If you are using a XAML AutosuggestBox or the HTML intrinsic controls, then this experience is already hooked up for you by default. This is common in the To: line of a mail field, the Cortana search box in Windows, the URL entry field in Microsoft Edge, the location entry field in the Weather app, and so on. When a user types into an entry field and a list of potential suggestions appears, this type of scenario is called auto-suggest. You should test this out yourself with Narrator to get a sense of the user experience with your app when using a screen reader to examine your app's static text. Assistive technology users expect that anything in the tab order is interactive, and if they encounter static text there, that is more confusing than helpful. So don't put your static text into focusable containers just so that tab order gets the user there. Screen readers are typically designed to support multiple modes of reading the content in an app, including a dedicated reading mode or navigation patterns that go beyond focus and the tab order, like a "virtual cursor". But that does not mean that assistive technologies can't or won't read them. Neither of these are a Control subclass, and as such neither of them are keyboard-focusable or can appear in the tab order. In the text models for XAML, there are two elements that are primarily used for static text, TextBlock and RichTextBlock. So if you put static text in a TextBox, you are misreporting the role and thus misreporting the structure of your app to the accessibility user. When a control reports that is has a role of Edit, assistive technologies assume that there are ways for users to change the values. RichTextBlock (and overflow class RichTextBlockOverflow): role is Text.You may need to enter foreground and background color values manually in the tool, or make screen captures of app UI and then run the contrast ratio tool over the screen capture image.Ī UWP app can use these default elements (commonly called text elements or textedit controls): Some of the tools listed by Techniques for WCAG 2.0 G18 can't be used interactively with a UWP app. See Techniques for WCAG 2.0 G18 (Resources section) for tools that can test contrast ratios. Use color contrast tools to verify that the visible text contrast ratio is acceptable. For example, if random words are used to create a background, and the words can be rearranged or substituted without changing meaning, the words are considered to be decorative and do not need to meet this criterion. Text that is decorative and conveys no information is excluded. Exceptions include logos and incidental text, such as text that is part of an inactive UI component. To be considered accessible, visible text must have a minimum luminosity contrast ratio of 4.5:1 against the background. This guidance exists in the W3C Techniques for WCAG 2.0 specification. The recommendations for text contrast documented here are based on a web accessibility standard, G18: Ensuring that a contrast ratio of at least 4.5:1 exists between text (and images of text) and background behind the text. Checking and correcting the contrast ratio can prevent these types of accessibility issues. For example, if you have red text on a green background, that text might not be readable to someone with a color blindness impairment. Evaluation of the level of contrast is based on deterministic techniques that do not consider color hue. A much better practice is to make sure that your app text meets certain established guidelines for the level of contrast between text and its background. This topic also discusses the Microsoft UI Automation roles that text elements in a Universal Windows Platform (UWP) app can have, and best practices for text in graphics.Īlthough users always have the option to switch to a high-contrast mode, your app design for text should regard that option as a last resort. This topic describes best practices for accessibility of text in an app, by assuring that colors and backgrounds satisfy the necessary contrast ratio.
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