Xcolorsel(1) Xcolorsel(1)
Xcolorsel User's Guide Xcolorsel User's Guide
27th December 1993
NAME
xcolorsel - display contents of rgb.txt files together with color
probes.
SYNOPSIS
xcolorsel [options] [RgbTxtFile]
DESCRIPTION
This utility displays the contents of the rgb.txt file (usually found
as /usr/lib/X11/rgb.txt) or a file with this format specified as the
optional [RgbTxtFile] parameter. Each line of this file consists of 3
integers (usually 0-255) representing the RGB values and a nickname
for this color separated by spaces. The RGB values can be displayed in
every color representation X11R5/6 supports. Also it is possible to
show the values in either resource definition or C-style. An
additional option to display the RGB values the current server would
be able to actually display is also implemented. The main feature of
Xcolorsel is that a small example tile of each color is also shown. I
will describe each button/X11-control in Xcolorsel's window in the
next section. This version has now also support for servers with read
only colormaps (That is StaticColor, StaticGray, TrueColor). Actually
I did not realize that this would be needed before I got a TrueColor
server myself. However since colors have to be allocated one by one in
these modes, the startup time of xcolorsel has reduced dramatically.
USAGE
Xcolorsel's window is divided into four main parts:
(Usually) two rows of command buttons.
The RgbText Widget displaying the input file and (if needed) vertical
and/or horizontal scrollbars.
A message line displaying help messages, comments, or results of
commands or actions.
(Usually) one row of action buttons. The main (or better intended)
difference between commands and actions is that action operate on
colors selected in the display area and commands perform general
tasks. The title bar of Xcolorsel's window should (if supported
by the window manager) show the name of the current displayed
file. Depending from the window size the actual layout may
differ. Also the names of the buttons may differ (if for example
a german application default file is used). However the position
and order of the buttons and other elements should be the same,
s.t. you may rely on the order in which the controls are
described in this file.
Command Buttons (first row)
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About me opens a new window displaying an ASCII-Version of this manual
page. When this window is open the About me is inactive. In the lower
left edge of this window a Dismiss button can be seen. Press this
button to dismiss the help window. If the window is to small to
display the whole file vertical and/or horizontal scrollbars are
provided. The text is displayed in a standard Xaw AsciiText Widget.
Text selection and <Ctrl>-S (search) work as usual. For a full
description of the capabilities of this Widget see the Athena Widget
Reference Manual. If the help window is dismissed the About me button
is reactivated. Fileinfo displays the number of entries in the input
file. Also the number of different RGB triples is displayed.
Furthermore the Xserver is queried to see how many different colors
the current server will show if given all these values. The last
value will differ depending on the color depth of the colormaps on the
server. Xfree86 Servers usually use 6 bit for each RGB value yielding
to a lower number of different colors on the server than different
colors are given in the input file where RGB values are usually 8 bit
each. Grab color. When you press this button, the cursor changes
into a magnification glass with a transparent hole at its hot spot.
Move this hole over any colored pixel in any window you are interested
in and press the left button. While the cursor is a magnifying glass
Xcolorsel takes over the whole mouse. Xcolorsel itself ensures that
each window the cursor is in is displayed with its correct colormap.
After you pressed the left button the color selected is searched in
the input file. The color definition in the current display format is
given in the message line. Also the number of acceptable colors, exact
matches and percentage of equality of the best match are given (if
any). (Exception: If display format is values from input file each of
the 16 bit RGB values is given like with 16 bit scaled rgb but in
decimal.) Also the line containing the best match found is selected in
the RgbText Widget, and the text is scrolled, s.t. the line can be
seen. The Best match, Previous, and Next actions are appropriately
activated. The algorithm to compare colors is (too!) simple. Two
colors R1 G1 B1 and R2 G2 B2 are compared by calculating (R1-R2)*(R1-
R2) + (G1-G2)*(G1-G2) + (B1-B2)*(B1-B2). The result is scaled to 0-
100%, where 100% means equivalence and 0% is the difference between
black and white (aka between (0,0,0) and (255,255,255)). It is ensured
that even almost equal colors compare only up to 99.99%. 100% is only
possible for exact equivalence. The value above which colors are
acceptable equal can be changed and defaults to 95%. Grabbed colors
are compared against the color values as they can be realized on the
current server not the theoretic values from the input file. Reverse
exchanges the text fore- and background color in the RgbText Widget.
