This is in particular to avoid flickering in dwm (and high CPU usage)
when hovering the mouse over a tabbed window that was previously
managed by dwm.
Consider the following two scenarios:
1)
We start tabbed (window 0xc000003), tabbed is managed by the
window manager.
We start st being embedded into tabbed.
$ st -w 0xc000003
What happens here is that:
- tabbed gets a MapRequest for the st window
- tabbed reparents the st window
- tabbed will receive X events for the window
The window manager will have no awareness of the st window and the
X server will not send X events to the window manager relating to
the st window.
There is no flickering or any other issues relating to focus.
2)
We start tabbed (window 0xc000003), tabbed is managed by the
window manager.
We start st as normal (window 0xd400005).
What happens here is that:
- the window manager gets a MapRequest for the st window
- dwm manages the st window as a normal client
- dwm will receive X events for the window
Now we use xdotool to trigger a reparenting of the st window into
tabbed.
$ xdotool windowreparent 0xd400005 0xc000003
What happens here is that:
- tabbed gets a MapRequest for the st window
- tabbed reparents the st window
- the window manager gets an UnmapNotify
- the window manager no longer manages the st window
- both the window manager and tabbed will receive X events
for the st window
In dwm move the mouse cursor over the tabbed window.
What happens now is that:
- dwm will receive a FocusIn event for the tabbed window
- dwm will set input focus for the tabbed window
- tabbed will receive a FocusIn event for the main window
- tabbed will give focus to the window on the currently selected
tab
- which again triggers a FocusIn event which dwm receives
- dwm determines that the window that the FocusIn event is for
(0xd400005) is not the currently selected client (tabbed)
- dwm sets input focus for the tabbed window
- this causes an infinite loop as long as the mouse cursor hovers
the tabbed window, resulting in flickering and high CPU usage
The fix here is to tell the X server that we are no longer interested
in receiving events for this window when the window manager stops
managing the window.
Commit 8806b6e237 ("manage: propertynotify: Reduce cost of unused size
hints") mistakenly removed an early size hints update that's needed to
populate c->isfixed for floating checks at manage() time. This resulted
in fixed (size hint min dimensions == max dimensions) subset of windows
not floating when they should.
See https://lists.suckless.org/dev/2204/34730.html for discussion.
When monitors are removed, the coordinates of existing monitors may
change, if the removed monitors had smaller coordinates than the
remaining ones.
Remove special case handling so that the same update-if-necessary loop
is run also in the case when monitors are removed.
This patch defers all size hint calculations until they are actually
needed, drastically reducing the number of calls to updatesizehints(),
which can be expensive when called repeatedly (as it currently is during
resizes).
In my unscientific testing this reduces calls to updatesizehints() by
over 90% during a typical work session. There are no functional changes
for users other than an increase in responsiveness after resizes and
a reduction in CPU time.
In slower environments or X servers, this patch also offers an
improvement in responsiveness that is often tangible after resizing a
client that changes hints during resizes.
There are two main motivations to defer this work to the time of hint
application:
1. Some clients, especially terminals using incremental size hints,
resend XA_WM_NORMAL_HINTS events on resize to avoid fighting with the
WM or mouse resizing. For example, some terminals like urxvt clear
PBaseSize and PResizeInc during XResizeWindow and restore them
afterwards.
For this reason, after the resize is concluded, we typically receive
a backlogged XA_WM_NORMAL_HINTS message for each update period with
movement, which is useless. In some cases one may get hundreds or
thousands of XA_WM_NORMAL_HINTS messages on large resizes, and
currently all of these result in a separate updatesizehints() call,
of which all but the final one are immediately outdated.
(We can't just blindly discard these messages during resizes like we
do for EnterNotify, because some of them might actually be for other
windows, and may not be XA_WM_NORMAL_HINTS events.)
2. For users which use resizehints=0 most of these updates are unused
anyway -- in the normal case where the client is not floating these
values won't be used, so there's no need to calculate them up front.
A synthetic test using the mouse to resize a floating terminal window
from roughly 256x256 to 1024x1024 and back again shows that the number
of calls to updatesizehints() goes from over 500 before this patch (one
for each update interval with movement) to 2 after this patch (one for
each hint application), with no change in user visible behaviour.
This also reduces the delay before dwm is ready to process new events
again after a large resize on such a client, as it avoids the thundering
herd of updatesizehints() calls when hundreds of backlogged
XA_WM_NORMAL_HINTS messages appear at once after a resize is finished.
In certain instances trans may be set to a window that doesn't actually
map to a client via wintoclient; in this case it doesn't make sense
to set isfloating/oldstate since trans is essentially invalid in that
case / correlates to the above condition check where trans is set /
XGetTransientForHint is called.
maybe leak isn't the best word, given that the object lives for the
entire duration of the program's lifetime.
however, all elements of scheme are free-ed, can't think of any reason
why scheme itself should be an exception.
