feat: add temp template.

src/Ursa/Controls/Form/Form.cs

@@ -1,25 +1,32 @@
 using Avalonia;
-using Avalonia.Collections;
 using Avalonia.Controls;
-using Avalonia.Markup.Xaml.Templates;
-using Avalonia.Metadata;
 
 namespace Ursa.Controls;
 
 public class Form: ItemsControl
 {
-
-    public static readonly StyledProperty<AvaloniaList<FormItem>> ItemsProperty = AvaloniaProperty.Register<Form, AvaloniaList<FormItem>>(
-        "Items");
+    public static readonly AttachedProperty<string> LabelProperty =
+        AvaloniaProperty.RegisterAttached<Form, Control, string>("Label");
+    public static void SetLabel(Control obj, string value) => obj.SetValue(LabelProperty, value);
+    public static string GetLabel(Control obj) => obj.GetValue(LabelProperty);
     
-    public AvaloniaList<FormItem> Items
-    {
-        get => GetValue(ItemsProperty);
-        set => SetValue(ItemsProperty, value);
-    }
 
-    public void AddChild(object child)
+    public static readonly AttachedProperty<bool> IsRequiredProperty =
+        AvaloniaProperty.RegisterAttached<Form, Control, bool>("IsRequired");
+    public static void SetIsRequired(Control obj, bool value) => obj.SetValue(IsRequiredProperty, value);
+    public static bool GetIsRequired(Control obj) => obj.GetValue(IsRequiredProperty);
+
+    protected override bool NeedsContainerOverride(object? item, int index, out object? recycleKey)
     {
-        throw new NotImplementedException();
+        recycleKey = null;
+        return item is FormItem or FormGroup;
+    }
+    
+    protected override Control CreateContainerForItemOverride(object? item, int index, object? recycleKey)
+    {
+        if (item is not Control control) return new FormItem();
+        string label = GetLabel(control);
+        bool isRequired = GetIsRequired(control);
+        return new FormItem() { Label = label, IsRequired = isRequired, Content = control };
     }
 }

src/Ursa/Controls/Form/FormGroup.cs

@@ -3,7 +3,19 @@ using Avalonia.Controls.Primitives;
 
 namespace Ursa.Controls;
 
-public class FormGroup: HeaderedItemsControl, IFormItem
+public class FormGroup: HeaderedItemsControl
 {
-    
+    protected override bool NeedsContainerOverride(object? item, int index, out object? recycleKey)
+    {
+        recycleKey = null;
+        return item is not FormItem or FormGroup;
+    }
+
+    protected override Control CreateContainerForItemOverride(object? item, int index, object? recycleKey)
+    {
+        if (item is not Control control) return new FormItem();
+        var label = Form.GetLabel(control);
+        var isRequired = Form.GetIsRequired(control);
+        return new FormItem() { Label = label, IsRequired = isRequired, Content = control };
+    }
 }

src/Ursa/Controls/Form/FormItem.cs

@@ -1,8 +1,27 @@
-using Avalonia.Controls.Primitives;
+using Avalonia;
+using Avalonia.Controls;
+using Avalonia.Controls.Primitives;
 
 namespace Ursa.Controls;
 
-public class FormItem: TemplatedControl, IFormItem
+public class FormItem: ContentControl
 {
+    public static readonly StyledProperty<string> LabelProperty = AvaloniaProperty.Register<FormItem, string>(
+        nameof(Label));
+
+    public string Label
+    {
+        get => GetValue(LabelProperty);
+        set => SetValue(LabelProperty, value);
+    }
+
+    public static readonly StyledProperty<bool> IsRequiredProperty = AvaloniaProperty.Register<FormItem, bool>(
+        nameof(IsRequired));
+
+    public bool IsRequired
+    {
+        get => GetValue(IsRequiredProperty);
+        set => SetValue(IsRequiredProperty, value);
+    }
     
 }

src/Ursa/Controls/Form/IFormItem.cs

@@ -1,9 +0,0 @@
-using Avalonia.Controls;
-using Avalonia.Controls.Primitives;
-
-namespace Ursa.Controls;
-
-public interface IFormItem
-{
-    
-}