From d60d6a65a6972b9778398ac8a2ac18e6356cb384 Mon Sep 17 00:00:00 2001
From: Justin Swanson <justin.c.swanson@gmail.com>
Date: Sun, 13 Oct 2019 03:03:41 -0500
Subject: [PATCH] Removed unnecessary command subject

The bug was that the way commands were defined, a new instance was made every property access.  Swapped to readonly gets so it's a single instance.
---
 Wabbajack/AppState.cs                 | 23 +++++++++++++----------
 Wabbajack/Extensions/ReactiveUIExt.cs |  8 ++++++++
 2 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/Wabbajack/AppState.cs b/Wabbajack/AppState.cs
index 85e2d20e..dd0f5455 100644
--- a/Wabbajack/AppState.cs
+++ b/Wabbajack/AppState.cs
@@ -74,17 +74,14 @@ namespace Wabbajack
         public bool Installing { get => _Installing; set => this.RaiseAndSetIfChanged(ref _Installing, value); }
 
         // Command properties
-        public IReactiveCommand ChangePathCommand => ReactiveCommand.Create(ExecuteChangePath);
-        public IReactiveCommand ChangeDownloadPathCommand => ReactiveCommand.Create(ExecuteChangeDownloadPath);
+        public IReactiveCommand ChangePathCommand { get; }
+        public IReactiveCommand ChangeDownloadPathCommand { get; }
         public IReactiveCommand BeginCommand { get; }
-        public IReactiveCommand ShowReportCommand => ReactiveCommand.Create(ShowReport);
-        public IReactiveCommand VisitNexusSiteCommand => ReactiveCommand.Create(VisitNexusSite);
+        public IReactiveCommand ShowReportCommand { get; }
+        public IReactiveCommand VisitNexusSiteCommand { get; }
         public IReactiveCommand OpenReadmeCommand { get; }
-        public IReactiveCommand OpenModListPropertiesCommand => ReactiveCommand.Create(OpenModListProperties);
-        // ToDo
-        // This subject is not desirable.  Need to research why command's IsExecuting observable not firing, as we'd prefer to hook onto that instead
-        private Subject<Unit> _slideshowCommandTriggeredSubject = new Subject<Unit>();
-        public ReactiveCommand<Unit, Unit> SlideShowNextItemCommand => ReactiveCommand.Create(() => _slideshowCommandTriggeredSubject.OnNext(Unit.Default));
+        public IReactiveCommand OpenModListPropertiesCommand { get; }
+        public IReactiveCommand SlideShowNextItemCommand { get; } = ReactiveCommand.Create(() => { });
 
         public AppState(TaskMode mode)
         {
@@ -101,6 +98,12 @@ namespace Wabbajack
 
             Mode = mode;
 
+            // Define commands
+            this.ChangePathCommand = ReactiveCommand.Create(ExecuteChangePath);
+            this.ChangeDownloadPathCommand = ReactiveCommand.Create(ExecuteChangeDownloadPath);
+            this.ShowReportCommand = ReactiveCommand.Create(ShowReport);
+            this.VisitNexusSiteCommand = ReactiveCommand.Create(VisitNexusSite);
+            this.OpenModListPropertiesCommand = ReactiveCommand.Create(OpenModListProperties);
             this.OpenReadmeCommand = ReactiveCommand.Create(
                 execute: this.OpenReadmeWindow,
                 canExecute: this.WhenAny(x => x.ModList)
@@ -179,7 +182,7 @@ namespace Wabbajack
                     // If the natural timer fires
                     Observable.Interval(TimeSpan.FromSeconds(10)).Unit(),
                     // If user requests one manually
-                    _slideshowCommandTriggeredSubject)
+                    this.SlideShowNextItemCommand.StartingExecution())
                 // When enabled, fire an initial signal
                 .StartWith(Unit.Default)
                 // Only subscribe to slideshow triggers if enabled and installing
diff --git a/Wabbajack/Extensions/ReactiveUIExt.cs b/Wabbajack/Extensions/ReactiveUIExt.cs
index a86a9827..0f1bda7a 100644
--- a/Wabbajack/Extensions/ReactiveUIExt.cs
+++ b/Wabbajack/Extensions/ReactiveUIExt.cs
@@ -84,6 +84,14 @@ namespace Wabbajack
                 .Switch();
         }
 
+        public static IObservable<Unit> StartingExecution(this IReactiveCommand cmd)
+        {
+            return cmd.IsExecuting
+                .DistinctUntilChanged()
+                .Where(x => x)
+                .Unit();
+        }
+
         /// These snippets were provided by RolandPheasant (author of DynamicData)
         /// They'll be going into the official library at some point, but are here for now.
         #region Dynamic Data EnsureUniqueChanges