NAME¶
X11::Protocol::WM -- window manager things for client programs
SYNOPSIS¶
use X11::Protocol::WM;
DESCRIPTION¶
This is some window manager related functions for use by client programs, as per
the "Inter-Client Communication Conventions Manual" and some of the
Net-WM "Extended Window Manager Hints".
Usual Properties¶
Every toplevel client window should usually
- •
- "set_wm_class()" to identify itself to other programs (see
"WM_CLASS").
- •
- "set_wm_name()" and "set_wm_icon_name()" for
user-visible identification (see "WM_NAME, WM_ICON_NAME").
- •
- "set_wm_client_machine_from_syshostname()" and
"set_net_wm_pid()" for the running process (see
"WM_CLIENT_MACHINE" and "_NET_WM_PID").
Then optionally,
- •
- If you have an icon image then "set_wm_hints()" with a bitmap or
a window (see "WM_HINTS").
- •
- If the user gave an initial size or position on the command line then
"set_wm_normal_hints()". The same if the program has min/max
sizes or aspect ratio desired (see "WM_NORMAL_HINTS").
- •
- If a command to re-run the program can be constructed then
"set_wm_command()", and preferably keep that up-to-date with
changes such as currently open file etc (see "WM_COMMAND").
FUNCTIONS¶
Text Properties¶
Property functions taking text strings such as "set_wm_name()" accept
either byte strings or Perl 5.8 wide char strings. Byte strings in 5.8 and all
strings in earlier Perl are presumed to be Latin-1 and set as
"STRING" type in properties. Perl 5.8 wide char strings are stored
as "STRING" if entirely Latin-1, or encoded to
"COMPOUND_TEXT" for other chars (see Encode::X11).
In the future perhaps the string functions could accept some sort of compound
text object to represent segments of various encodings to become
"COMPOUND_TEXT", together with manipulations for such content etc.
If text is bytes in one of the ICCCM encodings then it might save some work to
represent it directly as "COMPOUND_TEXT" segments rather than going
to wide chars and back again.
- "set_text_property ($X, $window, $prop, $str)"
- Set the given $prop (integer atom) property on $window (integer XID) using
either "STRING" or "COMPOUND_TEXT" as described above.
If $str is "undef" then $prop is deleted.
$str is limited to "$X->maximum_request_length()". There's no
attempt to store very long strings piecewise. The protocol makes this
limit at least 16384 bytes and the server may allow more, possibly much
more.
WM_CLASS¶
- "X11::Protocol::WM::set_wm_class ($X, $window, $instance,
$class)"
- Set the "WM_CLASS" property on $window (an XID).
This property may be used by the window manager to lookup settings and
preferences for the program through the X Resource system (see
"RESOURCES" in X(7)) or similar.
Usually the instance name is the program command such as "xterm"
and the class name something like "XTerm". Some programs have
command line options to set the class and/or instance so the user can have
different window manager settings applied to a particular running copy of
a program.
X11::Protocol::WM::set_wm_class ($X, $window,
"myprog", "MyProg");
$instance and $class must be ASCII or Latin-1 only. Perl 5.8 wide-char
strings which are Latin-1 are converted as necessary.
WM_CLIENT_MACHINE¶
- "X11::Protocol::WM::set_wm_client_machine ($X, $window,
$hostname)"
- Set the "WM_CLIENT_MACHINE" property on $window to $hostname (a
string).
$hostname should be the name of the client machine as seen from the server.
If $hostname is "undef" then the property is deleted.
Usually a machine name is ASCII-only, but anything per "Text
Properties" above is accepted.
- "X11::Protocol::WM::set_wm_client_machine_from_syshostname ($X,
$window)"
- Set the "WM_CLIENT_MACHINE" property on $window using the
Sys::Hostname module.
If "Sys::Hostname" can't determine a hostname by its various
gambits then currently the property is deleted. Would it be better to
leave it unchanged, or return a flag to say if set?
Some of the "Sys::Hostname" cases might return
"localhost". That's put through unchanged, on the assumption
that it would be when there's no networking beyond the local host so
client and server are always on the same machine and name
"localhost" suffices.
WM_COMMAND¶
- "X11::Protocol::WM::set_wm_command ($X, $window, $command,
$arg...)"
- Set the "WM_COMMAND" property on $window (an XID).
This should be a program name and argument strings which will restart the
client. $command is the program name, followed by any argument strings.
X11::Protocol::WM::set_wm_command ($X, $window,
'myprog',
'--option',
'filename.txt');
A client can set this at any time, or if participating in the
"WM_SAVE_YOURSELF" session manager protocol then it should set
in response to a "WM_SAVE_YOURSELF" "ClientMessage".
