X11::Protocol::Ext::Composite(3)
NAME
X11::Protocol::Ext::Composite - off-screen window contents
SYNOPSIS
use X11::Protocol;
my $X = X11::Protocol->new;
$X->init_extension('Composite')
or print "Composite extension not available";
$X->CompositeRedirectWindow ($mywindow, 'Automatic');
DESCRIPTION
The Composite extension holds the full pixel contents of windows in
off-screen storage, ready for things like "CopyArea()". Normally the
server only keeps the visible parts of a window, not areas overlapped
or obscured.
In "Automatic" mode the visible parts of a window are displayed on
screen as normal. The off-screen storage is then a little like the
backing store feature, but just when one or more clients declare an
interest in the full content.
In "Manual" mode the window contents are not drawn on screen, only kept
off-screen. This mode is for use by special "composite manager"
programs which might make a composite display (hence the name of the
extension) of the overlapping windows with partial-transparency or
shadowing effects.
There's nothing here to draw or combine to actually make a composite
window result. When required that's done with the usual core protocol
drawing or with drawing extensions such as RENDER (see
X11::Protocol::Ext::RENDER).
REQUESTS
The following requests are made available with an "init_extension()",
as per "EXTENSIONS" in X11::Protocol.
my $is_available = $X->init_extension('Composite');
Composite 0.1
"($server_major, $server_minor) = $X->CompositeQueryVersion
($client_major, $client_minor)"
Negotiate a protocol version with the server. $client_major and
$client_minor is what the client would like, the returned
$server_major and $server_minor is what the server will do, which
might be less than requested (but not more than).
Actually the X.org server circa 1.10 will return a higher minor
version than the client requests.
The current code supports up to 0.3 and the intention is to
automatically negotiate in "init_extension()" if/when necessary.
"$X->CompositeRedirectWindow ($window, $update)"
"$X->CompositeRedirectSubwindows ($window, $update)"
"$X->CompositeUnredirectWindow ($window, $update)"
"$X->CompositeUnredirectSubwindows ($window, $update)"
Enable or disable a redirect of $window to off-screen storage.
"Window()" acts on just the given $window. "Subwindows()" acts on
$window and also any subwindows it has now or in the future. The
root window cannot be redirected.
$update is string "Automatic" or "Manual". Only one client at a
time may use Manual mode on a given $window (normally a "composite
manager" program).
Redirection is a per-client setting and is automatically
unredirected if the client disconnects. An unredirect when not
redirected is a "BadValue" error. Off-screen storage remains in
effect while at least one current client has requested it.
"$X->CompositeCreateRegionFromBorderClip ($region, $window)"
Create $region (a new XID) as a server-side region object
initialized to, umm, something about $window and its current border
or visible parts or whatnot.
Region objects are from XFIXES 2.0 (X11::Protocol::Ext::XFIXES).
"CompositeCreateRegionFromBorderClip()" can be used without
"init_extension()" of XFIXES, but there's not much which can be
done with a region except through XFIXES.
Composite 0.2
"$X->CompositeNameWindowPixmap ($window, $pixmap)"
Set $pixmap (a new XID) to refer to the off-screen storage of
$window. $window must be viewable (mapped and all of its parents
mapped) and must be redirected (by any client).
my $pixmap = $X->new_rsrc;
$X->CompositeNameWindowPixmap ($window, $pixmap);
$pixmap is released with "FreePixmap()" in the usual way. If
$window or a parent is unmapped then $pixmap continues to exist,
but it's association with $window is lost. If $window is mapped
and redirected again later then it has a new off-screen storage and
a new "CompositeNameWindowPixmap()" must be called to get a new
pixmap for it.
Composite 0.3
"$overlay_window = $X->CompositeGetOverlayWindow ($window)"
Return the composite overlay window for the screen of $window.
This window covers the whole screen and is always above ordinary
windows but below any screen saver, and doesn't appear in a
"QueryTree()". It's created when the first client asks for it, and
shared by any further clients who ask.
"$X->CompositeReleaseOverlayWindow ($window)"
Release the composite overlay window for the screen of $window.
When all clients release it the overlay window is destroyed.
SEE ALSO
X11::Protocol(3), X11::Protocol::Ext::XFIXES(3),
X11::Protocol::Ext::DOUBLE_BUFFER(3)
"Composite Extension", Version 0.4, 2007-7-3,
/usr/share/doc/x11proto-composite-dev/compositeproto.txt.gz,
"http://cgit.freedesktop.org/xorg/proto/compositeproto/plain/compositeproto.txt"
HOME PAGE
<http://user42.tuxfamily.org/x11-protocol-other/index.html>
LICENSE
Copyright 2011, 2012, 2013, 2014 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/>.
perl v5.28.1 2014-01-18 X11::Protocol::Ext::Composite(3)
x11-protocol-other 30 - Generated Tue Feb 19 13:17:34 CST 2019