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\input texinfo @c -*-texinfo-*-
%
% doc.gpm - main file for the documentation
%
% Copyright 1994,1995,1998 rubini@linux.it (Alessandro Rubini)
% Copyright (C) 1998 Ian Zimmerman <itz@speakeasy.org>
% Copyright (C) 2001-2005 Nico Schottelius <nico-gpm@schottelius.org>
%
%%%%
%------------------------------------------------------------------------------
%
% NOTE FOR THE UNAWARE USER
% =========================
%
% This file is a texinfo source. It isn't the binary file of some strange
% editor of mine. If you want ASCII, you should "make gpm.txt".
%
% Some strings maybe changed from the configure script.
%
%------------------------------------------------------------------------------
%
% This is not a conventional info file...
% I use two extra features:
% - The '%' as a comment marker ("\%" -> "%")
% - leading blanks are allowed (and removed)
%
@comment %**start of header
@setfilename gpm.info
@settitle gpm @value{version}
@iftex
@afourpaper
@end iftex
@comment %**end of header
@ifinfo
@format
@dircategory Miscellaneous
@direntry
* Gpm: (gpm). Text-mode mouse library and server daemon.
@end direntry
@end format
@end ifinfo
@setchapternewpage off
@set version @release@
@set update-month @release_date@
@finalout
@ifinfo
%ASCII_BEGIN
This file is a user's and programmer's manual for gpm @value{version}.
Copyright (C) 1994,1995,1998 Alessandro Rubini
Copyright (C) 2001-2005 Nico Schottelius
Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
are preserved on all copies.
@ignore
Permission is granted to process this file through TeX and print the
results, provided the printed document carries copying permission
notice identical to this one except for the removal of this paragraph
(this paragraph not being relevant to the printed manual).
@end ignore
Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the entire
resulting derived work is distributed under the terms of a permission
notice identical to this one.
Permission is granted to copy and distribute translations of this manual
into another language, under the above conditions for modified versions,
except that this permission notice may be stated in a translation approved
by the Free Software Foundation.
@end ifinfo
@setchapternewpage odd
@titlepage
@c use the new format for titles
@title gpm @value{version}
@subtitle A general purpose mouse server for the Linux console
@subtitle @value{update-month}
@author by Nico Schottelius <nico@@schottelius.org>
@end titlepage
@setchapternewpage off
@headings single
@ifinfo
This file documents the @value{version} release of the "General Purpose
Mouse" (gpm) server for the Linux text console (@value{update-month}).
@node Top, Overview, (dir), (dir)
@top gpm
@menu
* Overview::
* Server Invocation::
* Gpm Internals::
* The ClientLib::
* Demo Clients::
* Type Index::
* Function Index::
* Variable Index::
@end menu
@end ifinfo
%##########################################################################
%##########################################################################
@node Overview, Server Invocation, Top, Top
@chapter Overview
@cindex Overview of Gpm
@cindex Gpm Overview
The @dfn{gpm} package is a mouse server for the Linux console. It is
meant to provide cooked mouse events to text-only applications, such as
editors and simple menu-based apps. The daemon is also able to repeat
packets in "msc" format to a graphic application. This last feature is
meant to override the single-open problem of busmice. The roots of
@code{gpm} come from the @file{selection-1.5} package, by Andrew Haylett.
The first application to support the mouse has been The Midnight Commander,
by Miguel de Icaza. @file{mc-0.11} and later releases offer
mouse support if you have the mouse server running on your system.
The file @file{t-mouse.el} provides support for using the
mouse from within Emacs. @xref{Emacs Support}.
As of release 0.96, a default-handler is released with gpm, and can be
used to handle Control-Mouse events to draw menus on the screen.
The @code{gpm-root} program, however, needs kernel 1.1.73 or newer.
@xref{gpm-root}.
Release 1.00 has been an incompatible one (is is incompatible with
releases older than 0.97), but is compatible with the kernel-level mouse
driver (available as @file{kmouse-?.??.tar.gz} from the mirrors of
@uref{ftp://tsx-11.mit.edu}. With 1.0 the high level library is available,
together with a demonstration/test program. A small utility to help in
detecting your mouse-type is also included.
As of release 1.20.0 the default device is removed. Now -m is a must.
Release 1.20.1 introduces the must for -t and a specific way to use -m,-t,-o:
Now you've got to use -m first, then -t and at last -o.
This seems to be more complex, but makes using of multiply mice possible with
clean code.
@menu
* Building the Release::
@end menu
%=========================================================================
@node Building the Release, , Overview, Overview
@section Compiling and Installing
@cindex Building Gpm
Just say @code{./configure && make && make install} to your
shell. You'll need gpm installed to compile the latest release of
The Midnight Commander with mouse support enabled.
Binaries are not released with the package because it's safer for you to
compile the package by yourself.
%=========================================================================
%@node Kernel Patches
%@section Kernel Patches
%@cindex Kernel Patches
%@cindex Patches to Apply
%
%Old Linux kernels need to be patched to provide features I rely on. As
%of 1.1.32, however, my patches are in the official release, so you won't
%need any kernel recompilation. Remember, anyway, to enable selection while
%compiling the kernel, or this package won't work. Refer to
%@file{kernel/README} to probe further.
%
%Other features are needed to run the @t{gpm-root} client. They are
%really functional only since 1.1.73. 1.1.68, however, should be sufficient.
%
%##########################################################################
@node Server Invocation, Gpm Internals, Overview, Top
@chapter Server Invocation
@cindex The Server
@cindex Command Line (gpm)
%MANPAGE gpm.8
%M .TH GPM 8 "February 2002"
%M .UC 4
%M .SH NAME
%M gpm \- a cut and paste utility and mouse server for virtual consoles
%M .SH SYNOPSIS
%M .B gpm
%M [
%M .I options
%M ]
%M .br
%M .SH DESCRIPTION
%M This package tries to be a useful
%M mouse server for applications running on the Linux console. It is
%M based on the "selection" package, and some of its code
%M comes from selection itself. This package is intended as a replacement
%M for "selection" as a cut-and-paste mechanism; it also provides
%M additional facilities. The "selection"
%M package offered the first cut-and-paste implementation for Linux using
%M two mouse buttons, and the cut buffer is still called "selection buffer"
%M or just "selection" throughout this document.
%M
%M The information below is extracted from the texinfo file, which is the
%M preferred source of information.
The @code{gpm} executable is meant to act like a daemon (thus, @code{gpmd}
would be a better name for it). This section is meant to describe the
command-line options for @code{gpm}, while its internals are outlined in
the next section.
@xref{Gpm Internals}.
Due to restrictions in the @code{ioctl(TIOCLINUX)} system call, @code{gpm} must
be run by the superuser. The restrictions have been added in the last 1.1
kernels to fix a security hole related to selection and screen dumping.
The server can be configured to match the user's taste, and any
application using the mouse will inherit the server's
attitude. From release 1.02 up to 1.19.2 is was possible
for any user logged on the system console to change the mouse @emph{feeling}
using the @t{-q} option. This is no longer possible for security
reasons.
As of 0.97 the server program puts itself in the background. To kill
@code{gpm} you can just reinvoke it with the @samp{-k} cmdline switch,
although @code{killall gpm} can be a better choice.
@menu
* Special Commands::
* Command Line::
* Bugs and Problems::
* Mouse Types::
@end menu
%M .SH SPECIAL COMMANDS
%==========================================================================
@node Special Commands, Command Line, Server Invocation, Server Invocation
@section Special Commands
Version 1.10 adds the capability to execute @emph{special} commands on
certain circumstances. Special commands default to rebooting and halting
the system, but the user can specify his/her personal choice. The
capability to invoke commands using the mouse is a handy one for
programmers, because it allows to issue a clean shutdown when the
keyboard is locked and no network is available to restore the system to
a sane state.
Special commands are toggled by triple-clicking the left and right button --
an unlikely event during normal mouse usage. The easiest way to triple-click
is pressing one of the buttons and triple-click the other one. When special
processing is toggled, a message appears on the console (and the speaker
beeps twice, if you have a speaker); if the user releases all the buttons
and presses one of them again within three seconds, then the special
command corresponding to the button is executed.
The default special commands are:
@table @var
@item left button
Reboot the system by signalling the init process
@item middle button (if any)
Execute @code{/sbin/shutdown -h now}
@item right button
Execute @code{/sbin/shutdown -r now}
@end table
The @samp{-S} command line switch enables special command processing and
allows to change the three special commands. To accept the default
commands use @samp{-S ""} (i.e., specify an empty argument). To specify
your own commands, use a colon-separated list to specify commands
associated to the left, middle and right button. If any of the commands
is empty, it is interpreted as `send a signal to the init process'. This
particular operation is supported, in addition to executing external
commands, because sometimes bad bugs put the system to the impossibility
to fork; in these rare case the programmer should be able to shutdown
the system anyways, and killing init from a running process is the only
way to do it.
As an example, @samp{-S ":telinit 1:/sbin/halt"}, associates killing
init to the left button, going single user to the middle one, and halting
the system to the right button.
System administrators should obviously be careful about special
commands, as gpm runs with superuser permissions. Special commands are
best suited for computers whose mouse can be physically accessed only by
trusted people.
%M .SH COMMAND LINE OPTIONS
%==========================================================================
@node Command Line, Bugs and Problems, Special Commands, Server Invocation
@section Command Line Options
Available command line options are the following:
@table @code
@item -a @var{accel}
Set the acceleration value used when a single motion event is
longer than @var{delta} (see @samp{-d}).
