Support auto focus on dedicated field

NZazu.Contracts/FormDefinition.cs

@@ -4,5 +4,6 @@ public class FormDefinition
     {
         public FieldDefinition[] Fields { get; set; }
         public string Layout { get; set; }
+        public string FocusOn { get; set; }
     }
 }

NZazu/Extensions/FocusExtensions.cs

@@ -0,0 +1,53 @@
+using System;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Input;
+using System.Windows.Threading;
+
+namespace NZazu.Extensions
+{
+    public static class FocusExtensions
+    {
+        // cf.: https://wpf.codeplex.com/workitem/13476
+        public static Task DelayedFocus(this UIElement uiElement)
+        {
+            if (uiElement == null) throw new ArgumentNullException("uiElement");
+
+            return uiElement.Dispatcher.BeginInvoke(SetFocusAction(uiElement), DispatcherPriority.Render).Task;
+        }
+
+        static Action SetFocusAction(UIElement uiElement)
+        {
+            return () => SetFocus(uiElement);
+        }
+
+        public static void SetFocus(this UIElement uiElement)
+        {
+            RemoveFocus(uiElement);
+
+            uiElement.Focusable = true;
+            FocusManager.SetFocusedElement(uiElement, uiElement);
+            uiElement.Focus();
+            Keyboard.Focus(uiElement);
+        }
+
+        public static void RemoveFocus(this UIElement uiElement)
+        {
+            // cf.: http://stackoverflow.com/questions/2914495/wpf-how-to-programmatically-remove-focus-from-a-textbox
+            //Keyboard.ClearFocus();
+
+            var frameWorkElement = uiElement as FrameworkElement;
+            if (frameWorkElement == null) return;
+
+            // Move to a parent that can take focus
+            var parent = frameWorkElement.Parent as FrameworkElement;
+            while (parent != null && !parent.Focusable)
+            {
+                parent = parent.Parent as FrameworkElement;
+            }
+
+            var scope = FocusManager.GetFocusScope(uiElement);
+            FocusManager.SetFocusedElement(scope, parent);
+        }
+    }
+}

NZazu/FieldBehavior/EmptyNZazuFieldBehavior.cs

@@ -1,14 +1,14 @@
 using System;
-using System.Windows.Controls;
 
 namespace NZazu.FieldBehavior
 {
     internal class EmptyNZazuFieldBehavior : NZazuFieldBehavior
     {
-        public override void AttachTo(Control valueControl)
+        public override void AttachTo(INZazuWpfField field)
         {
-            if (valueControl == null) throw new ArgumentNullException("valueControl");
+            if (field == null) throw new ArgumentNullException("field");
         }
+
         public override void Detach() { }
     }
 }

NZazu/FieldBehavior/EmptyNZazuFieldBehavior_Should.cs

@@ -33,13 +33,13 @@ public void Throw_Excepion_If_No_Control_Provided()
         [Test]
         public void Do_Nothing()
         {
-            var ctrl = Substitute.For<Control>();
+            var field = Substitute.For<INZazuWpfField>();
             var sut = new EmptyNZazuFieldBehavior();
 
-            sut.AttachTo(ctrl);
+            sut.AttachTo(field);
             sut.Detach();
 
-            ctrl.ReceivedCalls().Should().BeEmpty();
+            field.ReceivedCalls().Should().BeEmpty();
         }
     }
 }

NZazu/FieldBehavior/NZazuFieldBehavior.cs

@@ -1,10 +1,8 @@
-using System.Windows.Controls;
-
 namespace NZazu.FieldBehavior
 {
     internal abstract class NZazuFieldBehavior : INZazuWpfFieldBehavior
     {
-        public abstract void AttachTo(Control valueControl);
+        public abstract void AttachTo(INZazuWpfField field);
         public abstract void Detach();
     }
 }

NZazu/FieldBehavior/NZazuFieldBehaviorFactory_Should.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Diagnostics.CodeAnalysis;
-using System.Windows.Controls;
 using FluentAssertions;
 using NUnit.Framework;
 using NZazu.Contracts;
@@ -40,7 +39,7 @@ public void Verify_Parameter_On_CreateFieldBehavior()
         [ExcludeFromCodeCoverage]
         private class SimpleInterfaceImplementation : INZazuWpfFieldBehavior
         {
-            public void AttachTo(Control valueControl) { }
+            public void AttachTo(INZazuWpfField field) { }
             public void Detach() { }
         }
 

