From 1b2ebcb1e8e84a8f2a39cfe3f408ed902c2d3759 Mon Sep 17 00:00:00 2001
From: Matt Parker <61717342+MattParkerDev@users.noreply.github.com>
Date: Fri, 12 Sep 2025 18:04:20 +1000
Subject: [PATCH] add reactive binding

---
 .../BottomPanel/BottomPanelManager.cs         |  16 +-
 .../Features/Problems/ProblemEntry.cs         |   8 +
 .../Features/Problems/ProblemEntry.cs.uid     |   1 +
 .../Features/Problems/ProblemsPanel.cs        |  30 ++
 .../Features/Problems/ProblemsPanel.cs.uid    |   1 +
 .../Features/Problems/ProblemsPanel.tscn      |  25 +-
 .../Problems/ProblemsPanelProjectEntry.cs     |  14 +
 .../Problems/ProblemsPanelProjectEntry.cs.uid |   1 +
 .../Problems/ProblemsPanelProjectEntry.tscn   |  12 +
 src/SharpIDE.Godot/IdeRoot.cs                 |   4 +
 src/SharpIDE.Godot/IdeRoot.tscn               |   1 +
 src/SharpIDE.Godot/NodeExtensions.cs          |  32 ++-
 src/SharpIDE.Godot/SharpIDE.Godot.csproj      |   4 +
 .../R3.Godot/FrameProviderDispatcher.cs       |  33 +++
 .../R3.Godot/FrameProviderDispatcher.cs.uid   |   1 +
 .../addons/R3.Godot/GodotFrameProvider.cs     |  80 ++++++
 .../addons/R3.Godot/GodotFrameProvider.cs.uid |   1 +
 .../addons/R3.Godot/GodotNodeExtensions.cs    |  32 +++
 .../R3.Godot/GodotNodeExtensions.cs.uid       |   1 +
 .../R3.Godot/GodotObservableExtensions.cs     |  78 ++++++
 .../R3.Godot/GodotObservableExtensions.cs.uid |   1 +
 .../R3.Godot/GodotProviderInitializer.cs      |  21 ++
 .../R3.Godot/GodotProviderInitializer.cs.uid  |   1 +
 .../addons/R3.Godot/GodotR3Plugin.cs          |  32 +++
 .../addons/R3.Godot/GodotR3Plugin.cs.uid      |   1 +
 .../addons/R3.Godot/GodotSignalMapper.cs      | 261 ++++++++++++++++++
 .../addons/R3.Godot/GodotSignalMapper.cs.uid  |   1 +
 .../addons/R3.Godot/GodotTimeProvider.cs      | 196 +++++++++++++
 .../addons/R3.Godot/GodotTimeProvider.cs.uid  |   1 +
 .../addons/R3.Godot/GodotUINodeExtensions.cs  |  82 ++++++
 .../R3.Godot/GodotUINodeExtensions.cs.uid     |   1 +
 .../ObservableTrackerDebuggerPlugin.cs        | 150 ++++++++++
 .../ObservableTrackerDebuggerPlugin.cs.uid    |   1 +
 .../R3.Godot/ObservableTrackerRuntimeHook.cs  |  58 ++++
 .../ObservableTrackerRuntimeHook.cs.uid       |   1 +
 .../addons/R3.Godot/ObservableTrackerTab.cs   | 146 ++++++++++
 .../R3.Godot/ObservableTrackerTab.cs.uid      |   1 +
 .../addons/R3.Godot/ObservableTrackerTree.cs  |  67 +++++
 .../R3.Godot/ObservableTrackerTree.cs.uid     |   1 +
 src/SharpIDE.Godot/addons/R3.Godot/plugin.cfg |   8 +
 src/SharpIDE.Godot/project.godot              |   9 +
 41 files changed, 1411 insertions(+), 4 deletions(-)
 create mode 100644 src/SharpIDE.Godot/Features/Problems/ProblemEntry.cs
 create mode 100644 src/SharpIDE.Godot/Features/Problems/ProblemEntry.cs.uid
 create mode 100644 src/SharpIDE.Godot/Features/Problems/ProblemsPanel.cs
 create mode 100644 src/SharpIDE.Godot/Features/Problems/ProblemsPanel.cs.uid
 create mode 100644 src/SharpIDE.Godot/Features/Problems/ProblemsPanelProjectEntry.cs
 create mode 100644 src/SharpIDE.Godot/Features/Problems/ProblemsPanelProjectEntry.cs.uid
 create mode 100644 src/SharpIDE.Godot/Features/Problems/ProblemsPanelProjectEntry.tscn
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/FrameProviderDispatcher.cs
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/FrameProviderDispatcher.cs.uid
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/GodotFrameProvider.cs
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/GodotFrameProvider.cs.uid
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/GodotNodeExtensions.cs
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/GodotNodeExtensions.cs.uid
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/GodotObservableExtensions.cs
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/GodotObservableExtensions.cs.uid
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/GodotProviderInitializer.cs
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/GodotProviderInitializer.cs.uid
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/GodotR3Plugin.cs
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/GodotR3Plugin.cs.uid
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/GodotSignalMapper.cs
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/GodotSignalMapper.cs.uid
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/GodotTimeProvider.cs
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/GodotTimeProvider.cs.uid
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/GodotUINodeExtensions.cs
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/GodotUINodeExtensions.cs.uid
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerDebuggerPlugin.cs
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerDebuggerPlugin.cs.uid
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerRuntimeHook.cs
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerRuntimeHook.cs.uid
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerTab.cs
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerTab.cs.uid
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerTree.cs
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerTree.cs.uid
 create mode 100644 src/SharpIDE.Godot/addons/R3.Godot/plugin.cfg

diff --git a/src/SharpIDE.Godot/Features/BottomPanel/BottomPanelManager.cs b/src/SharpIDE.Godot/Features/BottomPanel/BottomPanelManager.cs
index d6fe54c..7d56e39 100644
--- a/src/SharpIDE.Godot/Features/BottomPanel/BottomPanelManager.cs
+++ b/src/SharpIDE.Godot/Features/BottomPanel/BottomPanelManager.cs
@@ -1,13 +1,25 @@
 using Godot;
+using SharpIDE.Application.Features.SolutionDiscovery.VsPersistence;
+using SharpIDE.Godot.Features.Problems;
 
 namespace SharpIDE.Godot.Features.BottomPanel;
 
 public partial class BottomPanelManager : Panel
 {
+    public SharpIdeSolutionModel? Solution
+    {
+        get;
+        set
+        {
+            field = value;
+            _problemsPanel.Solution = value;
+        }
+    }
+
     private Control _runPanel = null!;
     private Control _debugPanel = null!;
     private Control _buildPanel = null!;
-    private Control _problemsPanel = null!;
+    private ProblemsPanel _problemsPanel = null!;
 
     private Dictionary<BottomPanelType, Control> _panelTypeMap = [];
     
@@ -16,7 +28,7 @@ public partial class BottomPanelManager : Panel
         _runPanel = GetNode<Control>("%RunPanel");
         _debugPanel = GetNode<Control>("%DebugPanel");
         _buildPanel = GetNode<Control>("%BuildPanel");
-        _problemsPanel = GetNode<Control>("%ProblemsPanel");
+        _problemsPanel = GetNode<ProblemsPanel>("%ProblemsPanel");
         
         _panelTypeMap = new Dictionary<BottomPanelType, Control>
         {
diff --git a/src/SharpIDE.Godot/Features/Problems/ProblemEntry.cs b/src/SharpIDE.Godot/Features/Problems/ProblemEntry.cs
new file mode 100644
index 0000000..5fedc43
--- /dev/null
+++ b/src/SharpIDE.Godot/Features/Problems/ProblemEntry.cs
@@ -0,0 +1,8 @@
+using Godot;
+
+namespace SharpIDE.Godot.Features.Problems;
+
+public partial class ProblemEntry : Control
+{
+    
+}
\ No newline at end of file
diff --git a/src/SharpIDE.Godot/Features/Problems/ProblemEntry.cs.uid b/src/SharpIDE.Godot/Features/Problems/ProblemEntry.cs.uid
new file mode 100644
index 0000000..8119a60
--- /dev/null
+++ b/src/SharpIDE.Godot/Features/Problems/ProblemEntry.cs.uid
@@ -0,0 +1 @@
+uid://dkgiknux4rqit
diff --git a/src/SharpIDE.Godot/Features/Problems/ProblemsPanel.cs b/src/SharpIDE.Godot/Features/Problems/ProblemsPanel.cs
new file mode 100644
index 0000000..41c3d12
--- /dev/null
+++ b/src/SharpIDE.Godot/Features/Problems/ProblemsPanel.cs
@@ -0,0 +1,30 @@
+using System.Collections.Specialized;
+using Godot;
+using ObservableCollections;
+using R3;
+using SharpIDE.Application.Features.SolutionDiscovery.VsPersistence;
+
+namespace SharpIDE.Godot.Features.Problems;
+
+public partial class ProblemsPanel : Control
+{
+    private PackedScene _problemsPanelProjectEntryScene = GD.Load<PackedScene>("uid://do72lghjvfdp3");
+    private VBoxContainer _vBoxContainer = null!;
+    // TODO: Use observable collections in the solution model and downwards
+    public SharpIdeSolutionModel? Solution { get; set; }
+    private readonly ObservableHashSet<SharpIdeProjectModel> _projects = [];
+
+    public override void _Ready()
+    {
+        Observable.EveryValueChanged(this, manager => manager.Solution)
+            .Where(s => s is not null)
+            .Subscribe(s =>
+            {
+                GD.Print($"ProblemsPanel: Solution changed to {s?.Name ?? "null"}");
+                _projects.Clear();
+                _projects.AddRange(s!.AllProjects);
+            });
+        _vBoxContainer = GetNode<VBoxContainer>("ScrollContainer/VBoxContainer");
+        _vBoxContainer.BindChildren(_projects, _problemsPanelProjectEntryScene);
+    }
+}
\ No newline at end of file
diff --git a/src/SharpIDE.Godot/Features/Problems/ProblemsPanel.cs.uid b/src/SharpIDE.Godot/Features/Problems/ProblemsPanel.cs.uid
new file mode 100644
index 0000000..76ad7ea
--- /dev/null
+++ b/src/SharpIDE.Godot/Features/Problems/ProblemsPanel.cs.uid
@@ -0,0 +1 @@
+uid://b1r3no4u3khik
diff --git a/src/SharpIDE.Godot/Features/Problems/ProblemsPanel.tscn b/src/SharpIDE.Godot/Features/Problems/ProblemsPanel.tscn
index 1c30411..ff60dc8 100644
--- a/src/SharpIDE.Godot/Features/Problems/ProblemsPanel.tscn
+++ b/src/SharpIDE.Godot/Features/Problems/ProblemsPanel.tscn
@@ -1,4 +1,7 @@
-[gd_scene format=3 uid="uid://tqpmww430cor"]
+[gd_scene load_steps=3 format=3 uid="uid://tqpmww430cor"]
+
+[ext_resource type="Script" uid="uid://b1r3no4u3khik" path="res://Features/Problems/ProblemsPanel.cs" id="1_bnenc"]
+[ext_resource type="PackedScene" uid="uid://do72lghjvfdp3" path="res://Features/Problems/ProblemsPanelProjectEntry.tscn" id="2_xj8le"]
 
