[Core/Win] Add Navigate to Source support

5 files changed, 68 insertions, 0 deletions

diff --git a/Xamarin.PropertyEditing/ICanNavigateToSource.cs b/Xamarin.PropertyEditing/ICanNavigateToSource.cs
new file mode 100644
index 0000000..564883d
--- /dev/null
+++ b/Xamarin.PropertyEditing/ICanNavigateToSource.cs
@@ -0,0 +1,24 @@
+using System;
+
+namespace Xamarin.PropertyEditing
+{
+	/// <summary>
+	/// <see cref="IPropertyInfo"/> light-up interface for navigating to value sources.
+	/// </summary>
+	/// <remarks>
+	/// Not all possible values and value sources must be navigatable to implement this interface. That determination can
+	/// be made in <see cref="CanNavigateToSource"/>. Implementing this interface will simply light-up the UI element, but
+	/// its enabled status will depend on <see cref="CanNavigateToSource"/> and other dynamic factors.
+	/// </remarks>
+	public interface ICanNavigateToSource
+	{
+		/// <summary>
+		/// Gets whether the value of the property attached to in the <paramref name="editor"/> can be navigated to.
+		/// </summary>
+		/// <exception cref="ArgumentNullException"><paramref name="editor"/> is <c>null</c>.</exception>
+		bool CanNavigateToSource (IObjectEditor editor);
+
+		/// <exception cref="ArgumentNullException"><paramref name="editor"/> is <c>null</c>.</exception>
+		void NavigateToSource (IObjectEditor editor);
+	}
+}
\ No newline at end of file
diff --git a/Xamarin.PropertyEditing/Properties/Resources.Designer.cs b/Xamarin.PropertyEditing/Properties/Resources.Designer.cs
index 4805f4b..6ce3cde 100644
--- a/Xamarin.PropertyEditing/Properties/Resources.Designer.cs
+++ b/Xamarin.PropertyEditing/Properties/Resources.Designer.cs
@@ -259,6 +259,15 @@ namespace Xamarin.PropertyEditing.Properties {
         }
         
         /// <summary>
+        ///   Looks up a localized string similar to Go to Source.
+        /// </summary>
+        public static string GoToSource {
+            get {
+                return ResourceManager.GetString("GoToSource", resourceCulture);
+            }
+        }
+        
+        /// <summary>
         ///   Looks up a localized string similar to Green.
         /// </summary>
         public static string Green {
diff --git a/Xamarin.PropertyEditing/Properties/Resources.resx b/Xamarin.PropertyEditing/Properties/Resources.resx
index a64ada5..1adfec2 100644
--- a/Xamarin.PropertyEditing/Properties/Resources.resx
+++ b/Xamarin.PropertyEditing/Properties/Resources.resx
@@ -455,4 +455,7 @@
     <value>Resource ({0})</value>
     <comment>Resource with the raw embedded resource name</comment>
   </data>
+  <data name="GoToSource" xml:space="preserve">
+    <value>Go to Source</value>
+  </data>
 </root>
\ No newline at end of file
diff --git a/Xamarin.PropertyEditing/ViewModels/PropertyViewModel.cs b/Xamarin.PropertyEditing/ViewModels/PropertyViewModel.cs
index 2c3d12a..b17eb11 100644
--- a/Xamarin.PropertyEditing/ViewModels/PropertyViewModel.cs
+++ b/Xamarin.PropertyEditing/ViewModels/PropertyViewModel.cs
@@ -25,8 +25,10 @@ namespace Xamarin.PropertyEditing.ViewModels
 		{
 			this.coerce = property as ICoerce<TValue>;
 			this.validator = property as IValidator<TValue>;
+			this.valueNavigator = property as ICanNavigateToSource;
 			this.isNullable = (!property.ValueSources.HasFlag (ValueSources.Default) || property.Type.Name == NullableName);
 
+			NavigateToValueSourceCommand = new RelayCommand (OnNavigateToSource, CanNavigateToSource);
 			SetValueResourceCommand = new RelayCommand<Resource> (OnSetValueToResource, CanSetValueToResource);
 			ClearValueCommand = new RelayCommand (OnClearValue, CanClearValue);
 			ConvertToLocalValueCommand = new RelayCommand(OnConvertToLocalValue, CanClearToLocalValue);
@@ -89,6 +91,8 @@ namespace Xamarin.PropertyEditing.ViewModels
 			}
 		}
 
+		public override bool SupportsValueSourceNavigation => this.valueNavigator != null;
+
 		protected virtual TValue CoerceValue (TValue validationValue)
 		{
 			if (!this.isNullable && validationValue == null) {
@@ -194,6 +198,7 @@ namespace Xamarin.PropertyEditing.ViewModels
 
 		private readonly ICoerce<TValue> coerce;
 		private readonly IValidator<TValue> validator;
+		private readonly ICanNavigateToSource valueNavigator;
 		internal const string NullableName = "Nullable`1";
 		private bool isNullable;
 		private ValueInfo<TValue> value;
@@ -220,6 +225,7 @@ namespace Xamarin.PropertyEditing.ViewModels
 
 			((RelayCommand) ConvertToLocalValueCommand)?.ChangeCanExecute ();
 			((RelayCommand) ClearValueCommand)?.ChangeCanExecute ();
+			((RelayCommand) NavigateToValueSourceCommand)?.ChangeCanExecute ();
 
 			return true;
 		}
@@ -270,6 +276,23 @@ namespace Xamarin.PropertyEditing.ViewModels
 			});
 		}
 
+		private bool CanNavigateToSource ()
+		{
+			if (this.valueNavigator == null)
+				return false;
+			if (Editors.Count != 1)
+				return false;
+			if (ValueSource == ValueSource.Default || ValueSource == ValueSource.Unset)
+				return false;
+
+			return this.valueNavigator.CanNavigateToSource (Editors.Single());
+		}
+
+		private void OnNavigateToSource ()
+		{
+			this.valueNavigator?.NavigateToSource (Editors.FirstOrDefault ());
+		}
+
 		private static TValue DefaultValue;
 	}
 
@@ -374,6 +397,14 @@ namespace Xamarin.PropertyEditing.ViewModels
 			protected set;
 		}
 
+		public ICommand NavigateToValueSourceCommand
+		{
+			get;
+			protected set;
+		}
+
+		public virtual bool SupportsValueSourceNavigation => false;
+
 		public bool HasErrors => this.error != null;
 
 		public IEnumerable GetErrors (string propertyName)
diff --git a/Xamarin.PropertyEditing/Xamarin.PropertyEditing.csproj b/Xamarin.PropertyEditing/Xamarin.PropertyEditing.csproj
index 91c10ec..fdc38df 100644
--- a/Xamarin.PropertyEditing/Xamarin.PropertyEditing.csproj
+++ b/Xamarin.PropertyEditing/Xamarin.PropertyEditing.csproj
@@ -72,6 +72,7 @@
     <Compile Include="Drawing\CommonImageBrush.cs" />
     <Compile Include="IAssemblyInfo.cs" />
     <Compile Include="IAvailabilityConstraint.cs" />
+    <Compile Include="ICanNavigateToSource.cs" />
     <Compile Include="IClampedPropertyInfo.cs" />
     <Compile Include="IColorSpaced.cs" />
     <Compile Include="ICoerce.cs" />