[Core] Support refreshing resourcesermau-refresh-resources

While most resource UIs have a popup or window that doesn't really
require a live refresh, the brush resource tab does have a persistent
list so it needs to be able to update. Since the view model is shared,
we get the former for free anyway.

2 files changed, 30 insertions, 0 deletions

diff --git a/Xamarin.PropertyEditing/IResourceProvider.cs b/Xamarin.PropertyEditing/IResourceProvider.cs
index 9b2b143..b67945a 100644
--- a/Xamarin.PropertyEditing/IResourceProvider.cs
+++ b/Xamarin.PropertyEditing/IResourceProvider.cs
@@ -8,6 +8,8 @@ namespace Xamarin.PropertyEditing
 {
 	public interface IResourceProvider
 	{
+		event EventHandler<ResourcesChangedEventArgs> ResourcesChanged;
+
 		/// <summary>
 		/// Gets whether or not the resource provider can create resources.
 		/// </summary>
@@ -85,4 +87,25 @@ namespace Xamarin.PropertyEditing
 			get;
 		}
 	}
+
+	public class ResourcesChangedEventArgs
+		: EventArgs
+	{
+		public ResourcesChangedEventArgs ()
+		{
+		}
+
+		public ResourcesChangedEventArgs (ResourceSource source)
+		{
+			if (source == null)
+				throw new ArgumentNullException (nameof(source));
+
+			Source = source;
+		}
+
+		public ResourceSource Source
+		{
+			get;
+		}
+	}
 }
\ No newline at end of file
diff --git a/Xamarin.PropertyEditing/ViewModels/ResourceSelectorViewModel.cs b/Xamarin.PropertyEditing/ViewModels/ResourceSelectorViewModel.cs
index f2c3aeb..9b1f0cc 100644
--- a/Xamarin.PropertyEditing/ViewModels/ResourceSelectorViewModel.cs
+++ b/Xamarin.PropertyEditing/ViewModels/ResourceSelectorViewModel.cs
@@ -21,6 +21,8 @@ namespace Xamarin.PropertyEditing.ViewModels
 				throw new ArgumentNullException (nameof (property));
 
 			Provider = provider;
+			provider.ResourcesChanged += OnResourcesChanged;
+
 			this.targets = targets.ToArray();
 			Property = property;
 			UpdateResources();
@@ -170,6 +172,11 @@ namespace Xamarin.PropertyEditing.ViewModels
 			return true;
 		}
 
+		private void OnResourcesChanged (object sender, EventArgs e)
+		{
+			UpdateResources ();
+		}
+
 		private async void UpdateResources ()
 		{
 			await UpdateResourcesAsync();