 [node name="ProblemsPanel" type="Control"]
 layout_mode = 3
@@ -7,3 +10,23 @@ anchor_right = 1.0
 anchor_bottom = 1.0
 grow_horizontal = 2
 grow_vertical = 2
+script = ExtResource("1_bnenc")
+
+[node name="ScrollContainer" type="ScrollContainer" parent="."]
+layout_mode = 1
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+
+[node name="VBoxContainer" type="VBoxContainer" parent="ScrollContainer"]
+layout_mode = 2
+size_flags_horizontal = 3
+size_flags_vertical = 3
+
+[node name="ProblemsPanelProjectEntry" parent="ScrollContainer/VBoxContainer" instance=ExtResource("2_xj8le")]
+layout_mode = 2
+
+[node name="ProblemsPanelProjectEntry2" parent="ScrollContainer/VBoxContainer" instance=ExtResource("2_xj8le")]
+layout_mode = 2
diff --git a/src/SharpIDE.Godot/Features/Problems/ProblemsPanelProjectEntry.cs b/src/SharpIDE.Godot/Features/Problems/ProblemsPanelProjectEntry.cs
new file mode 100644
index 0000000..60d0235
--- /dev/null
+++ b/src/SharpIDE.Godot/Features/Problems/ProblemsPanelProjectEntry.cs
@@ -0,0 +1,14 @@
+using Godot;
+using SharpIDE.Application.Features.SolutionDiscovery.VsPersistence;
+
+namespace SharpIDE.Godot.Features.Problems;
+
+public partial class ProblemsPanelProjectEntry : MarginContainer
+{
+    public SharpIdeProjectModel Project { get; set; } = null!;
+
+    public override void _Ready()
+    {
+        GetNode<Label>("Label").Text = Project?.Name ?? "NULL";
+    }
+}
\ No newline at end of file
diff --git a/src/SharpIDE.Godot/Features/Problems/ProblemsPanelProjectEntry.cs.uid b/src/SharpIDE.Godot/Features/Problems/ProblemsPanelProjectEntry.cs.uid
new file mode 100644
index 0000000..882eb78
--- /dev/null
+++ b/src/SharpIDE.Godot/Features/Problems/ProblemsPanelProjectEntry.cs.uid
@@ -0,0 +1 @@
+uid://bx5v8rr87343o
diff --git a/src/SharpIDE.Godot/Features/Problems/ProblemsPanelProjectEntry.tscn b/src/SharpIDE.Godot/Features/Problems/ProblemsPanelProjectEntry.tscn
new file mode 100644
index 0000000..8bc6ef0
--- /dev/null
+++ b/src/SharpIDE.Godot/Features/Problems/ProblemsPanelProjectEntry.tscn
@@ -0,0 +1,12 @@
+[gd_scene load_steps=2 format=3 uid="uid://do72lghjvfdp3"]
+
+[ext_resource type="Script" uid="uid://bx5v8rr87343o" path="res://Features/Problems/ProblemsPanelProjectEntry.cs" id="1_2yh8u"]
+
+[node name="ProblemsPanelProjectEntry" type="MarginContainer"]
+offset_right = 40.0
+offset_bottom = 40.0
+script = ExtResource("1_2yh8u")
+
+[node name="Label" type="Label" parent="."]
+layout_mode = 2
+text = "Project"
diff --git a/src/SharpIDE.Godot/IdeRoot.cs b/src/SharpIDE.Godot/IdeRoot.cs
index a736bbc..34c886a 100644
--- a/src/SharpIDE.Godot/IdeRoot.cs
+++ b/src/SharpIDE.Godot/IdeRoot.cs
@@ -2,6 +2,7 @@ using Godot;
 using Microsoft.Build.Locator;
 using SharpIDE.Application.Features.Analysis;
 using SharpIDE.Application.Features.SolutionDiscovery.VsPersistence;
+using SharpIDE.Godot.Features.BottomPanel;
 using SharpIDE.Godot.Features.CustomControls;
 using SharpIDE.Godot.Features.Run;
 using SharpIDE.Godot.Features.SolutionExplorer;
@@ -19,6 +20,7 @@ public partial class IdeRoot : Control
 	private RunPanel _runPanel = null!;
 	private Button _runMenuButton = null!;
 	private Popup _runMenuPopup = null!;
+	private BottomPanelManager _bottomPanelManager = null!;
 	
 	private readonly PackedScene _runMenuItemScene = ResourceLoader.Load<PackedScene>("res://Features/Run/RunMenuItem.tscn");
 	public override void _Ready()
@@ -34,6 +36,7 @@ public partial class IdeRoot : Control
 		_solutionExplorerPanel = GetNode<SolutionExplorerPanel>("%SolutionExplorerPanel");
 		_runPanel = GetNode<RunPanel>("%RunPanel");
 		_invertedVSplitContainer = GetNode<InvertedVSplitContainer>("%InvertedVSplitContainer");
+		_bottomPanelManager = GetNode<BottomPanelManager>("%BottomPanel");
 		
 		_runMenuButton.Pressed += OnRunMenuButtonPressed;
 		_solutionExplorerPanel.FileSelected += OnSolutionExplorerPanelOnFileSelected;
@@ -71,6 +74,7 @@ public partial class IdeRoot : Control
 			var solutionModel = await VsPersistenceMapper.GetSolutionModel(path);
 			_solutionExplorerPanel.SolutionModel = solutionModel;
 			_sharpIdeCodeEdit.Solution = solutionModel;
+			_bottomPanelManager.Solution = solutionModel;
 			Callable.From(_solutionExplorerPanel.RepopulateTree).CallDeferred();
 			RoslynAnalysis.StartSolutionAnalysis(path);
 				
diff --git a/src/SharpIDE.Godot/IdeRoot.tscn b/src/SharpIDE.Godot/IdeRoot.tscn
index 35324f8..757b485 100644
--- a/src/SharpIDE.Godot/IdeRoot.tscn
+++ b/src/SharpIDE.Godot/IdeRoot.tscn
@@ -153,6 +153,7 @@ item_0/text = "Getting Context Actions..."
 item_0/id = 0
 
 [node name="BottomPanel" type="Panel" parent="VBoxContainer/HBoxContainer/InvertedVSplitContainer"]
+unique_name_in_owner = true
 layout_mode = 2
 script = ExtResource("7_i62lx")
 
diff --git a/src/SharpIDE.Godot/NodeExtensions.cs b/src/SharpIDE.Godot/NodeExtensions.cs
index 7a743c1..9ec8154 100644
--- a/src/SharpIDE.Godot/NodeExtensions.cs
+++ b/src/SharpIDE.Godot/NodeExtensions.cs
@@ -1,7 +1,37 @@
-using Godot;
+using System.Collections.Specialized;
+using Godot;
+using ObservableCollections;
+using SharpIDE.Application.Features.SolutionDiscovery.VsPersistence;
+using SharpIDE.Godot.Features.Problems;
 
 namespace SharpIDE.Godot;
 
