Clean up dispose pattern, remove sentence fragment

dotnet/ios/ios12/ScanningAndDetecting3DObjects/README.md

@@ -124,7 +124,7 @@ The Swift code uses five files to organize the behavior of the single class `Vie
 
 I occasionally refactored the Swift code where I thought it helped legibility or reduced repetition. Usually this was in the form of extracting a function.
 
-One area where there is considerably variance from the Swift code is in the "Utility_Extensions" folder. Xamarin.iOS uses OpenTK vector and matrix classes for manipulating 3D objects and transforms. The OpenTK classes have different APIs and 
+One area where there is considerably variance from the Swift code is in the "Utility_Extensions" folder. Xamarin.iOS uses OpenTK vector and matrix classes for manipulating 3D objects and transforms.
 
 A matter of internal debate was the clearest form for porting Swift `guard` statements that assign a local variable if the passed-in variable is not `null`. The options are:
 

dotnet/ios/ios12/ScanningAndDetecting3DObjects/ScanningApp/3D_UI/BoundingBox.cs

@@ -801,26 +801,16 @@ internal class BoundingBox : SCNNode
 	// Dispose pattern for debugging purposes
 	bool disposed = false;
 
-	internal bool IsDisposed
-	{
-		get
-		{
-			return disposed;
-		}
-	}
+	internal bool IsDisposed => disposed;
 
 	override protected void Dispose (bool disposing)
 	{
 		if (!disposed)
 		{
 			disposed = true;
-			if (disposing)
-			{
-				base.Dispose ();
-			}
-
 			NSNotificationCenter.DefaultCenter.RemoveObserver (notificationObserverHandle);
 		}
+		base.Dispose (disposing);
 	}
 
 	internal new void Dispose ()

dotnet/ios/ios12/ScanningAndDetecting3DObjects/ScanningApp/3D_UI/ObjectOrigin.cs

@@ -515,13 +515,9 @@ internal class ObjectOrigin : SCNNode
 		{
 			disposed = true;
 
-			if (disposing)
-			{
-				base.Dispose ();
-			}
-
 			NSNotificationCenter.DefaultCenter.RemoveObserver (notificationObserverHandles [0]);
 			NSNotificationCenter.DefaultCenter.RemoveObserver (notificationObserverHandles [1]);
 		}
+		base.Dispose (disposing);
 	}
 }

dotnet/ios/ios12/ScanningAndDetecting3DObjects/ScanningApp/3D_UI/ScannedObject.cs

@@ -341,16 +341,12 @@ internal class ScannedObject : SCNNode
 		if (!disposed)
 		{
 			disposed = true;
-			if (disposing)
-			{
-				base.Dispose ();
-			}
-
 			NSNotificationCenter.DefaultCenter.RemoveObserver (notificationObserverHandle);
 			Origin?.Dispose ();
 			BoundingBox?.Dispose ();
 			GhostBoundingBox?.Dispose ();
 		}
+		base.Dispose (disposing);
 	}
 
 	#endregion

dotnet/ios/ios12/ScanningAndDetecting3DObjects/ScanningApp/3D_UI/ScannedPointCloud.cs

@@ -142,15 +142,11 @@ internal class ScannedPointCloud : SCNNode
 		if (!disposed)
 		{
 			disposed = true;
-			if (disposing)
-			{
-				base.Dispose ();
-			}
-
 			foreach (var notificationObserverHandle in notificationObservationHandles)
 			{
 				NSNotificationCenter.DefaultCenter.RemoveObserver (notificationObserverHandle);
 			}
 		}
+		base.Dispose (disposing);
 	}
 }

dotnet/ios/ios12/ScanningAndDetecting3DObjects/ScanningApp/Controllers/Scan.cs

@@ -152,6 +152,7 @@ Do you want to go back and adjust the bounding box of the scanned object?""";
 		sceneView.Scene.RootNode.AddChildNode (pointCloud);
 	}
 
+	bool disposed;
 	internal new void Dispose ()
 	{
 		Dispose (true);
@@ -160,14 +161,19 @@ Do you want to go back and adjust the bounding box of the scanned object?""";
 
 	protected override void Dispose (bool disposing)
 	{
-		if (disposing)
+		if (!disposed)
 		{
-			scannedObject?.RemoveFromParentNode ();
-			pointCloud?.RemoveFromParentNode ();
+			disposed = true;
+			if (disposing)
+			{
+				scannedObject?.RemoveFromParentNode ();
+				pointCloud?.RemoveFromParentNode ();
 
-			scannedObject?.Dispose ();
-			pointCloud?.Dispose ();
+				scannedObject?.Dispose ();
+				pointCloud?.Dispose ();
+			}
 		}
+		base.Dispose (disposing);
 	}
 
 	void ApplicationStateChanged (NSNotification notification)

dotnet/ios/ios12/ScanningAndDetecting3DObjects/ScanningApp/Controllers/TestRun.cs

@@ -115,6 +115,8 @@ internal class TestRun : NSObject, IDisposable
 		noDetectionTimer = null;
 	}
 
+	bool disposed;
+
 	internal new void Dispose ()
 	{
 		Dispose (true);
@@ -123,18 +125,23 @@ internal class TestRun : NSObject, IDisposable
 
 	protected override void Dispose (bool disposing)
 	{
-		if (disposing)
+		if (!disposed)
 		{
-			DetectedObject?.RemoveFromParentNode ();
-
-			if (sceneView.Session.Configuration as ARWorldTrackingConfiguration is not null)
+			disposed = true;
+			if (disposing)
 			{
-				// Make sure we switch back to an object scanning configuration & no longer
-				// try to detect the object.
-				var configuration = new ARObjectScanningConfiguration ();
-				configuration.PlaneDetection = ARPlaneDetection.Horizontal;
-				sceneView.Session.Run (configuration, ARSessionRunOptions.ResetTracking);
+				DetectedObject?.RemoveFromParentNode ();
+
+				if (sceneView.Session.Configuration as ARWorldTrackingConfiguration is not null)
+				{
+					// Make sure we switch back to an object scanning configuration & no longer
+					// try to detect the object.
+					var configuration = new ARObjectScanningConfiguration ();
+					configuration.PlaneDetection = ARPlaneDetection.Horizontal;
+					sceneView.Session.Run (configuration, ARSessionRunOptions.ResetTracking);
+				}
 			}
+			base.Dispose (disposing);
 		}
 	}
 }