@item -A[@var{limit}]
Start up with selection pasting disabled. This is intended as a
security measure; a plausible attack on a system seems to be to
stuff a nasty shell command into the selection buffer
(@code{rm -rf /}) including the terminating line break, then all the
victim has to do is click the middle mouse button ..
As of version 1.17.2, this has developed
into a more general aging mechanism; the
gpm daemon can disable (@emph{age}) selection pasting
automatically after a period of inactivity. To enable this mode
just give the optional @var{limit} parameter (no space in between !)
which is interpreted as the time in seconds for which a selection is
considered valid and pastable.
As of version 1.15.7, a trivial program called
@code{disable-paste} is provided. The following makes a good
addition to @file{/etc/profile} if you allow multiple users to
work on your console.
@code{case $( /usr/bin/tty ) in @* /dev/tty[0-9]*) /usr/bin/disable-paste ;; @* esac}
@item -b @var{baud}
Set the baud rate.
@item -B @var{sequence}
Set the button sequence. @samp{123} is the
normal sequence, @samp{321} can be used by left-handed people,
and @samp{132} can be useful with two-button mice (especially within
Emacs). All the button permutations are allowable.
@item -d @var{delta}
Set the delta value. When a single motion event
is longer than @var{delta}, @var{accel} is used as a multiplying
factor. (Must be 2 or above)
@item -D
Do not automatically enter background operation when started,
and log messages to the standard error stream, not the syslog
mechanism. This is useful for debugging; in previous releases
it was done with a compile-time option.
@item -g @var{number}
With glidepoint devices, emulate the specified button with tapping.
@var{number} must be @samp{1}, @samp{2}, or @samp{3}, and refers to the
button number @emph{before} the @samp{-B} button remapping is performed.
This option applies to the mman and ps2 decoding. No button is
emulated by default because the ps2 tapping is incompatible with
some normal ps2 mice
@item -h
Print a summary of command line options.
@item -i @var{interval}
Set @var{interval} to be used as an upper time limit
for multiple clicks. If the interval between button-up and
button-down events is less than @var{limit}, the press is considered
a double or triple click. Time is in milliseconds.
@item -k
Kill a running gpm. This can be used by busmouse users to kill gpm
before running X (unless they use @samp{-R} or the single-open
limitation is removed from the kernel).
@item -l @var{charset}
Choose the @code{inword()} look up table. The
@var{charset} argument is a list of characters. @samp{-} is used to
specify a range and @samp{\ } is used to escape the next character
or to provide octal codes.
Only visible character can appear in @var{charset} because control
characters can't appear in text-mode video memory, whence selection
is cut.
@item -m @var{filename}
Choose the mouse file to open. Must be before -t and -o.
@item -M
Enable multiple mode. The daemon will read two different mouse devices.
Any subsequent option will refer to the second device, while any
preceding option will be used for the first device. This option
automatically forces the @emph{repeater} (@samp{-R}) option on.
@item -o @var{list-of-extra-options}
The option works similary to the ``-o'' option of mount; it is
used to specify a list of ``extra options'' that are specific
to each mouse type. The list is comma-separated. The options
@samp{dtr}, @samp{rts} or @samp{both} are used by the serial
initialization to toggle the modem lines like, compatibly with
earlier @i{gpm} versions; note however that using @t{-o dtr}
associated with non-plain-serial mouse types may now generate
an error. @xref{Mouse Types}.
And by the way, use -o after -m and after -t.
@item -p
Forces the pointer to be visible while selecting. This is the
behaviour of @file{selection-1.7}, but it is sometimes confusing.
The default is not to show the pointer, which can be confusing as well.
@item -r @var{number}
Set the responsiveness. A higher responsiveness is used for a faster
cursor motion.
@item -R[@var{name}]
Causes @code{gpm} to act as a repeater: any mouse data received while
in graphic mode will be produced on the fifo @file{/dev/gpmdata}
in protocol @var{name}, given as an optional argument (no space in
between !). In principle, you can use the same
names as for the @samp{-t} option, although repeating into some
protocols may not be implemented for a while. @xref{Mouse Types}.
In addition, you can specify @samp{raw} as the @var{name}, to repeat
the mouse data byte by byte, without any protocol translation.
If @var{name} is omitted, it defaults to @samp{msc}.
Using @i{gpm} in repeater mode, you can configure the X
server to use its fifo as a mouse device. This option is useful for
bus-mouse owners to override the single-open limitation. It is also
an easy way to manage those stupid dual-mode mice which force you
to keep the middle button down while changing video mode. The option
is forced on by the @samp{-M} option.
@item -s @var{number}
Set the sample rate for the mouse device.
@item -S @var{commands}
Enable special-command processing, and optionally specify custom
commands as a colon-separated list. See above for a detailed
description of special commands.
@item -t @var{name}
Set the mouse type. Use @samp{-t help} to get a list
of allowable types. Since version 1.18.1, the list also shows
which protocols are available as repeaters (see @t{-R} above),
by marking them with an asterisk (``@t{*}'').
@xref{Mouse Types}.
Use -t after you selected the mouse device with -m.
@item -v
Print version information and exit.
@item -V[@var{verbosity increment}]
Raise or decrease the maximum level of messages that will be
logged. Thus a positive argument has the effect of making the
program more verbose. One can also give a negative argument to
hush the program; due to @b{getopt(3)} rules, any optional
argument needs to be passed without a space in between!
When omitting the argument, the increment defaults to 1.
Default verbosity level is 5 (@code{LOG_NOTICE}).
@xref{Program Arguments,,,libc}.
@item -2
Force two buttons. This means that the middle button, if any,
will be taken as it was the right one.
@item -3
Force three buttons. By default the
mouse is considered to be a 2-buttons one, until the middle button
is pressed. If three buttons are there, the right one is used
to extend the selection, and the middle one is used to paste it.
Beware: if you use the @samp{-3} option with a 2-buttons mouse, you
won't be able to paste the selection.
@end table
@ignore
.SH OPERATION
To select text press the left mouse button and drag the mouse.
To paste text in the same or another console, press the middle button.
The right button is used to extend the selection, like in `xterm'.
Two-button mice use the right button to paste text.
Double and triple clicks select whole word and whole lines. Use of
the `-p' option is recommended for best visual feedback.
If a trailing space after the contents of a line is highlighted, and if
there is no other text on the remainder of the line, the rest of the
line will be selected automatically. If a number of lines are selected,
highlighted trailing spaces on each line will be removed from the
selection buffer.
Any output on the virtual console holding the selection will clear the
highlighted selection from the screen, to maintain integrity of the
display, although the contents of the paste buffer will be unaffected.
The selection mechanism is disabled if the controlling virtual console
is placed in graphics mode, for example when running X11, and is
re-enabled when text mode is resumed. (But see BUGS section below.)
@end ignore
%MSKIP
@menu
* Bugs and Problems::
@end menu
@node Bugs and Problems, Mouse Types, Command Line, Server Invocation
@section Bugs and Problems
%M .SH BUGS
The @code{gpm} server may have problems interacting with X: if your
mouse is a single-open device (i.e. a bus mouse), you should kill
@code{gpm} before starting X, or use the @samp{-R} option (see
above). To kill @code{gpm} just invoke @code{gpm -k}. This problem doesn't
apply to serial mice.
Two instances of gpm can't run on the same system. If you have two mice use
the @samp{-M} option (see above).
While the current console is in graphic mode, @code{gpm} sleeps until
text mode is back (unless @samp{-R} is used). Thus, it won't reply to
clients. Anyways, it is unlikely that mouse-eager clients will spur
out in hidden consoles.
The clients shipped out with gpm are not updated, thus there are potential
security risks when using them.
@ignore
.SH AUTHORS
.nf
Andrew Haylett <ajh@gec-mrc.co.uk> (the original selection code)
Ian Zimmerman <itz@speakeasy.org> (old maintainer)
Alessandro Rubini <rubini@linux.it> (old maintainer (still helps a lot))
Nico Schottelius <nico-gpm@schottelius.org> (maintainer)
Many many contributors, to both selection and gpm.
.fi
.SH MAINTAINERS
The current maintainer is Nico Schottelius. But without the help of
Alessandro Rubini and the mailing list it would be impossible for him to
maintain gpm. The development mailing list can be reached under
gpm@lists.linux.it. More information on the list is in the README file part of
the source distribution of gpm.
.SH FILES
.nf
/var/run/gpm.pid The PID of the running gpm
/dev/gpmctl A control socket for clients
/dev/gpmdata The fifo written to by a \fBrepeater\fP (`-R') daemon.
.fi
.SH SEE ALSO
.nf
\fB mev(1)\fP A sample client for the gpm daemon.
\fB gpm-root(1)\fP An handler for Control-Mouse events.
.fi
The info file about `gpm', which gives more complete information and
explains how to write a gpm client.
@end ignore
%MANPAGE END
%==========================================================================
@node Mouse Types, , Bugs and Problems, Server Invocation
@section Mouse Types
%MANPAGE gpm-types.7
%M .TH GPM-TYPES 7 "July 2000"
%M .UC 4
%M .SH NAME
%M gpm-types \- pointer types (mice, tablets, etc.) managed by gpm.
%M .br
%M The information below is extracted from the texinfo file, which is the
%M preferred source of information.
