Qt doesn't print proper error messages for any errors caused by
extensions. As KWin is a heavy user of extensions not of interest to Qt
(e.g. damage or composite) we do our own error code mapping.
The Xcb::ExtensionData is extended by a vector of OpCodes and ErrorNames.
In ::workspaceEvent it's checked whether the event is an error and if
that is the case KWin tries to map the error to one of the extensions.
If that is successful it prints a warning looking like Qt's one:
XCB error: 151 (BadDamage), sequence: 12534, resource id: 127926362, \
major code: 143 (DAMAGE), minor code: 2 (Destroy)
and the event gets filtered out, so that the Qt error messages is not
printed in addition.
If the error is not from one of the extensions the error is not filtered
out and so the default Qt behavior gets applied.
REVIEW: 117421
KWin::Cursor can track changes to the cursor image. It supports a
start/stop tracking to not handle these events if nobody is interested in
them. When enabled and the cursor image changes a signal is emitted with
the serial number of the new cursor image.
To track cursor image changes xcb_xfixes_select_cursor_input is used (see
XFixes Version 5.0 protocol, section 7).
This could be useful for the zoom effect when it replaces the cursor.
REVIEW: 110519
Code section had been in an #ifndef NDEBUG which is the reason why I did
not find the usage of Extensions there and why it always compiled
successfully.
Some data elements which got dropped needed to be added again like a name
for the extension and errorBase, etc.
Sorry for the inconvenience of a semi-broken master.
The extension handling is removed from kwinglobals and moved into the
xcbutils in KWin core in namespace KWin::Xcb. The motivation for this
change is that the Extensions are only used in KWin core and are marked
as internal. So there is no need to have them in the library.
What remains in Extensions are the non-native pixmaps. This will be
removed once we are on Qt 5 as QPixmap can no longer reference an XPixmap.
The remaining code in kwinglobals also still initialize the XLib versions
of extensions emitting events. It seems like there are no XEvents emitted
if not done so even if the extension is correctly initialized with xcb.
This needs to be removed once the event handling is ported over to xcb.
REVIEW: 107832