The command should start the client in its current state as far as possible,
so the command might include a filename, command line options for current
settings, etc.
Non-ASCII is allowed per "Text Properties" above. The ICCCM spec
is for Latin-1 to work on a POSIX Latin-1 system, but how well anything
else survives a session manager etc is another matter.
WM_ICON_SIZE¶
- "($min_width,$min_height, $max_width,$max_height,
$width_inc,$height_inc) =
X11::Protocol::WM::get_wm_icon_size($X,$root)"
- Return the window manager's "WM_ICON_SIZE" recommended icon
sizes (in pixels) as a range, and increment above the minimum. If there's
no "WM_ICON_SIZE" property then return an empty list.
$root is the root window to read. If omitted then read the
"$X->root" default.
An icon pixmap or window in "WM_HINTS" should be a size in this
range. Many window managers don't set a preferred icon size. 32x32 might
be typical on a small screen or 48x48 on a bigger screen.
WM_HINTS¶
- "X11::Protocol::WM::set_wm_hints ($X, $window, key=>value,
...)"
- Set the "WM_HINTS" property on $window (an XID). For example,
X11::Protocol::WM::set_wm_hints
($X, $my_window,
input => 1,
initial_state => 'NormalState',
icon_pixmap => $my_pixmap);
The key/value parameters are as follows.
input integer 0 or 1
initial_state enum string or number
icon_pixmap pixmap (XID integer), depth 1
icon_window window (XID integer)
icon_x \ integer coordinate
icon_y / integer coordinate
icon_mask pixmap (XID integer)
window_group window (XID integer)
urgency boolean
"input" is 1 if the client wants the window manager to give
$window the keyboard input focus. This will be with
"$X->SetInputFocus()", or if "WM_TAKE_FOCUS" is in
"WM_PROTOCOLS" then instead by a "ClientMessage".
"input" is 0 if the window manager should not give the client the
focus. This is either because $window is output-only, or if
"WM_TAKE_FOCUS" is in "WM_PROTOCOLS" then because the
client will do a "SetInputFocus()" to itself on an appropriate
button press etc.
"initial_state" is a string or number. The ICCCM allows
"NormalState" or "IconicState" as initial states.
"NormalState" 1
"IconicState" 3
"icon_pixmap" should be a pixmap (an XID) with depth 1, ie. a
bitmap. The window manager will draw it in suitable contrasting colours.
"1" pixels are foreground and "0" is background.
"icon_mask" bitmap is applied to the displayed icon. It can be
used to make a non-rectangular icon.
"icon_window" is a window which the window manager may show when
$window is iconified. This can be used for a multi-colour icon, either by
a background or by client drawing (in response to "Expose"
events, or updated periodically for a clock, etc). The window should be a
child of the root and should use the default visual and colormap of the
screen. The window manager might resize the window and/or border.
The window manager might set a "WM_ICON_SIZE" property on the root
window for good icon sizes. See "WM_ICON_SIZE".
"window_group" is the XID of a window which is the group leader of
a group of top-level windows being used by the client. The window manager
might provide a way to manipulate the group as a whole, for example to
iconify it all. If iconified then the icon hints of the leader are used
for the icon. The group leader can be an unmapped window. It can be
convenient to use a never-mapped window as the leader for all subsequent
windows.
"urgency" true means the window is important and the window
manager should draw the user's attention to it in some way. The client can
change this hint at any time to change the current importance.
- "(key => $value, ...) = X11::Protocol::WM::get_wm_hints ($X,
$window)"
- Return the "WM_HINTS" property from $window. The return is a
list of key/value pairs as per "set_wm_hints()" above
input => 1,
icon_pixmap => 1234,
...
Only fields with their flag bits set in the hints are included in the
return. If there's no "WM_HINTS" at all or or its flags field is
zero then the return is an empty list.
The return can be put into a hash to get fields by name,
my %hints = X11::Protocol::WM::get_wm_hints ($X, $window);
if (exists $hints{'icon_pixmap'}) {
print "icon_pixmap is ", $hints{'icon_pixmap'}, "\n";
}
"initial_state" is a string such as "NormalState". The
pixmaps and windows are string "None" if set but zero (which is
probably unusual). If "$X->{'do_interp'}" is disabled then
all are numbers.
X11R2 Xlib had a bug in its "XSetWMHints()" which chopped off the
"window_group" value from the hints stored. The
"window_group" field is omitted from the return in that
case.
- "(key => $value, ...) = X11::Protocol::WM::change_wm_hints ($X,
$window, key=>value, ...)"
