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mirror of https://github.com/NixOS/mobile-nixos.git synced 2024-12-13 12:35:48 +03:00
mobile-nixos/boot/lib/evdev/__init.rb
2021-01-01 21:37:29 -05:00

61 lines
1.8 KiB
Ruby

module Evdev
module FFI
extend Fiddle::BasicTypes
extend Fiddle::Importer
# Indirection to pass an int as an output argument.
Int = union ["int value"]
dlload("libevdev.so.2")
# https://www.freedesktop.org/software/libevdev/doc/latest/
extern "struct libevdev * libevdev_new ()"
extern "int libevdev_set_fd ( struct libevdev * , int )"
extern "void libevdev_free ( struct libevdev * )"
extern "int libevdev_has_event_type ( const struct libevdev * , unsigned int )"
extern "const char* libevdev_get_name ( const struct libevdev * )"
extern "int libevdev_fetch_event_value ( const struct libevdev *, unsigned int, unsigned int, int *)"
end
# Checks whether any of the given keys (by symbol) are held.
# Thus, this is an OR type of operation.
def self.keys_held(keys)
# Temp var for holding return value while we clean up.
ret = false
# `evdev` works on `/dev/input/event*` nodes.
# Check them *all*. We can't know which is a keyboard.
Dir.glob("/dev/input/event*").each do |dev_path|
File.open(dev_path, "r") do |dev|
fd = dev.fileno
evdev = FFI.libevdev_new()
if FFI.libevdev_set_fd(evdev, fd) != 0
$stderr.puts("warning: Could not set fd for #{dev_path}.")
else
# 0 is the initial value.
buf = FFI::Int.malloc(0)
keys.each do |key_name|
FFI.libevdev_fetch_event_value(
evdev,
Linux::InputEventCodes::EV_KEY,
Linux::InputEventCodes.const_get(key_name),
buf
)
# Delay returning until after we free'd
ret = true if buf.value == 1
end
end
FFI.libevdev_free(evdev)
return ret if ret
end
end
return false
end
end