private string GetSimpleAccessibilityName()
{
if (FeatureConfiguration.AutomationPeer.UseSimpleAccessibility &&
Owner is View view &&
AutomationProperties.GetAccessibilityView(Owner) != AccessibilityView.Raw)
{
/// We get our name by aggregating the name of all our children.
/// See <see cref="FeatureConfiguration.AutomationPeer.UseSimpleAccessibility" /> for details.
return(string.Join(", ", view
.EnumerateAllChildren()
.OfType <IFrameworkElement>()
.Where(child => child.Visibility == Visibility.Visible)
.Select(child =>
{
// We set this for two reasons:
// - We want to disable accessibility focus for elements whose names are aggregated into the name of their parent.
// - We want to prevent these elements from enumerating their own children in GetSimpleAccessibilityName(),
// which might be called as a result of calling automationPeer.GetName() below.
AutomationProperties.SetAccessibilityView(child, AccessibilityView.Raw);
return child;
})
.Select(FromIFrameworkElement)
.Where(automationPeer => automationPeer != null)
.Select(automationPeer => automationPeer.GetName())
.Where(childName => !string.IsNullOrEmpty(childName))
));
}
/// <summary>
/// Updates name on <paramref name="element"/> from <see cref="AccessibilityLabelAttachedProperty"/>
/// or from generation, and then updates all parents' generated names where update is due.
/// </summary>
/// <param name="element"></param>
private static void UpdateName(UIElement element)
{
// Update name on the element itself from AccessibilityLabel or name generation.
var peer = FrameworkElementAutomationPeer.FromElement(element);
if (IsInGenerativeState(element))
{
if (AutomationProperties.GetAccessibilityView(element) != AccessibilityView.Raw)
{
var generatedName = GenerateNameFromUpdated(peer);
AutomationProperties.SetName(element, generatedName);
}
}
else
{
var accessibilityLabel = GetAccessibilityLabelAttached(element);
if (string.IsNullOrEmpty(accessibilityLabel))
{
element.ClearValue(AutomationProperties.NameProperty);
}
else
{
AutomationProperties.SetName(element, accessibilityLabel);
}
}
// Update generated names only starting from parent and up.
var parentPeer = peer.Navigate(AutomationNavigationDirection.Parent) as AutomationPeer;
if (parentPeer != null)
{
UpdateGeneratedNameHereAndUp(parentPeer);
}
}
public ImplicitTextBlock(DependencyObject parent)
{
// Propagate the parent's (ContentPresenter or ContentControl) AutomationProperties.AccessibilityView to ImplicitTextBlock once.
var accessibilityView = AutomationProperties.GetAccessibilityView(parent);
AutomationProperties.SetAccessibilityView(this, accessibilityView);
}
internal override void OnInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info)
{
if (!AutomationConfiguration.IsAccessibilityEnabled)
{
return;
}
var isAccessible = AutomationProperties.GetAccessibilityView(Owner) != AccessibilityView.Raw;
if (isAccessible)
{
// TODO: Set View.Focusable and View.FocusableInTouchMode to true to ensure SendAccessibilityEvent gets called?
info.Focusable = isAccessible;
info.ContentDescription = GetName();
info.Password = IsPassword();
info.Enabled = IsEnabled();
// TODO: Use GetAutomationControlType() and GetPattern() instead
info.Clickable = GetClickable();
info.Checked = GetChecked();
info.Checkable = GetCheckable();
info.Editable = GetEditable();
info.InputType = GetInputType();
info.MultiLine = GetMultiline();
info.Selected = GetSelected();
info.MaxTextLength = GetMaxTextLength();
info.Scrollable = GetScrollable();
}
}
public void VerifyAccessibilityView()
{
RunOnUIThread.Execute(() =>
{
var progressRing = new ProgressRing();
progressRing.IsActive = true;
Verify.AreNotEqual(AccessibilityView.Raw, AutomationProperties.GetAccessibilityView(progressRing));
progressRing.IsActive = false;
Verify.AreEqual(AccessibilityView.Raw, AutomationProperties.GetAccessibilityView(progressRing));
});
}
/// <summary>
/// Update <see cref="AutomationProperties.NameProperty"/> on <paramref name="peer"/>'s owner
/// and all its parents as far up as needed and only when the name is generated. This must be called
/// when anything influencing generated names has changed in <paramref name="peer"/>'s owner or somewhere in its subtree.
/// </summary>
/// <param name="peer"></param>
private static void UpdateGeneratedNameHereAndUp(AutomationPeer peer)
{
var current = peer;
while (current != null)
{
UIElement element = GetUIElementFromAutomationPeer(current);
if (IsElementIgnoresChildrenForName(element))
{
break;
}
if (IsInGenerativeState(element) &&
(AutomationProperties.GetAccessibilityView(element) != AccessibilityView.Raw))
{
var generatedName = GenerateNameFromUpdated(current);
AutomationProperties.SetName(element, generatedName);
}
current = current.Navigate(AutomationNavigationDirection.Parent) as AutomationPeer;
}
}
internal override bool UpdateAccessibilityElement()
{
if (!AutomationConfiguration.IsAccessibilityEnabled)
{
return(false);
}
var isAccessible = AutomationProperties.GetAccessibilityView(Owner) != AccessibilityView.Raw;
if (isAccessible && Owner is UIView view)
{
view.AccessibilityLabel = GetName();
view.AccessibilityTraits = GetAccessibilityTraits();
// TODO
//view.AccessibilityHint
//view.AccessibilityValue
//view.AccessibilityElementsHidden
//view.AccessibilityNavigationStyle
}
return(isAccessible);
}
/// <summary>
/// Sets AccessibilityView property for <paramref name="element"/> and its children according to
/// the element's <paramref name="importantForAccessibility"/> property and
/// <see cref="AccessibilityLabelAttachedProperty"/> values.
