← Otto User GuideAccessibility

Otto supports screen readers through AT-SPI, the standard Linux accessibility bus. Orca is the screen reader this is built and tested against.

What works

Orca’s keyboard shortcuts. Otto hands Orca the keys it asks for, including its modifier. This is the part that does not work on most Wayland compositors: without it Orca starts but every one of its commands does nothing.
The desktop itself. The dock is announced by application name and says which applications are running; the app switcher reads out the entry you are moving to; workspaces are read with their names. The top bar reads its menus, its clock and each tray icon, and a notification is read as it arrives.
Otto’s own applications (Settings, Files, the launcher) describe what they are showing, down to a file’s kind and size and the contents of a preview.
The keyboard reaches them. Every control in an Otto application is a Tab stop with a ring drawn around it, and can be operated without a pointer. See the next section.
Pointing at things works. Each window tells the compositor where it is, so Orca’s mouse review, a magnifier following the focus, and braille routing all land on the control actually under the pointer rather than on whatever happens to sit at the same offset from the corner of the screen.
It speaks your language. Descriptions follow the desktop’s locale, not Otto’s development language: an Italian desktop is read in Italian.
Other applications read as they do anywhere else. GTK and Qt applications publish themselves to the accessibility bus on their own.

Using Otto’s applications from the keyboard

This works with or without a screen reader. It is ordinary keyboard operation, and the ring shows where you are.

Key	What it does
`Tab` / `Shift+Tab`	Move between the controls of the focused window, wrapping at the ends and skipping anything disabled
`Space` / `Enter`	Operate the control: flip a switch, press a button, open a pop-up, start editing a text field
`←` `→`	Move a slider
`↑` `↓`	Move within a list, or open a pop-up
`Esc`	Close a pop-up without changing anything

A pop-up button opens rather than cycling. Arrowing along a closed pop-up would change the setting once per value you passed, and every value in one of these lists commits the moment it is chosen — so Space, Enter, ↑ or ↓ opens the list instead, on the value it is currently showing. Inside it the arrows move a highlight, Home and End go to the ends, Enter chooses, and Esc closes it with the setting untouched.

Setting it up

Install the accessibility bus and a screen reader:

sudo pacman -S at-spi2-core orca      # Arch
sudo dnf install at-spi2-core orca    # Fedora
sudo apt install at-spi2-core orca    # Debian/Ubuntu

Then start Orca from a terminal, the launcher, or your autostart:

orca --replace

Nothing else has to be configured. Otto publishes the accessibility interfaces whenever it is running a real session.

Orca still needs Xwayland for some of its own machinery, so leave Otto’s Xwayland support enabled.

Turning it off

Add this to your config to stop Otto exposing accessibility altogether:

[accessibility]
enabled = false

The only reason to is if something else on your system is trying to own the same interfaces.

Known limitations

The lock screen and the greeter are not accessible. Every key there belongs to the locker, screen readers included.
Text fields are read as a whole, not character by character: Otto’s own applications report what a field contains, but not caret-by-caret review.
There is no built-in magnifier, and no screen curtain.
In Files, the listing and the previews are described but the sidebar, the path bar and the toolbar are not yet: you can read a folder, but moving to another one needs the pointer.
In Settings, the arrangement diagram at the top of the Displays pane, the one you drag screens around in, is not described, so choosing which display the settings below apply to needs the pointer. Every other control in the pane is reachable. The shortcut lines in the Keyboard pane are not reachable yet either.
A nested Otto (otto --winit, for development) does not publish its own desktop: the session hosting it owns the accessibility bus and the key grabs. Applications running inside it still describe themselves normally.

Otto and its applications only publish themselves once something declares itself an assistive technology. Orca does that; if you are testing without one, nothing will be on the bus until you set it yourself: busctl --user set-property org.a11y.Bus /org/a11y/bus org.a11y.Status IsEnabled b true
Check the accessibility bus is there: busctl --user status org.a11y.Bus
Check Otto is offering key grabs: busctl --user introspect org.freedesktop.a11y.Manager /org/freedesktop/a11y/Manager If the name is unowned, either accessibility.enabled is false or another process claimed it first. Check Otto’s log for “Could not own the a11y manager name”.
Check the application itself is on the bus with accerciser, which lists every accessible application. If it is not there, the problem is that application’s, not Otto’s.