I noticed that a non-trivial amount of dwm's work on my machine was from
drw_text, which seemed weird, because I have the bar disabled and we
only use drw_text as part of bar drawing.
Looking more closely, I realised that while we use m->showbar when
updating the monitor bar margins, but don't skip actually drawing the
bar if it is hidden. This patch skips drawing it entirely if that is the
case.
On my machine, this takes 10% of dwm's on-CPU time, primarily from
restack() and focus().
When the bar is toggled on again, the X server will generate an Expose
event, and we'll redraw the bar as normal as part of expose().
It generally doesn't make much sense to allow focusstack() to navigate
away from the selected fullscreen client, as you can't even see which
client you're selecting behind it.
I have had this up for a while on the wiki as a separate patch[0], but
it seems reasonable to avoid this behaviour in dwm mainline, since I'm
struggling to think of any reason to navigate away from a fullscreen
client other than a mistake.
0: https://dwm.suckless.org/patches/alwaysfullscreen/
Many users new to dwm find themselves caught out by being kicked out to the login manager (dwm crashing) when they open 50+ clients for demonstration purposes. The number of clients reported varies depending on the resolution of the monitor.
The cause of this is due to how the default tile layout calculates the height of the next client based on the position of the previous client. Because clients have a minimum size the (ty) position can exceed that of the window height, resulting in (m->wh - ty) becoming negative. The negative height stored as an unsigned int results in a very large height ultimately resulting in dwm crashing.
This patch adds safeguards to prevent the ty and my positions from exceeding that of the window height.
This jarred me a bit while reading the code, since "sw" usually refers
to the global screen geometry, but in drawbar() only it refers to
text-related geometry. Renaming it makes it more obvious that these are
not related.
There are two places that mfact can be set:
- In the mfact global, which is defined at compile time and passed
into m->mfact during monitor setup. No bounds checks are performed,
but the comment alongside it says that valid values are [0.05..0.95]:
static const float mfact = 0.55; /* factor of master area size [0.05..0.95] */
- By setmfact, which adjusts m->mfact at runtime. It also does some
minimum and maximum bounds checks, allowing [0.1..0.9]. Values outside
of that range are ignored, and mfact is not adjusted.
These different thresholds mean that one cannot setmfact 0.95 or 0.05,
despite the comment above that lists the legal range for mfact.
Clarify this by enforcing the same bounds in setmfact at runtime as
those listed for mfact at compile time.
In dwm.c function declarations are in alphabetical order except for
updategeom(). There doesn't appear to be any reason for this, so this
patch corrects that, and now all function declarations are in
alphabetical order.
Reported by Kernc, thanks!
"This makes a particular program that uses libwnck [1] fail after:
Wnck-WARNING **: Property _NET_WM_NAME contained invalid UTF-8
in this code [2] because the returned string contains a '\0' and the
documentation for g_utf8_validate() [3] explicitly states that when
string length is provided, no nul bytes are allowed."
It is not entirely clear it is incorrect, other WM's seem to not
NUL terminate it either though.
Before this change it is not possible to press a button in a client on the first
click if the client is not yet focused. The first click on the button would
only focus the client and a second click on the button is needed to activate it.
This situation can occur when moving the mouse over a client (therefore focusing
it) and then moving the focus to another client with keyboard shortcuts.
After this commit the behavior is fixed and button presses on unfocused clients
are passed to the client correctly.
- unify multi-line expression alignment style.
- unify multi-line function call alignment style.
- simplify client moving on monitor count decrease.
- clarify comment for focusin().
- remove old confusing comment about input focus fix in focusmon(). The
explanation is already in the old commit message, so no need to keep it in the
code.
- remove old comment describing even older state of the code in focus().
- unify comment style.
- break up some long lines.
- fix some typos and grammar.
Configuring geometry before applying rules makes it possible to have
more complex constraints in applyrules that depend on the initial window
dimensions and location.
Some clients try to set _NET_WM_STATE_FULLSCREEN even when the window is
already in fullscreen.
For example, c->oldstate was set two times in a raw and window would
then always be floating.
We must check that it's not the case before processing it.
(original patch modified with suggestion from Markus Teich
<markus.teich@stusta.mhn.de>)
Stein
Hiltjo Posthuma
NRK
Chris Down
Santtu Lakkala
Miles Alan
Quentin Rameau
Ian Remmler
Klemens Nanni
Christopher Drelich
Omar Sandoval
Daniel Cousens
Anselm R Garbe
Markus Teich
Eric Pruitt
Quentin Rameau