+public static class ControlExtensions
+{
+    extension(Control control)
+    {
+        public void BindChildren(ObservableHashSet<SharpIdeProjectModel> list, PackedScene scene)
+        {
+            var view = list.CreateView(x =>
+            {
+                var node = scene.Instantiate<ProblemsPanelProjectEntry>();
+                node.Project = x;
+                Callable.From(() => control.AddChild(node)).CallDeferred();
+                return node;
+            });
+            view.ViewChanged += OnViewChanged;
+        }
+        private static void OnViewChanged(in SynchronizedViewChangedEventArgs<SharpIdeProjectModel, ProblemsPanelProjectEntry> eventArgs)
+        {
+            GD.Print("View changed: " + eventArgs.Action);
+            if (eventArgs.Action == NotifyCollectionChangedAction.Remove)
+            {
+                eventArgs.OldItem.View.QueueFree();
+            }
+        }
+    }
+}
+
 public static class NodeExtensions
 {
     extension(Node node)
diff --git a/src/SharpIDE.Godot/SharpIDE.Godot.csproj b/src/SharpIDE.Godot/SharpIDE.Godot.csproj
index eed785f..b6b3dbf 100644
--- a/src/SharpIDE.Godot/SharpIDE.Godot.csproj
+++ b/src/SharpIDE.Godot/SharpIDE.Godot.csproj
@@ -8,4 +8,8 @@
   <ItemGroup>
     <ProjectReference Include="..\SharpIDE.Application\SharpIDE.Application.csproj" />
   </ItemGroup>
+  <ItemGroup>
+    <PackageReference Include="ObservableCollections" Version="3.3.4" />
+    <PackageReference Include="R3" Version="1.3.0" />
+  </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/FrameProviderDispatcher.cs b/src/SharpIDE.Godot/addons/R3.Godot/FrameProviderDispatcher.cs
new file mode 100644
index 0000000..1c8270b
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/FrameProviderDispatcher.cs
@@ -0,0 +1,33 @@
+#nullable enable
+
+using System.Runtime.CompilerServices;
+
+namespace R3;
+
+public partial class FrameProviderDispatcher : global::Godot.Node
+{
+    StrongBox<double> processDelta = new StrongBox<double>();
+    StrongBox<double> physicsProcessDelta = new StrongBox<double>();
+
+    public override void _Ready()
+    {
+        GodotProviderInitializer.SetDefaultObservableSystem();
+
+        ((GodotFrameProvider)GodotFrameProvider.Process).Delta = processDelta;
+        ((GodotFrameProvider)GodotFrameProvider.PhysicsProcess).Delta = physicsProcessDelta;
+    }
+
+    public override void _Process(double delta)
+    {
+        processDelta.Value = delta;
+        ((GodotTimeProvider)GodotTimeProvider.Process).time += delta;
+        ((GodotFrameProvider)GodotFrameProvider.Process).Run(delta);
+    }
+
+    public override void _PhysicsProcess(double delta)
+    {
+        physicsProcessDelta.Value = delta;
+        ((GodotTimeProvider)GodotTimeProvider.PhysicsProcess).time += delta;
+        ((GodotFrameProvider)GodotFrameProvider.PhysicsProcess).Run(delta);
+    }
+}
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/FrameProviderDispatcher.cs.uid b/src/SharpIDE.Godot/addons/R3.Godot/FrameProviderDispatcher.cs.uid
new file mode 100644
index 0000000..6b8b8fd
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/FrameProviderDispatcher.cs.uid
@@ -0,0 +1 @@
+uid://ngclnv5y220f
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/GodotFrameProvider.cs b/src/SharpIDE.Godot/addons/R3.Godot/GodotFrameProvider.cs
new file mode 100644
index 0000000..15e3e7a
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/GodotFrameProvider.cs
@@ -0,0 +1,80 @@
+#nullable enable
+
+using Godot;
+using R3.Collections;
+using System;
+using System.Runtime.CompilerServices;
+
+namespace R3;
+
+internal enum PlayerLoopTiming
+{
+    Process,
+    PhysicsProcess
+}
+
+public class GodotFrameProvider : FrameProvider
+{
+    public static readonly GodotFrameProvider Process = new GodotFrameProvider(PlayerLoopTiming.Process);
+    public static readonly GodotFrameProvider PhysicsProcess = new GodotFrameProvider(PlayerLoopTiming.PhysicsProcess);
+
+    FreeListCore<IFrameRunnerWorkItem> list;
+    readonly object gate = new object();
+
+    PlayerLoopTiming PlayerLoopTiming { get; }
+
+    internal StrongBox<double> Delta = default!; // set from Node before running process.
+
+    internal GodotFrameProvider(PlayerLoopTiming playerLoopTiming)
+    {
+        this.PlayerLoopTiming = playerLoopTiming;
+        this.list = new FreeListCore<IFrameRunnerWorkItem>(gate);
+    }
+
+    public override long GetFrameCount()
+    {
+        if (PlayerLoopTiming == PlayerLoopTiming.Process)
+        {
+            return (long)Engine.GetProcessFrames();
+        }
+        else
+        {
+            return (long)Engine.GetPhysicsFrames();
+        }
+    }
+
+    public override void Register(IFrameRunnerWorkItem callback)
+    {
+        list.Add(callback, out _);
+    }
+
+    internal void Run(double _)
+    {
+        long frameCount = GetFrameCount();
+
+        var span = list.AsSpan();
+        for (int i = 0; i < span.Length; i++)
+        {
+            ref readonly var item = ref span[i];
+            if (item != null)
+            {
+                try
+                {
+                    if (!item.MoveNext(frameCount))
+                    {
+                        list.Remove(i);
+                    }
+                }
+                catch (Exception ex)
+                {
+                    list.Remove(i);
+                    try
+                    {
+                        ObservableSystem.GetUnhandledExceptionHandler().Invoke(ex);
+                    }
+                    catch { }
+                }
+            }
+        }
+    }
+}
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/GodotFrameProvider.cs.uid b/src/SharpIDE.Godot/addons/R3.Godot/GodotFrameProvider.cs.uid
new file mode 100644
index 0000000..f2faeb8
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/GodotFrameProvider.cs.uid
@@ -0,0 +1 @@
+uid://bus13cr6ba71l
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/GodotNodeExtensions.cs b/src/SharpIDE.Godot/addons/R3.Godot/GodotNodeExtensions.cs
new file mode 100644
index 0000000..52053ba
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/GodotNodeExtensions.cs
@@ -0,0 +1,32 @@
+using System;
+using Godot;
+
+namespace R3;
+
+public static class GodotNodeExtensions
+{
+    /// <summary>
+    /// Dispose self on target node has bee tree exited.
+    /// </summary>
+    /// <param name="disposable"></param>
+    /// <param name="node"></param>
+    /// <typeparam name="T"></typeparam>
+    /// <returns>Self disposable</returns>
+    public static T AddTo<T>(this T disposable, Node node) where T : IDisposable
+    {
+        // Note: Dispose when tree exited, so if node is not inside tree, dispose immediately.
+        if (!node.IsInsideTree()) 
+        {
+            if (!node.IsNodeReady()) // Before enter tree
+            {
+                GD.PrintErr("AddTo does not support to use before enter tree.");
+            }
+
+            disposable.Dispose();
+            return disposable;
+        }
+        
+        node.TreeExited += () => disposable.Dispose();
+        return disposable;
+    }
+}
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/GodotNodeExtensions.cs.uid b/src/SharpIDE.Godot/addons/R3.Godot/GodotNodeExtensions.cs.uid
new file mode 100644
index 0000000..0eef4e1
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/GodotNodeExtensions.cs.uid
@@ -0,0 +1 @@
+uid://cob4ct214hg4v
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/GodotObservableExtensions.cs b/src/SharpIDE.Godot/addons/R3.Godot/GodotObservableExtensions.cs
new file mode 100644
index 0000000..328496d
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/GodotObservableExtensions.cs
@@ -0,0 +1,78 @@
+using System;
+
+namespace R3;
+
+public static class GodotObservableExtensions
+{
+    public static Observable<double> Delta(this Observable<Unit> source)
+    {
+        return Delta(source, GodotFrameProvider.Process);
+    }
+
+    public static Observable<double> Delta(this Observable<Unit> source, GodotFrameProvider frameProvider)
+    {
+        return new Delta(source, frameProvider);
+    }
+
+    public static Observable<(double Delta, T Item)> Delta<T>(this Observable<T> source)
+    {
+        return Delta(source, GodotFrameProvider.Process);
+    }
+
+    public static Observable<(double Delta, T Item)> Delta<T>(this Observable<T> source, GodotFrameProvider frameProvider)
+    {
+        return new Delta<T>(source, frameProvider);
+    }
+}
+
+internal sealed class Delta(Observable<Unit> source, GodotFrameProvider frameProvider) : Observable<double>
+{
+    protected override IDisposable SubscribeCore(Observer<double> observer)
+    {
+        return source.Subscribe(new _Delta(observer, frameProvider));
+    }
+
+    sealed class _Delta(Observer<double> observer, GodotFrameProvider frameProvider) : Observer<Unit>
+    {
+        protected override void OnNextCore(Unit value)
+        {
+            observer.OnNext(frameProvider.Delta.Value);
+        }
+
+        protected override void OnErrorResumeCore(Exception error)
+        {
+            observer.OnErrorResume(error);
+        }
+
+        protected override void OnCompletedCore(Result result)
+        {
+            observer.OnCompleted(result);
+        }
+    }
+}
+
+internal sealed class Delta<T>(Observable<T> source, GodotFrameProvider frameProvider) : Observable<(double Delta, T Item)>
+{
+    protected override IDisposable SubscribeCore(Observer<(double Delta, T Item)> observer)
+    {
+        return source.Subscribe(new _Delta(observer, frameProvider));
+    }
+
+    sealed class _Delta(Observer<(double Delta, T Item)> observer, GodotFrameProvider frameProvider) : Observer<T>
+    {
+        protected override void OnNextCore(T value)
+        {
+            observer.OnNext((frameProvider.Delta.Value, value));
+        }
+
+        protected override void OnErrorResumeCore(Exception error)
+        {
+            observer.OnErrorResume(error);
+        }
+
+        protected override void OnCompletedCore(Result result)
+        {
+            observer.OnCompleted(result);
+        }
+    }
+}
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/GodotObservableExtensions.cs.uid b/src/SharpIDE.Godot/addons/R3.Godot/GodotObservableExtensions.cs.uid
new file mode 100644
index 0000000..c9d82da
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/GodotObservableExtensions.cs.uid
@@ -0,0 +1 @@
+uid://8lnifa1x4o6e
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/GodotProviderInitializer.cs b/src/SharpIDE.Godot/addons/R3.Godot/GodotProviderInitializer.cs
new file mode 100644
index 0000000..8381f9f
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/GodotProviderInitializer.cs
@@ -0,0 +1,21 @@
+#nullable enable
+
+using Godot;
+using System;
+
+namespace R3;
+
+public static class GodotProviderInitializer
+{
+    public static void SetDefaultObservableSystem()
+    {
+        SetDefaultObservableSystem(ex => GD.PrintErr(ex));
+    }
+
+    public static void SetDefaultObservableSystem(Action<Exception> unhandledExceptionHandler)
+    {
+        ObservableSystem.RegisterUnhandledExceptionHandler(unhandledExceptionHandler);