%M .SH DESCRIPTION
%MSKIP
This section of the gpm documentation manual
%M This manpage
describes the various pointer types currently available in @i{gpm}. If you
look at the source code, you'll find that pointer-specific code is
confined to @file{mice.c} (while it used to only include mouse decoders,
@i{gpm} now supports tablets and touchscreens as well).
The mouse type is specified on command line with the @samp{-t}
option. The option takes an argument, which represents the name of a
mouse type. Each type can be associated to different names. For old
mouse types, one name is the old selection-compatible name, and another
is the XFree name. After version 1.18.1 of @i{gpm}, the number of
synonyms was made arbitrary and the actual name being used is made
available to the function responsible for mouse
initialization. Therefore it is possible for a mouse decoder to behave
slightly differently according to the name being used for the device (if
this feature was already present, we wouldn't have for example @t{ms+}
and @t{ms+lr} as different mouse types).
The initialization procedure of each mouse type can also receive extra
option, by means of the @t{-o} command line option. Since
interpretation of the option string is decoder-specific, the allowed
options are described in association to each mouse type. When no
description of option strings is provided, that means the option
string is unused for that mouse type and specifying one generates an
error. When the document refer to ``standard serial options'' it means
that one of @t{-o dtr}, @t{-o rts}, @t{-o both} can be specified to
toggle the control lines of the serial port.
The following mouse type are corrently recognized:
@table @code
@item bare Microsoft
The Microsoft protocol, without any extension. It only reports
two buttons. If your device has three, you should either try
running the @t{mman} decoder or @t{msc}. In the latter case,
you need to tell the mouse to talk @t{msc} protocol by
toggling the DTR and RTS lines (with one of @t{-o drt}, @t{-o
rts} or @t{-o both}) or invoking @code{gpm -t msc} while
keeping the middle button pressed. Very annoying, indeed.
This mouse decoder accepts standard serial options, although they
should not be needed.
@item ms
This is the original Microsoft protocol, with a middle-button
extension. Some old two-button devices send some spurious
packets which can be misunderstood as middle-button events. If
this is your case, use the @samp{bare} mouse type. Some new
two-button devices are ``plug and play'', and they don't play
fair at all; in this case try @t{-t pnp}. Many (most)
three-button devices that use the microsoft protocol fail to
report some middle-button events during mouse motion. Since
the protocol does not distinguish between the middle button
going up and the middle button going down it would be liable
to get out of step, so this decoder declares the middle button
to be up whenever the mouse moves. This prevents dragging with
the middle button, so you should probably use @samp{-t ms+lr}
instead of this decoder, especially if you want to use X.
This mouse decoder accepts standard serial options, although
they should not be needed.
@item ms+
This is the same as @samp{-t ms} except that the middle button
is not reset during mouse motion. So you can drag with the
middle button. However, if your mouse exhibits the usual buggy
behaviour the decoder is likely to get out of step with
reality, thinking the middle button is up when it's down and
vice versa. You should probably use @samp{-t ms+lr} instead
of this decoder. This mouse decoder accepts standard serial
options, although they should not be needed.
@item ms+lr
This is the same as @samp{-t ms+} except that there is an
additional facility to reset the state of the middle button by
pressing the other two buttons together. Do this when the
decoder gets into a confused state where it thinks the middle
button is up when it's down and vice versa. (If you get sick
of having to do this, please don't blame gpm; blame your buggy
mouse! Note that most three-button mice that do the microsoft
protocol can be made to do the MouseSystems protocol
instead. The ``3 Button Serial Mouse mini-HOWTO'' has
information about this.) This mouse decoder accepts standard
serial options, although they should not be needed.
@item msc MouseSystems
This is the standard protocol for three-button serial devices.
Some of such devices only enter MouseSystem mode if the RTS, DTR
or both lines are pushed low. Thus, you may try @t{-t msc}
associated with @t{-o rts}, @t{-o dtr} or @t{-o both}.
@item mman Mouseman
The protocol used by the new Logitech devices with three
buttons. It is backward compatible with the Microsoft
protocol, so if your mouse has three buttons and works with
@t{-t ms} or similar decoders you may try @t{-t mman} instead
to use the middle button. This mouse decoder accepts standard
serial options, although they should not be needed.
@item sun
The protocol used on Sparc computers and a few others.
This mouse decoder accepts standard serial options, although
they should not be needed.
@item mm MMSeries
Title says it all.
This mouse decoder accepts standard serial options, although
they should not be needed.
@item logi Logitech
This is the protocol used by old serial Logitech mice.
@item bm BusMouse
Some bus devices use this protocol, including those produced
by Logitech.
@item ps2 PS/2
The protocol used by most busmice.
@item ncr
This `type' is able to decode the pointing pen found
on some laptops (the NCR 3125 pen)
@item wacom
The protocol used by the Wacom tablet. Since version 1.18.1
we have a new Wacom decoder, as the old one was not working
with new tablets. This decoder was tested with Ultrapad,
PenPartner, and Graphire tablets.
Options:
@t{-o relative} (default) for relative mode,
@t{-o absolute} for absolute mode.
@item genitizer
The \"Genitizer\" tablet, in relative mode.
This mouse decoder accepts standard serial options, although
they should not be needed.
@item logim
Used to turn Logitech mice into Mouse-Systems-Compatible.
Obviously, it only works with some of the Logitech mice.
@item pnp
This decoder works with the new mice produces by our friend Bill,
and maybe with the old ones as well. The Pnp protocol is
hardwired at 1200 baud and is upset by normal initialization, so
this is a @t{-t bare} decoder with no initialization at all.
This mouse decoder accepts standard serial options, although
they should not be needed.
@item ms3
A decoder for the new serial IntelliMouse devices, the ones
with three buttons and a protocol incompatible with older
ones. The wheel is currently unused.
@item imps2
``IntelliMouse'' on the ps/2 port. This type can also be used for
a generic 2-button ps/2 mouse too, since it will auto-detect the type.
@item netmouse
Decodes the ``Genius NetMouse'' type of devices on the ps/2
port. For serial ``Netmouse'' devices, use the ``ms3'' decoder.
@item cal
A decoder of the ``Calcomp UltraSlate device.
@item calr
Same as above, but in relative mode.
@item twid
Support for the twiddler keyboard. As of gpm-1.14 this decoder
includes a char generator for the text console, but doesn't
yet support X keycodes. If used with @samp{-R}, @code{gpm} will anyway
repeat mouse events to the X server. More information about twiddler
support can be found in @file{README.twiddler}, in the gpm
distribution.
@item syn synaptics
A decoder for the Synaptics TouchPad connected to the serial port.
This mouse decoder accepts standard serial options, although
they should not be needed.
@item synps2 synaptics_ps2
Same as above, but for the devices attached to the ps2 port.
@item brw
A decoder for the Fellowes Browser, a device with 4 buttons
and a wheel.
This mouse decoder accepts standard serial options, although
they should not be needed.
@item js Joystick
This mouse type uses the joystick device to generate mouse
events. It is only available if the header @file{linux/joystick.h}
is found at compile time. The header (and the device as well)
has been introduced only during 2.1 development, and is not
present in version 2.0 of the kernel.
@item summa
This is a decode for the Symmagraphics of Genius tablet, run in
absolute mode. A repeater is associated to this decoder, so it
can @t{-R summa} can be used to generate X events even for other
absolute-pointing devices, like touchscreens. To use the repeated
data from X, you need a modified @t{xf86Summa.o} module.
@item mtouch
A decoder for the MicroTouch touch screen. Please refer to the
file @file{README.microtouch} in the source tree of gpm for
further information. In the near future, anyways, I plan to fold
back to this documentation the content of that file.
@item gunze
A decoder for the gunze touch screen. Please refer to the
file @file{README.gunze} in the source tree of gpm for
further information. In the near future, anyways, I plan to fold
back to this documentation the content of that file. The decoder
accepts the following options: @t{smooth=}, @t{debounce=}. An
higher smoothness results in slower motion as well; a smaller
smoothness gives faster motion but, obviously, less smooth.
The default smoothness is 9. The debounce time is express in
milliseconds and is the minimum duration of an up-down event
to be taken as a tap. Smaller bounces are ignored.
@item acecad
The Acecad tablet in absolute mode.
@item wp wizardpad
Genius WizardPad tablet
@end table
@ignore
.SH FILES
.nf
src/mice.c The source file for pointer decoders
.fi
.SH SEE ALSO
.nf
\fB gpm(8) \fP The General Purpose Mouse server
.fi
The info file about `gpm', which gives more complete information and
explains how to write a gpm client.
@end ignore
%MANPAGE END
%##########################################################################
@node Gpm Internals, The ClientLib, Server Invocation, Top
@chapter Gpm Internals
@cindex Internals
The server is organized as a main loop built around a @code{select()}
system call. It responds both to mouse events and to input from the
clients, which are connected to the server through a unix domain
socket. The connection is used to tell the server what a client is
interested in, and to get mouse events.
When no clients are connected to the active console, the server runs
the selection mechanism (cut and paste of text). The selection
mechanism is a simple and well-designed application, whose behaviour
can be cloned by clients, by telling the server to inherit the default
response for certain mouse events (motion being the most
interesting).
@menu
* Events::
* Margins::
* Event Types::
* Connection Details::
* Default Handlers::
@end menu
%==========================================================================
@node Events, Margins, Gpm Internals, Gpm Internals
@section Events
@cindex Events
Whenever the mouse generates an event, the event is dispatched to the
active client for the current console, or to the default handler, if
present. Otherwise selection is run. A default handler is a client
process which gets mouse events form all the virtual
consoles.
