See Understanding Techniques for WCAG Success Criteria for important information about the usage of these informative techniques and how they relate to the normative WCAG 2.0 success criteria. The Applicability section explains the scope of the technique, and the presence of techniques for a specific technology does not imply that the technology can be used in all situations to create content that meets WCAG 2.0.
Microsoft Silverlight, versions 3 and greater
Silverlight managed programming model and Silverlight XAML
This technique relates to:
See User Agent Support Notes for SL25. Also see Silverlight Technology Notes.
The objective of this technique is to use the combination of Silverlight control activation and programmatic focus to enable the user to skip regions of content in a Silverlight application user interface.
The control that the user activates should clearly indicate that its purpose is to skip content, so that the resulting programmatic focus shift is not interpreted as an undesired change of context.
The object to call focus to (the receiver of focus after the user-initiated
action is triggered) has to be a Control in the Silverlight
programming model. This is because the Focus method
must be called on the target, and therefore the target must inherit
the Control class. So, an application author might
call focus to a read-only TextBox, or perhaps a RichTextBox,
depending on the purpose of the Silverlight application and its user
interface design. You can also focus a UserControl,
for cases where the area to call focus to represents a custom control
implementation.
Silverlight provides a TabIndex attribute that can
be used to override the default-generated tab sequence. Do not attempt
to adjust tab index as a technique for getting past content blocks.
Doing so will create a focus order that does not match the apparent
visual order, as described in SC
2.4.3.
The following is the XAML for the user interface.
<StackPanel Name="LayoutRoot">
<Button Name="bypassbtn1" Click="bypassbtn1_Click">Skip menus, go to main page content</Button>
<!intervening content-->
<StackPanel>
<RichTextBox Name="rtb_MainContent" IsReadOnly="True">
<Paragraph>Here is the main content ....</Paragraph>
</RichTextBox>
</StackPanel>
</StackPanel>
The following is the event handler that forces focus.
private void bypassbtn1_Click(object sender, RoutedEventArgs e)
{
rtb_MainContent.Focus();
}
This example is shown in operation in the working example of Programmatic Focus.
Resources are for information purposes only, no endorsement implied.
Open the test HTML page for a Silverlight application.
Check for a control that indicates that activating that control can skip to some particular region of the content.
Activate that control. Verify that activating the control causes focus to go to that region, and that a repeated block or blocks of content are skipped.
#2 and #3 are true.
If this is a sufficient technique for a success criterion, failing this test procedure does not necessarily mean that the success criterion has not been satisfied in some other way, only that this technique has not been successfully implemented and can not be used to claim conformance.