- Change some fields of the "WM_HINTS" property on $window. The
given key/value fields are changed. Other fields are left alone. For
example,
X11::Protocol::WM::set_wm_hints ($X, $window,
urgency => 1);
A value "undef" means delete a field,
X11::Protocol::WM::set_wm_hints ($X, $window,
icon_pixmap => undef,
icon_mask => undef);
The change requires a server round-trip to fetch the current values from
$window. An application might prefer to remember its desired hints and
send a full "set_wm_hints()" each time.
- "$bytes = X11::Protocol::WM::pack_wm_hints ($X,
key=>value...)"
- Pack a set of values into a byte string of "WM_HINTS" format.
The key/value arguments are per "set_wm_hints()" above and the
result is the raw bytes stored in a "WM_HINTS" property.
The $X argument is not actually used currently, but is present in case
"initial_state" or other values might use an
"$X->num()" lookup in the future.
- "(key => $value, ...) = X11::Protocol::WM::unpack_wm_hints ($X,
$bytes)"
- Unpack a byte string as a "WM_HINTS" structure. The return is
key/value pairs as per "get_wm_hints()" above. The $X parameter
is used for "do_interp". There's no communication with the
server.
WM_NAME, WM_ICON_NAME¶
- "X11::Protocol::WM::set_wm_name ($X, $window, $name)"
- Set the "WM_NAME" property on $window (an integer XID) to $name
(a string).
The window manager might display this as a title above the window, or in a
menu of windows, etc. It can be a Perl 5.8 wide-char string per "Text
Properties" above. A good window manager ought to support non-ASCII
or non-Latin-1 titles, but how well it displays might depend on fonts
etc.
- "X11::Protocol::WM::set_wm_icon_name ($X, $window, $name)"
- Set the "WM_ICON_NAME" property on $window (an integer XID) to
$name (a string).
The window manager might display this when $window is iconified. If $window
doesn't have an icon (in "WM_HINTS" or from the window manager
itself) then this text might be all that's shown. Either way it should be
something short. It can be a Perl 5.8 wide-char string per "Text
Properties" above.
WM_NORMAL_HINTS¶
- "X11::Protocol::WM::set_wm_normal_hints ($X, $window,
key=>value,...)"
- Set the "WM_NORMAL_HINTS" property on $window (an integer XID).
This is a "WM_SIZE_HINTS" structure which tells the window
manager what sizes the client would like. For example,
set_wm_normal_hints ($X, $window,
min_width => 200,
min_height => 100);
Generally the window manager restricts user resizing to the hint limits.
Most window managers use these hints, but of course they're only hints and
a good program should be prepared for other sizes even if it won't look
good or can't do much useful when too big or too small etc.
The key/value parameters are
user_position boolean, window x,y is user specified
user_size boolean, window width,height is user specified
program_position boolean, window x,y is program specified
program_size boolean, window width,height is program specified
min_width \ integers, min size in pixels
min_height /
max_width \ integers, max size in pixels
max_height /
base_width \ integers, size base in pixels
base_height /
width_inc \ integers, size increment in pixels
height_inc /
min_aspect \ fraction 2/3 or decimal 2 or 1.5
min_aspect_num | or integer num/den up to 0x7FFFFFFF
min_aspect_den |
max_aspect |
max_aspect_num |
max_aspect_den /
win_gravity WinGravity enum "NorthEast" etc
"user_position" and "user_size" are flags meaning that
the window's x,y or width,height (in the usual core
"$X->SetWindowAttributes()") were given by the user, for
example from a "-geometry" command line option. The window
manager will generally obey these values and skip any auto-placement or
interactive placement it might otherwise do.
"program_position" and "program_size" are flags meaning
the window x,y or width,height were calculated by the program. The window
manager might override with its own positioning or sizing policy. There's
generally no need to set these fields unless the program has a definite
idea of where and how big it should be. For a size it's enough to set the
core window width,height and let the window manager (if there's one
running) go from there.
Items shown grouped above must be given together, so for instance if a
"min_width" is given then "min_height" should be given
too.
"base_width","base_height" and
"width_inc","height_inc" ask that the window be a
certain base size in pixels then a multiple of "inc" pixels
above that. This can be used by things like "xterm" which want a
fixed size for border or scrollbar and then a multiple of the character
size above that. If "base_width","base_height" are not
given then "min_width","min_height" is the base size.
"base_width","base_height" can be smaller than
"min_width","min_height". This means the size should
still be a base+inc multiple, but the first such which is at least the min
size. The window manager generally presents the "inc" multiple
to the user, so that for example on an xterm the user sees a count of
characters. A min size can then demand for example a minimum 1x1 or 2x2
character size.