@xref{Default Handlers}.
When a client is involved, it is handled a @code{Gpm_Event}
structure, built by the server. The fields for @code{Gpm_Event} are the
following:
@tindex Gpm_Event
@table @code
@item unsigned char buttons;
An or-mask of the values @code{GPM_B_LEFT},
@code{GPM_B_MIDDLE} and @code{GPM_B_RIGHT}. It corresponds to
the state of the mouse buttons when the event is reported. The
current implementation of gpm allows at most three buttons.
@item unsigned char modifiers;
The value of the kernel variable
@code{shift_state}, as of @file{keyboard.c}, when the event is
reported. It is a bitmask value, and corresponds to the least
significant byte of the value used by the @code{loadkeys}
program. Use of symbolic
names in source code is available after inclusion of
@file{linux/keyboard.h}, as exemplified in @file{mev.c}.
@item unsigned short vc;
The number of the active virtual console when
the event is reported. The client is not expected to use this value,
which corresponds to the controlling terminal of the client process,
unless it gets events form multiple consoles.
@xref{Default Handlers}.
@item short x, y;
The position of the mouse pointer where the event
is reported. It is 1-based by default, to be compatible with
@code{selection} and @code{libcurses}. This behavior can be
overriden, though, by setting the library variable
@code{gpm_zerobased}.
@xref{Variables}.
@item short dx, dy;
The change in position since the last reported
event.
@item enum Gpm_Etype type;
A bit-mask, representing the
type of reported event, as described later.
@xref{Event Types}.
@item int clicks;
A counter, which is valid at button-down, drag or
button-up. It can be 0, 1 or 2 to mean single, double or triple
click.
@item enum Gpm_Margin margin;
A bit-mask, telling if the pointer has
gone out of the visible screen. The indivudual bits are
named @code{GPM_TOP}, @code{GPM_BOT}, @code{GPM_LFT},
@code{GPM_RGT}. Only one
of them is active at a time, to allow using @code{switch} on the
value. Vertical outrun takes precedence on horizontal outrun.
@xref{Margins}.
@end table
%==========================================================================
@node Margins, Event Types, Events, Gpm Internals
@section How margins are managed
Motion and button-press events are constrained to remain within the
visible screen. This means that the @code{x} will be within 1 and 80 and
@code{y} will be within 1 and 25 when the console is 80x25
cells. However, a client can keep track of movements outside the
screen, by using the @code{dx} and @code{dy} fields, which aren't subject to
clipping.
The server helps applications in detecting margin conditions by filling the
@code{margin} field. Whenever the pointer tries to cross screen boundaries,
it is forced to remain on the border, but a flag is set in @code{margin}.
A different policy is in force for drag and button-release events. In this
case the pointer is allowed to go outside the physical screen by exactly
one position. This allows, for example, selecting to end of line
by dragging down-left. The peculiar situation is nonetheless signaled
through the @code{margin} flags. The client should be careful to
fit the values within the screen if needed.
@xref{Utility Functions}.
%==========================================================================
@node Event Types, Connection Details, Margins, Gpm Internals
@section Event Types
The @code{type} field in @code{Gpm_Event} is made up of bit-wide
flags. The existing bit masks belong to two groups: bare events and
cooked events. The bit-mask @code{GPM_BARE_EVENTS} is provided to
extract bare events, by and-ing (@samp{&}) it with the @code{type} field.
For any event, exactly one bit will be set in the resulting bitmask.
Bare events are the following:
@table @code
@item GPM_MOVE
A motion event, with all buttons up.
@item GPM_DRAG
A motion event, but one or more buttons are kept pressed.
@item GPM_DOWN
A button press event. The @code{buttons} field will report
which buttons are pressed after the event.
@item GPM_UP
A button release event. The @code{buttons} field will report
which buttons are being released. Note that this is different from
the previous case.
@item GPM_ENTER
This means "enter in the current Region of Interest", and such
event can only happen if the high-level library is used.
When the type is @code{GPM_ENTER}, all the other fields are undefined.
@xref{High Level Lib}.
@item GPM_LEAVE
This is only delivered by the high level library, too. Events
of type @code{GPM_LEAVE} have all other fields undefined.
@end table
Cooked events are the following:
@table @code
@item GPM_SINGLE
This bit may be set at button-press,
drag and button release events, and can be used to identify a
single press. The time interval used to choose a double click
from two single clicks is set by a parameter in the daemon
(configurable at daemon invocation).
@item GPM_DOUBLE
Used to identify a double click (press, drag, release)
@item GPM_TRIPLE
Used to identify a triple click (press, drag, release)
@item GPM_MFLAG
The ``motion flag'' is true if some dragging happened
between button-press and button-release. It can be used by
those applications which respond to events at button release.
It is available at drag and release.
@end table
%==========================================================================
@node Connection Details, Default Handlers, Event Types, Gpm Internals
@section Connection Details
Each virtual console has a stack of clients attached to it. They talk to
gpm by writing to a control socket and get mouse events by reading
it. All the clients in the stack can receive events. Gpm-1.10 and earlier
only sent events to the top client, but sometimes users play with
multiple programs using suspend-resume (thanks Ian).
In addition to the per-console stacks, another stack is there to store
default-handling clients.
@xref{Default Handlers}.
Each client registers with the server and tells which events it is
interested in. Events not managed by the client can be handled by the
selection mechanism, which is compiled in the server itself. This
approach simplifies writing clients which respond only to button
press/release events, because highlighting the mouse pointer can be
performed by the server. A default handler in turn can respond only to
mouse events associated with modifier keys, so that selection is used
for any mouse-only event.
Clients are required to fill a @code{Gpm_Connect} structure and pass
it to the server. The structure is made up by four @code{unsigned int}
fields.
@xref{Open and Close}.
@tindex Gpm_Connect
@table @code
@item eventMask
A bitmask of the events the client wants
to receive. Both bare and cooked events are
allowed to appear in the mask.
@item defaultMask
A mask to tell which events allow
a default treatment (the selection one). These are mouse events,
independent of the modifier keys.
@item minMod
The minimum amount of modifiers
required by the client. This field is used for default-handlers
which manage control-mouse events without interfering
with mouse-only ones.
@xref{Default Handlers}.
@item maxMod
The maximum amount of modifiers the client is willing to receive.
Events featuring a modifier key not included in @code{maxMod} won't
be passed to the client.
@end table
@noindent
Two more fields are there to tell about the connection itself, and you're
not asked to fill them, because @code{Gpm_Open} will do it for you.
@table @code
@item int pid
The process id of the connecting application.
@item int vc
Which virtual console to gain control of.
@end table
Keyboard modifiers are used to multiplex clients on the same virtual
console. You (as a programmer) don't need to care about the internal
workings. They are detailed in @ref{Default Handlers}, but you only
need to choose the right values for your application.
Examples:
@table @code
@item minMod=0; maxMod=0;
specifies a client which senses mouse-only events, but neither
shift-mouse nor alt-mouse nor control-mouse.
@item minMod=0; maxMod=~0;
is a client which gets any mouse event.
@item minMod=1<<KG_SHIFT; maxMod=1<<KG_SHIFT;
is a client which senses all shift-mouse events and
nothing more.
@item minMod=1<<KG_SHIFT; maxMod=~0;
is a client interested in shift-and-whatever-else mouse events,
but disregarding mouse-only events.
@end table
If the modifier keys in the event are too few or too many, the event
won't be reported to the client. If the modifiers are right but the
current event is not part of the @code{eventMask}, it is not reported as
well. If the event is not used by the client, it can nonetheless be
passed to another client (a default handler or the internal selection
mechanism), according to the @code{defaultMask}. If the event has been
already reported to the current application, it will also be passed
along the chain, if the GPM_HARD bit is set the @code{defaultMask}.
Good values for @code{defaultMask} can thus be the following:
@table @code
@item 0
To sink any event, even those I don't use.
@item ~eventMask
Pass along any event I don't use.
@item ~GPM_HARD
Just the same, independently of @code{eventMask}.
@item GPM_MOVE|GPM_HARD
Pass motion events, even if I use them.
This is the good choice for an application which wants information on
mouse motion, but leaves the task of cursor-drawing to the server.
@end table
%==========================================================================
@node Default Handlers, , Connection Details, Gpm Internals
@section Default Handlers
In addition to console-specific clients, @code{gpm} allows for
console-independent clients -- those clients which handle events ignored
by conventional clients
Keyboard modifiers are used to multiplex the different clients on the
same console, and a default handler should specify a non-zero minimum
modifier set.
To summarize, events which get to the server can be delivered to
the following @emph{clients}, in the order of decreasing priority:
@enumerate 1
@item The current client for the current console, if any.
@item The default handler, if any.
@item The builtin `selection' mechanism.
@end enumerate
A keyboard modifier which connected with a @code{minMod} equal to the
"Control" modifier and a @code{maxMod} of @samp{~0} (all bits on), will then
get any event including the control key, if the application disregards it.
This means that if the foreground application gets only the "Meta" key,
control-mouse is sufficient to invoke the default handler. If the application
gets control-mouse but disregards "Meta", conversely, meta-control-mouse will
invoke the default handler, and meta-mouse will be delivered to selection.
