Style + clean up some of the Disposable usage

Author: anaisbetts

ReactiveUI.Blend/ObservableTriggerBehavior.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Reactive.Disposables;
 using System.Reactive.Linq;
 using System.Text;
 using System.Threading.Tasks;
@@ -13,54 +14,65 @@ namespace ReactiveUI.Blend
     [ContentProperty(Name = "Actions")]
     public sealed class ObservableTriggerBehavior : Behavior<DependencyObject>
     {
-        private object resolvedSource;
+        object resolvedSource;
+        SerialDisposable watcher;
+
+        public ObservableTriggerBehavior()
+        {
+            watcher = new SerialDisposable();
+            watcher.Disposable = Disposable.Empty;
+        }
 
         public ActionCollection Actions
         {
             get {
-                ActionCollection actionCollection = (ActionCollection) this.GetValue(ObservableTriggerBehavior.ActionsProperty);
+                var actionCollection = (ActionCollection) this.GetValue(ObservableTriggerBehavior.ActionsProperty);
+
                 if (actionCollection == null) {
                     actionCollection = new ActionCollection();
                     this.SetValue(ObservableTriggerBehavior.ActionsProperty, actionCollection);
                 }
+
                 return actionCollection;
             }
         }
+
         public static readonly DependencyProperty ActionsProperty =
             DependencyProperty.Register("Actions", typeof(ActionCollection), typeof(ObservableTriggerBehavior), new PropertyMetadata(null));
 
-        public object SourceObject
-        {
+        public object SourceObject {
             get { return this.GetValue(ObservableTriggerBehavior.SourceObjectProperty); }
             set { this.SetValue(ObservableTriggerBehavior.SourceObjectProperty, value); }
         }
         public static readonly DependencyProperty SourceObjectProperty =
             DependencyProperty.Register("SourceObject", typeof(object), typeof(ObservableTriggerBehavior), new PropertyMetadata(null, OnSourceObjectChanged));
 
-        private static void OnSourceObjectChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs args)
-        {
-            ObservableTriggerBehavior observableTriggerBehavior = (ObservableTriggerBehavior)dependencyObject;
-            observableTriggerBehavior.SetResolvedSource(observableTriggerBehavior.ComputeResolvedSource());
-        }
+        public bool AutoResubscribeOnError { get; set; }
 
-        public IObservable<object> Observable
-        {
+        public IObservable<object> Observable {
             get { return (IObservable<object>)GetValue(ObservableProperty); }
             set { SetValue(ObservableProperty, value); }
         }
         public static readonly DependencyProperty ObservableProperty =
             DependencyProperty.Register("Observable", typeof(IObservable<object>), typeof(ObservableTriggerBehavior), new PropertyMetadata(null, onObservableChanged));
 
-        private void SetResolvedSource(object newSource)
+        static void OnSourceObjectChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs args)
+        {
+            var observableTriggerBehavior = (ObservableTriggerBehavior)dependencyObject;
+
+            observableTriggerBehavior.setResolvedSource(observableTriggerBehavior.computeResolvedSource());
+        }
+
+        void setResolvedSource(object newSource)
         {
-            if (this.AssociatedObject == null || this.resolvedSource == newSource)
-            {
+            if (this.AssociatedObject == null || this.resolvedSource == newSource) {
                 return;
             }
+
             this.resolvedSource = newSource;
         }
 
-        private object ComputeResolvedSource()
+        object computeResolvedSource()
         {
             if (this.ReadLocalValue(ObservableTriggerBehavior.SourceObjectProperty) != DependencyProperty.UnsetValue) {
                 return this.SourceObject;
@@ -69,19 +81,11 @@ private object ComputeResolvedSource()
             }
         }
 
-        public bool AutoResubscribeOnError { get; set; }
-
-        IDisposable watcher;
-        protected static void onObservableChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
+        static void onObservableChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
         {
             ObservableTriggerBehavior This = (ObservableTriggerBehavior)sender;
-            if (This.watcher != null)
-            {
-                This.watcher.Dispose();
-                This.watcher = null;
-            }
 
-            This.watcher = ((IObservable<object>)e.NewValue).ObserveOn(RxApp.MainThreadScheduler).Subscribe(
+            This.watcher.Disposable = ((IObservable<object>)e.NewValue).ObserveOn(RxApp.MainThreadScheduler).Subscribe(
                 x => Interaction.ExecuteActions(This.resolvedSource, This.Actions, x),
                 ex =>
                 {
@@ -94,13 +98,15 @@ protected static void onObservableChanged(DependencyObject sender, DependencyPro
         protected override void OnAttached()
         {
             base.OnAttached();
-            this.SetResolvedSource(this.ComputeResolvedSource());
+            this.setResolvedSource(this.computeResolvedSource());
         }
 
         protected override void OnDetaching()
         {
-            this.SetResolvedSource(null);
+            this.setResolvedSource(null);
             base.OnDetaching();
+
+            watcher.Dispose();
         }
     }
 }