Merge pull request #4508 from noubar/#2166-automatiopeer-numericupdown

#2166 automatiopeer for numericupdown

Author: punker76

src/MahApps.Metro.Samples/MahApps.Metro.Demo/ExampleViews/TextExamples.xaml

@@ -376,7 +376,8 @@
                 </mah:MetroHeader>
 
                 <mah:MetroHeader Header="Min">
-                    <mah:NumericUpDown Margin="{StaticResource ControlMargin}"
+                    <mah:NumericUpDown AutomationProperties.AutomationId="AutomationIdTested" 
+                                       Margin="{StaticResource ControlMargin}"
                                        mah:TextBoxHelper.ClearTextButton="True"
                                        Maximum="{Binding ElementName=NUD, Path=Maximum, Mode=OneWay}"
                                        Value="{Binding ElementName=NUD, Path=Minimum, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />

src/MahApps.Metro/Automation/Peers/NumericUpdDownAutomationPeer.cs

@@ -0,0 +1,28 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Windows.Automation.Peers;
+using JetBrains.Annotations;
+using MahApps.Metro.Controls;
+
+namespace MahApps.Metro.Automation.Peers
+{
+    public class NumericUpdDownAutomationPeer : FrameworkElementAutomationPeer
+    {
+        public NumericUpdDownAutomationPeer([NotNull] NumericUpDown owner)
+            : base(owner)
+        {
+        }
+
+        protected override string GetClassNameCore()
+        {
+            return nameof(NumericUpDown);
+        }
+
+        protected override AutomationControlType GetAutomationControlTypeCore()
+        {
+            return AutomationControlType.Edit;
+        }
+    }
+}

src/MahApps.Metro/Controls/NumericUpDown.cs

@@ -16,6 +16,8 @@
 using System.Windows.Input;
 using JetBrains.Annotations;
 using MahApps.Metro.ValueBoxes;
+using MahApps.Metro.Automation.Peers;
+using System.Windows.Automation.Peers;
 
 namespace MahApps.Metro.Controls
 {
@@ -1019,6 +1021,14 @@ public override void OnApplyTemplate()
             this.scrollViewer = null;
         }
 
+        /// <summary>
+        /// Creates AutomationPeer (<see cref="UIElement.OnCreateAutomationPeer"/>)
+        /// </summary>
+        protected override AutomationPeer OnCreateAutomationPeer()
+        {
+            return new NumericUpdDownAutomationPeer(this);
+        }
+
         private void ToggleReadOnlyMode(bool isReadOnly)
         {
             if (this.repeatUp is null || this.repeatDown is null || this.valueTextBox is null)