+        ObservableSystem.DefaultTimeProvider = GodotTimeProvider.Process;
+        ObservableSystem.DefaultFrameProvider = GodotFrameProvider.Process;
+    }
+}
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/GodotProviderInitializer.cs.uid b/src/SharpIDE.Godot/addons/R3.Godot/GodotProviderInitializer.cs.uid
new file mode 100644
index 0000000..8f320f3
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/GodotProviderInitializer.cs.uid
@@ -0,0 +1 @@
+uid://cfm1x8aucvw47
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/GodotR3Plugin.cs b/src/SharpIDE.Godot/addons/R3.Godot/GodotR3Plugin.cs
new file mode 100644
index 0000000..5f29c72
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/GodotR3Plugin.cs
@@ -0,0 +1,32 @@
+#if TOOLS
+#nullable enable
+
+using Godot;
+
+namespace R3;
+
+[Tool]
+public partial class GodotR3Plugin : EditorPlugin
+{
+    static ObservableTrackerDebuggerPlugin? observableTrackerDebugger;
+    public override void _EnterTree()
+    {
+        observableTrackerDebugger ??= new ObservableTrackerDebuggerPlugin();
+        AddDebuggerPlugin(observableTrackerDebugger);
+        // Automatically install autoloads here for ease of use.
+        AddAutoloadSingleton(nameof(FrameProviderDispatcher), "res://addons/R3.Godot/FrameProviderDispatcher.cs");
+        AddAutoloadSingleton(nameof(ObservableTrackerRuntimeHook), "res://addons/R3.Godot/ObservableTrackerRuntimeHook.cs");
+    }
+
+    public override void _ExitTree()
+    {
+        if (observableTrackerDebugger != null)
+        {
+            RemoveDebuggerPlugin(observableTrackerDebugger);
+            observableTrackerDebugger = null;
+        }
+        RemoveAutoloadSingleton(nameof(FrameProviderDispatcher));
+        RemoveAutoloadSingleton(nameof(ObservableTrackerRuntimeHook));
+    }
+}
+#endif
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/GodotR3Plugin.cs.uid b/src/SharpIDE.Godot/addons/R3.Godot/GodotR3Plugin.cs.uid
new file mode 100644
index 0000000..ef8dd19
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/GodotR3Plugin.cs.uid
@@ -0,0 +1 @@
+uid://cdglfkymcq38j
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/GodotSignalMapper.cs b/src/SharpIDE.Godot/addons/R3.Godot/GodotSignalMapper.cs
new file mode 100644
index 0000000..b501c1c
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/GodotSignalMapper.cs
@@ -0,0 +1,261 @@
+using System;
+using System.Threading;
+using Godot;
+
+namespace R3;
+
+public static class GodotObjectExtensions
+{
+    /// <summary>Returns a <see cref="CancellationToken"/> that cancels when <paramref name="obj"/> emits the specified signal, this cancellation is one-shot unless <paramref name="oneShot"/> is false.</summary>
+    public static CancellationToken CancelOnSignal(this GodotObject obj, StringName signalName, bool oneShot = true)
+    {
+        CancellationTokenSource cts = new();
+        obj.Connect(signalName, Callable.From(cts.Cancel), oneShot ? (uint) GodotObject.ConnectFlags.OneShot : 0);
+        return cts.Token;
+    }
+
+    /// <summary>Returns an observable that: publishes a <see cref="Unit"/> when <paramref name="node"/> emits the specified signal (except for <see cref="Node.SignalName.TreeExited"/>); finishes when <paramref name="node"/> emits <see cref="Node.SignalName.TreeExited"/>.</summary>
+    public static Observable<Unit> SignalAsObservable(this Node node, StringName signalName)
+    {
+        return node.SignalAsObservable(signalName, node.CancelOnSignal(Node.SignalName.TreeExited));
+    }
+
+    /// <summary>Returns an observable that: publishes data of type <typeparamref name="T"/> when <paramref name="node"/> emits the specified signal (except for <see cref="Node.SignalName.TreeExited"/>); finishes when <paramref name="node"/> emits <see cref="Node.SignalName.TreeExited"/>.</summary>
+    public static Observable<T> SignalAsObservable<[MustBeVariant] T>(this Node node, StringName signalName)
+    {
+        return node.SignalAsObservable<T>(signalName, node.CancelOnSignal(Node.SignalName.TreeExited));
+    }
+
+    /// <summary>Returns an observable that: publishes a tuple (<typeparamref name="T0"/>, <typeparamref name="T1"/>) when <paramref name="node"/> emits the specified signal (except for <see cref="Node.SignalName.TreeExited"/>); finishes when <paramref name="node"/> emits <see cref="Node.SignalName.TreeExited"/>.</summary>
+    public static Observable<(T0, T1)> SignalAsObservable<[MustBeVariant] T0, [MustBeVariant] T1>(this Node node, StringName signalName)
+    {
+        return node.SignalAsObservable<T0, T1>(signalName, node.CancelOnSignal(Node.SignalName.TreeExited));
+    }
+
+    /// <summary>Returns an observable that: publishes a tuple (<typeparamref name="T0"/>, <typeparamref name="T1"/>, <typeparamref name="T2"/>) when <paramref name="node"/> emits the specified signal (except for <see cref="Node.SignalName.TreeExited"/>); finishes when <paramref name="node"/> emits <see cref="Node.SignalName.TreeExited"/>.</summary>
+    public static Observable<(T0, T1, T2)> SignalAsObservable<[MustBeVariant] T0, [MustBeVariant] T1, [MustBeVariant] T2>(this Node node, StringName signalName)
+    {
+        return node.SignalAsObservable<T0, T1, T2>(signalName, node.CancelOnSignal(Node.SignalName.TreeExited));
+    }
+
+    /// <summary>Returns an observable that: publishes a tuple (<typeparamref name="T0"/>, <typeparamref name="T1"/>, <typeparamref name="T2"/>, <typeparamref name="T3"/>) when <paramref name="node"/> emits the specified signal (except for <see cref="Node.SignalName.TreeExited"/>); finishes when <paramref name="node"/> emits <see cref="Node.SignalName.TreeExited"/>.</summary>
+    public static Observable<(T0, T1, T2, T3)> SignalAsObservable<[MustBeVariant] T0, [MustBeVariant] T1, [MustBeVariant] T2, [MustBeVariant] T3>(this Node node, StringName signalName)
+    {
+        return node.SignalAsObservable<T0, T1, T2, T3>(signalName, node.CancelOnSignal(Node.SignalName.TreeExited));
+    }
+
+    /// <summary>Returns an observable that: publishes a tuple (<typeparamref name="T0"/>, <typeparamref name="T1"/>, <typeparamref name="T2"/>, <typeparamref name="T3"/>, <typeparamref name="T4"/>) when <paramref name="node"/> emits the specified signal (except for <see cref="Node.SignalName.TreeExited"/>); finishes when <paramref name="node"/> emits <see cref="Node.SignalName.TreeExited"/>.</summary>
+    public static Observable<(T0, T1, T2, T3, T4)> SignalAsObservable<[MustBeVariant] T0, [MustBeVariant] T1, [MustBeVariant] T2, [MustBeVariant] T3, [MustBeVariant] T4>(this Node node, StringName signalName)
+    {
+        return node.SignalAsObservable<T0, T1, T2, T3, T4>(signalName, node.CancelOnSignal(Node.SignalName.TreeExited));
+    }
+
+    /// <summary>Returns an observable that: publishes a tuple (<typeparamref name="T0"/>, <typeparamref name="T1"/>, <typeparamref name="T2"/>, <typeparamref name="T3"/>, <typeparamref name="T4"/>, <typeparamref name="T5"/>) when <paramref name="node"/> emits the specified signal (except for <see cref="Node.SignalName.TreeExited"/>); finishes when <paramref name="node"/> emits <see cref="Node.SignalName.TreeExited"/>.</summary>
+    public static Observable<(T0, T1, T2, T3, T4, T5)> SignalAsObservable<[MustBeVariant] T0, [MustBeVariant] T1, [MustBeVariant] T2, [MustBeVariant] T3, [MustBeVariant] T4, [MustBeVariant] T5>(this Node node, StringName signalName)
+    {
+        return node.SignalAsObservable<T0, T1, T2, T3, T4, T5>(signalName, node.CancelOnSignal(Node.SignalName.TreeExited));
+    }
+
+    /// <summary>Returns an observable that: publishes a tuple (<typeparamref name="T0"/>, <typeparamref name="T1"/>, <typeparamref name="T2"/>, <typeparamref name="T3"/>, <typeparamref name="T4"/>, <typeparamref name="T5"/>, <typeparamref name="T6"/>) when <paramref name="node"/> emits the specified signal (except for <see cref="Node.SignalName.TreeExited"/>); finishes when <paramref name="node"/> emits <see cref="Node.SignalName.TreeExited"/>.</summary>
+    public static Observable<(T0, T1, T2, T3, T4, T5, T6)> SignalAsObservable<[MustBeVariant] T0, [MustBeVariant] T1, [MustBeVariant] T2, [MustBeVariant] T3, [MustBeVariant] T4, [MustBeVariant] T5, [MustBeVariant] T6>(this Node node, StringName signalName)
+    {
+        return node.SignalAsObservable<T0, T1, T2, T3, T4, T5, T6>(signalName, node.CancelOnSignal(Node.SignalName.TreeExited));
+    }
+
+    /// <summary>Returns an observable that: publishes a tuple (<typeparamref name="T0"/>, <typeparamref name="T1"/>, <typeparamref name="T2"/>, <typeparamref name="T3"/>, <typeparamref name="T4"/>, <typeparamref name="T5"/>, <typeparamref name="T6"/>, <typeparamref name="T7"/>) when <paramref name="node"/> emits the specified signal (except for <see cref="Node.SignalName.TreeExited"/>); finishes when <paramref name="node"/> emits <see cref="Node.SignalName.TreeExited"/>.</summary>
+    public static Observable<(T0, T1, T2, T3, T4, T5, T6, T7)> SignalAsObservable<[MustBeVariant] T0, [MustBeVariant] T1, [MustBeVariant] T2, [MustBeVariant] T3, [MustBeVariant] T4, [MustBeVariant] T5, [MustBeVariant] T6, [MustBeVariant] T7>(this Node node, StringName signalName)
+    {
+        return node.SignalAsObservable<T0, T1, T2, T3, T4, T5, T6, T7>(signalName, node.CancelOnSignal(Node.SignalName.TreeExited));
+    }
+
+    /// <summary>Returns an observable that: publishes a tuple (<typeparamref name="T0"/>, <typeparamref name="T1"/>, <typeparamref name="T2"/>, <typeparamref name="T3"/>, <typeparamref name="T4"/>, <typeparamref name="T5"/>, <typeparamref name="T6"/>, <typeparamref name="T7"/>, <typeparamref name="T8"/>) when <paramref name="node"/> emits the specified signal (except for <see cref="Node.SignalName.TreeExited"/>); finishes when <paramref name="node"/> emits <see cref="Node.SignalName.TreeExited"/>.</summary>
+    public static Observable<(T0, T1, T2, T3, T4, T5, T6, T7, T8)> SignalAsObservable<[MustBeVariant] T0, [MustBeVariant] T1, [MustBeVariant] T2, [MustBeVariant] T3, [MustBeVariant] T4, [MustBeVariant] T5, [MustBeVariant] T6, [MustBeVariant] T7, [MustBeVariant] T8>(this Node node, StringName signalName)
+    {
+        return node.SignalAsObservable<T0, T1, T2, T3, T4, T5, T6, T7, T8>(signalName, node.CancelOnSignal(Node.SignalName.TreeExited));
+    }
+
+    /// <summary>Returns an observable that: publishes a <see cref="Unit"/> when <paramref name="obj"/> emits the specified signal; finishes when <paramref name="cancellationToken"/> cancels, or when all subscriptions are disposed, if only <paramref name="cancellationToken"/> is default (= <see cref="CancellationToken.None"/>).</summary>
+    public static Observable<Unit> SignalAsObservable(this GodotObject obj, StringName signalName, CancellationToken cancellationToken = default)
+    {
+        return new GodotSignalMapper(obj, signalName, cancellationToken).RefCount();
+    }
+
+    /// <summary>Returns an observable that: publishes data of type <typeparamref name="T"/> when <paramref name="obj"/> emits the specified signal; finishes when <paramref name="cancellationToken"/> cancels, or when all subscriptions are disposed, if only <paramref name="cancellationToken"/> is default (= <see cref="CancellationToken.None"/>).</summary>
