Summary:
So far KWin always updated the active window property even if the actual
window id hasn't changed. E.g. if a Wayland window was active and another
Wayland window gets activated the window id was and stays 0.
Nevertheless KWin updated the property causing wakeups in X server and
any application listening to property changes on the root window.
Futhermore this situation is an information leak: we leak when a Wayland
window gets activated to X11.
To solve this problem RootInfo caches the active window id and only
updates if it changes.
Test Plan:
Verified with xev -root that the active window does not get
updated needlessly.
Reviewers: #kwin, #plasma
Subscribers: plasma-devel, kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D7096
As can be seen in [1] the patches to KWin were in CVS HEAD before the
protocol got standardized and it never got any adoption. It's neither in
the NETWM spec, nor implemented in Qt4 nor in Qt5. KWin did not even add
the protocol to the NET::Supported property.
Thus it doesn't make much sense to keep a protocol which nobody speaks.
Still the code around the protocol is kept and also the names are kept.
Only difference is that Client::takeActivity got removed and the code
moved to the only calling place in Workspace. Motivated by that change
the enum defined in utils.h is moved into Workspace, it's turned into
a proper QFlags class and used as a type in the method argument instead
of a generic long.
[1] https://mail.gnome.org/archives/wm-spec-list/2004-April/msg00013.html
REVIEW: 116922
It's not a typical singleton as the ctor is not taking a Workspace* and
needs addtional data to be passed to NETRootInfo.
All the initialization code is moved to RootInfo::create() and the tear-
down code is moved to RootInfo::destroyed(). This includes the support
window which used to be a member of Workspace. It's only needed by
RootInfo, so there is no need to have the ownership inside Workspace.
Instead of using a QWidget we just create a normal window through xcb.
It gets destroyed again in the tear-down code after the RootInfo got
destroyed.
REVIEW: 110238
Main motivation for this change is that it's unhandy to have the class
definition in workspace.h and client.h while the implementation is in
events.cpp although nothing in events.cpp uses it directly.
By getting it out of workspace.h we get the header a little bit smaller
which should improve compile time given that it's included almost
everywhere.
In events.cpp the enum usage is changed to NETWinInfo as that's the class
where they are defined.
RootInfo does no longer hold a workspace pointer. Where it's needed it
uses the singleton accessor of Workspace.
REVIEW: 110199
