[FZ Editor] Custom button with automation event on click (#12338)

* Custom button with automation event on click

* Rename MyButton to ClickAutomationEventButton

* Rename property to OnClickAutomationValue

* Remove unneeded line

src/modules/fancyzones/editor/FancyZonesEditor/CanvasEditor.xaml

@@ -2,7 +2,8 @@
              xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
-             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+             xmlns:local="clr-namespace:FancyZonesEditor"
              mc:Ignorable="d" 
              d:DesignHeight="300" d:DesignWidth="300">
     <Grid x:Name="Body">

src/modules/fancyzones/editor/FancyZonesEditor/CanvasEditorWindow.xaml

@@ -34,8 +34,7 @@
         <StackPanel Margin="16"
                     FocusManager.FocusedElement="{Binding ElementName=newZoneButton}">
 
-            <Button x:Name="newZoneButton"
-                    AutomationProperties.LabeledBy="{Binding ElementName=newZoneName}"
+            <local:ClickAutomationEventButton x:Name="newZoneButton"
                     HorizontalAlignment="Stretch"
                     Height="64"
                     Width="64"
@@ -49,7 +48,8 @@
                     ToolTip="{x:Static props:Resources.Add_zone}"
                     DataContext="{Binding Path=Model, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Window}}"
                     IsEnabled="{Binding IsZoneAddingAllowed}"
-                    Click="OnAddZone" />
+                    Click="OnAddZone"
+                    OnClickAutomationValue="{x:Static props:Resources.New_zone_added}" />
 
             <Grid Margin="0,24,0,0">
                 <Grid.ColumnDefinitions>

src/modules/fancyzones/editor/FancyZonesEditor/ClickAutomationEventButton.xaml

@@ -0,0 +1,9 @@
+<Button x:Class="FancyZonesEditor.ClickAutomationEventButton"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
+             xmlns:local="clr-namespace:FancyZonesEditor"
+             mc:Ignorable="d" 
+             d:DesignHeight="450" d:DesignWidth="800">
+</Button>

src/modules/fancyzones/editor/FancyZonesEditor/ClickAutomationEventButton.xaml.cs

@@ -0,0 +1,105 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Windows;
+using System.Windows.Automation;
+using System.Windows.Automation.Peers;
+using System.Windows.Automation.Provider;
+using System.Windows.Controls;
+
+namespace FancyZonesEditor
+{
+    public partial class ClickAutomationEventButton : Button
+    {
+        public ClickAutomationEventButton()
+            : base()
+        {
+            InitializeComponent();
+            Click += OnClick;
+        }
+
+        public string OnClickAutomationValue
+        {
+            get { return (string)GetValue(OnClickAutomationValueProperty); }
+            set { SetValue(OnClickAutomationValueProperty, value); }
+        }
+
+        public static readonly DependencyProperty OnClickAutomationValueProperty =
+        DependencyProperty.Register(
+            "Value", typeof(string), typeof(ClickAutomationEventButton));
+
+        private void OnClick(object sender, RoutedEventArgs e)
+        {
+            if (AutomationPeer.ListenerExists(AutomationEvents.PropertyChanged))
+            {
+                ClickAutomationEventButtonAutomationPeer peer =
+                    UIElementAutomationPeer.FromElement(this) as ClickAutomationEventButtonAutomationPeer;
+
+                if (peer != null)
+                {
+                    peer.RaisePropertyChangedEvent(
+                        ValuePatternIdentifiers.ValueProperty,
+                        null,
+                        OnClickAutomationValue);
+                }
+            }
+        }
+
+        protected override AutomationPeer OnCreateAutomationPeer()
+        {
+            return new ClickAutomationEventButtonAutomationPeer(this);
+        }
+
+        public class ClickAutomationEventButtonAutomationPeer : FrameworkElementAutomationPeer, IValueProvider
+        {
+            public ClickAutomationEventButtonAutomationPeer(ClickAutomationEventButton control)
+                : base(control)
+            {
+            }
+
+            protected override string GetClassNameCore()
+            {
+                return nameof(ClickAutomationEventButton);
+            }
+
+            protected override AutomationControlType GetAutomationControlTypeCore()
+            {
+                return AutomationControlType.Button;
+            }
+
+            public override object GetPattern(PatternInterface patternInterface)
+            {
+                if (patternInterface == PatternInterface.Value)
+                {
+                    return this;
+                }
+
+                return base.GetPattern(patternInterface);
+            }
+
+            public void SetValue(string value)
+            {
+                MyOwner.OnClickAutomationValue = value;
+            }
+
+            private ClickAutomationEventButton MyOwner
+            {
+                get
+                {
+                    return (ClickAutomationEventButton)Owner;
+                }
+            }
+
+            public string Value
+            {
+                get { return MyOwner.OnClickAutomationValue; }
+            }
+
+            public bool IsReadOnly
+            {
+                get { return !IsEnabled(); }
+            }
+        }
+    }
+}

src/modules/fancyzones/editor/FancyZonesEditor/Properties/Resources.resx

@@ -120,6 +120,9 @@
   <data name="Add_zone" xml:space="preserve">
     <value>Add new zone</value>
   </data>
+  <data name="New_zone_added" xml:space="preserve">
+    <value>New zone added</value>
+  </data>
   <data name="Apply" xml:space="preserve">
     <value>Apply</value>
   </data>