Allow user to set Modal Dialog initial focus element

demo/Ursa.Demo/Dialogs/CustomDemoDialog.axaml

@@ -17,7 +17,10 @@
             <GradientStop Offset="0.9" Color="{DynamicResource SemiLightBlue1Color}" />
         </LinearGradientBrush>
     </UserControl.Background>
-    <Grid Margin="24" RowDefinitions="Auto, *, Auto" MinWidth="400">
+    <Grid
+        MinWidth="400"
+        Margin="24"
+        RowDefinitions="Auto, *, Auto">
         <TextBlock
             Grid.Row="0"
             Margin="8"
@@ -45,7 +48,10 @@
                 Grid.Column="1"
                 Margin="32,8,0,8"
                 Label="Owner">
-                <TextBox u:FormItem.Label="Owner" Text="{Binding Owner}" />
+                <TextBox
+                    u:FocusHelper.DialogFocusHint="True"
+                    u:FormItem.Label="Owner"
+                    Text="{Binding Owner}" />
             </u:FormItem>
             <u:FormItem
                 Grid.Row="1"
@@ -69,15 +75,26 @@
             HorizontalAlignment="Right"
             Orientation="Horizontal"
             Spacing="8">
-            <Button Command="{Binding DialogCommand}" Content="Dialog" Theme="{DynamicResource SolidButton}" />
-            <Button Command="{Binding OKCommand}" Content="OK" Theme="{DynamicResource SolidButton}" Classes="Tertiary"/>
-            <Button Command="{Binding CancelCommand}" Content="Cancel" Theme="{DynamicResource SolidButton}" Classes="Tertiary"/>
+            <Button
+                Command="{Binding DialogCommand}"
+                Content="Dialog"
+                Theme="{DynamicResource SolidButton}" />
+            <Button
+                Classes="Tertiary"
+                Command="{Binding OKCommand}"
+                Content="OK"
+                Theme="{DynamicResource SolidButton}" />
+            <Button
+                Classes="Tertiary"
+                Command="{Binding CancelCommand}"
+                Content="Cancel"
+                Theme="{DynamicResource SolidButton}" />
             <ComboBox>
                 <ComboBoxItem>A</ComboBoxItem>
                 <ComboBoxItem>B</ComboBoxItem>
                 <ComboBoxItem>C</ComboBoxItem>
             </ComboBox>
         </StackPanel>
     </Grid>
-    
+
 </UserControl>

src/Ursa/AssemblyInfo.cs

@@ -3,4 +3,5 @@
 [assembly:XmlnsPrefix("https://irihi.tech/ursa", "u")]
 [assembly:XmlnsDefinition("https://irihi.tech/ursa", "Ursa")]
 [assembly:XmlnsDefinition("https://irihi.tech/ursa", "Ursa.Controls")]
-[assembly:XmlnsDefinition("https://irihi.tech/ursa", "Ursa.Controls.Shapes")]
+[assembly:XmlnsDefinition("https://irihi.tech/ursa", "Ursa.Controls.Shapes")]
+[assembly:XmlnsDefinition("https://irihi.tech/ursa", "Ursa.Helpers")]

src/Ursa/Controls/OverlayShared/OverlayDialogHost.Dialog.cs

@@ -4,6 +4,7 @@
 using Irihi.Avalonia.Shared.Helpers;
 using Irihi.Avalonia.Shared.Shapes;
 using Ursa.Controls.OverlayShared;
+using Ursa.Helpers;
 
 namespace Ursa.Controls;
 
@@ -111,14 +112,20 @@ internal void AddModalDialog(DialogControlBase control)
         SetToPosition(control);
         control.AddHandler(OverlayFeedbackElement.ClosedEvent, OnDialogControlClosing);
         control.AddHandler(DialogControlBase.LayerChangedEvent, OnDialogLayerChanged);
+        // Notice: mask animation here is not really awaited, because currently dialogs appears immediately.
         if (!IsAnimationDisabled) MaskAppearAnimation.RunAsync(mask);
 
-        var element = control.GetVisualDescendants().OfType<InputElement>().FirstOrDefault(a => a.Focusable);
+        var element = control.GetVisualDescendants().OfType<InputElement>()
+                             .FirstOrDefault(FocusHelper.GetDialogFocusHint);
+        if (element is null)
+        {
+            element = control.GetVisualDescendants().OfType<InputElement>().FirstOrDefault(a => a.Focusable);
+        }
         element?.Focus();
         _modalCount++;
         IsInModalStatus = _modalCount > 0;
         control.IsClosed = false;
-        control.Focus();
+        // control.Focus();
     }
 
