Added a diagnostic to print the visual tree.

Perspex/Diagnostics/Debug.cs

@@ -0,0 +1,57 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Perspex.Diagnostics
+{
+    public static class Debug
+    {
+        public static string PrintVisualTree(IVisual visual)
+        {
+            StringBuilder result = new StringBuilder();
+            PrintVisualTree(visual, result, 0);
+            return result.ToString();
+        }
+
+        private static void PrintVisualTree(IVisual visual, StringBuilder builder, int indent)
+        {
+            builder.Append(Indent(indent - 1));
+
+            if (indent > 0)
+            {
+                builder.Append(" +- ");
+            }
+
+            builder.AppendLine(visual.GetType().Name);
+
+            PerspexObject p = visual as PerspexObject;
+
+            if (p != null)
+            {
+                foreach (var value in p.GetSetValues())
+                {
+                    builder.Append(Indent(indent));
+                    builder.Append(" |  ");
+                    builder.Append(value.Item1.Name);
+                    builder.Append(" = ");
+                    builder.Append(value.Item2);
+                    builder.Append(" (");
+                    builder.Append(value.Item3);
+                    builder.AppendLine(")");
+                }
+            }
+
+            foreach (var child in visual.VisualChildren)
+            {
+                PrintVisualTree(child, builder, indent + 1);
+            }
+        }
+
+        private static string Indent(int indent)
+        {
+            return string.Join("", Enumerable.Repeat("    ", Math.Max(indent, 0)));
+        }
+    }
+}

Perspex/Perspex.csproj

@@ -94,6 +94,7 @@
     <Compile Include="Controls\Panel.cs" />
     <Compile Include="Controls\StackPanel.cs" />
     <Compile Include="IHeadered.cs" />
+    <Compile Include="Diagnostics\Debug.cs" />
     <Compile Include="Input\InputElement.cs" />
     <Compile Include="Input\IFocusManager.cs" />
     <Compile Include="Input\FocusManager.cs" />

Perspex/PerspexObject.cs

@@ -321,6 +321,20 @@ namespace Perspex
             return (T)this.GetValue((PerspexProperty)property);
         }
 
+        /// <summary>
+        /// Gets all of the <see cref="PerspexProperty"/> values explicitly set on this object.
+        /// </summary>
+        public IEnumerable<Tuple<PerspexProperty, object, BindingPriority>> GetSetValues()
+        {
+            foreach (var value in this.values)
+            {
+                yield return Tuple.Create(
+                    value.Key,
+                    value.Value.Value,
+                    (BindingPriority)value.Value.ValuePriority);
+            }
+        }
+
         /// <summary>
         /// Checks whether a <see cref="PerspexProperty"/> is set on this object.
         /// </summary>

Perspex/PriorityValue.cs

@@ -40,17 +40,13 @@ namespace Perspex
         /// </summary>
         private object value;
 
-        /// <summary>
-        /// The priority of the binding that is currently active.
-        /// </summary>
-        private int valuePriority = int.MaxValue;
-
         /// <summary>
         /// Initializes a new instance of the <see cref="PriorityValue"/> class.
         /// </summary>
         public PriorityValue()
         {
             this.value = PerspexProperty.UnsetValue;
+            this.ValuePriority = int.MaxValue;
         }
 
         /// <summary>
@@ -69,6 +65,15 @@ namespace Perspex
             get { return this.value; }
         }
 
+        /// <summary>
+        /// Gets the priority of the binding that is currently active.
+        /// </summary>
+        public int ValuePriority
+        {
+            get;
+            private set;
+        }
+
         /// <summary>
         /// Adds a new binding.
         /// </summary>
@@ -127,7 +132,7 @@ namespace Perspex
                 item = next;
             }
 
-            if (removed && priority <= this.valuePriority)
+            if (removed && priority <= this.ValuePriority)
             {
                 this.UpdateValue();
             }
@@ -148,7 +153,7 @@ namespace Perspex
         /// <param name="changed">The changed entry.</param>
         private void EntryChanged(BindingEntry changed)
         {
-            if (changed.Priority <= this.valuePriority)
+            if (changed.Priority <= this.ValuePriority)
             {
                 this.UpdateValue();
             }
@@ -172,7 +177,7 @@ namespace Perspex
         {
             object old = this.value;
 
-            this.valuePriority = priority;
+            this.ValuePriority = priority;
 
             if (!EqualityComparer<object>.Default.Equals(old, value))
             {

TestApplication/Program.cs

@@ -82,6 +82,8 @@ namespace TestApplication
                 }
             };
 
+            System.Console.WriteLine(Perspex.Diagnostics.Debug.PrintVisualTree(window));
+
             window.Show();
             Dispatcher.Run();
         }