Default colors returns the text fore- and background color in the
RgbText Widget to the values at the start of Xcolorsel. This is
(together with Reverse) useful to return to readable text after you
changed to colors with the Set foreground and Set background actions
to values making it impossible to read anything in the RgbText Widget.
Quit quits Xcolorsel and closes all its windows.
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Command Buttons (second row)
Display format displays a submenu that allows you to define the format
in which color RGB values are displayed (Press and hold left button
down over Display format button and release the button over the
desired format. The possible color values are the color formats that
X11R5/6 supports. Values from input file displays the RGB values like
given in the input file (see also comment in Grab color. Note that
conversion to TekHVC is slow for not trivially short input files.
While the color conversion calculation takes place the cursor in the
xcolorsel windows (except scrollbars) is changed to a busy cursor and
all controls are inactive. Note the difference between scaled and
truncated rgb formats: Scaled scales the internal 16 bit RGB integer
values to 4/8/12 bits whereas truncated means the most significant
4/8/12 bits. Truncated RGB values are only supported for
compatibility. Their use in new programs is discouraged. C-Style is a
toggle control switching C support on/off. With C support RGB values
are separated with , instead of the / used in X-Windows resource
definitions. Also Hex-Numbers are given in the format that is needed
in C source codes. Together with the selection capabilities of the
RgbText widget this allows inclusion of color definitions in programs
or Application Default Files. See next sub section. This option is
meaningless with the Values from input file display format. Show real
server values is again a toggle control. If enabled the server is
queried which RGB values for each color it is actually able to
display. Then these values are displayed instead of the theoretic
values calculated by Xcolorsel and Xlib itself. Note the when
searching/grabbing colors Xcolorsel always compares with the color
values like they would be used by the server, because the searched
color is also only known by its actually realized values. This option
is meaningless with the Values from input file display format.
The RgbText Widget Display area
In this box (part of) the input file is displayed. Depending of the
length and width of the displayed information scrollbars are provided.
Each line consists of an example tile of the color, the defining color
values in the selected output format, and the nickname of the color.
The RgbText Widget inherits all capabilities of the AsciiText Widget,
s.t. scrollbars, <Ctrl>-S (searching) and selection work as usual.
There is only one exception: Double clicking with the left button does
not select words separated by white space but here senseful subparts.
That is double clicking in the nickname selects the whole nickname
regardless of included whitespace. Double clicking on the color
definitions selects the whole color definition. If C-Style is
selected the color format prefix is not selected, because it would not
be useful to paste this into a C-source file. This is done to make
cutting and pasting color definitions into source codes or Application
Default Files as convenient as possible.
The message line
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This line contains one line messages informing you about the state and
results of Xcolorsel's actions.
Action buttons
Best match selects and scrolls the display to the best match found
during the last Grab color, if one was found and is not currently
selected. Previous selects and scrolls the display to the previous
(next better) match, if there is one. Next selects and scrolls the
display to the next (next worse) match, if there is one. Set
foreground sets the text foreground color in the display window to the
color currently selected in it (actually the color defined in the line
where the first selected character resides). Set background sets the
text background color in the display window to the color currently
selected in it (actually the color defined in the line where the first
selected character resides).
OPTIONS
As a standard Xaw application Xcolorsel accepts all standard toolkit
options (see X(1)). Additional options for Xcolorsel that can also be
set via Xresources (mentioned in parentheses) in the application
default file (or with general resource manager facilities) are:
-breakpercentage n (*.breakPercentage: n) sets the break percentage to
n/100 (n integer). Colors with equivalence equal to or above
this value are found and displayed when grabbing colors. (see
Grab color above). This option defaults to 9500.