"min_aspect","max_aspect" ask that the window have a
certain minimum or maximum width/height ratio. For example aspect 2/1
means it should be twice as wide as it is high. This is applied to the
size above "base_width","base_height", or if base not
given then to the whole window size.
"min_aspect_num","min_aspect_den" and
"max_aspect_num","max_aspect_den" set numerator and
denominator values directly (INT32, so maximum 0x7FFF_FFFF). Or
"min_aspect" and "max_aspect" accept a single value in
various forms which are turned into num/den values.
2 integer
1.125 decimal, meaning 1125/1000
2/3 fraction
1.5/4.5 fraction with decimals
Values bigger than 0x7FFFFFFF in these forms are reduced proportionally as
necessary. A Perl floating point value will usually have more bits of
precision than 0x7FFFFFFF and is truncated to something that fits.
"win_gravity" is how the client would like to be shifted to make
room for any surrounding frame the window manager might add. For example
if the program calculated the window size and position to ensure the
north-east corner is at a desired position, then give "win_gravity
=> "NorthEast"" so that the window manager keeps the
north-east corner the same when it applies its frame.
"win_gravity => "Static"" means the frame is put
around the window and the window not moved at all. Of course that might
mean some of the frame ends up off-screen.
- "$bytes = X11::Protocol::WM::pack_size_hints ($X,
key=>value,...)"
- Return a bytes string which is a "WM_SIZE_HINTS" structure made
from the given key/value parameters. "WM_SIZE_HINTS" is
structure type for "WM_NORMAL_HINTS" described above and the
key/value parameters are as described above.
The $X parameter is used to interpret "win_gravity" enum values.
There's no communication with the server.
- "($num,$den) = X11::Protocol::WM::aspect_to_num_den
($aspect)"
- Return a pair of INT32 integers 0 to 0x7FFF_FFFF for the given aspect
ratio $aspect. This is the conversion applied to "min_aspect"
and "max_aspect" above. $aspect can be any of the integer,
decimal or fraction described.
WM_PROTOCOLS¶
- "X11::Protocol::WM::set_wm_protocols ($X, $window,
$protocol,...)"
- Set the "WM_PROTOCOLS" property on $window (an XID). Each
argument is a string protocol name or an integer atom ID.
X11::Protocol::WM::set_wm_protocols
($X, $window, 'WM_DELETE_WINDOW', '_NET_WM_PING')
For example "WM_DELETE_WINDOW" means that when the user clicks the
close button the window manager sends a "ClientMessage" event
rather than doing a "KillClient()". The
"ClientMessage" event allows a program to clean-up or ask the
user about saving a document before exiting, etc.
WM_STATE¶
The window manager maintains a state for each client window it manages,
WithdrawnState
NormalState
IconicState
Withdrawn means the window is not mapped and the window manager is not managing
it. A Newly created window ("$X->CreateWindow()") is initially
withdrawn state and on first "$X->MapWindow()" goes to normal
state (or to iconic state if that's the initial state asked for in
"WM_HINTS").
"iconify()" and "withdraw()" below can change the state to
iconic or withdrawn. A window can be restored from iconic to normal state by a
"MapWindow()".
- "($state, $icon_window) = X11::Protocol::WM::get_wm_state ($X,
$window)"
- Return the "WM_STATE" property from $window. This is set by the
window manager on top-level application windows. If there's no such
property then the return is an empty list.
$state returned is an enum string, or an integer value if
"$X->{'do_interp'}" is disabled or the value unrecognised.
"WithdrawnState" 0 not displayed
"NormalState" 1 window displayed
"IconicState" 3 iconified in some way
"ZoomState" 2 \ no longer in ICCCM
"InactiveState" 4 / (zoom meant maximized)
$icon_window returned is the window (integer XID) used by the window manager
to display an icon of $window. If there's no such window then $icon_window
is "None" (or 0 if "$X->{'do_interp'}" is
disabled).
$icon_window might be the icon window from the client's "WM_HINTS"
or it might be a window created by the window manager. The client can draw
into it for animations etc, perhaps selecting "Expose" events on
it to know when to redraw.
"WM_STATE" is set by the window manager when a toplevel window is
first mapped (or perhaps earlier), and then kept up-to-date. Generally no
"WM_STATE" property or a "WM_STATE" set to
WithdrawnState means the window manager is not managing the window, or not
yet doing so. A client can select "PropertyChange" event mask in
the usual way to listen for "WM_STATE" changes.
