Add Frame component to enable rounded corners

samples/BlaxamarinSample/TodoList.razor

@@ -1,39 +1,43 @@
 @inject AppState AppState
 
 <StackLayout>
-    <StackLayout Orientation="StackOrientation.Horizontal">
-        @* Input area *@
-        <Entry @bind-Text="newText"
-               Placeholder="What's to be done?"
-               OnCompleted="@AddItem"
-               IsEnabled="@(!isAdding)"
-               HorizontalOptions="LayoutOptions.FillAndExpand" />
-        <Button Text="Add"
-                OnClick="@AddItem"
-                IsEnabled="@(!isAdding && !string.IsNullOrWhiteSpace(newText))" />
-        <ActivityIndicator Color="Color.Orange"
-                           IsRunning="@isAdding" />
-    </StackLayout>
-    <ScrollView>
-        <StackLayout>
-            @* List of todos *@
-            @if (items == null)
-            {
-                <StackLayout Orientation="StackOrientation.Horizontal">
-                    <Label Text="Loading..." />
-                    <ActivityIndicator Color="Color.Purple"
-                                       IsRunning="true" />
-                </StackLayout>
-            }
-            else
-            {
-                foreach (var item in items)
-                {
-                    <TodoEntry Item="@item" />
-                }
-            }
+    <Frame BorderColor="@Color.LightBlue" CornerRadius="10" Margin="5" Padding="10">
+        <StackLayout Orientation="StackOrientation.Horizontal">
+            @* Input area *@
+            <Entry @bind-Text="newText"
+                   Placeholder="What's to be done?"
+                   OnCompleted="@AddItem"
+                   IsEnabled="@(!isAdding)"
+                   HorizontalOptions="LayoutOptions.FillAndExpand" />
+            <Button Text="Add"
+                    OnClick="@AddItem"
+                    IsEnabled="@(!isAdding && !string.IsNullOrWhiteSpace(newText))" />
+            <ActivityIndicator Color="Color.Orange"
+                               IsRunning="@isAdding" />
         </StackLayout>
-    </ScrollView>
+    </Frame>
+    <Frame BorderColor="@Color.LightBlue" CornerRadius="10" Margin="5" Padding="10">
+        <ScrollView>
+            <StackLayout>
+                @* List of todos *@
+                @if (items == null)
+                {
+                    <StackLayout Orientation="StackOrientation.Horizontal">
+                        <Label Text="Loading..." />
+                        <ActivityIndicator Color="Color.Purple"
+                                           IsRunning="true" />
+                    </StackLayout>
+                }
+                else
+                {
+                    foreach (var item in items)
+                    {
+                        <TodoEntry Item="@item" />
+                    }
+                }
+            </StackLayout>
+        </ScrollView>
+    </Frame>
 </StackLayout>
 
 @code

src/Blaxamarin.Framework/Elements/AttributeHelper.Common.cs

@@ -33,5 +33,21 @@ namespace Blaxamarin.Framework.Elements
         {
             return double.Parse(doubleString, CultureInfo.InvariantCulture);
         }
+
+        /// <summary>
+        /// Helper method to serialize <see cref="System.Single" /> objects.
+        /// </summary>
+        public static string SingleToString(float color)
+        {
+            return color.ToString("R", CultureInfo.InvariantCulture); // "R" --> Round-trip format specifier guarantees fidelity when parsing
+        }
+
+        /// <summary>
+        /// Helper method to deserialize <see cref="System.Single" /> objects.
+        /// </summary>
+        public static float StringToSingle(string singleString)
+        {
+            return float.Parse(singleString, CultureInfo.InvariantCulture);
+        }
     }
 }

src/Blaxamarin.Framework/Elements/ContentView.cs

@@ -0,0 +1,22 @@
+using Blaxamarin.Framework.Elements.Handlers;
+using Emblazon;
+using Microsoft.AspNetCore.Components;
+using XF = Xamarin.Forms;
+
+namespace Blaxamarin.Framework.Elements
+{
+    public class ContentView : TemplatedView
+    {
+        static ContentView()
+        {
+            ElementHandlerRegistry.RegisterElementHandler<ContentView>(
+                renderer => new ContentViewHandler(renderer, new XF.ContentView()));
+        }
+
+#pragma warning disable CA1721 // Property names should not match get methods
+        [Parameter] public RenderFragment ChildContent { get; set; }
+#pragma warning restore CA1721 // Property names should not match get methods
+
+        protected override RenderFragment GetChildContent() => ChildContent;
+    }
+}