-busycursor cursor (*.busyCursor: cursor) allows you to specify the
cursor shown while calculating color conversions.
-color (*.customization: -color) sets the customization resource to
force use of the Xcolorsel-color application default file. If no
application resource file can be found at all, the compiled in
Xcolorsel-color defaults are used.
-columns n (*.columns: n) sets the number of character columns
initially displayed. This option usually defaults to 30.
-cstyle (*.comma: True) lets Xcolorsel startup with C-Style selected.
-file filename (*.file: filename) sets the file to be read in and
displayed. Default is usually You can specify the filename as
command parameter without the prefixing -file.
-grabcursor cursor (*.grabCursor: cursor) allows you to specify the
cursor shown while grabbing colors.
-helpfile filename (*.helpfile: filename ) sets the path to the
helpfile. (can also be done at compile time in config.h). If set
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to the empty string ("", the default). Xcolorsel tries to locate
the file with standard X techniques. This usually leads to
filenames like /usr/lib/X11/Xcolorsel.help or /usr/lib/X11/app-
defaults/Xcolorsel.help. Just trust the make install created by
imake. It should know where to put the file. However people
(read: vendor specific X11 releases) had problems with this so
/usr/lib/X11/xcolorsel/Xcolorsel.help is now hardcoded in the
Imakefile.
-input, -rgb4, -rgb8, -rgb12, -rgb16, -rgbi, -ciexyz, -cieuvy,
-ciexyy, -cielab, -cieluv, -tekhvc, -#4, -#8, -#12, and -#16
(*.displayFormat: format, where format is one of , rgb12, rgb16,
rgbi , ciexyz, cieuvy, ciexyy , cielab, cieluv, tekhvc , #rgb,
#rrggbb, #rrrgggbbb , or #rrrrggggbbbb) lets Xcolorsel startup
displaying in the specified color format. The default and value
chosen if set to an undefined string value is
-internal (*.realized: False) lets Xcolorsel startup showing the
internal theoretic color values. This is the default.
-maxred n (*.maxRed: n)
-maxgreen n (*.maxGreen: n)
-maxblue n (*.maxBlue: n) When reading in the input file Xcolorsel
calculates the maximum of each of the input RGB values and uses
this as the maximum (white) value for this component. Each of
these option values is incorporated in this calculation for the
appropriate color component as if such a color would have been
read from the input file. This is implemented to allow input
file with more (or less) than 8 bit for each RGB value. This
options default to 0 but note the next option:
-maxintensity n (*.maxIntensity: n) is comparable to the last three
options but is incorporated into each of the color components.
This value usually defaults to 255.
-maxrows n (*.maxRows: n) sets the maximum number of rows to be
displayed at the same time. This restriction is needed because
this many color cells have to be allocated at the Xserver and the
number of colorcells is usually limited (usually to 256). If
Xcolorsel can't allocate this much colorcells a lower number is
chosen and the user is informed via stderr. Only if not a single
color can be allocated Xcolorsel gives up. Xcolorsel instructs
the window manager not to allow resizes yielding to more lines
getting displayed. If more lines are displayed in the display
RgbText Widget area the displayed color examples will be wrong.
This option usually defaults to 30.
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-nocolor (*.customization: '') sets the customization resource to
force use of the non-color Xcolorsel application default file. If
no application resource file can be found at all, the compiled in
non-color Xcolorsel defaults are used. BTW, actually you have to
use " to specify this in resource files.
-realized (*.realized: True) lets Xcolorsel startup showing color
values how they are displayed on the server.
-resourcestyle (*.comma: False) lets Xcolorsel startup with C-Style
deselected. This is the default.
-rows n (*.rows: n) sets the number of character rows initially
displayed. This option usually defaults to 10.
-tilewidth n (*.tilewidth: n) sets the width of the example color
tiles measured in spaces. This option usually defaults to 3.