Both the @code{minMod} and @code{maxMod} fields are bitmasks, and their values
are bitwise or-ed and and-ed with the current modifier mask.
@code{gpm-root} is an example of default handler. It gets control-mouse events
by default, and reads user-specific configuration files in order to draw
menus on the background of your screen.
@xref{gpm-root}.
%##########################################################################
@node The ClientLib, Demo Clients, Gpm Internals, Top
@chapter The Client Library
The @file{libgpm.a} archive is meant to provide the mouse protocol at
different levels of abstraction. Applications linking to the @code{gpm}
server are expected to benefit from using the library, as compared to
managing the raw socket interface. Any source file using the library
should include @file{gpm.h} to get gpm specific macros and
prototypes.
Delivery of events within the library makes heavy use of the concept
of "Handling Function" (or "handler", for short).
@menu
* Handling Functions::
* Low Level Library::
* High Level Lib::
* Xterm::
@end menu
%==========================================================================
@node Handling Functions, Low Level Library, The ClientLib, The ClientLib
@section Handling Functions
A mouse handler is a function which registers itself within the
library, and is called whenever a mouse event is reported to the
application. It is passed two arguments and returns an integer value,
according to the following typedef:
@code{typedef int Gpm_Handler(Gpm_Event *@var{event}, void *@var{clientdata});}
@tindex Gpm_Handler
The @var{event} is used to instantiate the mouse event just received,
and the @var{clientdata} pointer is needed to implement some higher
level functionality. An handler will be typically invoked by
@code{Gpm_Getc}, or by the high-level library, and the following
discussion assumes the invoking function is @code{Gpm_Getc} (the
high-level library only runs on behalf of @code{Gpm_Getc}).
Handling functions can do whatever they want to, and return to the caller
an integer value, which can be used to generate a keyboard event. This
feature is useful in that often the mouse is a shortcut for something which
could be made by means of the keyboard.
The application main loop can detect if the keyboard event is a physical
or generated one by looking at the global variable @code{gpm_hflag}, which
is not zero only for handler-generated events.
An handling function can generate more than one key in response of a single
mouse event. If it sets the global variable @code{gpm_morekeys} to a non-zero
variable before returning, it will be invoked again without waiting for
mouse events. You can use @code{gpm_morekeys} as a counter of how
many times you want to be called again -- the client library only compares
it to zero.
The return value from an handler is used as follows:
@table @code
@item EOF
This value is used to signal a fatal error, and will cause
@code{Gpm_Getc} to return the same value to the caller, after setting
@code{gpm_hflag} to 1.
@item 0
A zero return value means that @code{Gpm_Getc} should go on as
before, without returning to the caller. The event has been eaten
by the handler and no key-press is simulated.
@item @var{anything-else}
Any other value is considered a simulated
character, and is returned to the caller after setting
@code{gpm_hflag}. This allows a quick way to implement yes/no
boxes and simple menus without interfering with the main body
of an existing application. Moreover, if return values greater
than 255 are used a single switch loop can parse both keyboard
and mouse events.
@end table
@noindent
A mouse handler is passed as second argument the content of the
@code{gpm_data} variable, i.e. the current clientdata. The clientdata is
almost unuseful unless you use the high-level library, because it holds
a static value. Delivering the clientdata however allows the
high-level management of mouse events to be a superset of the
low-level code, rather than an incompatible alternative.
%==========================================================================
@node Low Level Library, High Level Lib, Handling Functions, The ClientLib
@section Low Level Library
The library offers utility functions to establish the connection and
to get mouse events. They are designed to work painlessly if the
server is not running on the host machine. Xterm support is available
as well.
@xref{Xterm}.
@menu
* Variables ::
* Open and Close::
* Getting Events::
* Utility Functions::
* Extra Functions::
@end menu
%--------------------------------------------------------------------------
@node Variables , Open and Close, Low Level Library, Low Level Library
@subsection Global Variables
This is the list of all the global variables present in the client
library:
@table @code
@vindex gpm_flag
@item int gpm_flag
Initially zero, it is used to tell if the process
is connected with a mouse server or not. It is used as a counter to
manage multiple opens as well.
@vindex gpm_tried
@item int gpm_tried
A flag, used to avoid retrying a connection if
the server is not available on the system.
@vindex gpm_fd
@item int gpm_fd
Initially @samp{-1}, it is the file descriptor used
to talk with the server. If we run under xterm, it will be -2.
@vindex gpm_zerobased
@item int gpm_zerobased
Since selection and curses has always been one-based,
this variable, zero by default, can be used to trigger zero-based
coordinates in event reporting. It must be set before opening the mouse
connection, and never changed later.
@xref{Events}.
@vindex gpm_visiblepointer
@item int gpm_visiblepointer
If not zero, causes the mouse cursor to be always visible on the
window. It is zero by default.
@vindex gpm_mx
@vindex gpm_my
@item gpm_mx
@itemx gpm_my
These variables (max X and max Y) are used when fitting events
inside the screen. They are initialized by @code{Gpm_Open}, and
updated by a @code{SIGWINCH} handler internal to the library.
(Don't worry, the library doesn't @emph{replace} any
@code{SIGWINCH} handler your program may already have installed;
instead the library @emph{hooks} the signal, that is, it calls
any preexisting handler after taking care of its own needs.)
@vindex gpm_hflag
@item int gpm_hflag
Used to signal if a character has been generated
by a mouse handler.
@xref{Handling Functions}.
@vindex gpm_handler
@vindex gpm_data
@item Gpm_Handler *gpm_handler; void *gpm_data
Both initially @code{NULL},
they're used to setup asynchronous mouse handling, as
described below under the @code{Gpm_Getc()} item.
@vindex gpm_morekeys
@item gpm_morekeys
Used by the mouse handler to provide more than one key:
if @code{gpm_morekeys} is not zero, @code{Gpm_Getc} will
invoke the handler without waiting for events. @code{gpm_morekeys}
is never set by the mouse library.
@end table
%--------------------------------------------------------------------------
@node Open and Close, Getting Events, Variables , Low Level Library
@subsection Connecting and Disconnecting
%.........................................................................
@deftypefun int Gpm_Open (Gpm_Connect *@var{conn}, int @var{flag});
Open a connection with the server. The @var{conn} parameter points to
the connection information for the being-created connection, as already
described.
@xref{Connection Details}.
It is passed to the server after
filling the @code{pid} and @code{vc} fields.
@var{flag} should be @samp{0} for normal applications, those interested
in events related to their own console. The own console is considered to
be the one attached to @code{stdin}, and it must match the string
@samp{/dev/tty*}. A negative value for @var{flag} is used to make the
invoking application a default handler @ref{Default Handlers}, while a
positive value is used to force connection to a particular console,
either for debugging issues or whenever @code{stdin} is not a tty when
@code{Gpm_Open} is invoked.
Multiple opens are allowed, and a stack of @code{Gpm_Connect} structures
is managed by the library. You can, thus, re-open the connection in
order to temporarily change the range of events you're interested
in. When you invoke an external program, for example, you should re-open
the connection with @code{eventMask} zeroed, and @code{defaultMask},
@code{minMod} and @code{maxMod} all equal to @samp{~0}.
The return value is either @samp{-1} or the file descriptor used to
communicate with the server. When run under xterm, a gpm client gets event
through @code{stdin}, and the return value for @code{Gpm_Open()} will be @samp{-2}.
This value is always available in @code{gpm_fd}.
@end deftypefun
%.........................................................................
@deftypefun int Gpm_Close (void);
Pops the connection stack. It is used to restore the previous situation
after a change in the connection masks. Closes the actual connection
when the stack gets empty. On last close it returns 0, -1 otherwise.
@end deftypefun
%--------------------------------------------------------------------------
@node Getting Events, Utility Functions, Open and Close, Low Level Library
@subsection Getting Events
%.........................................................................
@deftypefun int Gpm_GetEvent (Gpm_Event *@var{event});
Reads an event form @code{gpm_fd}. It should be called only when the
@code{gpm_fd} descriptor is reported as readable by a @code{select()}
system call, or it will block until an event arrives (unless you put the
mouse file in non-blocking mode). It returns 1 on success, -1 on
failure, and 0 after closing the connection. Failure can happen if a
signal interrupted the read system call. This function doesn't work with
xterm mouse reporting and is meant for internal use by the library.
@end deftypefun
%.........................................................................
@deftypefun int Gpm_CharsQueued (void);
It returns the number of characters (contained in @code{nbprevchar} index)
queued into the array @code{prevchar} by function @code{Gpm_Getc}.
This call is useful i.e. in recognition of function or arrow keys, when we
need to know the next character read by @code{Gpm_getc} in order to
subsequently get it.
@end deftypefun
%.........................................................................
@deftypefun int Gpm_CharsQueued (void);
It returns the number of characters (contained in @code{nbprevchar} index)
queued into the array @code{prevchar} by function @code{Gpm_Getc}.
This call is useful i.e. in recognition of function or arrow keys, when we
need to know the next character read by @code{Gpm_getc} in order to
subsequently get it.
@end deftypefun
%.........................................................................
@deftypefun int Gpm_Getc (FILE *@var{f});
@deftypefunx int Gpm_Getchar (void);
These are intended to be replacements for @code{getc()} and
@code{getchar()} to be used by applications which are interested in the
mouse. Their external behaviour is the same as @code{getc()}, but a mouse
handler gets invoked whenever an event is available.
@xref{Handling Functions}.
