xdaliclock

NAME
xdaliclock - melting digital clock

SYNOPSIS
xdaliclock [-toolkitoption ...] [-option ...]

DESCRIPTION
The xdaliclock program displays a digital clock; when a
digit changes, it ``melts'' into its new shape.

This program was inspired by the Alto and Macintosh programs
of the same name, written by Steve Capps in 1983 or 1984.

OPTIONS
xdaliclock accepts all of the standard toolkit options, and
also accepts the following options:

-help   Print a brief summary of the allowed options on the
	  standard error output.

-12     Use a twelve hour clock.

-24     Use a twenty-four hour clock.

-seconds
	  Update every second.

-noseconds
	  Update once per minute; don't display seconds at
	  all.

-cycle  Do color-cycling.

-nocycle
	  Don't do color-cycling.

-visual visual
	  Specify which visual to use.  Legal values are:

	  best    Use the visual which supports the most
			  writable color cells; this is the default.

	  default Use the screen's default visual (the visual
			  of the root window.)  This is not
			  necessarily the most colorful visual, which
			  is why it is not the default.

	  class   One of StaticGray, StaticColor, TrueColor,
			  GrayScale, PseudoColor, or DirectColor.
			  Selects the deepest visual of the given
			  class.

	  number  A number (decimal or hex) is interpreted as
			  a visual id number, as reported by the
			  xdpyinfo(1) program; in this way you can
			  select a shallower visual if desired.

-shape  Use the Shape Extension, if it's available, to make
	  the window background be transparent.

	  This doesn't interact terribly well with the twm or
	  tvtwm window managers, unless they have been
	  configured to not put a titlebar on the xdaliclock
	  window.  If this isn't specified in your .twmrc or
	  .tvtwmrc file, then the window will flicker
	  constantly, as the window manager tries to add and
	  remove the titlebar ten times each second.

	  Also, this turns most X servers into huge cycle
	  hogs.  This is probably because of inefficient
	  implementations of the Shape extension.

-noshape
	  Don't use the Shape Extension.

-memory low
	  Use high-bandwidth, low-memory mode.  If you have a
	  very fast connection between the machine this
	  program is running on and the X server it is
	  displaying on, then xdaliclock can work correctly by
	  simply making the drawing requests it needs when it
	  needs them.  This is the elegant method.  However,
	  the amount of data necessary to animate the display
	  ends up being a bit over 10 kilobytes worth of X
	  Protocol per second.  On a fast machine with a local
	  display, or over a fast network, that's almost
	  negligible, but (for example) an NCD X Terminal at
	  38.4 kilobaud can't keep up.  That is the reason
	  for:

-memory medium
	  Use high-memory, low-bandwidth mode.  In this mode,
	  xdaliclock precomputes most of the frames that it
	  will ever need.  This is the sleazy copout method.
	  The bandwidth requirements are drastically reduced,
	  because instead of telling the server what bits to
	  draw where, it merely tells it what pixmaps to copy
	  into the window.  Aside from the fact that I
	  consider this to be cheating, the only downside of
	  this method is that those pixmaps (about 170 of
	  them, each the size of one character) are consuming
	  server-memory.  This probably isn't a very big deal,
	  unless you're using an exceptionally large font.

-memory high
	  With memory set to high, the cache is twice as large
	  (the n -> n+2 transitions are cached as well as the
	  n -> n+1 ones).  Even with memory set to medium,
	  this program can seem sluggish when using the
	  builtin font over a very slow connection to the
	  display server.

-font fontname
	  Specifies the X font to use; xdaliclock can
	  correctly animate any font that contains all the
	  digits plus colon and slash, and in which the
	  letters aren't excessively curly.

	  The xdaliclock program contains a pair of builtin
	  bitmapped fonts, which are larger and more
	  attractive than the standard X fonts.  One of these
	  fonts will be used if the -font option is given one
	  of the fontnames BUILTIN or BUILTIN2.

-builtin
	  This is the same as specifying -font BUILTIN.

-builtin2
	  This is the same as specifying -font BUILTIN2.

-fullscreen
	  Make the window take up the whole screen.  When
	  -fullscreen is specified, the displayed time will
	  wander around a little, to prevent any pixels from
	  being on continuously and causing phosphor burn-in.

-root   Display the clock on the root window instead of in
	  its own window.  This makes the digits wander around
	  too.

The following standard X Toolkit command line arguments are
commonly used with xdaliclock:

-display host:dpy
	  This option specifies the X server to contact.

-geometry geometry
	  This option specifies the prefered size and position
	  of the clock window.

-bg color
	  This option specifies the color to use for the
	  background of the window.  The default is ``white.''

-fg color
	  This option specifies the color to use for the
	  foreground of the window.  The default is ``black.''

-bd color
	  This option specifies the color to use for the
	  border of the window.  The default is the same as
	  the foreground color.

-rv     This option indicates that reverse video should be
	  simulated by swapping the foreground and background
	  colors.

-bw number
	  This option specifies the width in pixels of the
	  border surrounding the window.

-xrm resourcestring
	  This option specifies a resource string to be used.