+    public static Observable<T> SignalAsObservable<[MustBeVariant] T>(this GodotObject obj, StringName signalName, CancellationToken cancellationToken = default)
+    {
+        return new GodotSignalMapper<T>(obj, signalName, cancellationToken).RefCount();
+    }
+
+    /// <summary>Returns an observable that: publishes a tuple (<typeparamref name="T0"/>, <typeparamref name="T1"/>) when <paramref name="obj"/> emits the specified signal; finishes when <paramref name="cancellationToken"/> cancels, or when all subscriptions are disposed, if only <paramref name="cancellationToken"/> is default (= <see cref="CancellationToken.None"/>).</summary>
+    public static Observable<(T0, T1)> SignalAsObservable<[MustBeVariant] T0, [MustBeVariant] T1>(this GodotObject obj, StringName signalName, CancellationToken cancellationToken = default)
+    {
+        return new GodotSignalMapper<T0, T1>(obj, signalName, cancellationToken).RefCount();
+    }
+
+    /// <summary>Returns an observable that: publishes a tuple (<typeparamref name="T0"/>, <typeparamref name="T1"/>, <typeparamref name="T2"/>) when <paramref name="obj"/> emits the specified signal; finishes when <paramref name="cancellationToken"/> cancels, or when all subscriptions are disposed, if only <paramref name="cancellationToken"/> is default (= <see cref="CancellationToken.None"/>).</summary>
+    public static Observable<(T0, T1, T2)> SignalAsObservable<[MustBeVariant] T0, [MustBeVariant] T1, [MustBeVariant] T2>(this GodotObject obj, StringName signalName, CancellationToken cancellationToken = default)
+    {
+        return new GodotSignalMapper<T0, T1, T2>(obj, signalName, cancellationToken).RefCount();
+    }
+
+    /// <summary>Returns an observable that: publishes a tuple (<typeparamref name="T0"/>, <typeparamref name="T1"/>, <typeparamref name="T2"/>, <typeparamref name="T3"/>) when <paramref name="obj"/> emits the specified signal; finishes when <paramref name="cancellationToken"/> cancels, or when all subscriptions are disposed, if only <paramref name="cancellationToken"/> is default (= <see cref="CancellationToken.None"/>).</summary>
+    public static Observable<(T0, T1, T2, T3)> SignalAsObservable<[MustBeVariant] T0, [MustBeVariant] T1, [MustBeVariant] T2, [MustBeVariant] T3>(this GodotObject obj, StringName signalName, CancellationToken cancellationToken = default)
+    {
+        return new GodotSignalMapper<T0, T1, T2, T3>(obj, signalName, cancellationToken).RefCount();
+    }
+
+    /// <summary>Returns an observable that: publishes a tuple (<typeparamref name="T0"/>, <typeparamref name="T1"/>, <typeparamref name="T2"/>, <typeparamref name="T3"/>, <typeparamref name="T4"/>) when <paramref name="obj"/> emits the specified signal; finishes when <paramref name="cancellationToken"/> cancels, or when all subscriptions are disposed, if only <paramref name="cancellationToken"/> is default (= <see cref="CancellationToken.None"/>).</summary>
+    public static Observable<(T0, T1, T2, T3, T4)> SignalAsObservable<[MustBeVariant] T0, [MustBeVariant] T1, [MustBeVariant] T2, [MustBeVariant] T3, [MustBeVariant] T4>(this GodotObject obj, StringName signalName, CancellationToken cancellationToken = default)
+    {
+        return new GodotSignalMapper<T0, T1, T2, T3, T4>(obj, signalName, cancellationToken).RefCount();
+    }
+
+    /// <summary>Returns an observable that: publishes a tuple (<typeparamref name="T0"/>, <typeparamref name="T1"/>, <typeparamref name="T2"/>, <typeparamref name="T3"/>, <typeparamref name="T4"/>, <typeparamref name="T5"/>) when <paramref name="obj"/> emits the specified signal; finishes when <paramref name="cancellationToken"/> cancels, or when all subscriptions are disposed, if only <paramref name="cancellationToken"/> is default (= <see cref="CancellationToken.None"/>).</summary>
+    public static Observable<(T0, T1, T2, T3, T4, T5)> SignalAsObservable<[MustBeVariant] T0, [MustBeVariant] T1, [MustBeVariant] T2, [MustBeVariant] T3, [MustBeVariant] T4, [MustBeVariant] T5>(this GodotObject obj, StringName signalName, CancellationToken cancellationToken = default)
+    {
+        return new GodotSignalMapper<T0, T1, T2, T3, T4, T5>(obj, signalName, cancellationToken).RefCount();
+    }
+
+    /// <summary>Returns an observable that: publishes a tuple (<typeparamref name="T0"/>, <typeparamref name="T1"/>, <typeparamref name="T2"/>, <typeparamref name="T3"/>, <typeparamref name="T4"/>, <typeparamref name="T5"/>, <typeparamref name="T6"/>) when <paramref name="obj"/> emits the specified signal; finishes when <paramref name="cancellationToken"/> cancels, or when all subscriptions are disposed, if only <paramref name="cancellationToken"/> is default (= <see cref="CancellationToken.None"/>).</summary>
+    public static Observable<(T0, T1, T2, T3, T4, T5, T6)> SignalAsObservable<[MustBeVariant] T0, [MustBeVariant] T1, [MustBeVariant] T2, [MustBeVariant] T3, [MustBeVariant] T4, [MustBeVariant] T5, [MustBeVariant] T6>(this GodotObject obj, StringName signalName, CancellationToken cancellationToken = default)
+    {
+        return new GodotSignalMapper<T0, T1, T2, T3, T4, T5, T6>(obj, signalName, cancellationToken).RefCount();
+    }
+
+    /// <summary>Returns an observable that: publishes a tuple (<typeparamref name="T0"/>, <typeparamref name="T1"/>, <typeparamref name="T2"/>, <typeparamref name="T3"/>, <typeparamref name="T4"/>, <typeparamref name="T5"/>, <typeparamref name="T6"/>, <typeparamref name="T7"/>) when <paramref name="obj"/> emits the specified signal; finishes when <paramref name="cancellationToken"/> cancels, or when all subscriptions are disposed, if only <paramref name="cancellationToken"/> is default (= <see cref="CancellationToken.None"/>).</summary>
+    public static Observable<(T0, T1, T2, T3, T4, T5, T6, T7)> SignalAsObservable<[MustBeVariant] T0, [MustBeVariant] T1, [MustBeVariant] T2, [MustBeVariant] T3, [MustBeVariant] T4, [MustBeVariant] T5, [MustBeVariant] T6, [MustBeVariant] T7>(this GodotObject obj, StringName signalName, CancellationToken cancellationToken = default)
+    {
+        return new GodotSignalMapper<T0, T1, T2, T3, T4, T5, T6, T7>(obj, signalName, cancellationToken).RefCount();
+    }
+
+    /// <summary>Returns an observable that: publishes a tuple (<typeparamref name="T0"/>, <typeparamref name="T1"/>, <typeparamref name="T2"/>, <typeparamref name="T3"/>, <typeparamref name="T4"/>, <typeparamref name="T5"/>, <typeparamref name="T6"/>, <typeparamref name="T7"/>, <typeparamref name="T8"/>) when <paramref name="obj"/> emits the specified signal; finishes when <paramref name="cancellationToken"/> cancels, or when all subscriptions are disposed, if only <paramref name="cancellationToken"/> is default (= <see cref="CancellationToken.None"/>).</summary>
+    public static Observable<(T0, T1, T2, T3, T4, T5, T6, T7, T8)> SignalAsObservable<[MustBeVariant] T0, [MustBeVariant] T1, [MustBeVariant] T2, [MustBeVariant] T3, [MustBeVariant] T4, [MustBeVariant] T5, [MustBeVariant] T6, [MustBeVariant] T7, [MustBeVariant] T8>(this GodotObject obj, StringName signalName, CancellationToken cancellationToken = default)
+    {
+        return new GodotSignalMapper<T0, T1, T2, T3, T4, T5, T6, T7, T8>(obj, signalName, cancellationToken).RefCount();
+    }
+}
+
+internal abstract class GodotSignalMapperBase<T> : ConnectableObservable<T>, IDisposable
+{
+    protected readonly Subject<T> subject = new();
+
+    private readonly GodotObject godotObject;
+    private readonly StringName godotSignalName;
+    private readonly CancellationTokenRegistration? cancellationTokenRegistration;
+    private Callable? godotCallableOnNext;
+    private int connected;
+    private int disposed;
+
+    private bool ShouldDisposeOnDisconnect => !cancellationTokenRegistration.HasValue;
+
+    protected GodotSignalMapperBase(GodotObject obj, StringName signalName, CancellationToken cancellationToken)
+    {
+        godotObject = obj;
+        godotSignalName = signalName;
+        if (cancellationToken.CanBeCanceled)
+        {
+            cancellationTokenRegistration = cancellationToken.UnsafeRegister((state) => ((GodotSignalMapperBase<T>) state!).Dispose(), this);
+        }
+    }
+
+    protected override IDisposable SubscribeCore(Observer<T> observer)
+    {
+        return subject.Subscribe(observer.Wrap());
+    }
+
+    public override IDisposable Connect()
+    {
+        if (Interlocked.CompareExchange(ref connected, 1, 0) == 0)
+        {
+            godotCallableOnNext ??= OnNextAsGodotCallable();
+            godotObject.Connect(godotSignalName, godotCallableOnNext.Value);
+        }
+        return new Connection(this);
+    }
+
+    private void Disconnect()
+    {
+        if (Interlocked.CompareExchange(ref connected, 0, 1) == 1)
+        {
+            godotObject.Disconnect(godotSignalName, godotCallableOnNext!.Value);
+        }
+    }
+
+    private class Connection(GodotSignalMapperBase<T> parent) : IDisposable
+    {
+        public void Dispose()
+        {
+            parent.Disconnect();
+            if (parent.ShouldDisposeOnDisconnect) { parent.Dispose(); }
+        }
+    }
+
+    public void Dispose()
+    {
+        if (Interlocked.CompareExchange(ref disposed, 1, 0) == 1) { return; }
+        Disconnect();
+        subject.Dispose(true);
+        cancellationTokenRegistration?.Dispose();
+    }
+
+    protected abstract Callable OnNextAsGodotCallable();
+}
+
+internal class GodotSignalMapper(GodotObject obj, StringName signalName, CancellationToken cancellationToken) : GodotSignalMapperBase<Unit>(obj, signalName, cancellationToken) {
+    protected override Callable OnNextAsGodotCallable() => Callable.From((Action) OnNextWithUnit);
+    private void OnNextWithUnit() => subject.OnNext(Unit.Default);
+}
+
+internal class GodotSignalMapper<[MustBeVariant] T>(GodotObject obj, StringName signalName, CancellationToken cancellationToken) : GodotSignalMapperBase<T>(obj, signalName, cancellationToken)
+{
+    protected override Callable OnNextAsGodotCallable() => Callable.From((Action<T>) OnNextWithArgs);
+    private void OnNextWithArgs(T _a) => subject.OnNext(_a);
+}
+
+internal class GodotSignalMapper<[MustBeVariant] T0, [MustBeVariant] T1>(GodotObject obj, StringName signalName, CancellationToken cancellationToken) : GodotSignalMapperBase<(T0, T1)>(obj, signalName, cancellationToken)
+{
+    protected override Callable OnNextAsGodotCallable() => Callable.From((Action<T0, T1>) OnNextWithArgs);
+    private void OnNextWithArgs(T0 _0, T1 _1) => subject.OnNext((_0, _1));
+}
+
+internal class GodotSignalMapper<[MustBeVariant] T0, [MustBeVariant] T1, [MustBeVariant] T2>(GodotObject obj, StringName signalName, CancellationToken cancellationToken) : GodotSignalMapperBase<(T0, T1, T2)>(obj, signalName, cancellationToken)
+{
+    protected override Callable OnNextAsGodotCallable() => Callable.From((Action<T0, T1, T2>) OnNextWithArgs);
+    private void OnNextWithArgs(T0 _0, T1 _1, T2 _2) => subject.OnNext((_0, _1, _2));
+}
+
