AGL shell

agl-shell

agl_shell

version 7
User interface for Automotive Grade Linux platform

Starting with version 2 of the protocol, the client is required to wait for the 'bound_ok' or 'bound_fail' events in order to proceed further.

In case the client gets a 'bound_fail' event then it should consider that there's another client already bound to the agl_shell protocol. A client that receives a 'bound_ok' event should consider that there's no other client already bound to the interface and can proceed further.

If the client uses an older version of the protocol it will receive automatically an error and the compositor will terminate the connection, if there's another client already bound the interface.

If the client receives the 'bound_fail' event and attempts to use the interface further it will receive an error and the compositor will terminate the connection. After the 'bound_fail' event was received the client should call the destructor, which has been added with version 2 of the protocol. The client is free to try at a later point in time to see if it will receive the 'bound_ok' event, but there's no explicit way of finding out when that event will be delivered. It is assumed that it can infer that information through other means/other channels.

ready()
Client is ready to be shown

Tell the server that this client is ready to be shown. The server will delay presentation during start-up until all shell clients are ready to be shown, and will display a black screen instead. This gives the client an opportunity to set up and configure several surfaces into a coherent interface.

The client that binds to this interface must send this request, otherwise they may stall the compositor unnecessarily.

If this request is called after the compositor has already finished start-up, no operation is performed.

set_background(surface: object<wl_surface>, output: object<wl_output>)
Argument
Type
Description
surfaceobject<wl_surface>
outputobject<wl_output>
Set surface as output's background

Set the surface to act as the background of an output. After this request, the server will immediately send a configure event with the dimensions the client should use to cover the entire output.

The surface must have a "desktop" surface role, as supported by libweston-desktop.

Only a single surface may be the background for any output. If a background surface already exists, a protocol error is raised.

set_panel(surface: object<wl_surface>, output: object<wl_output>, edge: uint<agl_shell.edge>)
Argument
Type
Description
surfaceobject<wl_surface>
outputobject<wl_output>
edgeuint<agl_shell.edge>
Set surface as panel

Set the surface to act as a panel of an output. The 'edge' argument says what edge of the output the surface will be anchored to. After this request, the server will send a configure event with the corresponding width/height that the client should use, and 0 for the other dimension. E.g. if the edge is 'top', the width will be the output's width, and the height will be 0.

The surface must have a "desktop" surface role, as supported by libweston-desktop.

The compositor will take the panel's window geometry into account when positioning other windows, so the panels are not covered.

XXX: What happens if e.g. both top and left are used at the same time? Who gets to have the corner?

Only a single surface may be the panel for an output's edge. If a surface already exists on an edge, a protocol error is raised.

activate_app(app_id: string, output: object<wl_output>)
Argument
Type
Description
app_idstring
outputobject<wl_output>
Make client current window

Ask the compositor to make a toplevel to become the current/focused window for window management purposes.

See xdg_toplevel.set_app_id from the xdg-shell protocol for a description of app_id.

If multiple toplevels have the same app_id, the result is unspecified.

XXX: Do we need feedback to say it didn't work? (e.g. client does not exist)

destroy
Type: destructorsince 2
destroy()
Destroys the factory object
set_activate_region(output: object<wl_output>, x: int, y: int, width: int, height: int)
Argument
Type
Description
outputobject<wl_output>
xint
x position of rectangle
yint
y position of rectangle
widthint
width of rectangle
heightint
height of rectangle
Sets a specific region to activate

A hint for the compositor to use a custom area, rather than inferring the activation area. If any panels are used the compositor computes the activation area by subtracting the panels geometry area. If no panels are used then the entire output is being used. This request changes that as to hint the compositor to use the supplied rectangle and ignore any potential panels that might been set-up previously.

In order for this request to take effect it will need to happen before the 'ready' request in order for the compositor to make use of it. Note that any 'set_panel' request be will not be honored, if this request has been called.