/// </summary>
/// <param name="element"></param>
/// <param name="elementPeer"></param>
/// <param name="importantForAccessibility"></param>
private static void UpdateAccessibilityViewForUIElement(UIElement element, AutomationPeer elementPeer, ImportantForAccessibility importantForAccessibility)
{
switch (importantForAccessibility)
{
case ImportantForAccessibility.Auto when GetAccessibilityLabelAttached(element) == null:
element.ClearValue(AutomationProperties.AccessibilityViewProperty);
SetChildrenAccessibilityViewFromImportantForAccessibility(elementPeer);
break;
case ImportantForAccessibility.Auto when GetAccessibilityLabelAttached(element) != null:
case ImportantForAccessibility.Yes:
var currentAccessibilityView = AutomationProperties.GetAccessibilityView(element);
AutomationProperties.SetAccessibilityView(element, AccessibilityView.Content);
// Generate the label in case the element was hidden.
if (currentAccessibilityView == AccessibilityView.Raw)
{
UpdateName(element);
}
SetChildrenAccessibilityView(elementPeer, AccessibilityView.Raw);
break;
case ImportantForAccessibility.No:
AutomationProperties.SetAccessibilityView(element, AccessibilityView.Raw);
SetChildrenAccessibilityViewFromImportantForAccessibility(elementPeer);
break;
case ImportantForAccessibility.NoHideDescendants:
AutomationProperties.SetAccessibilityView(element, AccessibilityView.Raw);
SetChildrenAccessibilityView(elementPeer, AccessibilityView.Raw);
break;
default:
break;
}
}
/// <summary> /// True if the <paramref name="element"/> generates name, but it is not visible to narrator. /// </summary> /// <param name="element"></param> /// <returns></returns> private static bool IsInGenerativeStateAndHidden(UIElement element) => AutomationProperties.GetAccessibilityView(element) == AccessibilityView.Raw && IsInGenerativeState(element);
protected override bool IsControlElementCore() => AutomationProperties.GetAccessibilityView(Owner) >= AccessibilityView.Control;
public void ExpanderAutomationPeerTest()
{
RunOnUIThread.Execute(() =>
{
var root = (StackPanel)XamlReader.Load(
@"<StackPanel xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'
xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
xmlns:primitives='using:Microsoft.UI.Xaml.Controls.Primitives'
xmlns:controls='using:Microsoft.UI.Xaml.Controls'>
<controls:Expander x:Name ='ExpandedExpander' AutomationProperties.Name='ExpandedExpander' IsExpanded='True' Margin='12' HorizontalAlignment='Left'>
<controls:Expander.Header>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition />
<ColumnDefinition Width='80'/>
</Grid.ColumnDefinitions>
<StackPanel Margin='0,14,0,16'>
<TextBlock AutomationProperties.Name='test' Text='This expander is expanded by default.' Margin='0,0,0,4' />
<TextBlock Text='This is the second line of text.' />
</StackPanel>
<ToggleSwitch Grid.Column='1'/>
</Grid>
</controls:Expander.Header>
<Button AutomationProperties.AutomationId = 'ExpandedExpanderContent'> Content </Button>
</controls:Expander>
</StackPanel>");
Content = root;
Content.UpdateLayout();
var expander = VisualTreeHelper.GetChild(root, 0) as Expander;
expander.IsExpanded = true;
Content.UpdateLayout();
var grid = VisualTreeHelper.GetChild(expander, 0);
var toggleButton = VisualTreeHelper.GetChild(grid, 0);
var toggleButtonGrid = VisualTreeHelper.GetChild(toggleButton, 0);
var contentPresenter = VisualTreeHelper.GetChild(toggleButtonGrid, 0);
var grid2 = VisualTreeHelper.GetChild(contentPresenter, 0);
var stackPanel = VisualTreeHelper.GetChild(grid2, 0);
var textBlock1 = VisualTreeHelper.GetChild(stackPanel, 0) as TextBlock;
var textBlock2 = VisualTreeHelper.GetChild(stackPanel, 1) as TextBlock;
var toggleSwitch = VisualTreeHelper.GetChild(grid2, 1) as ToggleSwitch;
var border = VisualTreeHelper.GetChild(grid, 1);
var expanderContentBorder = VisualTreeHelper.GetChild(border, 0);
var expanderContentContentPresenter = VisualTreeHelper.GetChild(expanderContentBorder, 0);
var button = VisualTreeHelper.GetChild(expanderContentContentPresenter, 0) as Button;
Verify.AreEqual("ExpandedExpander", AutomationProperties.GetName(expander));
// Verify ExpandedExpander header content are included in the accessibility tree
Verify.AreEqual(AutomationProperties.GetAccessibilityView(textBlock1), AccessibilityView.Content);
Verify.AreEqual(AutomationProperties.GetAccessibilityView(textBlock2), AccessibilityView.Content);
Verify.AreEqual(AutomationProperties.GetAccessibilityView(toggleSwitch), AccessibilityView.Content);
// Verify ExpandedExpander content is included in the accessibility tree
Verify.AreEqual(AutomationProperties.GetAccessibilityView(button), AccessibilityView.Content);
expander.IsExpanded = false;
Content.UpdateLayout();
// Verify ExpandedExpander content is not included in the accessibility tree and not readable once collapsed
Verify.AreNotEqual(AutomationProperties.GetAccessibilityView(button), AccessibilityView.Raw);
});
}