+internal class GodotSignalMapper<[MustBeVariant] T0, [MustBeVariant] T1, [MustBeVariant] T2, [MustBeVariant] T3>(GodotObject obj, StringName signalName, CancellationToken cancellationToken) : GodotSignalMapperBase<(T0, T1, T2, T3)>(obj, signalName, cancellationToken)
+{
+    protected override Callable OnNextAsGodotCallable() => Callable.From((Action<T0, T1, T2, T3>) OnNextWithArgs);
+    private void OnNextWithArgs(T0 _0, T1 _1, T2 _2, T3 _3) => subject.OnNext((_0, _1, _2, _3));
+}
+
+internal class GodotSignalMapper<[MustBeVariant] T0, [MustBeVariant] T1, [MustBeVariant] T2, [MustBeVariant] T3, [MustBeVariant] T4>(GodotObject obj, StringName signalName, CancellationToken cancellationToken) : GodotSignalMapperBase<(T0, T1, T2, T3, T4)>(obj, signalName, cancellationToken)
+{
+    protected override Callable OnNextAsGodotCallable() => Callable.From((Action<T0, T1, T2, T3, T4>) OnNextWithArgs);
+    private void OnNextWithArgs(T0 _0, T1 _1, T2 _2, T3 _3, T4 _4) => subject.OnNext((_0, _1, _2, _3, _4));
+}
+
+internal class GodotSignalMapper<[MustBeVariant] T0, [MustBeVariant] T1, [MustBeVariant] T2, [MustBeVariant] T3, [MustBeVariant] T4, [MustBeVariant] T5>(GodotObject obj, StringName signalName, CancellationToken cancellationToken) : GodotSignalMapperBase<(T0, T1, T2, T3, T4, T5)>(obj, signalName, cancellationToken)
+{
+    protected override Callable OnNextAsGodotCallable() => Callable.From((Action<T0, T1, T2, T3, T4, T5>) OnNextWithArgs);
+    private void OnNextWithArgs(T0 _0, T1 _1, T2 _2, T3 _3, T4 _4, T5 _5) => subject.OnNext((_0, _1, _2, _3, _4, _5));
+}
+
+internal class GodotSignalMapper<[MustBeVariant] T0, [MustBeVariant] T1, [MustBeVariant] T2, [MustBeVariant] T3, [MustBeVariant] T4, [MustBeVariant] T5, [MustBeVariant] T6>(GodotObject obj, StringName signalName, CancellationToken cancellationToken) : GodotSignalMapperBase<(T0, T1, T2, T3, T4, T5, T6)>(obj, signalName, cancellationToken)
+{
+    protected override Callable OnNextAsGodotCallable() => Callable.From((Action<T0, T1, T2, T3, T4, T5, T6>) OnNextWithArgs);
+    private void OnNextWithArgs(T0 _0, T1 _1, T2 _2, T3 _3, T4 _4, T5 _5, T6 _6) => subject.OnNext((_0, _1, _2, _3, _4, _5, _6));
+}
+
+internal class GodotSignalMapper<[MustBeVariant] T0, [MustBeVariant] T1, [MustBeVariant] T2, [MustBeVariant] T3, [MustBeVariant] T4, [MustBeVariant] T5, [MustBeVariant] T6, [MustBeVariant] T7>(GodotObject obj, StringName signalName, CancellationToken cancellationToken) : GodotSignalMapperBase<(T0, T1, T2, T3, T4, T5, T6, T7)>(obj, signalName, cancellationToken)
+{
+    protected override Callable OnNextAsGodotCallable() => Callable.From((Action<T0, T1, T2, T3, T4, T5, T6, T7>) OnNextWithArgs);
+    private void OnNextWithArgs(T0 _0, T1 _1, T2 _2, T3 _3, T4 _4, T5 _5, T6 _6, T7 _7) => subject.OnNext((_0, _1, _2, _3, _4, _5, _6, _7));
+}
+
+internal class GodotSignalMapper<[MustBeVariant] T0, [MustBeVariant] T1, [MustBeVariant] T2, [MustBeVariant] T3, [MustBeVariant] T4, [MustBeVariant] T5, [MustBeVariant] T6, [MustBeVariant] T7, [MustBeVariant] T8>(GodotObject obj, StringName signalName, CancellationToken cancellationToken) : GodotSignalMapperBase<(T0, T1, T2, T3, T4, T5, T6, T7, T8)>(obj, signalName, cancellationToken)
+{
+    protected override Callable OnNextAsGodotCallable() => Callable.From((Action<T0, T1, T2, T3, T4, T5, T6, T7, T8>) OnNextWithArgs);
+    private void OnNextWithArgs(T0 _0, T1 _1, T2 _2, T3 _3, T4 _4, T5 _5, T6 _6, T7 _7, T8 _8) => subject.OnNext((_0, _1, _2, _3, _4, _5, _6, _7, _8));
+}
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/GodotSignalMapper.cs.uid b/src/SharpIDE.Godot/addons/R3.Godot/GodotSignalMapper.cs.uid
new file mode 100644
index 0000000..f616157
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/GodotSignalMapper.cs.uid
@@ -0,0 +1 @@
+uid://cwsypls11xo1t
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/GodotTimeProvider.cs b/src/SharpIDE.Godot/addons/R3.Godot/GodotTimeProvider.cs
new file mode 100644
index 0000000..3ef44a8
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/GodotTimeProvider.cs
@@ -0,0 +1,196 @@
+#nullable enable
+
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace R3;
+
+public class GodotTimeProvider : TimeProvider
+{
+    public static readonly GodotTimeProvider Process = new GodotTimeProvider(GodotFrameProvider.Process);
+    public static readonly GodotTimeProvider PhysicsProcess = new GodotTimeProvider(GodotFrameProvider.PhysicsProcess);
+
+    readonly GodotFrameProvider frameProvider;
+
+    internal double time;
+
+    GodotTimeProvider(FrameProvider frameProvider)
+    {
+        this.frameProvider = (GodotFrameProvider)frameProvider;
+    }
+
+    public override ITimer CreateTimer(TimerCallback callback, object? state, TimeSpan dueTime, TimeSpan period)
+    {
+        return new FrameTimer(callback, state, dueTime, period, frameProvider);
+    }
+
+    public override long GetTimestamp()
+    {
+        return TimeSpan.FromSeconds(time).Ticks;
+    }
+}
+
+internal sealed class FrameTimer : ITimer, IFrameRunnerWorkItem
+{
+    enum RunningState
+    {
+        Stop,
+        RunningDueTime,
+        RunningPeriod,
+        ChangeRequested
+    }
+
+    readonly TimerCallback callback;
+    readonly object? state;
+    readonly GodotFrameProvider frameProvider;
+    readonly object gate = new object();
+
+    TimeSpan dueTime;
+    TimeSpan period;
+    RunningState runningState;
+    double elapsed;
+    bool isDisposed;
+
+    public FrameTimer(TimerCallback callback, object? state, TimeSpan dueTime, TimeSpan period, GodotFrameProvider frameProvider)
+    {
+        this.callback = callback;
+        this.state = state;
+        this.dueTime = dueTime;
+        this.period = period;
+        this.frameProvider = frameProvider;
+        Change(dueTime, period);
+    }
+
+    public bool Change(TimeSpan dueTime, TimeSpan period)
+    {
+        if (isDisposed) return false;
+
+        lock (gate)
+        {
+            this.dueTime = dueTime;
+            this.period = period;
+
+            if (dueTime == Timeout.InfiniteTimeSpan)
+            {
+                if (runningState == RunningState.Stop)
+                {
+                    return true;
+                }
+            }
+
+            if (runningState == RunningState.Stop)
+            {
+                frameProvider.Register(this);
+            }
+
+            runningState = RunningState.ChangeRequested;
+        }
+        return true;
+    }
+
+    bool IFrameRunnerWorkItem.MoveNext(long frameCount)
+    {
+        if (isDisposed) return false;
+
+        RunningState runState;
+        TimeSpan p; // period
+        TimeSpan d; // dueTime
+        lock (gate)
+        {
+            runState = runningState;
+
+            if (runState == RunningState.ChangeRequested)
+            {
+                elapsed = 0;
+                if (dueTime == Timeout.InfiniteTimeSpan)
+                {
+                    runningState = RunningState.Stop;
+                    return false;
+                }
+
+                runState = runningState = RunningState.RunningDueTime;
+            }
+            p = period;
+            d = dueTime;
+        }
+
+        elapsed += frameProvider.Delta.Value;
+
+        try
+        {
+            if (runState == RunningState.RunningDueTime)
+            {
+                var dt = (double)d.TotalSeconds;
+                if (elapsed >= dt)
+                {
+                    callback(state);
+
+                    elapsed = 0;
+                    if (period == Timeout.InfiniteTimeSpan)
+                    {
+                        return ChangeState(RunningState.Stop);
+                    }
+                    else
+                    {
+                        return ChangeState(RunningState.RunningPeriod);
+                    }
+                }
+                else
+                {
+                    return true;
+                }
+            }
+            else
+            {
+                var dt = (double)p.TotalSeconds;
+                if (elapsed >= dt)
+                {
+                    callback(state);
+                    elapsed = 0;
+                }
+
+                return ChangeState(RunningState.RunningPeriod);
+            }
+        }
+        catch (Exception ex)
+        {
+            ObservableSystem.GetUnhandledExceptionHandler().Invoke(ex);
+            return ChangeState(RunningState.Stop);
+        }
+    }
+
+    bool ChangeState(RunningState state)
+    {
+        lock (gate)
+        {
+            // change requested is high priority
+            if (runningState == RunningState.ChangeRequested)
+            {
+                return true;
+            }
+
+            switch (state)
+            {
+                case RunningState.RunningPeriod:
+                    runningState = state;
+                    return true;
+                default: // otherwise(Stop)
+                    runningState = state;
+                    return false;
+            }
+        }
+    }
+
+    public void Dispose()
+    {
+        Change(Timeout.InfiniteTimeSpan, Timeout.InfiniteTimeSpan);
+        isDisposed = true;
+    }
+
+    public ValueTask DisposeAsync()
+    {
+        Dispose();
+        return default;
+    }
+}
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/GodotTimeProvider.cs.uid b/src/SharpIDE.Godot/addons/R3.Godot/GodotTimeProvider.cs.uid
new file mode 100644
index 0000000..d5e52e0
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/GodotTimeProvider.cs.uid
@@ -0,0 +1 @@
+uid://dvccr1jhyokui
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/GodotUINodeExtensions.cs b/src/SharpIDE.Godot/addons/R3.Godot/GodotUINodeExtensions.cs
new file mode 100644
index 0000000..ee177fa
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/GodotUINodeExtensions.cs
@@ -0,0 +1,82 @@
+using System;
+using System.Threading;
+using Godot;
+
+namespace R3;
+
+public static class GodotUINodeExtensions
+{
+    public static IDisposable SubscribeToLabel(this Observable<string> source, Label label)
+    {
+        return source.Subscribe(label, static (x, l) => l.Text = x);
+    }
+
+    public static IDisposable SubscribeToLabel<T>(this Observable<T> source, Label label)
+    {
+        return source.Subscribe(label, static (x, l) => l.Text = x?.ToString());
+    }
+
+    public static IDisposable SubscribeToLabel<T>(this Observable<T> source, Label label, Func<T, string> selector)
+    {
+        return source.Subscribe((label, selector), static (x, state) => state.label.Text = state.selector(x));
+    }
+
+    /// <summary>Observe Pressed event.</summary>
+    public static Observable<Unit> OnPressedAsObservable(this BaseButton button, CancellationToken cancellationToken = default)
+    {
+        return Observable.FromEvent(h => button.Pressed += h, h => button.Pressed -= h, cancellationToken);
+    }
+
+    /// <summary>Observe Toggled with current `ButtonPressed` value on subscribe.</summary>
+    public static Observable<bool> OnToggledAsObservable(this BaseButton button, CancellationToken cancellationToken = default)
+    {
+        if (!button.ToggleMode) return Observable.Empty<bool>();