- "($state, $icon_window) = X11::Protocol::WM::unpack_wm_state ($X,
$bytes)"
- Unpack the bytes of a "WM_STATE" property to a $state and
$icon_window as per "get_wm_state()" above.
$X is used for "$X->{'do_interp'}" but there's no communication
with the server.
- "X11::Protocol::WM::iconify ($X, $window)"
- "X11::Protocol::WM::iconify ($X, $window, $root)"
- Change $window to "IconicState" by sending a
"ClientMessage" to the window manager. If there's no window
manager running then iconification is not possible and this message does
nothing.
$root should be the root window of $window. If not given or
"undef" then it's obtained from a "QueryTree()". Any
client can iconify any top level window.
If $window has other windows which are "WM_TRANSIENT_FOR" for it
then generally the window manager will iconify or hide those windows too
(see "WM_TRANSIENT_FOR" below).
- "X11::Protocol::WM::withdraw ($X, $window)"
- "X11::Protocol::WM::withdraw ($X, $window, $root)"
- Change $window to "WithdrawnState" by an
"$X->UnmapWindow()" and a synthetic "UnmapNotify"
message to the window manager.
If there's no window manager running then the "UnmapWindow()"
unmaps and the "UnmapNotify" message does nothing.
$root should be the root window of $window. If not given or
"undef" then it's obtained from a
"$X->QueryTree()".
If other windows are "WM_TRANSIENT_FOR" this $window (eg. open
dialog windows) then generally the client should withdraw them too. The
window manager might make such other windows inaccessible anyway.
The ICCCM specifies an "UnmapNotify" message so the window manager
is notified of the desired state change even if $window is already
unmapped, such as in "IconicState" or perhaps during some window
manager reparenting, etc.
$window can be changed back to NormalState or IconicState later with
"$X->MapWindow()" the same as for a newly created window.
(And "WM_HINTS" "initial_state" can give a desired
initial iconic/normal state). But before doing so be sure the window
manager has recognised the "withdraw()". This will be when the
window manager changes the "WM_STATE" property to
"WithdrawnState", or deletes that property.
Any client can withdraw any toplevel window, but it's unusual for a client
to withdraw windows which are not its own.
WM_TRANSIENT_FOR¶
- "X11::Protocol::WM::set_wm_transient_for ($X, $window,
$transient_for)"
- Set the "WM_TRANSIENT_FOR" property on $window (an XID).
$transient_for is another window XID, or "undef" if $window is not
transient for anything so "WM_TRANSIENT_FOR" should be deleted.
"Transient for" means $window is some sort of dialog or menu
related to the given $transient_for window. The window manager will
generally iconify $window together with its $transient_for, etc. See
"set_motif_wm_hints()" below for "modal"
transients.
_MOTIF_WM_HINTS¶
- "X11::Protocol::WM::set_motif_wm_hints ($X, $window,
key=>value...)"
- Set the "MOTIF_WM_HINTS" property on $window (an XID).
These hints control window decorations and "modal" state. It
originated in the Motif "mwm" window manager but is recognised
by most other window managers. It should be set on a toplevel window
before mapping. Changes made later might not affect what the window
manager does.
X11::Protocol::WM::set_motif_wm_hints
($X, $dialog_window,
input_mode => "full_application_modal");
$X->MapWindow ($dialog_window);
Ordinary windows generally don't need to restrict their decorations etc, but
something special like a clock or gadget might benefit.
X11::Protocol::WM::set_motif_wm_hints
($X, $my_gadget_window,
functions => 4+32, # move+close
decorations => 1+4+8); # border+title+menu
The key/value arguments are
functions => integer bits
decorations => integer bits
input_mode => enum string or integer
status => integer bits
"functions" is what actions the window manager should offer to the
user in a drop-down menu or similar. It's an integer bitwise OR of the
following values. If not given then the default is normally all functions.
bit actions offered
--- ---------------
1 all functions
2 resize window
4 move window
8 minimize, to iconify
16 maximize, to full-screen (with a frame still)
32 close window
"decorations" is what visual decorations the window manager should
show around the window. It's an integer bitwise OR of the following
values. If not given then the default is normally all decorations.
bit decorations displayed
--- ---------------------
1 all decorations
2 border around the window
4 resizeh, handles to resize by dragging
8 title bar, showing WM_NAME
16 menu, drop-down menu of the "functions" above
32 minimize button, to iconify
64 maximize button, to full-screen
"input_mode" allows a window to be "modal", meaning the
user should interact only with $window. The window manager will generally
keep it on top, not move the focus to other windows, etc. The value is one
of the following strings or corresponding integer,
string integer
"modeless" 0 not modal (the default)
"primary_application_modal" 1 modal to its "transient for"
"system_modal" 2 modal to the whole display
"full_application_modal" 3 modal to the current client
"primary_application_modal" means $window is modal for the
"WM_TRANSIENT_FOR" set on $window (see
"WM_TRANSIENT_FOR" above), but other windows on the display can
be used normally. "full_application_modal" means modal for all
windows of the same client, but other clients can be used normally.
