Supported appearances of the indent field, which includes:
NONE- No actions are taken to change the indent field's appearance.
EMPTY- Indent field is set to be invisible (effectively removing it from the display).
SPACER- Blank field that occupies its currently set dimensions.
TYPE- Displays Unicode arrows according to the shortcut's event type (down for KEY_PRESSED, up
for KEY_RELEASED, bidirectional for KEY_TYPED, and an 'X' if disabled).
INDEX- Displays the field's index from the top (starting with one).
Elements of the display (ordered left to right):
Indent- Leading index label or icon.
Action- String component of mapping.
Shortcut- Keystroke component of mapping.