+
+        return Observable.Create<bool, (BaseButton, CancellationToken)>((button, cancellationToken), static (observer, state) =>
+        {
+            var (b, cancellationToken) = state;
+            observer.OnNext(b.ButtonPressed);
+            return Observable.FromEvent<BaseButton.ToggledEventHandler, bool>(h => new BaseButton.ToggledEventHandler(h), h => b.Toggled += h, h => b.Toggled -= h, cancellationToken).Subscribe(observer);
+        });
+    }
+
+    /// <summary>Observe ValueChanged with current `Value` on subscribe.</summary>
+    public static Observable<double> OnValueChangedAsObservable(this Godot.Range range, CancellationToken cancellationToken = default)
+    {
+        return Observable.Create<double, (Godot.Range, CancellationToken)>((range, cancellationToken), static (observer, state) =>
+        {
+            var (s, cancellationToken) = state;
+            observer.OnNext(s.Value);
+            return Observable.FromEvent<Godot.Range.ValueChangedEventHandler, double>(h => new Godot.Range.ValueChangedEventHandler(h), h => s.ValueChanged += h, h => s.ValueChanged -= h, cancellationToken).Subscribe(observer);
+        });
+    }
+
+    /// <summary>Observe TextSubmitted event.</summary>
+    public static Observable<string> OnTextSubmittedAsObservable(this LineEdit lineEdit, CancellationToken cancellationToken = default)
+    {
+        return Observable.FromEvent<LineEdit.TextSubmittedEventHandler, string>(h => new LineEdit.TextSubmittedEventHandler(h), h => lineEdit.TextSubmitted += h, h => lineEdit.TextSubmitted -= h, cancellationToken);
+    }
+
+    /// <summary>Observe TextChanged event.</summary>
+    public static Observable<string> OnTextChangedAsObservable(this LineEdit lineEdit, CancellationToken cancellationToken = default)
+    {
+        return Observable.FromEvent<LineEdit.TextChangedEventHandler, string>(h => new LineEdit.TextChangedEventHandler(h), h => lineEdit.TextChanged += h, h => lineEdit.TextChanged -= h, cancellationToken);
+    }
+
+    /// <summary>Observe TextChanged event.</summary>
+    public static Observable<Unit> OnTextChangedAsObservable(this TextEdit textEdit, CancellationToken cancellationToken = default)
+    {
+        return Observable.FromEvent(h => textEdit.TextChanged += h, h => textEdit.TextChanged -= h, cancellationToken);
+    }
+
+    /// <summary>Observe ItemSelected with current `Selected` on subscribe.</summary>
+    public static Observable<long> OnItemSelectedAsObservable(this OptionButton optionButton, CancellationToken cancellationToken = default)
+    {
+        return Observable.Create<long, (OptionButton, CancellationToken)>((optionButton, cancellationToken), static (observer, state) =>
+        {
+            var (b, cancellationToken) = state;
+            observer.OnNext(b.Selected);
+            return Observable.FromEvent<OptionButton.ItemSelectedEventHandler, long>(h => new OptionButton.ItemSelectedEventHandler(h), h => b.ItemSelected += h, h => b.ItemSelected -= h, cancellationToken).Subscribe(observer);
+        });
+    }
+}
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/GodotUINodeExtensions.cs.uid b/src/SharpIDE.Godot/addons/R3.Godot/GodotUINodeExtensions.cs.uid
new file mode 100644
index 0000000..169f320
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/GodotUINodeExtensions.cs.uid
@@ -0,0 +1 @@
+uid://syarh3o2acgh
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerDebuggerPlugin.cs b/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerDebuggerPlugin.cs
new file mode 100644
index 0000000..33bc441
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerDebuggerPlugin.cs
@@ -0,0 +1,150 @@
+#if TOOLS
+#nullable enable
+
+using Godot;
+using System;
+using System.Collections.Generic;
+using GDArray = Godot.Collections.Array;
+
+namespace R3;
+
+// ObservableTrackerDebuggerPlugin creates the Observable Tracker tab in the debugger, and communicates with ObservableTrackerRuntimeHook via EditorDebuggerSessions.
+[Tool]
+public partial class ObservableTrackerDebuggerPlugin : EditorDebuggerPlugin
+{
+    // Shared header used in IPC by ObservableTracker classes.
+    public const string MessageHeader = "ObservableTracker";
+
+    // Implemented by ObservableTrackerRuntimeHook.
+    public const string Message_RequestActiveTasks = "RequestActiveTasks";
+    public const string Message_SetEnableStates = "SetEnableStates";
+    public const string Message_InvokeGCCollect = "InvokeGCCollect";
+
+    // Implemented by ObservableTrackerDebuggerPlugin.
+    public const string Message_ReceiveActiveTasks = "ReceiveActiveTasks";
+
+    // A TrackerSession isolates each debugger session's states.
+    // There's no way to know if a session has been disposed for good, so we will never remove anything from this dictionary.
+    // This is similar to how it is handled in the Godot core (see: https://github.com/godotengine/godot/blob/master/modules/multiplayer/editor/multiplayer_editor_plugin.cpp)
+    readonly Dictionary<int, TrackerSession> sessions = new();
+
+    private class TrackerSession
+    {
+        public readonly EditorDebuggerSession debuggerSession;
+        public readonly List<TrackingState> states = new();
+        public event Action<IEnumerable<TrackingState>>? ReceivedActiveTasks;
+
+        public TrackerSession(EditorDebuggerSession debuggerSession)
+        {
+            this.debuggerSession = debuggerSession;
+        }
+
+        public void InvokeReceivedActiveTasks()
+        {
+            ReceivedActiveTasks?.Invoke(states);
+        }
+    }
+
+    public override void _SetupSession(int sessionId)
+    {
+        var currentSession = GetSession(sessionId);
+        sessions[sessionId] = new TrackerSession(currentSession);
+
+        // NotifyOnSessionSetup gives the tab a reference to the debugger plugin, as well as the sessionId which is needed for messages.
+		var tab = new ObservableTrackerTab();
+        tab.NotifyOnSessionSetup(this, sessionId);
+        currentSession.AddSessionTab(tab);
+
+        // As sessions don't seem to be ever disposed, we don't need to unregister these callbacks either.
+        currentSession.Started += () =>
+        {
+            if (IsInstanceValid(tab))
+            {
+                tab.SetProcess(true);
+                // Important! We need to tell the tab the session has started, so it can initialize the enabled states of the runtime ObservableTracker.
+                tab.NotifyOnSessionStart();
+            }
+        };
+        currentSession.Stopped += () =>
+        {
+            if (IsInstanceValid(tab))
+            {
+                tab.SetProcess(false);
+            }
+        };
+    }
+
+    public override bool _HasCapture(string capture)
+    {
+        return capture == MessageHeader;
+    }
+
+    public override bool _Capture(string message, GDArray data, int sessionId)
+    {
+        // When EditorDebuggerPlugin._Capture receives messages, the header isn't trimmed (unlike how it is in EngineDebugger),
+        // so we need to trim it here.
+        string messageWithoutHeader = message.Substring(message.IndexOf(':') + 1);
+        //GD.Print(nameof(ObservableTrackerDebuggerPlugin) + " received " + messageWithoutHeader);
+        switch(messageWithoutHeader)
+        {
+            case Message_ReceiveActiveTasks:
+                // Only invoke event if updated.
+                if (data[0].AsBool())
+                {
+                    var session = sessions[sessionId];
+                    session.states.Clear();
+                    foreach (GDArray item in data[1].AsGodotArray())
+                    {
+                        var state = new TrackingState()
+                        {
+                            TrackingId = item[0].AsInt32(),
+                            FormattedType = item[1].AsString(),
+                            AddTime = new DateTime(item[2].AsInt64()),
+                            StackTrace = item[3].AsString(),
+                        };;
+                        session.states.Add(state);
+                    }
+                    session.InvokeReceivedActiveTasks();
+                }
+                return true;
+        }
+        return base._Capture(message, data, sessionId);
+    }
+
+    public void RegisterReceivedActiveTasks(int sessionId, Action<IEnumerable<TrackingState>> action)
+    {
+        if (sessions.Count > 0)
+            sessions[sessionId].ReceivedActiveTasks += action;
+    }
+
+    public void UnregisterReceivedActiveTasks(int sessionId, Action<IEnumerable<TrackingState>> action)
+    {
+        if (sessions.Count > 0)
+            sessions[sessionId].ReceivedActiveTasks -= action;
+    }
+
+    public void UpdateTrackingStates(int sessionId, bool forceUpdate = false)
+    {
+        if (sessions.Count > 0 && sessions[sessionId].debuggerSession.IsActive())
+        {
+            sessions[sessionId].debuggerSession.SendMessage(MessageHeader + ":" + Message_RequestActiveTasks, new () { forceUpdate });
+        }
+    }
+
+    public void SetEnableStates(int sessionId, bool enableTracking, bool enableStackTrace)
+    {
+        if (sessions.Count > 0 && sessions[sessionId].debuggerSession.IsActive())
+        {
+            sessions[sessionId].debuggerSession.SendMessage(MessageHeader + ":" + Message_SetEnableStates, new () { enableTracking, enableStackTrace});
+        }
+    }
+
+    public void InvokeGCCollect(int sessionId)
+    {
+        if (sessions.Count > 0 && sessions[sessionId].debuggerSession.IsActive())
+        {
+            sessions[sessionId].debuggerSession.SendMessage(MessageHeader + ":" + Message_InvokeGCCollect);
+        }
+    }
+}
+#endif
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerDebuggerPlugin.cs.uid b/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerDebuggerPlugin.cs.uid
new file mode 100644
index 0000000..c89b4e4
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerDebuggerPlugin.cs.uid
@@ -0,0 +1 @@
+uid://bhe85bu3rgxja
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerRuntimeHook.cs b/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerRuntimeHook.cs
new file mode 100644
index 0000000..446a7fd
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerRuntimeHook.cs
@@ -0,0 +1,58 @@
+
+#nullable enable
+
+using Godot;
+using System;
+using GDArray = Godot.Collections.Array;
+
+namespace R3;
+
+// Sends runtime ObservableTracker information to ObservableTrackerDebuggerPlugin.
+// Needs to be an Autoload. Should not be instantiated manually.
+public partial class ObservableTrackerRuntimeHook : Node
+{
+    public override void _Ready()
+    {
+#if TOOLS
+        EngineDebugger.RegisterMessageCapture(ObservableTrackerDebuggerPlugin.MessageHeader, Callable.From((string message, GDArray data) =>
+        { 
+            //GD.Print(nameof(ObservableTrackerRuntimeHook) + " received " + message);
+            switch (message)
+            {
+                case ObservableTrackerDebuggerPlugin.Message_RequestActiveTasks:
+                    // data[0]: If true, force an update anyway.
+                    if (ObservableTracker.CheckAndResetDirty() || data[0].AsBool())
