Accessibility Behaviors for General UI Elements

Listed below are specific keystrokes for User Interface (UI) elements, as well as expected screen-reader behavior when a UI element has focus:

Table 2-2 User Interface Element Types

UI Element	Action
Button	Either Enter or Space activates the button, causing the same action as a left click. Note: In Microsoft Edge, the button accelerator is triggered by Alt+<letter>; in Mozilla Firefox, it is triggered by Alt+Shift+<letter>.
ComboBox	Up or down arrow keys display the popup menu and enable value selection. Space or Enter selects an item. If editable, alphanumeric keys cause an edit.
Dialog	If the dialog has an accept button defined, press Enter to activate it. The dialog is modal and blocks all other keyboard events.
Content Area (IFrame)	Press Ctrl+F6 to enter a frame. You may need to press Tab to select the first focusable item. Press Ctrl+Shift+F6 to exit the frame content area and return focus to the frame.
List	The up or down arrow keys move selection focus up or down through the list elements. The selection is continually updated. Ctrl+Up or Ctrl+Down moves focus up or down without changing the current selection. Press Spacebar to add the item to the selection. Shift+Up or Shift+Down key moves focus up or down and adds the item with focus to the selection. Note: If the list supports only a single selection, the Ctrl and Shift modifiers have no effect.
Tab Bar	Left or right arrow key moves selection focus and selects the new tab immediately. Selection focus wraps around the ends of the tab bar.
Text Field	If editable, alphanumeric keys cause an edit. Pressing Tab moves focus to the next element in tab order. Tab cannot be entered as a character in the text field.
Tree	The left and right arrow keys collapse or expand the current node if it has children. If it has no children, there is no effect. The expansion is not recursive. However, if the tree is capable of remembering the previous expansion state of any subnodes, it should do so.