ExTermbox v0.3.1 ExTermbox.EventManager View Source
This module implements an event manager that notifies subscribers of the keyboard, mouse and resize events received from the termbox API.
It works by running a poll loop that calls out to the NIFs in
ExTermbox.Bindings
:
- The
ExTermbox.Bindings.poll_event/1
NIF is called with the event manager's pid. - The NIF creates a new thread for the blocking poll routine and immediately returns with a resource representing a handle for the thread.
- The thread blocks until an event is received (e.g., a keypress), at which point it sends a message to the event manager with the event data and exits.
- The event manager notifies its subscribers of the event and returns to step 1.
Example Usage:
def event_loop do
receive do
{:event, %Event{ch: ?q} = event} ->
Bindings.shutdown()
{:event, %Event{} = event} ->
# handle the event and wait for another...
event_loop()
end
end
{:ok, pid} = EventManager.start_link()
:ok = EventManager.subscribe(self())
event_loop()
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
Subscribes the given pid to future event notifications
Link to this section Functions
child_spec(arg) View Source
Returns a specification to start this module under a supervisor.
See Supervisor
.
init(atom) View Source
Invoked when the server is started. start_link/3
or start/3
will
block until it returns.
args
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
c: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_link() View Source
subscribe(subscriber_pid) View Source
Subscribes the given pid to future event notifications.