPI.SetComponentEnabled<RepositionLine>(entity, true);
+                }    
             }
             
             configManaged.UIController.SetNumFiresDoused(totalFiresDoused);