NZazu/INZazuWpfFieldBehavior.cs

@@ -1,10 +1,8 @@
-using System.Windows.Controls;
-
-namespace NZazu
+namespace NZazu
 {
     public interface INZazuWpfFieldBehavior
     {
-        void AttachTo(Control valueControl);
+        void AttachTo(INZazuWpfField field);
         void Detach();
     }
 }

NZazu/INZazuWpfView.cs

@@ -13,6 +13,9 @@ public interface INZazuWpfView
         IResolveLayout ResolveLayout { get; set; }
 
         INZazuWpfField GetField(string key);
+        bool TryGetField(string key, out INZazuWpfField field);
+        bool TrySetFocusOn(string key);
+
         Dictionary<string, string> GetFieldValues();
         void ApplyChanges();
 

NZazu/NZazu.csproj

@@ -57,6 +57,7 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="Extensions\FieldExtensions.cs" />
+    <Compile Include="Extensions\FocusExtensions.cs" />
     <Compile Include="FieldBehavior\BehaviorExtender.cs" />
     <Compile Include="FieldBehavior\EmptyNZazuFieldBehavior.cs" />
     <Compile Include="FieldBehavior\EmptyNZazuFieldBehavior_Should.cs" />

NZazu/NZazuView.cs

@@ -1,7 +1,9 @@
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Windows;
 using System.Windows.Controls;
+using System.Windows.Input;
 using NZazu.Contracts;
 using NZazu.Contracts.Checks;
 using NZazu.Extensions;
@@ -30,6 +32,7 @@ private static void FormDefinitionChanged(DependencyObject d, DependencyProperty
             var view = (NZazuView)d;
             var formDefinition = (FormDefinition)e.NewValue;
             view.UpdateFields(formDefinition, view.FieldFactory, view.FieldBehaviorFactory, view.ResolveLayout);
+            view.TrySetFocusOn(formDefinition.FocusOn);
         }
 
         // ############# FieldFactory
@@ -151,10 +154,15 @@ public void ApplyChanges()
         public INZazuWpfField GetField(string key)
         {
             INZazuWpfField field;
-            if (!_fields.TryGetValue(key, out field)
-                && !_groupFields.TryGetValue(key, out field))
-                throw new KeyNotFoundException();
-            return field;
+            if (TryGetField(key, out field))
+                return field;
+            throw new KeyNotFoundException();
+        }
+
+        public bool TryGetField(string key, out INZazuWpfField field)
+        {
+            return _fields.TryGetValue(key, out field)
+                   || _groupFields.TryGetValue(key, out field);
         }
 
         public Dictionary<string, string> GetFieldValues()
@@ -195,6 +203,20 @@ private void UpdateFields(
             this.SetFieldValues(FormData.Values);
         }
 
+        public bool TrySetFocusOn(string focusOn)
+        {
+            INZazuWpfField field;
+            if (String.IsNullOrWhiteSpace(focusOn) || !TryGetField(focusOn, out field)) return false;
+
+            var control = field.ValueControl;
+            if (control == null) return false;
+
+            control.SetFocus();
+            control.DelayedFocus();
+
+            return true;
+        }
+
         private void CreateFields(FormDefinition formDefinition, INZazuWpfFieldFactory fieldFactory)
         {
             formDefinition.Fields.ToList().ForEach(f =>
@@ -232,7 +254,7 @@ private void AttachBehavior(FormDefinition formDefinition, INZazuWpfFieldBehavio
                 var field = GetField(fieldDefinition.Key) as NZazuField;
                 if (field == null) return;
 
-                behavior.AttachTo(field.ValueControl);
+                behavior.AttachTo(field);
                 field.Behavior = behavior;
             }
         }

NZazu/NZazuView_Should.cs

@@ -341,7 +341,7 @@ public void Attach_And_Detach_Behavior_To_Field()
             var sut = new NZazuView { FieldBehaviorFactory = behaviorFactory, FormDefinition = formDefinition, FormData = formData };
             sut.Should().NotBeNull();
 
-            behavior.ReceivedWithAnyArgs().AttachTo(Arg.Any<Control>());
+            behavior.ReceivedWithAnyArgs().AttachTo(Arg.Any<INZazuWpfField>());
             behavior.ClearReceivedCalls();
 
