Set DataContext when materializing data templates.

- Rename ApplyDataTemplate to MaterializeDataTemplate.
- Use MaterializeDataTemplate in ContentPresenter.
- Make DataContext property inherit.

Cherry-picked from GitHubClient branch.

Conflicts:
	Perspex.Controls/Control.cs

Perspex.Controls/Control.cs

@@ -20,6 +20,9 @@ namespace Perspex.Controls
 
     public class Control : InputElement, ILogical, IStyleable, IStyleHost
     {
+        public static readonly PerspexProperty<object> DataContextProperty =
+            PerspexProperty.Register<Control, object>("DataContext", inherits: true);
+
         public static readonly PerspexProperty<Control> ParentProperty =
             PerspexProperty.Register<Control, Control>("Parent");
 
@@ -67,6 +70,12 @@ namespace Perspex.Controls
             }
         }
 
+        public object DataContext
+        {
+            get { return this.GetValue(DataContextProperty); }
+            set { this.SetValue(DataContextProperty, value); }
+        }
+
         public DataTemplates DataTemplates
         {
             get

Perspex.Controls/DataTemplateExtensions.cs

@@ -12,22 +12,27 @@ namespace Perspex.Controls
 
     public static class DataTemplateExtensions
     {
-        public static Control ApplyDataTemplate(this Control control, object data)
+        public static Control MaterializeDataTemplate(this Control control, object data)
         {
-            IDataTemplate result = control.FindDataTemplate(data);
+            IDataTemplate template = control.FindDataTemplate(data);
+            Control result;
 
-            if (result != null)
+            if (template != null)
             {
-                return result.Build(data);
+                result = template.Build(data);
             }
             else if (data is Control)
             {
-                return (Control)data;
+                result = (Control)data;
             }
             else
             {
-                return DataTemplate.Default.Build(data);
+                result = DataTemplate.Default.Build(data);
             }
+
+            result.DataContext = data;
+
+            return result;
         }
 
         public static IDataTemplate FindDataTemplate(this Control control, object data)

Perspex.Controls/Generators/ItemContainerGenerator.cs

@@ -116,7 +116,7 @@ namespace Perspex.Controls.Generators
 
         protected virtual Control CreateContainerOverride(object item)
         {
-            return this.Owner.ApplyDataTemplate(item);
+            return this.Owner.MaterializeDataTemplate(item);
         }
 
         protected void AddInternal(object item, Control container)

Perspex.Controls/Generators/TypedItemContainerGenerator.cs

@@ -20,7 +20,7 @@ namespace Perspex.Controls.Generators
             if (result == null)
             {
                 result = new T();
-                result.Content = this.Owner.ApplyDataTemplate(item);
+                result.Content = this.Owner.MaterializeDataTemplate(item);
             }
 
             return result;

Perspex.Controls/Presenters/ContentPresenter.cs

@@ -85,27 +85,7 @@ namespace Perspex.Controls.Presenters
 
             if (content != null)
             {
-                if (content is Control)
-                {
-                    result = (Control)content;
-                }
-                else
-                {
-                    IDataTemplate dataTemplate = this.FindDataTemplate(content);
-
-                    if (dataTemplate != null)
-                    {
-                        result = dataTemplate.Build(content);
-                    }
-                    else
-                    {
-                        result = new TextBlock
-                        {
-                            Text = content.ToString(),
-                        };
-                    }
-                }
-
+                result = this.MaterializeDataTemplate(content);
                 var templatedParent = this.TemplatedParent as TemplatedControl;
 
                 if (templatedParent != null)