HISTORY
Xcolorsel was named xpalette when I wrote it. However there were so
many xpalettes that I was asked to change its name. Since xpalette is
somehow comparable to xfontsel, that is it shows you the available
colors and lets you select one, I call it xcolorsel now and hope that
there will be no more confusion. So when you see a xpalette.tgz, or
xpalette-1.0.tar.gz, or xpalette-1.0a.tar.gz it is probably a previous
version of xcolorsel.
INTERNALS
Most of the functionality of Xcolorsel is defined in an RgbText
Widget. This is a child of a TextWidget linking an RgbSrc and RgbSink
Widget together, which are childs of AsciiSrc and AsciiSink, resp.
Feel free to use these Widgets in your own programs. Most of
Xcolorsel's resources are resources of these Widgets. Interested
programmers should be able to find all needed information about the
programming interface of these Widgets in the corresponding .h files
(RgbSink.h, RgbSinkP.h , RgbSrc.h, RgbSrcP.h , RgbText.h, RgbTextP.h).
Anyway, I would love to hear if anyone finds a general purpose of any
of those widgets. (I can't think of any ;-) ). If you want to know
about the internal structure and names of the Widget tree use
editres(1), which is part of X11R5/6 and shows this information in a
more convenient way than I could ever put in the manual page.
RESTRICTIONS/MISFEATURES
Installing the colormaps of windows the cursor is in during grab of
colors is slow. This is because the Athena Widgets intercept
ENTER/LEAVE notifications send to Xcolorsel during a pointer
grab. As a work around Xcolorsel asks for notification of all
cursor motions during a pointer grab and explicitly queries the
X-Window the pointer is in, thus causing ex(t/p)ensive
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server/client communication.
Color conversion calculations are even performed when there is no need
to, that is when just the C-Style is toggled. This is really
annoying when using the TekHVC display format.
When Display format, C-Style, or Show real server values are changed
the current selection is unselected and the display scrolls up to
the first line.
The Best match, Previous, and Next action buttons are not
appropriately (de-)activated when the selection is either changed
manually in the display with the mouse or automatically (see
above misfeature).
The icons and cursors (especially the bigger magnifying glass) are
extremely ugly. Suggestions for nice bitmaps are welcome.
The color application default is even more ugly. It is an example of
what not to do with Xcolorsel. Actually the intention was to
classify operations with colors. (Negative commands like Quit in
red, positive commands like Default colors in bright or not that
bright (About me) green. Commands requiring user intervention
bright yellow. Other commands in standard yellow. And the
remaining toggles and actions in orange.) However the result just
makes me puke. Suggestions for nice colors are also welcome.
If the help window is displayed About me should not be inactive but
instead allow to raise the window.
The color compare formula (see Grab color above) is (at least) not
very sophisticated.
When showing the busy cursor during color conversions the standard
cursor is still shown when over scrollbars. This is because I
didn't find a way to change the cursor over Athena scrollbars.
Later I saw that one can of course hide all windows under an
invisible input only window that changes the cursor when it
enters it. (I got this from Mumail, where unfortunately only part
of the window is hidden under the invisible window).
You will notice that my programming style changed while coding
Xcolorsel, thus the look a like of the sources is not as
consistent as it should be.
BUGS
Under AIX (IBM RS/6000) at least when using 16 color monochrom
monitors and the Motif window manager, searching the window tree
sometimes finds windows with invalid colormaps and that are not
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drawable. There is a flag to not to try to install colormaps during
color grabbing. However if you click on a window border Xcolorsel will
crash. I assume that this is caused by mwm placing an invisible input
only window over the borders it draws. I did not find a way to make
Xcolorsel smart enough to not fall in this trap. Even if Xcolorsel
would see that this is an input only window, there is no way to get
the data it actually needs (colormap and pixelvalue at the location
you are clicking on). Just do not click on Mwm borders. Or better do
not use Mwm at all. Motif is no free software. Boycott it! Fvwm is
much better anyway.