src/Blaxamarin.Framework/Elements/Frame.cs

@@ -0,0 +1,38 @@
+using Blaxamarin.Framework.Elements.Handlers;
+using Emblazon;
+using Microsoft.AspNetCore.Components;
+using XF = Xamarin.Forms;
+
+namespace Blaxamarin.Framework.Elements
+{
+    public class Frame : ContentView
+    {
+        static Frame()
+        {
+            ElementHandlerRegistry
+                .RegisterElementHandler<Frame>(renderer => new FrameHandler(renderer, new XF.Frame()));
+        }
+
+        [Parameter] public bool? HasShadow { get; set; }
+        [Parameter] public XF.Color? BorderColor { get; set; }
+        [Parameter] public float? CornerRadius { get; set; }
+
+        protected override void RenderAttributes(AttributesBuilder builder)
+        {
+            base.RenderAttributes(builder);
+
+            if (HasShadow != null)
+            {
+                builder.AddAttribute(nameof(HasShadow), HasShadow.Value);
+            }
+            if (BorderColor != null)
+            {
+                builder.AddAttribute(nameof(BorderColor), AttributeHelper.ColorToString(BorderColor.Value));
+            }
+            if (CornerRadius != null)
+            {
+                builder.AddAttribute(nameof(CornerRadius), AttributeHelper.SingleToString(CornerRadius.Value));
+            }
+        }
+    }
+}

src/Blaxamarin.Framework/Elements/Handlers/ContentViewHandler.cs

@@ -0,0 +1,15 @@
+using Emblazon;
+using XF = Xamarin.Forms;
+
+namespace Blaxamarin.Framework.Elements.Handlers
+{
+    public class ContentViewHandler : TemplatedViewHandler
+    {
+        public ContentViewHandler(EmblazonRenderer renderer, XF.ContentView contentViewControl) : base(renderer, contentViewControl)
+        {
+            ContentViewControl = contentViewControl ?? throw new System.ArgumentNullException(nameof(contentViewControl));
+        }
+
+        public XF.ContentView ContentViewControl { get; }
+    }
+}

src/Blaxamarin.Framework/Elements/Handlers/FrameHandler.cs

@@ -0,0 +1,35 @@
+using Emblazon;
+using System;
+using XF = Xamarin.Forms;
+
+namespace Blaxamarin.Framework.Elements.Handlers
+{
+    public class FrameHandler : ContentViewHandler
+    {
+        public FrameHandler(EmblazonRenderer renderer, XF.Frame frameControl) : base(renderer, frameControl)
+        {
+            FrameControl = frameControl ?? throw new ArgumentNullException(nameof(frameControl));
+        }
+
+        public XF.Frame FrameControl { get; }
+
+        public override void ApplyAttribute(ulong attributeEventHandlerId, string attributeName, object attributeValue, string attributeEventUpdatesAttributeName)
+        {
+            switch (attributeName)
+            {
+                case nameof(XF.Frame.HasShadow):
+                    FrameControl.HasShadow = AttributeHelper.GetBool(attributeValue);
+                    break;
+                case nameof(XF.Frame.BorderColor):
+                    FrameControl.BorderColor = AttributeHelper.StringToColor((string)attributeValue);
+                    break;
+                case nameof(XF.Frame.CornerRadius):
+                    FrameControl.CornerRadius = AttributeHelper.StringToSingle((string)attributeValue);
+                    break;
+                default:
+                    base.ApplyAttribute(attributeEventHandlerId, attributeName, attributeValue, attributeEventUpdatesAttributeName);
+                    break;
+            }
+        }
+    }
+}

src/Blaxamarin.Framework/Elements/Handlers/TemplatedViewHandler.cs

@@ -0,0 +1,16 @@
+using Emblazon;
+using System;
+using XF = Xamarin.Forms;
+
+namespace Blaxamarin.Framework.Elements.Handlers
+{
+    public class TemplatedViewHandler : LayoutHandler
+    {
+        public TemplatedViewHandler(EmblazonRenderer renderer, XF.TemplatedView templatedViewControl) : base(renderer, templatedViewControl)
+        {
+            TemplatedViewControl = templatedViewControl ?? throw new ArgumentNullException(nameof(templatedViewControl));
+        }
+
+        public XF.TemplatedView TemplatedViewControl { get; }
+    }
+}

src/Blaxamarin.Framework/Elements/TemplatedView.cs

@@ -0,0 +1,8 @@
+namespace Blaxamarin.Framework.Elements
+{
+    public class TemplatedView : Layout
+    {
+        // TODO: Look in the future how to support a ControlTemplate:
+        // https://docs.microsoft.com/en-us/xamarin/xamarin-forms/app-fundamentals/templates/control-templates/creating
+    }
+}