     // Handle dialog layer change event

src/Ursa/Controls/OverlayShared/OverlayDialogHost.Drawer.cs

@@ -9,6 +9,7 @@
 using Ursa.Common;
 using Ursa.Controls.OverlayShared;
 using Ursa.EventArgs;
+using Ursa.Helpers;
 
 namespace Ursa.Controls;
 
@@ -69,7 +70,13 @@ internal async void AddModalDrawer(DrawerControlBase control)
         {
             await Task.WhenAll(animation.RunAsync(control), MaskAppearAnimation.RunAsync(mask));
         }
-        var element = control.GetVisualDescendants().OfType<InputElement>().FirstOrDefault(a => a.Focusable);
+
+        var element = control.GetVisualDescendants().OfType<InputElement>()
+                             .FirstOrDefault(FocusHelper.GetDialogFocusHint);
+        if (element is null)
+        {
+            element = control.GetVisualDescendants().OfType<InputElement>().FirstOrDefault(a => a.Focusable);
+        }
         element?.Focus();
     }
 

src/Ursa/Helpers/FocusHelper.cs

@@ -0,0 +1,13 @@
+using Avalonia;
+using Avalonia.Input;
+
+namespace Ursa.Helpers;
+
+public class FocusHelper
+{
+    public static readonly AttachedProperty<bool> DialogFocusHintProperty =
+        AvaloniaProperty.RegisterAttached<FocusHelper, InputElement, bool>("DialogFocusHint");
+
+    public static void SetDialogFocusHint(InputElement obj, bool value) => obj.SetValue(DialogFocusHintProperty, value);
+    public static bool GetDialogFocusHint(InputElement obj) => obj.GetValue(DialogFocusHintProperty);
+}

tests/HeadlessTest.Ursa/Controls/OverlayShared/Dialog_Primary_Focus/FocusDialog.axaml

@@ -0,0 +1,10 @@
+<UserControl xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+             xmlns:u="https://irihi.tech/ursa"
+             mc:Ignorable="d" d:DesignWidth="800"
+             d:DesignHeight="450"
+             x:Class="HeadlessTest.Ursa.Controls.OverlayShared.Dialog_Primary_Focus.FocusDialog">
+    <TextBox Text="Hello" u:FocusHelper.DialogFocusHint="True"></TextBox>
+</UserControl>

tests/HeadlessTest.Ursa/Controls/OverlayShared/Dialog_Primary_Focus/FocusDialog.axaml.cs

@@ -0,0 +1,13 @@
+using Avalonia;
+using Avalonia.Controls;
+using Avalonia.Markup.Xaml;
+
+namespace HeadlessTest.Ursa.Controls.OverlayShared.Dialog_Primary_Focus;
+
+public partial class FocusDialog : UserControl
+{
+    public FocusDialog()
+    {
+        InitializeComponent();
+    }
+}

tests/HeadlessTest.Ursa/Controls/OverlayShared/Dialog_Primary_Focus/NormalDialog.axaml

@@ -0,0 +1,9 @@
+<UserControl xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+             mc:Ignorable="d" d:DesignWidth="800"
+             d:DesignHeight="450"
+             x:Class="HeadlessTest.Ursa.Controls.OverlayShared.Dialog_Primary_Focus.NormalDialog">
+    <TextBox Text="Hello"></TextBox>
+</UserControl>

tests/HeadlessTest.Ursa/Controls/OverlayShared/Dialog_Primary_Focus/NormalDialog.axaml.cs

@@ -0,0 +1,13 @@
+using Avalonia;
+using Avalonia.Controls;
+using Avalonia.Markup.Xaml;
+
+namespace HeadlessTest.Ursa.Controls.OverlayShared.Dialog_Primary_Focus;
+
+public partial class NormalDialog : UserControl
+{
+    public NormalDialog()
+    {
+        InitializeComponent();
+    }
+}

