From d21c3cce1ef1a38037d589aad9d126a36b17df11 Mon Sep 17 00:00:00 2001
From: Tim U <tim.uniewki@gmail.com>
Date: Wed, 5 Jan 2022 11:17:38 +0100
Subject: [PATCH] Improve Demo

- Set the focus to the TextBox of the NumericUpDown
---
 samples/ControlCatalog/Pages/DataGridPage.xaml   |  2 +-
 .../ControlCatalog/Pages/DataGridPage.xaml.cs    | 16 ++++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/samples/ControlCatalog/Pages/DataGridPage.xaml b/samples/ControlCatalog/Pages/DataGridPage.xaml
index 451a774cb4..f7e3cf2441 100644
--- a/samples/ControlCatalog/Pages/DataGridPage.xaml
+++ b/samples/ControlCatalog/Pages/DataGridPage.xaml
@@ -72,7 +72,7 @@
                 </DataGridTemplateColumn.CellTemplate>
                 <DataGridTemplateColumn.CellEditingTemplate>
                   <DataTemplate DataType="local:Person">
-                    <NumericUpDown Value="{Binding Age}" FormatString="N0" HorizontalAlignment="Stretch" Minimum="0" Maximum="120" />
+                    <NumericUpDown Value="{Binding Age}" FormatString="N0" HorizontalAlignment="Stretch" Minimum="0" Maximum="120" TemplateApplied="NumericUpDown_OnTemplateApplied" />
                   </DataTemplate>
                 </DataGridTemplateColumn.CellEditingTemplate>
               </DataGridTemplateColumn>
diff --git a/samples/ControlCatalog/Pages/DataGridPage.xaml.cs b/samples/ControlCatalog/Pages/DataGridPage.xaml.cs
index ec2c6651de..c010d38eac 100644
--- a/samples/ControlCatalog/Pages/DataGridPage.xaml.cs
+++ b/samples/ControlCatalog/Pages/DataGridPage.xaml.cs
@@ -6,7 +6,9 @@ using Avalonia.Controls;
 using Avalonia.Markup.Xaml;
 using ControlCatalog.Models;
 using Avalonia.Collections;
+using Avalonia.Controls.Primitives;
 using Avalonia.Data;
+using Avalonia.Threading;
 
 namespace ControlCatalog.Pages
 {
@@ -84,5 +86,19 @@ namespace ControlCatalog.Pages
                 return Comparer.Default.Compare(x, y);
             }
         }
+
+        private void NumericUpDown_OnTemplateApplied(object sender, TemplateAppliedEventArgs e)
+        {
+            // We want to focus the TextBox of the NumericUpDown. To do so we search for this control when the template
+            // is applied, but we postpone the action until the control is actually loaded. 
+            if (e.NameScope.Find<TextBox>("PART_TextBox") is {} textBox)
+            {
+                Dispatcher.UIThread.InvokeAsync(() =>
+                {
+                    textBox.Focus();
+                    textBox.SelectAll();
+                }, DispatcherPriority.Loaded);
+            }
+        }
     }
 }