Add initial nativeeventfilter

See #7732

2 files changed, 129 insertions, 1 deletions

diff --git a/qutebrowser/app.py b/qutebrowser/app.py
index db7eea608..664fb4fa9 100644
--- a/qutebrowser/app.py
+++ b/qutebrowser/app.py
@@ -65,7 +65,7 @@ from qutebrowser.keyinput import macros, eventfilter
 from qutebrowser.mainwindow import mainwindow, prompt, windowundo
 from qutebrowser.misc import (ipc, savemanager, sessions, crashsignal,
                               earlyinit, sql, cmdhistory, backendproblem,
-                              objects, quitter)
+                              objects, quitter, nativeeventfilter)
 from qutebrowser.utils import (log, version, message, utils, urlutils, objreg,
                                resources, usertypes, standarddir,
                                error, qtutils, debug)
@@ -523,6 +523,7 @@ def _init_modules(*, args):
     log.init.debug("Misc initialization...")
     macros.init()
     windowundo.init()
+    nativeeventfilter.init()
 
 
 class Application(QApplication):
diff --git a/qutebrowser/misc/nativeeventfilter.py b/qutebrowser/misc/nativeeventfilter.py
new file mode 100644
index 000000000..feb0f7301
--- /dev/null
+++ b/qutebrowser/misc/nativeeventfilter.py
@@ -0,0 +1,127 @@
+# vim: ft=python fileencoding=utf-8 sts=4 sw=4 et:
+
+# Copyright 2023 Florian Bruhin (The Compiler) <mail@qutebrowser.org>
+#
+# This file is part of qutebrowser.
+#
+# qutebrowser is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# qutebrowser is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with qutebrowser.  If not, see <https://www.gnu.org/licenses/>.
+
+"""Native Qt event filter.
+
+This entire file is a giant WORKAROUND for https://bugreports.qt.io/browse/QTBUG-114334.
+"""
+
+import ctypes
+
+from qutebrowser.qt.core import QAbstractNativeEventFilter
+
+from qutebrowser.misc import objects
+
+
+# Needs to be saved to avoid garbage collection
+_instance = None
+
+
+class xcb_generic_event_t(ctypes.Structure):
+    """https://xcb.freedesktop.org/manual/structxcb__generic__event__t.html"""
+    _fields_ = [
+        ("response_type", ctypes.c_uint8),
+        ("pad0", ctypes.c_uint8),
+        ("sequence", ctypes.c_uint16),
+        ("pad", ctypes.c_uint32 * 7),
+        ("full_sequence", ctypes.c_uint32),
+    ]
+
+class xcb_ge_generic_event_t(ctypes.Structure):
+    """https://xcb.freedesktop.org/manual/structxcb__ge__generic__event__t.html"""
+    _fields_ = [
+        ("response_type", ctypes.c_uint8),
+        ("extension", ctypes.c_uint8),
+        ("sequence", ctypes.c_uint16),
+        ("length", ctypes.c_uint32),
+        ("event_type", ctypes.c_uint16),
+        ("pad0", ctypes.c_uint8 * 22),
+        ("full_sequence", ctypes.c_uint32),
+    ]
+
+
+_XCB_GE_GENERIC = 35
+_PROBLEMATIC_XINPUT_EVENTS = [
+    27,  # XCB_INPUT_GESTURE_PINCH_BEGIN
+    28,  # XCB_INPUT_GESTURE_PINCH_UPDATE
+    29,  # XCB_INPUT_GESTURE_PINCH_END
+    30,  # XCB_INPUT_GESTURE_SWIPE_BEGIN
+    31,  # XCB_INPUT_GESTURE_SWIPE_UPDATE
+    32,  # XCB_INPUT_GESTURE_SWIPE_END
+]
+
+class xcb_query_extension_reply_t(ctypes.Structure):
+    """https://xcb.freedesktop.org/manual/structxcb__query__extension__reply__t.html"""
+    _fields_ = [
+        ('response_type', ctypes.c_uint8),
+        ('pad0', ctypes.c_uint8),
+        ('sequence', ctypes.c_uint16),
+        ('length', ctypes.c_uint32),
+        ('present', ctypes.c_uint8),
+        ('major_opcode', ctypes.c_uint8),
+        ('first_event', ctypes.c_uint8),
+        ('first_error', ctypes.c_uint8),
+    ]
+
+
+class NativeEventFilter(QAbstractNativeEventFilter):
+
+    def __init__(self) -> None:
+        super().__init__()
+        xcb = ctypes.cdll.LoadLibrary('libxcb.so.1')
+        xcb.xcb_connect.restype = ctypes.POINTER(ctypes.c_void_p)
+        xcb.xcb_query_extension_reply.restype = ctypes.POINTER(xcb_query_extension_reply_t)
+
+        conn = xcb.xcb_connect(None, None)
+        assert conn
+        assert not xcb.xcb_connection_has_error(conn)
+
+        # Get major opcode ID of Xinput extension
+        name = b'XInputExtension'
+        cookie = xcb.xcb_query_extension(conn, len(name), name)
+        reply = xcb.xcb_query_extension_reply(conn, cookie, None)
+        assert reply
+
+        if not reply.contents.present:
+            self.xinput_opcode = None
+        else:
+            self.xinput_opcode = reply.contents.major_opcode
+
+        xcb.xcb_disconnect(conn)
+
+    def nativeEventFilter(self, evtype: bytes, message: int) -> Tuple[bool, int]:
+        assert evtype == b'xcb_generic_event_t', evtype
+        event = ctypes.cast(int(message), ctypes.POINTER(xcb_generic_event_t)).contents
+
+        if event.response_type == _XCB_GE_GENERIC:
+            event = ctypes.cast(int(message), ctypes.POINTER(xcb_ge_generic_event_t)).contents
+            if (
+                event.extension == self.xinput_opcode and
+                event.event_type in _PROBLEMATIC_XINPUT_EVENTS
+            ):
+                print("Ignoring problematic XInput event", event.event_type)
+                return (True, 0)
+
+        return (False, 0)
+
+
+def init() -> None:
+    global _instance
+    _instance = NativeEventFilter()
+    objects.qapp.installNativeEventFilter(_instance)