AUTHOR
Michael Weller
Heiderhoefen 116b
D 46049 Oberhausen
Germany reachable by means of Email as one of: eowmob@exp-math.uni-
essen.de
eowmob@pollux.exp-math.uni-essen.de
mat42b@aixrs1.hrz.uni-essen.de Please note that I did this as an
exercise to improve my understanding of the Athena Widgets and X. I
consider this project as (almost) finished. The priority of this
project is as low as possible for me. No further extensions are
planned so far. However I will put in patches to support other systems
(please make them controllable with #define's either out of config.h
or provided by your imake) and bug fixes and redistribute them to
ensure that only one consistent version floats through the net.
ACKNOWLEDGEMENTS
This work and much more would not have been possible without the Linux
project initiated by Linus Torvalds (and of course all other people
contributing their work to this project). This project together with
the GNU project made it possible for capable computer users of my
generation to choose a free, reliable and state of the art operating
system and to get rid of the arbitrariness of commercial software
vendors and business people squeezing just money out of people that
have to rely on them instead of supplying working and useful software.
I have much experience with different home computer OS's and
workstation UNIX implementations. You can trust me. Just use linux and
get rid of all your problems (What a pity it runs only on PCs and not
on higher performance workstations) Thanx go also to Nils Rennebarth
who convinced me I should implement the colormap install feature
during color grabbing and made me develop a way to accomplish this in
a fruitful discussion. Even more thanx to R.K.Lloyd@csc.liv.ac.uk (no
RL name known) for his patches that are needed to allow compilation
under HP-UX (but changed two of his patches that disabled grabbing of
colors by accident ;-) and Chris Olson (chris@Sterling.COM) for
pointing me at the compilation problems on SUN's (but who would use a
Sun? >;-> ). Thanks and greetings go to Chris Rouch
(chris@wg.estec.esa.nl). He was the first person that could provide a
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patch to make xcolorsel run on a Sun. Actually the patch had a bug as
well, however it did show where to look at, so the problem could be
solved in seconds. Many other people (far too many to list here) sent
me detailed debug sessions from their machines that approved the
detected bug. Thanks to all these as well. Maybe I should have
announced xcolorsel louder when it still was called xpalette. This way
the long existing segmentation fault problem would have been found
earlier. Many people searching for a bug on several machines are
obviously more succesful than a single one. Thus once again the power
of the Internet community was shown.
COPYRIGHTS
As I strongly believe in the usefulness of free software this program
is released under the GNU general public license: This program is free
software; you can redistribute it and/or modify it under the terms of
the GNU General Public License as published be the Free Software
Foundation; either version 2 of the License, or (at your opinion)
any later version. This program is distributed in the hope that it
will be useful, but WITHOUT ANY WARRANTY; without even the implied
warranty of MERCHANBILITY 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
this program; if not, write to the Free Software Foundation, Inc.,
675 Mass Ave, Cambridge, MA 02139, USA. Part of the files are derived
from the Template Widget of the Athena Widgets as published by the
Massachusetts Institute of Technology. Actually these files do not
contain any code by the M.I.T but only variable declarations.
Nevertheless these parts of these files are still distributed under
the terms of the M.I.T copyright which are here repeated: Copyright
Massachusetts Institute of Technology 1987, 1988 Permission to use,
copy, modify, distribute, and sell this software and its
documentation for any purpose is hereby granted without fee,
provided that the above copyright notice appear in all copies
and that both that copyright notice and this permission
notice appear in supporting documentation, and that the name of
M.I.T. not be used in advertising or publicity pertaining to
distribution of the software without specific, written prior
permission. M.I.T. makes no representations about the
suitability of this software for any purpose. It is provided
"as is" without express or implied warranty. M.I.T. DISCLAIMS ALL
WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL M.I.T.
BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY
DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
OF THIS SOFTWARE.
FILES
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/usr/lib/X11/rgb.txt
/usr/lib/X11/xcolorsel/Xcolorsel.help
/usr/lib/X11/app-defaults/Xcolorsel
/usr/lib/X11/app-defaults/Xcolorsel-color
SEE ALSO
X(1), xcolormap(1), xfontsel(1), editres(1)
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