tests/HeadlessTest.Ursa/Controls/OverlayShared/Dialog_Primary_Focus/Test.cs

@@ -0,0 +1,74 @@
+using Avalonia.Controls;
+using Avalonia.Headless.XUnit;
+using Avalonia.Threading;
+using Avalonia.VisualTree;
+using Ursa.Controls;
+
+namespace HeadlessTest.Ursa.Controls.OverlayShared.Dialog_Primary_Focus;
+
+public class Test
+{
+    [AvaloniaFact]
+    public async Task Normal_Drawer_Focus_On_Border()
+    {
+        var ursaWindow = new TestWindow();
+        ursaWindow.Show();
+        ursaWindow.InvokeNormalDrawer();
+        Dispatcher.UIThread.RunJobs();
+        await Task.Delay(500);
+        var dialog = ursaWindow.GetVisualDescendants().OfType<DefaultDrawerControl>().FirstOrDefault();
+        Assert.NotNull(dialog);
+        var border = dialog.GetVisualDescendants().OfType<Border>().FirstOrDefault(a=>a.Name == "PART_Root");
+        var text = dialog.GetVisualDescendants().OfType<TextBox>().FirstOrDefault();
+        Assert.True(border?.IsFocused);
+        Assert.False(text?.IsFocused);
+    }
+
+    [AvaloniaFact]
+    public async Task Focus_Drawer_Focus_On_Primary()
+    {
+        var ursaWindow = new TestWindow();
+        ursaWindow.Show();
+        ursaWindow.InvokeFocusDrawer();
+        Dispatcher.UIThread.RunJobs();
+        await Task.Delay(500);
+        var dialog = ursaWindow.GetVisualDescendants().OfType<DefaultDrawerControl>().FirstOrDefault();
+        Assert.NotNull(dialog);
+        var border = dialog.GetVisualDescendants().OfType<Border>().FirstOrDefault(a=>a.Name == "PART_Root");
+        var text = dialog.GetVisualDescendants().OfType<TextBox>().FirstOrDefault();
+        Assert.False(border?.IsFocused);
+        Assert.True(text?.IsFocused);
+    }
+
+    [AvaloniaFact]
+    public async Task Normal_Dialog_Focus_On_Border()
+    {
+        var ursaWindow = new TestWindow();
+        ursaWindow.Show();
+        ursaWindow.InvokeNormalDialog();
+        Dispatcher.UIThread.RunJobs();
+        await Task.Delay(100);
+        var dialog = ursaWindow.GetVisualDescendants().OfType<DefaultDialogControl>().FirstOrDefault();
+        Assert.NotNull(dialog);
+        var border = dialog.GetVisualDescendants().OfType<Border>().FirstOrDefault(a=>a.Name == "PART_Border");
+        var text = dialog.GetVisualDescendants().OfType<TextBox>().FirstOrDefault();
+        Assert.True(border?.IsFocused);
+        Assert.False(text?.IsFocused);
+    }
+
+    [AvaloniaFact]
+    public async Task Focus_Dialog_Focus_On_Primary() 
+    {
+        var ursaWindow = new TestWindow();
+        ursaWindow.Show();
+        ursaWindow.InvokeFocusDialog();
+        Dispatcher.UIThread.RunJobs();
+        await Task.Delay(100);
+        var dialog = ursaWindow.GetVisualDescendants().OfType<DefaultDialogControl>().FirstOrDefault();
+        Assert.NotNull(dialog);
+        var border = dialog.GetVisualDescendants().OfType<Border>().FirstOrDefault(a=>a.Name == "PART_Border");
+        var text = dialog.GetVisualDescendants().OfType<TextBox>().FirstOrDefault();
+        Assert.False(border?.IsFocused);
+        Assert.True(text?.IsFocused);
+    }
+}

tests/HeadlessTest.Ursa/Controls/OverlayShared/Dialog_Primary_Focus/TestWindow.axaml

@@ -0,0 +1,11 @@
+<u:UrsaWindow xmlns="https://github.com/avaloniaui"
+            xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+            xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+            xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+            xmlns:u="https://irihi.tech/ursa"
+            mc:Ignorable="d" d:DesignWidth="800"
+            d:DesignHeight="450"
+            x:Class="HeadlessTest.Ursa.Controls.OverlayShared.Dialog_Primary_Focus.TestWindow"
+            Title="TestWindow">
+    Welcome to Avalonia!
+</u:UrsaWindow>

tests/HeadlessTest.Ursa/Controls/OverlayShared/Dialog_Primary_Focus/TestWindow.axaml.cs

@@ -0,0 +1,36 @@
+using Ursa.Controls;
+using Ursa.Controls.Options;
+
+namespace HeadlessTest.Ursa.Controls.OverlayShared.Dialog_Primary_Focus;
+
+public partial class TestWindow : UrsaWindow
+{
+    public TestWindow()
+    {
+        InitializeComponent();
+    }
+
+    public void InvokeNormalDrawer()
+    {
+        Drawer.ShowModal<NormalDialog, object>("Hello World",
+            options: new DrawerOptions() { TopLevelHashCode = GetHashCode() });
+    }
+
+    public void InvokeFocusDrawer()
+    {
+        Drawer.ShowModal<FocusDialog, object>("Hello World",
+            options: new DrawerOptions() { TopLevelHashCode = GetHashCode() });
+    }
+
+    public void InvokeNormalDialog()
+    {
+        OverlayDialog.ShowModal<NormalDialog, object>("Hello World",
+            options: new OverlayDialogOptions() { TopLevelHashCode = GetHashCode() });
+    }
+
+    public void InvokeFocusDialog()
+    {
+        OverlayDialog.ShowModal<FocusDialog, object>("Hello World",
+            options: new OverlayDialogOptions() { TopLevelHashCode = GetHashCode() });
+    }
+}