A mouse handler can force @code{Gpm_Getc} to return a
specific value to the caller, and the ``simulated'' character is
signaled by setting @code{gpm_hflag} to 1.
@end deftypefun
%.........................................................................
@deftypefun int Gpm_Wgetch (WINDOW *@var{win});
@deftypefunx int Gpm_Getch (void);
These are intended to be replacements for @code{wgetch()} and
@code{getch()} to be used by applications which are interested in the
mouse. They are the curses equivalent of @code{Gpm_Getchar}.
@end deftypefun
%--------------------------------------------------------------------------
@node Utility Functions, Extra Functions, Getting Events, Low Level Library
@subsection Utility Functions
%.........................................................................
@deftypefun int Gpm_Repeat (int @var{millisecs});
It returns 1 if no mouse events arrive in the next @var{millicecs}
milliseconds, 0 otherwise. It is meant to be used by those handlers
which need to repeat an action as long as the mouse button is pressed
(@code{while(Gpm_Repeat(200))@dots{}}).
@end deftypefun
%.........................................................................
@deftypefun int Gpm_DrawPointer (int @var{x}, int @var{y}, int @var{fd});
@deftypefunx int GPM_DRAWPOINTER (Gpm_Event *@var{ePtr};)
These are actually macros. They should be used to draw the mouse pointer after
mangling the screen (while dragging on a menu, say), because letting it to
the server won't work nicely, due to lack of synchronism between client and
server. The file descriptor should refer to the console. The return value is
0 on success and -1 on failure. @code{Gpm_DrawPointer} is obsolete, and is
retained only for compatibility.
@end deftypefun
%.........................................................................
@deftypefun int Gpm_FitValuesM (int *@var{x}, int *@var{y}, int @var{margin});
@deftypefunx int Gpm_FitValues (@var{x},@var{y});
@deftypefunx void Gpm_FitEvent (@var{ePtr});
The first is a function, while the other are macros.
Note that @code{Gpm_FitEvent} does not return values.
These three procedures should be used to fit the pointer inside the visible
screen. They are needed for drag and release event. A connection
bit will be available in the future to force the pointer in the visible
region.
Note that fitting uses @code{gpm_mx} and @code{gpm_my}.
@xref{Variables}.
@end deftypefun
%--------------------------------------------------------------------------
@node Extra Functions, , Utility Functions, Low Level Library
@subsection Extra Functions
%.........................................................................
@deftypefun char* Gpm_GetLibVersion (int *@var{where});
This function returns a pointer to a static storage representing the
version number of the library. It is only available from 0.98.2 onward,
and returns a string like @samp{"0.98.2"}. The third number is optional,
and the second number will always be reported as two digits; thus 1.10 is
newer than 1.01. The @var{where} pointer, if not null, is used to store
a decimal number representing the version -- 0.98.2 is 9802 and 1.1.8 is
10108.
@end deftypefun
%.........................................................................
@deftypefun char* Gpm_GetServerVersion (int *@var{where});
This function returns a pointer to a static storage representing the
version number of the server. The version is retrieved through
@code{popen()}, so it could fail (and return @code{NULL})if no @code{gpm} program
is in the current path. Alternatively, it could fail (and return a wrong
value) if the @code{gpm} in the path is not the currently running one.
The function is only available in the clientlibrary version 0.98.2 or
newer, but it works with any daemon, from 0.01 onward. The string returned
can be parsed in the same way as for @code{Gpm_GetLibVersion()}. A preparsed
version is stored in *@var{where} if @var{where} is not null. Both these
functions do their calculations only the first time they are invoked.
@end deftypefun
%.........................................................................
@deftypefun int Gpm_GetSnapshot (Gpm_Event *@var{ePtr});
This function gives a non-blocking snapshot of the current situation:
it returns the number of mouse buttons, as known to the server, or -1
if that information is not available (under Xterm, or before connecting).
If @var{ePtr} is not null, it is filled with information about the current
state of the mouse. The fields have the following meaning: @code{x,y}: current
position of the cursor; @code{dx,dy} size of the window; @code{vc,modifiers} the
current console and the current shift state; @code{buttons} which buttons
are currently help down; @code{clicks} the number of clicks (0,1,2).
This function is only available from 0.98.2 onward, and will return -1
if run with an older server.
Since this information travels on the same file descriptor as the
events, and applications usually don't want to lose events, the function
returns 0 if the input queue is not empty.
@end deftypefun
%--------------------------------------------------------------------------
@node High Level Lib, Xterm, Low Level Library, The ClientLib
@section High Level Library
The high level library is part of the main @file{libgpm.a}, but it acts at
a different level of abstraction. The high level library depends in the
low-level one, so if you link your application with any object of the
high-level library, you're forced to link in the low-level one too.
If your application @emph{only} runs under xterm, please see
@file{gpm-xterm} in the @file{sample} subdirectory of the distribution,
which offers all the needed functionality.
The main role of the high-level library is to define a way to manage
windows (or "Regions of Interest" on your text screen). The regions
are arranged in a stack, and event are delivered to the different
windows according to their position both on the stack and on the screen.
@xref{hltest}.
@menu
* Concepts::
* hl-Variables::
* hl-Functions::
@end menu
%--------------------------------------------------------------------------
@node Concepts, hl-Variables, High Level Lib, High Level Lib
@subsection Concepts
The high-level library is completely independent of the low-level one,
so it uses @code{gpm_handler} and @code{gpm_data} as connection point with
@code{Gpm_Getc()}.
All the functionality is based on the concept of RoI's. each RoI is
described by a @code{Gpm_Roi} structure, which is made up by the following
fields:
@tindex Gpm_roi
@table @code
@item short xMin, xMax
These numbers identify the upper-left corner of the region.
When events are reported to the region, the event coordinate
will be relative to this position (zero-based).
@item short yMin, yMax
These numbers identify the lower-right corner of the region.
@item unsigned short minMod, maxMod
These modifier masks have the same role within the application as
the same fields have in inter-application multiplexing.
@item unsigned short eventMask
It is the mask of events which are to be reported to the current
region.
@item unsigned short owned
This is a bit, used to know if the region is owned by the
library or the application, in order to issue @code{free(0} when
needed.
@item Gpm_Handler *handler
The function to be called when events are to be reported to the
current region.
@item void *clientdata
The clientdata to be passed to the handler
@item Gpm_Roi *next, *prev
Links to the RoI chain.
@end table
%--------------------------------------------------------------------------
@node hl-Variables, hl-Functions, Concepts, High Level Lib
@subsection Variables
@table @code
@item Gpm_Roi* gpm_roi
The linked list of regions (pointer to the top one).
@vindex gpm_roi
@item Gpm_Roi* gpm_current_roi
The region which got the last event (used to generate enter and
leave events).
@vindex gpm_current_roi
@item Gpm_Handler* gpm_roi_handler
This variable is meant to be set by the user. It is the catch-all
region of interest, which will be called for any mouse event not
falling within any registered region. If NULL, the event will be
discarded.
@vindex gpm_roi_handler
@item void* gpm_roi_data
the client data to be passed to @code{gpm_roi_handler}.
@vindex gpm_roi_data
@end table
%--------------------------------------------------------------------------
@node hl-Functions, , hl-Variables, High Level Lib
@subsection Functions
%.........................................................................
@deftypefun Gpm_Roi* Gpm_PushRoi (int @var{xmin}, int @var{ymin}, int @var{xmax}, int @var{ymax},
int @var{mask}, Gpm_Handler *@var{fun}, void *@var{xtradata});
This function pushes a Region of Interest on top of the stack, after
allocating it and filling with the provided values. @var{fun} is the
function which will be called in order to handle events, and the
roi itself will be passed to the function as clientdata. The Roi is
represented by a @code{struct Gpm_Roi} structure, described in @file{gpm.h}.
The @code{xtradata} field will be used to fill the @code{xtradata} field in
@code{Gpm_Roi}.
the return value is the Roi just pushed (i.e. the top of stack).
@end deftypefun
%.........................................................................
@deftypefun char* Gpm_UseRoi (Gpm_Roi *@var{roi});
While @code{Gpm_PushRoi} has to allocate the Region before pushing it, this
function passes a pre-allocated function to the stack manager.
The return value is the Roi just used.
@end deftypefun
%.........................................................................
@deftypefun Gpm_Roi* Gpm_PopRoi (Gpm_Roi *@var{roi});
Used to extract a Region of Interest from the stack, this function will
also clear the Region if it is needed.
@end deftypefun
%.........................................................................
@deftypefun Gpm_Roi* Gpm_RaiseRoi (Gpm_Roi *@var{which}, Gpm_Roi *@var{before});
Raise the specified roi, either before the second Roi or at top-of-
stack (if @var{before} is @code{NULL}). The return value is the new top-of-stack.
@end deftypefun
%.........................................................................
@deftypefun Gpm_Roi* Gpm_LowerRoi (Gpm_Roi *@var{which}, Gpm_Roi *@var{after});
Lower the specified roi, either after the second Roi or at bottom-of-
stack (if @var{before} is NULL). The return value is the new top-of-stack.
@end deftypefun
%.........................................................................
@deftypefun Gpm_Roi* Gpm_HandleRoi (Gpm_Event *@var{ePtr}, void * @var{clientdata});
This function, which should not be invoked by the user, is the dispatching
manager within the application for mouse events. This function will
browse the stack of regions of interest in order to notify windows about
Enter and Leave events (if they are interested in them), and then
delivers the current event to the relevant Roi.