Modal behaviour is important for good user interaction and therefore ought
to be implemented by a window manager, but a good program should be
prepared to do something with input on other windows.
"status" field is a bitwise OR of the following bits (only one
currently).
bit
1 tearoff menu window
Tearoff menu flag is intended for tearoff menus, as the name suggests.
X11::Protocol::WM::set_motif_wm_hints
($X, $my_tearoff_window, status => 1);
Motif "mwm" will expand the window to make it wide enough for the
"WM_NAME" in the frame title bar. Otherwise a title is generally
truncated to as much as fits the window's current width. Expanding can be
good for tearoffs where the title bar is some originating item name etc
which the user should see. But don't be surprised if this flag is ignored
by other window managers.
Perhaps in the future the individual bits above will have some symbolic
names. Either constants or string values interpreted. What would a
possible "get_hints()" return, and what might be convenient to
add/subtract bits?
See /usr/include/Xm/MwmUtil.h on the hints bits, and see
"mwm" sources WmWinInfo.c
"ProcessWmWindowTitle()" for the "status" tearoff
window flag.
_NET_FRAME_EXTENTS¶
- "my ($left,$right, $top,$bottom) =
X11::Protocol::WM::get_net_frame_extents ($X, $window)"
- Get the "_NET_FRAME_EXTENTS" property from $window.
This is set on top-level windows by the window manager to report how many
pixels of frame or decoration it has added around $window.
If there's no such property set then the return is an empty list. So for
example
my ($left,$right,$top,$bottom)
= get_net_frame_extents ($X, $window)
or print "no frame extents";
my ($left,$right,$top,$bottom)
= get_net_frame_extents ($X, $window);
if (! defined $left) {
print "no frame extents";
}
A client might look at the frame size if moving a window programmatically so
as not to put the title bar etc off-screen. Oldish window managers might
not provide this information though.
_NET_WM_PID¶
- "X11::Protocol::WM::set_net_wm_pid ($X, $window)"
- "X11::Protocol::WM::set_net_wm_pid ($X, $window, $pid)"
- "X11::Protocol::WM::set_net_wm_pid ($X, $window, undef)"
- Set the "_NET_WM_PID" property on $window to the given $pid
process ID, or to the $$ current process ID if omitted. (See perlvar for
$$.) If $pid is "undef" then the property is deleted.
A window manager or similar might use the PID to forcibly kill an
unresponsive client. It's only useful if "WM_CLIENT_MACHINE"
(above) is set too, to know where the client is running.
_NET_WM_STATE¶
An EWMH compliant window manager maintains a set of state flags for each client
window. A state is an atom such as "_NET_WM_STATE_FULLSCREEN" and
each such state can be present or absent. The supported states are listed in
"_NET_SUPPORTED". Any client can ask the window manager to change
states on any window. A client might be able to ask for an initial set of
states for a new window (see "set_net_wm_state()" below). Possible
states include
- _NET_WM_STATE_MODAL
- The window is modal to its "WM_TRANSIENT_FOR" parent or if
"WM_TRANSIENT_FOR" not set then modal to its window group.
See "_MOTIF_WM_HINTS" to set modal with the Motif style
hints.
- _NET_WM_STATE_STICKY
- The window is kept in a fixed position on screen when the desktop
scrolls.
- _NET_WM_STATE_MAXIMIZED_VERT
- _NET_WM_STATE_MAXIMIZED_HORZ
- The window is maximum size vertically or horizontally or both. The window
still has its surrounding decoration and the size should obey size
increments specified in "WM_NORMAL_HINTS".
- _NET_WM_STATE_FULLSCREEN
- The window is the full screen with no decoration around it, thus being the
full screen.
The window manager remembers the "normal" size of the window so
that when maximize or fullscreen state is removed the previous size is
restored.
- _NET_WM_STATE_SHADED
- The window is "shaded" which generally means its title bar is
displayed but none of the client window. This is an alternative to
iconifying a window.
- _NET_WM_STATE_SKIP_TASKBAR
- _NET_WM_STATE_SKIP_PAGER
- Don't show the window on a task bar or in a pager, respectively.
- _NET_WM_STATE_HIDDEN (read-only)
- This state is set by the window manger when the window is iconified or
similar and so does not appear on screen. Clients cannot change this.