             // now lets create a ner form and detach the existing behavior
@@ -371,5 +371,33 @@ public void Skip_skip_fixed_fields_in_GetFieldValues()
             var actual = view.GetFieldValues();
             actual.ShouldBeEquivalentTo(expected);
         }
+
+        [Test]
+        public void Focus_specified_field_after_changing_FormDefinition()
+        {
+            var view = new NZazuView
+            {
+                FormDefinition = new FormDefinition
+                {
+                    Fields = new[]
+                    {
+                        new FieldDefinition {Key = "other", Type = "string"},
+                        new FieldDefinition {Key = "focus", Type = "string"}
+                    },
+                    FocusOn = "focus"
+                }
+            };
+
+            var otherCtrl = view.GetField("other").ValueControl;
+            var keyCtrl = view.GetField("focus").ValueControl;
+
+            otherCtrl.IsFocused.Should().BeFalse();
+            keyCtrl.IsFocused.Should().BeTrue();
+
+            view.TrySetFocusOn("other").Should().BeTrue();
+
+            keyCtrl.IsFocused.Should().BeFalse();
+            otherCtrl.IsFocused.Should().BeTrue();
+        }
     }
 }

NZazuFiddle/NZazuFiddle.csproj

@@ -139,6 +139,7 @@
     <Compile Include="AppBootstrapper.cs" />
     <Compile Include="IFiddle.cs" />
     <Compile Include="Samples\BehaviorSample.cs" />
+    <Compile Include="Samples\FocusSample.cs" />
     <Compile Include="Samples\IHaveSample.cs" />
     <Compile Include="Samples\MixedGroupLayout.cs" />
     <Compile Include="Samples\PrimitivesSample.cs" />

NZazuFiddle/PreviewViewModel.cs

@@ -62,6 +62,16 @@ private set
             }
         }
 
+        protected override void OnActivate()
+        {
+            base.OnActivate();
+
+            var view = GetView() as PreviewView;
+            if (view == null) return;
+
+            view.View.TrySetFocusOn(Definition.FocusOn);
+        }
+
         public void Handle(FormDefinition definition)
         {
             Definition = definition;

NZazuFiddle/Samples/BehaviorSample.cs

@@ -63,9 +63,10 @@ private class OpenUrlOnStringEnterBehavior : INZazuWpfFieldBehavior
             private Control _control;
             private KeyEventHandler _handler;
 
-            public void AttachTo(Control valueControl)
+            public void AttachTo(INZazuWpfField field)
             {
-                if (valueControl == null) throw new ArgumentNullException("valueControl");
+                if (field == null) throw new ArgumentNullException("field");
+                var valueControl = field.ValueControl;
 
                 _control = valueControl;
 

NZazuFiddle/Samples/FocusSample.cs

@@ -0,0 +1,33 @@
+using System.Collections.Generic;
+using NZazu.Contracts;
+
+namespace NZazuFiddle.Samples
+{
+    // ReSharper disable once UnusedMember.Global
+    class FocusSample : SampleBase
+    {
+        public FocusSample() : base(50)
+        {
+            Sample = new SampleViewModel
+            {
+                Name = "Focus",
+                Fiddle = ToFiddle(new FormDefinition
+                {
+                    Fields = new []
+                    {
+                        new FieldDefinition { Key="label", Type = "label", Prompt = "Focus should be on 'value2'"},
+                        new FieldDefinition { Key="key1", Type="string", Prompt="key1"},
+                        new FieldDefinition { Key="key2", Type="string", Prompt="key2"}
+                    }, 
+                    FocusOn = "key2"
+                },
+                new Dictionary<string, string>
+                {
+                    {"key1", "value1"},
+                    {"key2", "value2"}
+                })
+            };
+
+        }
+    }
+}

NZazuFiddle/Samples/PrimitivesSample.cs

@@ -3,6 +3,7 @@
 
 namespace NZazuFiddle.Samples
 {
+    // ReSharper disable once UnusedMember.Global
     class PrimitivesSample : SampleBase
     {
         public PrimitivesSample() : base(10)

NZazuFiddle/Samples/ValidationSample.cs

@@ -3,6 +3,7 @@
 
 namespace NZazuFiddle.Samples
 {
+    // ReSharper disable once UnusedMember.Global
     class ValidationSample : SampleBase
     {
         public ValidationSample() : base(30)

NZazuFiddle/ShellViewModel.cs

@@ -24,7 +24,7 @@ public IEnumerable<ISample> Samples
             {
                 if (Equals(value, _samples)) return;
                 _samples.Clear();
-                if (value != null) _samples.AddRange(value.OrderBy(s => s.Name));
+                if (value != null) _samples.AddRange(value);
                 SelectedSample = _samples.FirstOrDefault();
             }
         }