COMMANDS
Clicking and holding any mouse button in the xdaliclock
window will cause it to display the date while the button is
held.

Typing ``space'' at the xdaliclock window will toggle
between a twelve hour and twenty-four hour display.

Typing ``q'' or ``C-c'' at the window quits.

If the xdaliclock window is iconified or otherwise unmapped,
it will go to sleep until it is mapped again.

X DEFAULTS
As distributed in SCO Skunkware 96, the xdaliclock resource
file /usr/lib/X11/app-defaults/XDaliClock contains the following :

XDaliClock*geometry: -20-10
XDaliClock*shape: True
XDaliClock*cycle: True
XDaliClock*memory: Low
XDaliClock*font: BUILTIN
! Put one or both of the following in your $HOME/.Xdefaults file
! to get rid of the title bar and borders the window manager puts
! on xdaliclock. This makes the flashing go away and looks cleaner.
! After doing so, you will need to restart the window manager.
!
! *XDaliClock.clientDecoration: -all
! *XDaliClock.clientDecoration: none

xdaliclock understands all of the core resource names and
classes as well as:

seconds (class Seconds)
	  Whether to display seconds.  If true, this is the
	  same as the -seconds command line argument; if
	  false, this is the same as -noseconds.

cycle (class Cycle)
	  Whether to do color cycling.  If true, this is the
	  same as the -cycle command line argument; if false,
	  this is the same as -nocycle.

shape (class Shape)
	  Whether to use the Shape Extension, if available.
	  If true, this is the same as the -shape command line
	  argument; if false, this is the same as -noshape.

memory (class Memory)
	  This must be high, medium, or low, the same as the
	  -memory command-line option.

font (class Font)
	  The same as the -font command line option: the font
	  to melt.  If this is the string BUILTIN, then the
	  large builtin font is used.  If this is the string
	  BUILTIN2, then the even larger builtin font is used.
	  Otherwise, this must be the name of a valid X font.

mode (class Mode)
	  Whether to display 12-hour or 24-hour time.  If 12,
	  this is the same as the -12 command line argument;
	  if 24, this is the same as -24.

datemode (class DateMode)
	  Specifies how the date should be printed when a
	  mouse button is held down.  This may be one of the
	  strings mm/dd/yy, dd/mm/yy, yy/mm/dd, yy/dd/mm,
	  mm/yy/dd, or dd/yy/mm.  The default is mm/dd/yy.  If
	  seconds are not being displayed, then only the first
	  four digits will ever be displayed (mm/dd instead of
	  mm/dd/yy, for example.)

fullScreen (class FullScreen)
	  The same as the -fullscreen command-line option.

root (class Root)
	  The same as the -root command-line option.

visualID (class VisualID)
	  The same as the -visual command-line option.

ENVIRONMENT
DISPLAY
  to get the default host and display number.

XENVIRONMENT
  to get the name of a resource file that overrides the
  global resources stored in the RESOURCE_MANAGER
  property.

TZ  to get the current time zone.  If you want to force the
  clock to display some other time zone, set this variable
  before starting it.  For example:

	   $ TZ=GMT0 xdaliclock
	   % ( setenv TZ PST8PDT ; xdaliclock )

  You may notice that the format of the TZ variable (which
  is used by the C library ctime(3) and localtime(3)
  routines) is not actually documented anywhere.  The
  fourth character (the digit) is the only thing that
  really matters: it is the offset in hours from GMT.  The
  first three characters are ignored.  The last three
  characters are used to flag daylight savings time: their
  presence effectively adds 1 to the zone offset.  (I am
  not making this up...)

SEE ALSO
X(1), xrdb(1), xlsfonts(1), xclock(1), dclock(1), oclock(1),
tclock(1), xscreensaver(1)

BUGS
Other system load will sometimes cause the second-display to
increment by more than one second at a time, in order to
remain synchronized to the current time.

The -memory option is disgusting and shouldn't be necessary,
but I'm not clever enough to eliminate it.  It has been said
that hacking graphics in X is like finding sqrt(pi) with
roman numerals.

When using a small font (less than 48x56 or so) it's
possible that shipping a bitmap to the server would be more
efficient than sending a DrawSegments request (since the
endpoints are specified using 16 bits each, when all that we
really need is 6 or 7 bits.)

Support for the Shared Memory Extension would be a good
thing.

It should display the day of the week somewhere.

The color cycling should be less predictable; it should vary
saturation and intensity as well, and should be more careful
that foreground and background contrast well.

Should have a -analog mode (maybe someday...)

COPYRIGHT
Copyright 8c9 1991, 1992, 1993, 1994, 1995 by Jamie Zawinski.
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.  No representations are made about the
suitability of this software for any purpose.  It is
provided "as is" without express or implied warranty.

AUTHOR
Jamie Zawinski <jwz@netscape.com>, 18-sep-91.

Please let me know if you find any bugs or make any
improvements.

Thanks to Ephraim Vishniac <ephraim@think.com> for
explaining the format of the bitmap resources in the
Macintosh version of this, so that I could snarf them for
the -builtin fonts.

And thanks to Steve Capps for the really great idea.