+                    {
+                        GDArray states = new();
+                        ObservableTracker.ForEachActiveTask(state =>
+                        {
+                            // DateTime is not a Variant type, so we serialize it using Ticks instead.
+                            states.Add(new GDArray { state.TrackingId, state.FormattedType, state.AddTime.Ticks, state.StackTrace });
+                        });
+                        EngineDebugger.SendMessage(ObservableTrackerDebuggerPlugin.MessageHeader + ":" + ObservableTrackerDebuggerPlugin.Message_ReceiveActiveTasks, new () { true, states });
+                    }
+                    else
+                    {
+                        EngineDebugger.SendMessage(ObservableTrackerDebuggerPlugin.MessageHeader + ":" + ObservableTrackerDebuggerPlugin.Message_ReceiveActiveTasks, new () { false, });
+                    }
+                    break;
+                case ObservableTrackerDebuggerPlugin.Message_SetEnableStates:
+                    ObservableTracker.EnableTracking = data[0].AsBool();
+                    ObservableTracker.EnableStackTrace = data[1].AsBool();
+                    break;
+                case ObservableTrackerDebuggerPlugin.Message_InvokeGCCollect:
+                    GC.Collect(0);
+                    break;
+            }
+            return true;
+        }));
+#endif
+    }
+
+    public override void _ExitTree()
+    {
+#if TOOLS
+        EngineDebugger.UnregisterMessageCapture(ObservableTrackerDebuggerPlugin.MessageHeader);
+#endif
+    }
+}
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerRuntimeHook.cs.uid b/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerRuntimeHook.cs.uid
new file mode 100644
index 0000000..3e37185
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerRuntimeHook.cs.uid
@@ -0,0 +1 @@
+uid://dwd2efc46qc0v
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerTab.cs b/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerTab.cs
new file mode 100644
index 0000000..a52ee32
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerTab.cs
@@ -0,0 +1,146 @@
+#if TOOLS
+#nullable enable
+
+using Godot;
+using System;
+
+namespace R3;
+
+[Tool]
+public partial class ObservableTrackerTab : VBoxContainer
+{
+    public const string EnableAutoReloadKey = "ObservableTracker_EnableAutoReloadKey";
+    public const string EnableTrackingKey = "ObservableTracker_EnableTrackingKey";
+    public const string EnableStackTraceKey = "ObservableTracker_EnableStackTraceKey";
+    bool enableAutoReload, enableTracking, enableStackTrace;
+    ObservableTrackerTree? tree;
+    ObservableTrackerDebuggerPlugin? debuggerPlugin;
+    int interval = 0;
+    int sessionId = 0;
+
+    public void NotifyOnSessionSetup(ObservableTrackerDebuggerPlugin debuggerPlugin, int sessionId)
+    {
+        this.debuggerPlugin = debuggerPlugin;
+        this.sessionId = sessionId;
+        tree ??= new ObservableTrackerTree();
+        tree.NotifyOnSessionSetup(debuggerPlugin!, sessionId);
+    }
+
+    public void NotifyOnSessionStart()
+    {
+        debuggerPlugin!.SetEnableStates(sessionId, enableTracking, enableStackTrace);
+    }
+
+    public override void _Ready()
+    {
+        Name = "Observable Tracker";
+
+        tree ??= new ObservableTrackerTree();
+        
+        // Head panel
+        var headPanelLayout = new HBoxContainer();
+        headPanelLayout.SetAnchor(Side.Left, 0);
+        headPanelLayout.SetAnchor(Side.Right, 0);
+        AddChild(headPanelLayout);
+
+        // Toggle buttons (top left)
+        var enableAutoReloadToggle = new CheckButton
+        {
+            Text = "Enable AutoReload",
+            TooltipText = "Reload automatically."
+        };
+        var enableTrackingToggle = new CheckButton
+        {
+            Text = "Enable Tracking",
+            TooltipText = "Start to track Observable subscription. Performance impact: low"
+        };
+        var enableStackTraceToggle = new CheckButton
+        {
+            Text = "Enable StackTrace",
+            TooltipText = "Capture StackTrace when subscribed. Performance impact: high"
+        };
+
+        // For every button: Initialize pressed state and subscribe to Toggled event.
+        EditorSettings settings = EditorInterface.Singleton.GetEditorSettings();
+        enableAutoReloadToggle.ButtonPressed = enableAutoReload = GetSettingOrDefault(settings, EnableAutoReloadKey, false).AsBool();
+        enableAutoReloadToggle.Toggled += toggledOn =>
+        {
+            settings.SetSetting(EnableAutoReloadKey, toggledOn);
+            enableAutoReload = toggledOn;
+        };
+        enableTrackingToggle.ButtonPressed = enableTracking = GetSettingOrDefault(settings, EnableTrackingKey, false).AsBool();
+        enableTrackingToggle.Toggled += toggledOn =>
+        {
+            settings.SetSetting(EnableTrackingKey, toggledOn);
+            enableTracking = toggledOn;
+            debuggerPlugin!.SetEnableStates(sessionId, enableTracking, enableStackTrace);
+        };
+        enableStackTraceToggle.ButtonPressed = enableStackTrace = GetSettingOrDefault(settings, EnableStackTraceKey, false).AsBool();
+        enableStackTraceToggle.Toggled += toggledOn =>
+        {
+            settings.SetSetting(EnableStackTraceKey, toggledOn);
+            enableStackTrace = toggledOn;
+            debuggerPlugin!.SetEnableStates(sessionId, enableTracking, enableStackTrace);
+        };
+
+        // Regular buttons (top right)
+        var reloadButton = new Button
+        {
+            Text = "Reload",
+            TooltipText = "Reload View."
+        };
+        var GCButton = new Button
+        {
+            Text = "GC.Collect",
+            TooltipText = "Invoke GC.Collect."
+        };
+
+        reloadButton.Pressed += () =>
+        {
+            debuggerPlugin!.UpdateTrackingStates(sessionId, true);
+        };
+        GCButton.Pressed += () =>
+        {
+            debuggerPlugin!.InvokeGCCollect(sessionId);
+        };
+
+        // Button layout.
+        headPanelLayout.AddChild(enableAutoReloadToggle);
+        headPanelLayout.AddChild(enableTrackingToggle);
+        headPanelLayout.AddChild(enableStackTraceToggle);
+        // Kind of like Unity's FlexibleSpace. Pushes the first three buttons to the left, and the remaining buttons to the right.
+        headPanelLayout.AddChild(new Control()
+        {
+            SizeFlagsHorizontal = SizeFlags.Expand,
+        });
+        headPanelLayout.AddChild(reloadButton);
+        headPanelLayout.AddChild(GCButton);
+
+        // Tree goes last.
+        AddChild(tree);
+    }
+
+    public override void _Process(double delta)
+    {
+        if (enableAutoReload)
+        {
+            if (interval++ % 120 == 0)
+            {
+                debuggerPlugin!.UpdateTrackingStates(sessionId);
+            }
+        }
+    }
+
+    static Variant GetSettingOrDefault(EditorSettings settings, string key, Variant @default)
+    {
+        if (settings.HasSetting(key))
+        {
+            return settings.GetSetting(key);
+        }
+        else
+        {
+            return @default;
+        }
+    }
+}
+#endif
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerTab.cs.uid b/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerTab.cs.uid
new file mode 100644
index 0000000..5d46916
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerTab.cs.uid
@@ -0,0 +1 @@
+uid://c2u5u8xkqvh1c
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerTree.cs b/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerTree.cs
new file mode 100644
index 0000000..b356d0e
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerTree.cs
@@ -0,0 +1,67 @@
+#if TOOLS
+#nullable enable
+
+using Godot;
+using System;
+using System.Collections;
+using System.Collections.Generic;
+
+namespace R3;
+
+[Tool]
+public partial class ObservableTrackerTree : Tree
+{
+    ObservableTrackerDebuggerPlugin? debuggerPlugin;
+    int sessionId;
+    public void NotifyOnSessionSetup(ObservableTrackerDebuggerPlugin debuggerPlugin, int sessionId)
+    {
+        this.debuggerPlugin = debuggerPlugin;
+        this.sessionId = sessionId;
+        debuggerPlugin!.RegisterReceivedActiveTasks(sessionId, Reload);
+        Clear();
+    }
+
+    public override void _Ready()
+    {
+        AllowReselect = false;
+        Columns = 3;
+        ColumnTitlesVisible = true;
+        SetColumnTitle(0, "Type");
+        SetColumnTitle(1, "Elapsed");
+        SetColumnTitle(2, "StackTrace");
+        SetColumnExpand(0, true);
+        SetColumnExpand(1, true);
+        SetColumnExpand(2, true);
+        SetColumnExpandRatio(0, 3);
+        SetColumnExpandRatio(1, 1);
+        SetColumnExpandRatio(2, 6);
+        SetColumnClipContent(0, true);
+        SetColumnClipContent(1, true);
+        SetColumnClipContent(2, true);
+        HideRoot = true;
+        SizeFlagsVertical = SizeFlags.ExpandFill;
+    }
+
+    public override void _ExitTree()
+    {
+        debuggerPlugin!.UnregisterReceivedActiveTasks(sessionId, Reload);
+    }
+
+    public void Reload(IEnumerable<TrackingState> states)
+    {
+        Clear();
+        TreeItem root = CreateItem();
+        foreach(TrackingState state in states)
+        {
+            TreeItem row = CreateItem(root);
+            var now = DateTime.Now;
+            // Type
+            row.SetText(0, state.FormattedType);
+            // Elapsed
+            row.SetText(1, (now - state.AddTime).TotalSeconds.ToString("00.00"));
+            // StackTrace
+            row.SetText(2, state.StackTrace);
+        };
+    }
+}
+#endif
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerTree.cs.uid b/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerTree.cs.uid
new file mode 100644
index 0000000..a75cce3
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/ObservableTrackerTree.cs.uid
@@ -0,0 +1 @@
+uid://crct8t2w3hcce
diff --git a/src/SharpIDE.Godot/addons/R3.Godot/plugin.cfg b/src/SharpIDE.Godot/addons/R3.Godot/plugin.cfg
new file mode 100644
index 0000000..c6e5b66
--- /dev/null
+++ b/src/SharpIDE.Godot/addons/R3.Godot/plugin.cfg
@@ -0,0 +1,8 @@
+[plugin]
+
+name="R3.Godot"
+description="The new future of dotnet/reactive and UniRx."
+author="Cysharp"
+version="1.3.0"
+language="C-sharp"
+script="GodotR3Plugin.cs"
diff --git a/src/SharpIDE.Godot/project.godot b/src/SharpIDE.Godot/project.godot
index d6310fb..c1709e8 100644
--- a/src/SharpIDE.Godot/project.godot
+++ b/src/SharpIDE.Godot/project.godot
@@ -17,6 +17,11 @@ run/max_fps=157
 run/low_processor_mode=true
 config/icon="res://icon.svg"
 
+[autoload]
+
+FrameProviderDispatcher="*res://addons/R3.Godot/FrameProviderDispatcher.cs"
+ObservableTrackerRuntimeHook="*res://addons/R3.Godot/ObservableTrackerRuntimeHook.cs"
+
 [display]
 
 window/energy_saving/keep_screen_on=false
@@ -25,6 +30,10 @@ window/energy_saving/keep_screen_on=false
 
 project/assembly_name="SharpIDE.Godot"
 
+[editor_plugins]
+
+enabled=PackedStringArray("res://addons/R3.Godot/plugin.cfg", "res://addons/csharp_gdextension_bindgen/plugin.cfg")
+
 [input]
 
 CodeFixes={