QWaylandSurfaceRole Class

Detailed Description

QWaylandSurfaceRole is used to represent the role of a QWaylandSurface. According to the protocol specification, the role of a surface is permanent once set, and if the same surface is later reused for a different role, this constitutes a protocol error. Setting the surface to the same role multiple times is not an error.

As an example, the QWaylandXdgShell can assign either "popup" or "toplevel" roles to surfaces. If get_toplevel is requested on a surface which has previously received a get_popup request, then the compositor will issue a protocol error.

Roles are compared by pointer value, so any two objects of QWaylandSurfaceRole will be considered different roles, regardless of what their names are. A typical way of assigning a role is to have a static QWaylandSurfaceRole object to represent it.

class MyShellSurfaceSubType
{
    static QWaylandSurfaceRole s_role;
    // ...
};

// ...

surface->setRole(&MyShellSurfaceSubType::s_role, resource->handle, MY_ERROR_CODE);