Glib::MainLoop(3) User Contributed Perl Documentation Glib::MainLoop(3)NAMEGlib::MainLoop - An event source manager
DESCRIPTION
Event-driven programs need some sort of loop which watches for events
and launches the appropriate actions. Glib::MainLoop provides this
functionality.
Mainloops have context, provided by the MainContext object. For the
most part you can use the default context (see "default"), but if you
want to create a subcontext for a nested loop which doesn't have the
same event sources, etc, you can.
Event sources, attached to main contexts, watch for events to happen,
and launch appropriate actions. Glib provides a few ready-made event
sources, the Glib::Timeout, Glib::Idle, and io watch
("Glib::IO->add_watch").
Under the hood, Gtk+ adds event sources for GdkEvents to dispatch
events to your widgets. In fact, Gtk2 provides an abstraction of
Glib::MainLoop (See "Gtk2->main" and friends), so you may rarely have
cause to use Glib::MainLoop directly.
Note: As of version 1.080, the Glib module uses a custom event source
to ensure that perl's safe signal handling and the glib polling event
loop play nicely together. It is no longer necessary to install a
timeout to ensure that async signals get handled in a timely manner.
METHODS
maincontext thingamabob = Glib::MainContext->new
mainloop = Glib::MainLoop->new ($context=undef, $is_running=FALSE)
· $context (Glib::MainContext thingamabob)
· $is_running (boolean)
integer = Glib::Timeout->add ($interval, $callback, $data=undef,
$priority=G_PRIORITY_DEFAULT)
· $interval (integer) number of milliseconds
· $callback (subroutine)
· $data (scalar)
· $priority (integer)
Run $callback every $interval milliseconds until $callback returns
false. Returns a source id which may be used with
"Glib::Source->remove". Note that a mainloop must be active for
the timeout to execute.
integer = Glib::Idle->add ($callback, $data=undef,
$priority=G_PRIORITY_DEFAULT_IDLE)
· $callback (subroutine)
· $data (scalar)
· $priority (integer)
Run $callback when the mainloop is idle. If $callback returns
false, it will uninstall itself, otherwise, it will run again at
the next idle iteration. Returns a source id which may be used
with "Glib::Source->remove".
integer = Glib::IO->add_watch ($fd, $condition, $callback, $data=undef,
$priority=G_PRIORITY_DEFAULT)
· $fd (Glib::IO) file number, e.g. fileno($filehandle)
· $condition (Glib::IOCondition)
· $callback (subroutine)
· $data (scalar)
· $priority (integer)
Run $callback when there is an event on $fd that matches
$condition. The watch uninstalls itself if $callback returns
false. Returns a source id that may be used with
"Glib::Source->remove".
Glib's IO channels serve the same basic purpose as Perl's file
handles, so for the most part you don't see GIOChannels in Perl.
The IO watch integrates IO operations with the main loop, which
Perl file handles don't do. For various reasons, this function
requires raw file descriptors, not full file handles. See "fileno"
in perlfunc.
maincontext thingamabob = $loop->get_context
maincontext thingamabob = Glib::MainContext->default
boolean = $loop->is_running
boolean = $context->iteration ($may_block)
· $may_block (boolean)
integer = Glib::main_depth
Find the current main loop recursion level. This is handy in
fringe situations, but those are very rare; see the C API reference
for a more in-depth discussion.
boolean = $context->pending
$loop->quit
boolean = Glib::Source->remove ($tag)
· $tag (integer)
Remove an event source. $tag is the number returned by things like
"Glib::Timeout->add", "Glib::Idle->add", and "Glib::IO->add_watch".
$loop->run
ENUMS AND FLAGS
flags Glib::IOCondition
· 'in' / 'G_IO_IN'
· 'out' / 'G_IO_OUT'
· 'pri' / 'G_IO_PRI'
· 'err' / 'G_IO_ERR'
· 'hup' / 'G_IO_HUP'
· 'nval' / 'G_IO_NVAL'
SEE ALSO
Glib
COPYRIGHT
Copyright (C) 2003-2006 by the gtk2-perl team.
This software is licensed under the LGPL. See Glib for a full notice.
perl v5.10.0 2008-08-29 Glib::MainLoop(3)