WHEN I use the tab key to move focus to the launch button and use spacebar and/or enter key to activate the button
I SEE the sheet dialog opens and is in focus
Then when I use the arrow keys
I SEE content in the sheet dialog is browsed in logical order and does not leave the dialog
Then when I use the tab key
I SEE focus moves to interactive controls in the sheet dialog
Then when I use the escape key
I SEE focus returns to the launch button
Or when I use the tab key to move focus to the dismiss/close button AND THEN use the spacebar or enter key to activate the dismiss/close button
I SEE focus returns to the launch button
2 Desktop screenreader
WHEN I use a desktop screenreader (NVDA, JAWS, VoiceOver)
AND
I use the tab key to move focus to the launch button and use spacebar and/or enter key to activate the button
I HEARThe sheet dialog describes its purpose or title on launch
I HEARIt identifies itself as a dialog
I HEARWhen closed, focus returns to the launch button
I HEARWhen open, content behind the modal remains inert
Then when I use the arrow keys
I HEARcontent in the sheet dialog is browsed in logical order and does not leave the dialog
Then when I use the tab key
I HEARfocus moves to interactive controls in the sheet dialog
Then when I use the escape key
I HEARfocus returns to the launch button
Or when I use the tab key to move focus to the dismiss/close button AND THEN use the spacebar or enter key to activate the dismiss/close button
I HEARfocus returns to the launch button
3
Mobile screenreader
WHEN I use a screenreader
AND
I swipe to focus to the launch button
I HEARThe sheet dialog describes its purpose or title on launch
I HEARIt identifies itself as a dialog
I HEARWhen closed, focus returns to the launch button
I HEARWhen open, content behind the modal remains inert
Then when I doubletap with the button in focus
I HEARthe dialog opens
Then when I swipe within the sheet dialog
I HEARfocus stays trapped in the sheet dialog
Then when I swipe to move focus to the dismiss/close button AND THEN double tap on the close button
I HEARfocus returns to the launch button
1 Keyboard & screen reader actions
When I use
I see/hear
Launch button
Focus visibly moves to the open sheet dialog itself
Arrow keys
Content within the sheet dialog is browsed in logical order
Tab
Focus visibly moves to interactive controls in the sheet dialog, starting with the first interactive control (typically close button)
Escape
The sheet dialog closes and returns focus to the button that launched it
Space
Any buttons are activated
Enter
Any buttons or links are activated
2 Mobile screenreader gestures
When I use
I hear
Swipe
Focus moves within the sheet dialog and doesn't enter the rest of the page.
Doubletap
This typically activates most elements.
3 Screenreader output
Reads
I hear
Name
The sheet dialog describes its purpose or title on launch
Role
It identifies itself as a dialog
Group
When closed, focus returns to the launch button
State
When open, content behind the modal remains inert
A
dialog sheet
must meet WCAG principles:
1
Perceivable
Is easy to identify as a sheet dialog on top of a page (and not a new page)
2
Operable
Is keyboard operable
The close button click/tap target area is no smaller than 44x44px
The focus indication has a 3:1 minimum contrast ratio against adjacent elements
The focus indication has a minimum area equal to the width of the element and 2px in height
3
Understandable
Its purpose and title is clear in the context of the whole page
4
Robust
Conveys the correct semantic role
Meets criteria across platforms, devices and viewports
A sheet dialog is a modal dialog
Sheets are functionally the same as a modal dialog. The only reason there’s an entry for this is because people call it a sheet.