The x and y coordinates use the top-left corner as the origin. The rectangle area shouldn't exceed the output area, while an area smaller than the output, would basically result in showing up the background surface.

deactivate_app(app_id: string)
Argument
Type
Description
app_idstring
De-activate/hide window identified by app_id

Ask the compositor to hide the toplevel window for window management purposes. Depending on the window role, this request will either display the previously active window (or the background in case there's no previously active surface) or temporarily (or until a 'activate_app' is called upon) hide the surface.

All the surfaces are identifiable by using the app_id, and no actions are taken in case the app_id is not/was not present.

See xdg_toplevel.set_app_id from the xdg-shell protocol for a description of app_id.

set_app_float(app_id: string, x: int, y: int)
Argument
Type
Description
app_idstring
xint
x position
yint
y position
Set the window identified by app_id as float

Makes the application identified by app_id as floating. If the application's window is already mapped, in a maximized, normal state, it would transition to the float state.

For applications that want to modify their own state, this request must be done before the initial surface commit in order to take effect.

If the application is already in floating state, this request wouldn't do anything.

There's no persistence of this request, once the application terminated you'll to issue this request again for that particular app_id.

The x, and y values would be initial position of the window where the window surface will be placed.

See xdg_toplevel.set_app_id from the xdg-shell protocol for a description of app_id.

set_app_normal(app_id: string)
Argument
Type
Description
app_idstring
Set the window identified by app_id as normally started

Returns the application identified by app_id as it was in the normal state. This is useful to come back from other states to the maximized state, the normal state applications are started.

set_app_fullscreen(app_id: string)
Argument
Type
Description
app_idstring

Makes the application identified by app_id as fullscreen. If the application's window is already mapped, in a maximized, normal state, it would transition to the fullscreen state.

For applications that want to modify their own state, this request must be done before the initial surface commit in order to take effect.

If the application is already in fullscreen state, this request wouldn't do anything.

There's no persistence of this request, once the application terminated you'll to issue this request again for that particular app_id.

See xdg_toplevel.set_app_id from the xdg-shell protocol for a description of app_id.

bound_ok()
Event sent if binding was ok

Informs the client that it was able to bind the agl_shell interface succesfully. Clients are required to wait for this event before continuing further.

bound_fail()
Event sent if binding was nok

Informs the client that binding to the agl_shell interface was unsuccesfull. Clients are required to wait for this event for continuing further.

app_state(app_id: string, state: uint<agl_shell.app_state>)
Argument
Type
Description
app_idstring
stateuint<agl_shell.app_state>
Event sent when an application suffered state modification

Informs the client that an application has changed its state to another, specified by the app_state enum. Client can use this event to track current application state. For instance to know when the application has started, or when terminated/stopped.

edge { top, bottom, left, right } 
Argument
Value
Description
top0
bottom1
left2
right3

agl_shell_ext

version 1
Extended user interface for Automotive Grade Linux platform

This interface allows another client bind to the agl_shell interface, while there's another shell client already present.

The client should first bind to this interface and then inform the compositor with the 'doas_shell_client' request and it wants to bind to the agl_shell interface. The client is still expected, if using a new version of the agl_shell interface, to wait for the 'bound_ok' and 'bound_fail' events before issueing any other requests/events.

Note that this interface has its limitations, and the compositor would still refuse the act for 'set_panel' or 'set_background' requests of the agl_shell interface if there's already a client that used them.

Any other requests or events should be delievered and handled as it would a client bound to the agl_shell interface.

destroy
Type: destructor
destroy()
Destroys the factory object

Call the destructor once you're ready with agl_shell_ext interface. This would reset the state and would make any requests made on the agl_shell interface be terminated. The client would need to bind again the agl_shell_ext and issue a 'doas_shell_client' request.

doas_shell_client()
Informs the compositor it wants to bind to the agl_shell interface

Prior to binding to agl_shell interface, this request would inform the compositor that it wants to gain access the agl_shell interface. The client is expected to wait for 'doas_shell_client_done' event and check for a successful status before going further with binding to the agl_shell interface.

Event sent as a reply to doas_shell_client

The client should check the status event to verify that the compositor was able to handle the request.

doas_shell_client_status { success, failed } 
Argument
Value
Description
success0
failed1

Compositor Support

No compositor support found

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