If no Roi is interested in he event the @code{*gpm_roi_handler} function
is invoked (if not null), with null clientdata.
Reported events are all those in @code{Gpm_Event}, and also @code{GPM_ENTER}
and @code{GPM_LEAVE}. These can be used to toggle highlighting on a
button or to drop a menu if the menubutton is entered during a drag.
Remember that when Enter or Leave is notified, no other information in
the event item should be used.
@end deftypefun
%==========================================================================
@node Xterm, , High Level Lib, The ClientLib
@section Running under @code{xterm}
As of release 0.18, gpm-based applications can run under xterm
without any need for recompilation. The library is designed to convert
xterm mouse events to gpm-style structures, so that the client will get
the same events it got under the Linux console. Moreover, a source file
@file{sample/gpm-xterm.c} is available to mimic libgpm under a
different OS than Linux. Porting to other text-based consoles is an open
issue, but I myself have Linux alone.
The goal is to provide a uniform mouse interface with both xterm and the
Linux console. Some features of libgpm would not be available, but if
you run under xterm you know what you get, so you couldn't use them on
the console anyway.
The @file{sample} directory in the distribution tree is meant to show how
a simple mouse-sensitive application can be easily autoconfigured and
compiled. The @code{rmev} program has proved to compile and run smoothly
under Linux (both with and without @file{libgpm.a}), SunOS-4, Solaris-5,
hpux-8.x and Ultrix-3.0.
%##########################################################################
@node Demo Clients, Type Index, The ClientLib, Top
@chapter Demonstration Clients
@menu
* mev::
* sample/rmev::
* Emacs Support::
* gpm-root::
* hltest::
* mouse-test::
@end menu
%==========================================================================
@node mev, sample/rmev, Demo Clients, Demo Clients
@section @code{mev}
%MANPAGE mev.1
%M .TH MEV 1 "February 1995"
%M .UC 4
%M .SH NAME
%M mev \- a program to report mouse events
%M .SH SYNOPSIS
%M .B mev
%M [
%M .I options
%M ]
%M .br
%M .SH DESCRIPTION
%M The `mev' program is part of the gpm package.
%M
%M The information below is extracted from the texinfo file, which is the
%M preferred source of information.
The @code{mev} program is modeled after @code{xev}. It prints to @code{stdout} the
mouse console events it gets.
@code{mev}'s default behaviour is to get anything, but command line switches
can be used to set the various fields in the @code{Gpm_Connect} structure, in
order to customize the program's behaviour. I'm using @code{mev} to
handle mouse events to Emacs.
@xref{Emacs Support}.
Command line switches for @code{mev} are the following:
@table @code
@item -C @var{number}
Select a virtual console to get events from.
This is intended to be used for debugging.
@item -d @var{number}
Choose a default mask. By default the server gets
any events not belonging to the event mask. The mask can be
provided either as a
decimal number, or as a symbolic string.
@item -e @var{number}
Choose the event mask. By default any event
is received. The mask can be provided either as a
decimal number, or as a symbolic string.
@item -E
Enter emacs mode. In emacs mode events are reported as
lisp forms rather than numbers. This is the format used by the
t-mouse package within emacs.
@item -f
Fit events inside the screen before reporting them. This options
re-fits drag events, which are allowed to exit the screen border,
@xref{Margins}.
@item -i
Interactive. Accepts input from @code{stdin} to change connection
parameters.
@item -m @var{number}
Choose the minimum modifier mask. Any event with
fewer modifiers will not be reported to @code{mev}. It defaults to @samp{0}.
The mask must be provided either as a
decimal number, or as a symbolic string.
@item -M @var{number}
Choose the maximum modifier mask. Any event with
more modifier than specified will not be reported to @code{mev}.
It defaults to @samp{\~0}, i.e. all events are received.
The mask must be provided either as a
decimal number, or as a symbolic string.
@item -p
Requests to draw the pointer during drags. This option is used
by emacs to avoid invoking @code{ioctl()} from lisp code.
@end table
When the arguments are not decimal integers, they are considered lists
of alphanumeric characters, separated by a single non-alphanumeric
character. I use the comma (@samp{,}), but any will do.
Allowed names for events are @samp{move}, @samp{drag}, @samp{down} or
@samp{press}, @samp{up} or @samp{release}, @samp{motion} (which is both
@samp{move} and @samp{drag}), and @samp{hard}.
Allowed names for modifiers are @samp{shift}, @samp{leftAlt},
@samp{rightAlt}, @samp{anyAlt} (one or the other), @samp{control}.
When the @samp{-i} switch is specified, @code{mev} looks at its standard input as
command lines rather than events. The input lines are parsed, and the
commands @samp{push} and @samp{pop} are recognized.
The @samp{push} command, then, accepts the options @samp{-d}, @samp{-e}, @samp{-m}
and @samp{-M}, with the same meaning described above. Unspecified options
retain the previous value and the resulting masks are used to reopen
the connection with the server. @samp{pop} is used to pop the connection
stack. If an empty stack is popped the program exits.
Other commands recognized are @samp{info}, used to return the stack
depth; @samp{quit} to prematurely terminate the program; and
@samp{snapshot} to get some configuration information from the server.
@ignore
.SH BUGS
Beginning with release 1.16, \fBmev\fP no longer works under xterm.
Please use the \fBrmev\fP program (provided in the \fBsample\fP
directory) to watch gpm events under xterm or rxvt. \fBrmev\fP also
displays keyboard events besides mouse events.
.SH AUTHOR
Alessandro Rubini <rubini@linux.it>
.br
Ian Zimmerman <itz@speakeasy.org>
.SH FILES
.nf
/dev/gpmctl The socket used to connect to gpm.
.fi
.SH SEE ALSO
.nf
\fB gpm(8) \fP The mouse server
\fB gpm-root(1) \fP An handler for Control-Mouse events.
.fi
The info file about `gpm', which gives more complete information and
explains how to write a gpm client.
@end ignore
%MANPAGE END
%==========================================================================
@node sample/rmev, Emacs Support, mev, Demo Clients
@section @code{sample/rmev}
@code{rmev} is a reduced version of @code{mev}, but it is designed to be as
portable as possible. It uses a subset of the capabilities of @file{libgpm.a},
but works smoothly on both xterm and the Linux console. It is distributed
with @code{gpm} to show how a curses based application can support the mouse
with a small effort. Most of the xterm decoding is by Janne Kukonlehto.
@xref{Xterm}.
%==========================================================================
@node Emacs Support, gpm-root, sample/rmev, Demo Clients
@section Emacs Support
Emacs support is quite complete as of 0.14. The enclosed file
@file{t-mouse.el}, also available in byte-compiled form, is used to pass
mouse events to emacs. @file{t-mouse.elc} is installed in the correct
@t{site-lisp} directory for you emacs installation (as detected by the
configure phase).
Events with modifiers other than Meta, Control, and Shift are not
managed by the library. Managed events are passed to the lisp program,
which converts them to be similar to X mouse events inside
emacs. Actions are then invoked through a local keymap.
In my own environment I can use mouse-only and meta mouse within emacs,
shift-mouse to run selection and control-mouse to run @code{gpm-root}.
@xref{gpm-root}.
I suggest to put the following form in your own @file{.emacs} file, to
avoid loading @code{t-mouse} when you aren't working on the Linux console:
@lisp
(if (and (string-match ".*-linux" system-configuration)
(or (string-match "linux" (getenv "TERM"))
(string-match "con.*" (getenv "TERM"))))
(load-library "t-mouse"))
@end lisp
Mouse events are appended to the list variable
@code{unread-command-events} where the Emacs main event loop will find
them. They can be made to trigger any command (or interactive function,
in Emacs Lisp terminology) at all. Actually Emacs already comes with
reasonable bindings for most mouse events, so usually you won't have to
do anything beyond installing @code{t-mouse}. If you want to modify
what Emacs does in response to mouse events, please see
@ref{Keymaps,,,elisp}.
The scrollbar sits on the last column of the screen, though it is not
visible. When you click on the last column, a scroll-bar action is taken.
If this annoys you, again it can be turned off by changing the
appropriate Emacs keymap.
If you kill the @code{gpm} server, Emacs won't respond to mouse events
any more. If the server is then restarted, you can invoke `@kbd{M-x
t-mouse-run}' to restart mouse responsiveness in the editor.
%==========================================================================
@node gpm-root, hltest, Emacs Support, Demo Clients
@section The ``gpm-root'' program
%MANPAGE gpm-root.1
%M .TH GPM-ROOT 1 "February 1995"
%M .UC 4
%M .SH NAME
%M gpm-root \- a default handler for gpm, used to draw menus on
%M the root window
%M
%M .SH SYNOPSIS
%M .B gpm-root
%M [
%M .I options
%M ]
%M .br
%M .SH DESCRIPTION
The program @code{gpm-root} is designed to handle Control-Mouse events to
draw menus on the background of the current tty. The actual menus
are described by a configuration file in the user's home directory.
Please note that @code{gpm-root} needs to run with Linux 1.1.73 or
newer, because previous kernels lack some screen handling capabilities
required by the program.
The program uses the files @file{/dev/vcs*} to draw to the console screen.
These are available only from kernel 1.1.81 onward. If you miss those
device nodes, you should create them using @code{create_vcs} in the
distribution directory. The tool won't run with kernels older than 1.1.81,
because they lacked a full screen dump/restore capability.
