From f996808760f9bb869c60b7b8810725ff49b9b394 Mon Sep 17 00:00:00 2001
From: Peter Hutterer <peter.hutterer@who-t.net>
Date: Mon, 12 Aug 2019 13:22:18 +1000
Subject: [PATCH] Prefix undefined event codes with an underscore
Previously, event codes without a kernel define would resolve into properly
named objects, e.g. libevdev.EV_REL.REL_0B
This breaks the API whenever the kernel introduces a new define because that
named object will just disappear. e.g. the above REL_0B is now
REL_WHEEL_HI_RES.
Since the undefined names aren't supposed to be used by callers directly
anyway, rename them to be underscored instead: libevdev.EV_REL._REL_0B
This means we can still return them from evbit() and events() but the
underscore signals a private API.
The actual name remains the same, so print(_REL_0B.name) will not have an
underscore. This is to avoid bugs/breakage where the caller uses the 3-lettter
prefix for other purposes.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
---
libevdev/const.py | 24 +++++++++++++++++++-----
test/test_const.py | 4 ++++
2 files changed, 23 insertions(+), 5 deletions(-)
diff --git a/libevdev/const.py b/libevdev/const.py
index eeb19ee..b68c517 100644
--- a/libevdev/const.py
+++ b/libevdev/const.py
@@ -91,7 +91,17 @@ class EventCode(EvdevBit):
.. attribute:: name
- The string name of this event code
+ The string name of this event code. Where the name is not defined, a
+ fake name is generated by this module, consisting of the prefix and
+ the uppercase hexadecimal value, e.g. ``REL_0B``. These generated
+ names (see :func:`EventCode.is_defined()`) should never be used as
+ input.
+
+ Note that even defined names are not a stable API. From time to time
+ the kernel introduces a new name and aliases the old one. The same
+ numeric event code may then return a different name than before.
+ This does not affect the :func:`evbit()` function which continues to
+ return the correct event code.
.. attribute:: type
@@ -356,15 +366,19 @@ def _load_consts():
codes = []
for c in range(cmax + 1):
cname = Libevdev.event_to_name(t, c)
+ name = cname
has_name = cname is not None
- # For those without names, we just use the type name plus
- # hexcode
+ # For those without names, we use the type name plus
+ # hexcode for the actual name, but a prefixing underscore for
+ # the class name (it's not stable API).
+ # i.e. libedev.EV_REL._REL_0B.name == 'REL_0B'
if cname is None:
- cname = "{}_{:02X}".format(tname[3:], c)
+ name = "{}_{:02X}".format(tname[3:], c)
+ cname = "_{}".format(name)
new_class = type(cname, (EventCode, ),
{'type': type_object,
- 'name': cname,
+ 'name': name,
'value': c,
'is_defined': has_name})
code_object = new_class()
diff --git a/test/test_const.py b/test/test_const.py
index 6563d56..3c9ce28 100644
--- a/test/test_const.py
+++ b/test/test_const.py
@@ -97,6 +97,10 @@ class TestEventBits(unittest.TestCase):
else:
self.assertEqual(c.name, fake_name)
+ def test_evcode_undefined(self):
+ self.assertEqual(evbit('SYN_04'), libevdev.EV_SYN._SYN_04)
+ self.assertEqual(libevdev.EV_SYN._SYN_04.name, 'SYN_04')
+
def test_propbit_string(self):
self.assertEqual(propbit('INPUT_PROP_POINTER'), libevdev.INPUT_PROP_POINTER)
self.assertEqual(propbit('INPUT_PROP_DIRECT'), libevdev.INPUT_PROP_DIRECT)
--
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