- _NET_WM_STATE_ABOVE
- _NET_WM_STATE_BELOW
- The window is kept above or below other client windows. The stacking order
maintained is roughly
top
+-----------------------------+
| _NET_WM_WINDOW_TYPE_DOCK | "DOCK" panels etc on top,
+-----------------------------+ except perhaps FULLSCREEN
| _NET_WM_STATE_ABOVE | windows above those panels
+-----------------------------+ when focused
| normal |
+-----------------------------+
| _NET_WM_STATE_BELOW |
+-----------------------------+
| _NET_WM_WINDOW_TYPE_DESKTOP |
+-----------------------------+
bottom
- _NET_WM_STATE_DEMANDS_ATTENTION
- The window should be brought to the attention of the user in some way. A
client sets this and the window manager clears it after the window has
received user attention (which might mean keyboard focus or similar).
The following functions get or set the states.
- "change_net_wm_state($X, $window, $action, $state,
key=>value,...)"
- Change one of the "_NET_WM_STATE" state flags on $window by
sending a message to the window manager. For example,
change_net_wm_state ($X, $window, "toggle", "FULLSCREEN");
$window must be a managed window, ie. must have had its initial
"MapWindow()" and not be an override-redirect. If that's not so
or if there's no window manager or it doesn't have EWMH then this change
message will have no effect.
$action is a string or integer how to change the state,
"remove" 0
"add" 1
"toggle" 2
$state is a string such as "FULLSCREEN" or an atom integer such as
"$X->atom("_NET_WM_STATE_FULLSCREEN")".
The further optional key/value parameters are
state2 => string or atom
source => "none", "normal", "user", 0,1,2
root => integer XID, or undef
A change message can act on one or two states. For two states the second is
"state2". For example to maximize vertically and horizontally in
one operation,
change_net_wm_state ($X, $window, "add", "MAXIMIZED_VERT",
state2 => "MAXIMIZED_HORZ");
"source" is where the change request came from. The default is
"normal" which means a normal application. "user" is
for a user-interface control program such as a pager. ("none"=0
is what clients prior to EWMH 1.2 gave.)
"root" is the root window (integer XID) of $window. If
"undef" or not given then it's found with
"$X->QueryTree()". If you already know the root then giving
it avoids that round-trip query.
- "@strings = get_net_wm_state ($X, $window)"
- "@atoms = get_net_wm_state_atoms ($X, $window)"
- Get the "_NET_WM_STATE" property from $window.
"get_net_wm_state()" returns a list of strings such as
"FULLSCREEN". "get_net_wm_state_atoms()" returns a
list of atom integers such as
"$X->atom('_NET_WM_STATE_FULLSCREEN')". In both cases if
there's no such property or if it's empty then return an empty list.
- "set_net_wm_state ($X, $window, $state,...)"
- Set the "_NET_WM_STATE" property on $window. Each $state can be
a string such as "FULLSCREEN" or an atom integer such as
"$X->atom('_NET_WM_STATE_FULLSCREEN')".
A client can set "_NET_WM_STATE" on a new window to tell the
window manager of desired initial states. However this is only a
"should" in the EWMH spec so it might not be obeyed.
# initial desired state
set_net_wm_state ($X, $window,
"MAXIMIZED_HORZ", "MAXIMIZED_VERT");
After the window is managed by the window manager (once mapped) clients
should not set "_NET_WM_STATE" but instead ask the window
manager with "change_net_wm_state()" per above.
_NET_WM_USER_TIME¶
- "set_net_wm_user_time ($X, $window, $time)"
- Set the "_NET_WM_USER_TIME" property on $window.
$time should be a server time value (an integer) from the last user keypress
etc event in $window. Or when $window is created then the time from the
event which caused it to be opened.
On a newly created window a special $time value 0 means the window should
not receive the focus when mapped -- assuming the window manager
recognises "_NET_WM_USER_TIME" of course.
If the client has the active window it should update
"_NET_WM_USER_TIME" for every user input. Generally KeyPress and
ButtonPress events are user input, but KeyRelease and ButtonRelease are
not since it's the Press events which are the user actively doing
something.
The window manager might use "_NET_WM_USER_TIME" to control focus
and/or stacking order so that for example a slow popup doesn't steal the
focus if you've gone to another window to do other work in the
interim.
_NET_WM_WINDOW_TYPE¶
- "X11::Protocol::WM::set_net_wm_window_type ($X, $window,
$window_type)"
- Set the "_NET_WM_WINDOW_TYPE" property on $window (an XID).