Available command line options are the following:
@table @code
@item -m @var{number}
Choose the modifier to use (by default: @samp{control}). The modifier
can be provided either as a number or as a symbolic string.
Allowed strings are @samp{shift}, @samp{anyAlt}, @samp{leftAlt},
@samp{rightAlt}, @samp{control}.
@item -u
Deny using user-specific configuration files. With this
option on, only @file{/etc/gpm-root.conf} will be used as a source
of configuration information. This option
is intended for those system administrators who fear security could
be broken by this daemon. Things should be sufficiently secure, but
if you find a hole please tell me about it.
@item -D
Do not automatically enter background operation when started,
and log messages to the standard error stream, not the syslog
mechanism. This is useful for debugging; in previous releases
it was done with a compile-time option.
@item -V @var{verbosity increment}
Raise the maximum level of messages that will be logged. Thus a
positive argument has the effect of making the program more
verbose. One can also give a negative argument to hush the
program; however, note that due to @b{getopt(3)} rules a negative
argument must follow the option with no space betwixt (that is,
@samp{-V-1} but not @samp{-V -1}). @xref{Program Arguments,,,libc}.
The argument is optional and its default value is 1.
@end table
Each time a menu is drawn, the configuration file is reparsed if it has
changed. This allows modification of personal setup without reinvoking
the daemon.
%M The actual configuration file is better introduced by looking at your
%M @file{/etc/gpm-root.conf}.
%M
%MSKIP
The actual configuration file is better introduced by an example:
@lisp
# sample configuration file for gpm-root
# edit it to suit your taste
button 2 @{
name "system status"
foreground red
background black
border yellow
head bright yellow
"" f.nop
"load: " f.load
"free:" f.free
"---------" f.nop
"disk usage" f.bgcmd "du | sort -rn > /tmp/du"
@}
button 3 @{
name "jump"
foreground black
background red
border bright yellow
head bright yellow
"tty1" f.jptty "1"
"tty2" f.jptty "2"
"tty3" f.jptty "3"
"tty4" f.jptty "4"
"tty5" f.jptty "5"
"tty6" f.jptty "6"
"" f.nop
"more of them..." @{
"tty 17" f.jptty "17"
@}
@}
@end lisp
%M .fi
The syntax for the file won't be described here, being it quite apparent
from the example above. Blanks and newlines are unused in parsing the
file, and the layout of the file is free. Comments are allowed in the
file: any hash mark (@samp{#}) found at the beginning of the line or
after white space makes the parser discard anything up to the next
line. To insert quotes (@samp{"}) in strings precede them with a backslash.
Note that recursive menus are allowed, to any level of recursion.
Keywords belong to three groups: the button keyword, the cfg
keywords and the action keywords. They are all described in the table
below:
@table @code
@item button @var{number} @var{menu}
The @code{button} keyword is used to introduce a menu. It is
followed by the number of the relevant button (1=left,
2=middle, 3=right), an open brace, a menu and a closed brace.
A menu is made up of cfg statements, followed by
action statements. Cfg statements can come in any order,
while the order of action statements tells the actual order
in which actions will appear on the screen, top to bottom.
@end table
The following statements belong to the cfg set.
@table @code
@item name @var{string}
If the @code{name} keyword is present, the specified
@var{string} will be used as the name for the current menu.
@item background @var{color}
This statements is used to specify the
background color to be used in the current menu. The @var{color}
can be specified with one of the eight canonical strings @samp{black},
@samp{red}, @samp{cyan} etc. The background defaults to black.
@item foreground @var{color}
This statements is used to specify the
foreground color for menu items. Its value defaults to @samp{white}.
An optional @samp{bright} keyword can appear before the actual color.
@item border @var{color}
@code{border} is used to specify the
border color for the menu. Its value defaults to @samp{white}.
An optional @samp{bright} keyword can appear before the actual color.
@item head @var{color}
@code{head} is used to specify the
foreground color for the title of the menu. Its value defaults
to @samp{white}.
An optional @samp{bright} keyword can appear before the actual color.
@end table
The following statements belong to the action set.
@table @code
@item @var{string} f.fgcmd @var{cmdstring}
When the mouse button is
released above the corresponding menu item, the @var{cmdstring} is
pasted in the keyboard queue of the current console. This is
not yet implemented.
@item @var{string} f.bgcmd @var{cmdstring}
When the mouse button is released above the
corresponding menu item, a shell (@file{/bin/sh}) is forked to
execute the specified command, with @code{stdin}
connected to @file{/dev/null}, and @code{stdout}, @code{stderr} connected
to the active console.
@item @var{string} f.jptty @var{ttynumber}
When the mouse button is
released above the corresponding menu item, the console is
switched to the one specified. The @var{ttynumber} must be specified
as a string. Any tty can be reached this way, even those which are
not accessible via the keyboard.
@item @var{string} f.mktty @var{ttynumber}
When the mouse button is
released above the corresponding menu item, an unused console is
selected, and @file{/sbin/mingetty} is executed in it. The current console
is switched to the newly opened console. I use this command to save
kernel memory by opening a single console through @file{/etc/inittab}
and requesting the others only when i need to login.
@item @var{string} @var{Whole-menu}
A menu can directly follow the label string.
When the mouse pointer leaves the menu frame at the level of @var{string},
a second menu is posted on screen.
@item @var{string} f.lock
When the mouse button is
released above the corresponding menu item, the keyboard and the
screen are locked, and only the locking user or the superuser
can unlock them. This is not yet implemented.
@item @var{string} f.load
The current loadavg when the menu is posted is concatenated to @var{string}
to build the actual message displayed on screen. Nothing happens at
button release.
@item @var{string} f.free
The free memory and swap when the menu is posted is concatenated
to @var{string}
to build the actual message displayed on screen. Nothing happens at
button release.
@item @var{string} f.time
The current time is formatted with @b{strftime(3)}, according to
@var{string}. The resulting string is
the actual message displayed on screen. Nothing happens at
button release.
@item @var{string} f.pipe @var{cmdline}
When the mouse pointer leaves the menu frame at the level of @var{string},
a message box is posted on screen showing the last ten lines
of the output of @var{cmdline}. @var{cmdline} is executed
by @file{/bin/sh}. This is not yet implemented.
@item @var{string} f.nop
This does nothing, it only displays @var{string} on the menu.
@end table
The @code{HOME}, @code{LOGNAME} and @code{USER} environment variables are setup
to the values for the invoking user before spawning an external
process (@code{f.bgcmd}, @code{f.pipe}). The current directory is always @file{/}.
%M .SH BUGS
Known bugs have been fixed. In particular, if you invoke @code{gpm-root}
right after @code{gpm}, it will delay a few seconds before trying to connect
to the daemon.
@ignore
.SH AUTHOR
Alessandro Rubini <rubini@linux.it>
.SH FILES
.nf
/dev/gpmctl The socket used to connect to gpm.
/etc/gpm-root.conf The default configuration file.
$(HOME)/.gpm-root The user configuration file.
/dev/vcs* Virtual Console Screens
.fi
.SH SEE ALSO
.nf
\fB gpm(8) \fP
.fi
The info file about `gpm', which gives more complete information and
explains how to write a gpm client.
@end ignore
%MANPAGE END
%==========================================================================
@node hltest, mouse-test, gpm-root, Demo Clients
@section @code{hltest}
High-level test is a simple sample application using the high-level
library. It implements something like a window manager for text windows,
though it is small and unuseful.
The application is meant to be read by programmers trying to use the
high-level library. It is equipped with event reporting to help
in understanding the internal workings.
%==========================================================================
@node mouse-test, , hltest, Demo Clients
@section @code{mouse-test}
%MANPAGE mouse-test.1
%M .TH mouse-test 1 "March 26, 1998" ""
%M .SH NAME
%M mouse-test \- a tool for determining mouse type and device it's attached to.
%M .SH SYNTAX
%M \fBmouse-test\fR [ \fIdevice\fR ... ]
%M .SH DESCRIPTION
This experimental and incomplete application tries to help in detecting
which protocol does your mouse speak. It is able to detect MouseMan
devices, and to choose between @samp{-t ms} (three-buttons aware) and
@samp{-t bare} old two-buttons-only serial mice.
%M .SH BUGS
I know the application is buggy, but I only own one mouse device.
If you are interested in this application, just call me and awake me
from my laziness.
@ignore
.SS OPTIONS
.IP \fIdevice\fP
[ \fIdevice\fP ... ]
.PP
Check this \fIdevice\fP for a mouse. If no devices are listed, mouse-test will try all possible devices.
.SH AUTHOR
Alessandro Rubini <rubini@linux.it>
.SH FILES
.nf
/dev/* The devices used to search for a mouse
.fi
.SH SEE ALSO
.nf
gpm(8)
.fi
@end ignore
%MANPAGE END
%##########################################################################
@node Type Index, Function Index, Demo Clients, Top
@unnumbered Type Index
@printindex tp
@node Function Index, Variable Index, Type Index, Top
@unnumbered API Index
@printindex fn
@node Variable Index, , Function Index, Top
@unnumbered Variable Index
@printindex vr
%@iftex
%@unnumbered Table of Contents
%@contents
%@end iftex
@bye
/*
* This is because Linus uses 4-wide tabstops,
* forcing me to use the same default to manage kernel sources
*/
/* Local Variables: */
/* tab-width:8 */
/* End: */