Scenic v0.10.2 Scenic.ViewPort.Driver behaviour View Source
Drivers make up the bottom layer of the Scenic architectural stack. They draw everything on the screen and originate the raw user input. In general, different hardware platforms will need different drivers.
Drivers deal with graphs and do not know anything about scenes. This means that they are pretty generic. Drivers don't really understand that a component is a separate thing either, other than the fact that it has a graph that needs to be drawn.
Link to this section Summary
Functions
Returns a specification to start this module under a supervisor
Invoked when the server is started. start_link/3
or start/3
will
block until it returns
Link to this section Functions
child_spec(init_arg) View Source
Returns a specification to start this module under a supervisor.
See Supervisor
.
init(arg) View Source
Invoked when the server is started. start_link/3
or start/3
will
block until it returns.
init_arg
is the argument term (second argument) passed to start_link/3
.
Returning {:ok, state}
will cause start_link/3
to return
{:ok, pid}
and the process to enter its loop.
Returning {:ok, state, timeout}
is similar to {:ok, state}
except handle_info(:timeout, state)
will be called after timeout
milliseconds if no messages are received within the timeout.
Returning {:ok, state, :hibernate}
is similar to {:ok, state}
except the process is hibernated before entering the loop. See
handle_call/3
for more information on hibernation.
Returning {:ok, state, {:continue, continue}}
is similar to
{:ok, state}
except that immediately after entering the loop
the c:handle_continue/2
callback will be invoked with the value
continue
as first argument.
Returning :ignore
will cause start_link/3
to return :ignore
and
the process will exit normally without entering the loop or calling
c:terminate/2
. If used when part of a supervision tree the parent
supervisor will not fail to start nor immediately try to restart the
GenServer
. The remainder of the supervision tree will be started
and so the GenServer
should not be required by other processes.
It can be started later with Supervisor.restart_child/2
as the child
specification is saved in the parent supervisor. The main use cases for
this are:
- The
GenServer
is disabled by configuration but might be enabled later. - An error occurred and it will be handled by a different mechanism than the
Supervisor
. Likely this approach involves callingSupervisor.restart_child/2
after a delay to attempt a restart.
Returning {:stop, reason}
will cause start_link/3
to return
{:error, reason}
and the process to exit with reason reason
without
entering the loop or calling c:terminate/2
.
Callback implementation for GenServer.init/1
.
start(viewport, config) View Source
start_link(args) View Source
stop(driver_pid) View Source
Link to this section Callbacks
handle_call(any, any, any) View Source
handle_cast(any, any) View Source
handle_info(any, any) View Source
init(viewport, size, config)
View Source
init(
viewport :: GenServer.server(),
size :: Scenic.Math.point(),
config :: any()
) :: {:ok, any()}
init( viewport :: GenServer.server(), size :: Scenic.Math.point(), config :: any() ) :: {:ok, any()}