Xcolorsel(1) Xcolorsel User's Guide Xcolorsel(1)NAMExcolorsel - display contents of rgb.txt files together with color
probes.
SYNOPSISxcolorsel [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 addi‐
tional option to display the RGB values the current server would be
able to actually display is also implemented. The main feature of Xcol‐
orsel 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 sec‐
tion.
This version has now also support for servers with read only colormaps
(That is StaticColor, StaticGray, TrueColor). Actually I did not real‐
ize 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 com‐
mands 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 gen‐
eral 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)
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 but‐
ton 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 col‐
ormaps 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 usu‐
ally 8 bit each.
Grab color. When you press this button, the cursor changes into a mag‐
nification 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 deci‐
mal.)
Also the line containing the best match found is selected in the Rgb‐
Text 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 Rgb‐
Text 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.
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 dis‐
couraged.
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 pro‐
grams or Application Default Files. See next sub section.
This option is meaningless with the Values from input file display for‐
mat.
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 for‐
mat.
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 defi‐
nition. 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
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 dur‐
ing 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 ini‐
tially 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 dis‐
played. Default is usually /usr/lib/X11/rgb.txt. You can spec‐
ify 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 help‐
file. (can also be done at compile time in config.h). If set to
the empty string ("", the default). Xcolorsel tries to locate
the file with standard X techniques. This usually leads to file‐
names 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 (*.display‐
Format: format, where format is one of input, rgb4, rgb8 ,
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
input.
-internal (*.realized: False) lets Xcolorsel startup showing the inter‐
nal 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 cal‐
culates 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 dis‐
played 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.
-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 val‐
ues 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 dis‐
played. 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 col‐
ors 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 Wid‐
get tree use editres(1), which is part of X11R5/6 and shows this infor‐
mation 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
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 misfea‐
ture).
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 interven‐
tion 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 wel‐
come.
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 cur‐
sor 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 Xcol‐
orsel, 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 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) fin‐
ished. 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 gen‐
eration to choose a free, reliable and state of the art operating sys‐
tem 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 worksta‐
tion 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 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 MERCHAN‐
BILITY 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 Founda‐
tion, 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 dis‐
tribution of the software without specific, written prior per‐
mission. M.I.T. makes no representations about the suitability
of this software for any purpose. It is provided "as is" with‐
out express or implied warranty.
M.I.T. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUD‐
ING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
EVENT SHALL M.I.T. BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUEN‐
TIAL 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
/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 ALSOX(1), xcolormap(1), xfontsel(1), editres(1)
27th December 1993 Xcolorsel(1)