$window_type can be a type string as follows from the EWMH,
"NORMAL"
"DIALOG"
"DESKTOP"
"DOCK"
"TOOLBAR"
"MENU"
"UTILITY"
"SPLASH"
$window_type can also be an integer atom such as
"$X->atom('_NET_WM_WINDOW_TYPE_DIALOG')".
Frame to Client¶
- "$window = X11::Protocol::WM::frame_window_to_client ($X,
$frame)"
- Return the client window (XID) contained within window manager $frame
window (an XID). $frame is usually an immediate child of the root window.
If no client window can be found in $frame then return "undef".
This might happen if $frame is an icon window or similar created by the
window manager itself, or an override-redirect client without a frame, or
if there's no window manager running at all. In the latter two cases
$frame would be the client already.
The strategy is to look at $frame and down the window tree seeking a
"WM_STATE" property which the window manager puts on a client's
toplevel when mapped. The search depth and total windows are limited in
case the window manager does its decoration in some ridiculous way or the
client uses excessive windows (which would be traversed if there's no
window manager).
+-rootwin--------------------------+
| |
| |
| +-frame-win--------+ |
| | +-client-win---+ | |
| | | WM_STATE ... | | |
| | | | | |
| | +--------------+ | |
| +------------------+ |
| |
+----------------------------------+
Care is taken not to error out if some windows are destroyed during the
search. The windows may belong to other clients and could be destroyed at
any time. If $frame itself doesn't exist then the return is
"undef".
This function is similar to what "xwininfo" and similar programs
do to go from a toplevel root window child down to the client window, per
dmsimple.c "Select_Window()" or Xlib
"XmuClientWindow()". (See also
X11::Protocol::ChooseWindow.)
Virtual Root¶
Some window managers use a "virtual root" window covering the entire
screen. Application windows or frame windows are then children of that virtual
root. This can help the window manager implement a large desktop or multiple
desktops, though it tends to fail in subtle ways with various root oriented
programs, including for example
xsetroot(1) or the click-to-select in
xwininfo(1) and
xprop(1).
- "$window = X11::Protocol::WM::root_to_virtual_root ($X,
$root)"
- If the window manager is using a virtual root then return that window XID.
If not then return "undef".
The current implementation searches for a window with an
"__SWM_VROOT" property, as per the "swm",
"tvtwm" and "amiwm" window managers, and as used by
the "xscreensaver" program and perhaps some versions of KDE.
There's nothing yet for EWMH "_NET_VIRTUAL_ROOTS". Do any window
managers use it? Is "_NET_CURRENT_DESKTOP" an index into that
virtual roots list?
(See X11::Protocol::XSetRoot for changing the background of a root or
virtual root.)
EXPORTS¶
Nothing is exported by default, but the functions can be requested in usual
"Exporter" style,
use X11::Protocol::WM 'set_wm_hints';
set_wm_hints ($X, $window, input => 1, ...);
Or just call with full package name
use X11::Protocol::WM;
X11::Protocol::WM::set_wm_hints ($X, $window, input => 1, ...);
There's no ":all" tag since this module is meant as a grab-bag of
functions and to import as-yet unknown things would be asking for name
clashes.
BUGS¶
Not much attention is paid to text on an EBCDIC system. Wide char strings
probably work, but byte strings may go straight through where they ought to be
re-coded to Latin-1. But the same probably applies to parts of the core
"X11::Protocol" such as "$X->atom_name()" where you'd
want to convert Latin-1 from the server to native EBCDIC.
SEE ALSO¶
X11::Protocol, X11::Protocol::Other, X11::Protocol::ChooseWindow,
X11::Protocol::XSetRoot
"Inter-Client Communication Conventions Manual",
/usr/share/doc/xorg-docs/specs/ICCCM/icccm.txt.gz,
<
http://www.x.org/docs/ICCCM/>
"Compound Text Encoding" specification.
/usr/share/doc/xorg-docs/specs/CTEXT/ctext.txt.gz,
<
http://www.x.org/docs/CTEXT/>
"Extended Window Manager Hints" which is the "_NET_WM"
things. <
http://www.freedesktop.org/wiki/Specifications/wm-spec>,
<
http://mail.gnome.org/archives/wm-spec-list/>
wmctrl(1),
xwit(1),
X(7)
HOME PAGE¶
<
http://user42.tuxfamily.org/x11-protocol-other/index.html>
LICENSE¶
Copyright 2011, 2012, 2013 Kevin Ryde
X11-Protocol-Other 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, or (at your option) any later version.
X11-Protocol-Other 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
X11-Protocol-Other. If not, see <
http://www.gnu.org/licenses/>.