LeOS-Genesis/external/badvpn/ncd/examples/events.ncd

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#
# NCD input event handling example program.
#
# This program responds to volume key presses by synchronously calling an external
# script for muting and adjusting volume, and responds to power button presses by
# suspending using pm-suspend.
#
# It uses process_manager() and sys.watch_input() to dynamically create and remove
# processes that deal with specific input devices. The individual input device processes
# then use sys.evdev() to handle input events from their input device.
#
process events_main {
# Volume control script, called with argument "up", "down" or "mute".
var("/usr/local/bin/volumekey") volume_script;
# Suspend command.
list("/usr/sbin/pm-suspend") suspend_cmd;
provide("GLOBAL");
}
process events_watcher {
depend("GLOBAL");
# Create process manager.
process_manager() manager;
# Wait for input device events.
sys.watch_input("event") watcher;
# Dispatch.
concat("events_watcher_", watcher.event_type) func;
call(func, {});
# Next event.
watcher->nextevent();
}
template events_watcher_added {
# Start event handling process for this device.
_caller.manager->start(_caller.watcher.devname, "events_input_device", {_caller.watcher.devname});
}
template events_watcher_removed {
# Stop event handling process for this device.
_caller.manager->stop(_caller.watcher.devname);
}
template events_input_device {
# Alias arguments.
var(_arg0) dev;
# Get global.
depend("GLOBAL") gdep;
# Wait for input events.
sys.evdev(dev) evdev;
# Query event details.
strcmp(evdev.code, "KEY_MUTE") is_mute;
strcmp(evdev.code, "KEY_VOLUMEUP") is_vup;
strcmp(evdev.code, "KEY_VOLUMEDOWN") is_vdown;
strcmp(evdev.code, "KEY_POWER") is_power;
strcmp(evdev.value, "1") is_pressed;
# Compute where to dispatch the event.
and(is_mute, is_pressed) dispatch_mute;
and(is_vup, is_pressed) dispatch_vup;
and(is_vdown, is_pressed) dispatch_vdown;
and(is_power, is_pressed) dispatch_power;
# Dispatch event.
choose({
{dispatch_mute, "events_input_event_mute"},
{dispatch_vup, "events_input_event_vup"},
{dispatch_vdown, "events_input_event_vdown"},
{dispatch_power, "events_input_event_power"}},
"<none>"
) func;
call(func, {});
# Next event.
evdev->nextevent();
}
template events_input_event_mute {
runonce({_caller.gdep.volume_script, "mute"});
}
template events_input_event_vup {
runonce({_caller.gdep.volume_script, "up"});
}
template events_input_event_vdown {
runonce({_caller.gdep.volume_script, "down"});
}
template events_input_event_power {
runonce(_caller.gdep.suspend_cmd);
}