Progress bar
Design annotations are needed for specific instances shown below, but for the standard progress bar component, Carbon already incorporates accessibility.
What Carbon provides
Carbon bakes keyboard operation into its components, improving the experience of blind users and others who operate via keyboard. Carbon also incorporates other accessibility considerations, some of which are described below.
Keyboard interaction
The progress bar itself is not keyboard operable; however, when a progress bar is active, it may temporarily disable any dependent components. For example, if a progress bar is being used to upload a file, the Upload button is disabled until the progress bar state changes to either error or completed.
Progress bars are not interactive, but may temporarily disable dependent components.
Labelling and states
The label above the progress bar as well as the optional helper text below it are surfaced to assistive technologies. Changes to the helper text are provided programmatically as status updates.
The label, the progress bar’s status, and the optional helper text underneath are all surfaced to assistive technologies.
Design recommendations
Design annotations are needed for the following instance.
Provide status for indeterminate and errored progress bars
The indeterminate progress bar does not measure progress, and so cannot programmatically inform the user when the process is complete. Also, neither variant of the progress bar can programmatically indicate to assistive technologies when it is in error. Information on both outcomes must be presented in the help text below the progress bar.
Helper text is required when a progress bar is in error or indeterminate.
Development considerations
Keep this in mind if you’re modifying Carbon or creating a custom component:
- Carbon uses
aria-valuemin,aria-valuemax,aria-valuenow, andaria-busyto provide status on the progress bar. Due to inconsistent support for these attributes, Carbon also assigns anaria-live="polite"to the container holding the helper text. - Carbon uses
aria-labelledbyandaria-describedbyto associate the label and helper text with the component. - The red error and green success SVG icons have
aria-hidden="true"set, since the helper text and aria attributes provide the same information.