NumberBox: Forward information to the inner TextBox for better UIA experience

dev/NumberBox/APITests/NumberBoxTests.cs

@@ -11,6 +11,9 @@
 using Microsoft.UI.Xaml.Controls;
 using Windows.UI.Xaml.Controls.Primitives;
 using Windows.UI.Xaml.Input;
+using MUXControls.TestAppUtils;
+using Windows.UI.Xaml.Automation.Peers;
+using Windows.UI.Xaml.Automation;
 
 #if USING_TAEF
 using WEX.TestExecution;
@@ -49,7 +52,7 @@ public void VerifyTextAlignmentPropogates()
         [TestMethod]
         public void VerifyNumberBoxCornerRadius()
         {
-            if (PlatformConfiguration.IsOSVersionLessThan(OSVersion.Redstone5))
+            if (Common.PlatformConfiguration.IsOSVersionLessThan(Common.OSVersion.Redstone5))
             {
                 Log.Warning("NumberBox CornerRadius property is not available pre-rs5");
                 return;
@@ -171,6 +174,53 @@ public void VerifyIsEnabledChangeUpdatesVisualState()
             });
         }
 
+        [TestMethod]
+        public void VerifyUIANameBehavior()
+        {
+            NumberBox numberBox = null;
+            TextBox textBox = null;
+
+            RunOnUIThread.Execute(() =>
+            {
+                numberBox = new NumberBox();
+                Content = numberBox;
+                Content.UpdateLayout();
+
+                textBox = TestPage.FindVisualChildrenByType<TextBox>(numberBox)[0];
+                Verify.IsNotNull(textBox);
+                numberBox.Header = "Some header";
+            });
+
+            IdleSynchronizer.Wait();
+
+            RunOnUIThread.Execute(() =>
+            {
+                VerifyUIAName("Some header");
+                numberBox.Header = new Button();
+                AutomationProperties.SetName(numberBox, "Some UIA name");
+            });
+
+            IdleSynchronizer.Wait();
+
+            RunOnUIThread.Execute(() =>
+            {
+                VerifyUIAName("Some UIA name");
+                numberBox.Header = new Button();
+            });
+
+            IdleSynchronizer.Wait();
+
+            RunOnUIThread.Execute(() =>
+            {
+                VerifyUIAName("Some UIA name");
+            });
+
+            void VerifyUIAName(string value)
+            {
+                Verify.AreEqual(value, FrameworkElementAutomationPeer.CreatePeerForElement(textBox).GetName());
+            }
+        }
+
         private NumberBox SetupNumberBox()
         {
             NumberBox numberBox = null;

dev/NumberBox/NumberBox.cpp

@@ -46,6 +46,10 @@ NumberBox::NumberBox()
 
     SetDefaultStyleKey(this);
     SetDefaultInputScope();
+
+    // We are not revoking this since the event and the listener reside on the same object and as such have the same lifecycle.
+    // That means that as soon as the NumberBox gets removed so will the event and the listener.
+    this->RegisterPropertyChangedCallback(winrt::AutomationProperties::NameProperty(), { this , &NumberBox::OnAutomationPropertiesNamePropertyChanged });
 }
 
 void NumberBox::SetDefaultInputScope()
@@ -361,6 +365,32 @@ void NumberBox::OnIsEnabledChanged(const winrt::IInspectable&, const winrt::Depe
     UpdateVisualStateForIsEnabledChange();
 }
 
+void NumberBox::OnAutomationPropertiesNamePropertyChanged(const winrt::DependencyObject&, const winrt::DependencyProperty&)
+{
+    ReevaluateForwardedUIAName();
+}
+
+void NumberBox::ReevaluateForwardedUIAName()
+{
+    if (const auto textBox = m_textBox.get())
+    {
+        const auto name = winrt::AutomationProperties::GetName(*this);
+        if (!name.empty())
+        {
+            // AutomationProperties.Name is a non empty string, we will use that value.
+            winrt::AutomationProperties::SetName(textBox, name);
+        }
+        else
+        {
+            if (const auto headerAsString = Header().try_as<winrt::IReference<winrt::hstring>>())
+            {
+                // Header is a string, we can use that as our UIA name.
+                winrt::AutomationProperties::SetName(textBox, headerAsString.Value());
+            }
+        }
+    }
+}
+
 void NumberBox::UpdateVisualStateForIsEnabledChange()
 {
     winrt::VisualStateManager::GoToState(*this, IsEnabled() ? L"Normal" : L"Disabled", false);
@@ -686,6 +716,11 @@ void NumberBox::UpdateHeaderPresenterState()
         {
             // Header is not a string, so let's show header presenter
             shouldShowHeader = true;
+            // When our header isn't a string, we use the NumberBox's UIA name for the textbox's UIA name.
+            if (const auto textBox = m_textBox.get())
+            {
+                winrt::AutomationProperties::SetName(textBox, winrt::AutomationProperties::GetName(*this));
+            }
         }
     }
     if(const auto headerTemplate = HeaderTemplate())
@@ -706,6 +741,8 @@ void NumberBox::UpdateHeaderPresenterState()
     {
         headerPresenter.Visibility(shouldShowHeader ? winrt::Visibility::Visible : winrt::Visibility::Collapsed);
     }
+
+    ReevaluateForwardedUIAName();
 }
 
 void NumberBox::MoveCaretToTextEnd()

dev/NumberBox/NumberBox.h

@@ -70,6 +70,9 @@ class NumberBox :
     void OnNumberBoxScroll(winrt::IInspectable const& sender, winrt::PointerRoutedEventArgs const& args);
     void OnCornerRadiusPropertyChanged(const winrt::DependencyObject&, const winrt::DependencyProperty&);
     void OnIsEnabledChanged(const winrt::IInspectable&, const winrt::DependencyPropertyChangedEventArgs&);
+    void OnAutomationPropertiesNamePropertyChanged(const winrt::DependencyObject&, const winrt::DependencyProperty&);
+
+    void ReevaluateForwardedUIAName();
 
     void ValidateInput();
     void CoerceMinimum();