#!/usr/bin/env perl
# $Source: /home/keck/gen/RCS/mk.xscreens,v $
# $Revision: 1.24 $$Date: 2007/07/06 14:24:10 $
# Contents
#   1 standard     5 xterm           9 output/1   13 output/5
#   2 args         6 decide widths   10 output/2  14 notes
#   3 screen size  7 store widths    11 output/3  15 pod
#   4 fonts        8 decide heights  12 output/4

# ----------------------------------------------------------------------

#1# standard

use strict;
use warnings;

(my $cmd = "$0") =~ s%.*/%%;

sub usage { print "Usage: $cmd -help\n"; }
sub quit { (@_) ? print STDERR "$cmd quitting: @_\n" : &usage; exit 1 }

use Tk;

use Data::Dumper;
$Data::Dumper::Terse = 1;
$Data::Dumper::Indent = 1;
$Data::Dumper::Quotekeys = 0;
$Data::Dumper::Sortkeys = 1;

sub perldoc {
  my ($perldoc, $less);
  for (split /:/, $ENV{PATH}) {
    $perldoc = "$_/perldoc" if -x "$_/perldoc";
    last if $perldoc; next if $less;
    $less = "$_/less" if -x "$_/less";
  }
  if ($perldoc) {
    $ENV{LESSCHARSET} = 'latin1';
    exec $perldoc, $0
  } elsif ($less) {
    exec $less, '+/^# Sorry.*', $0
  } else {
    print
      "Sorry, there's no perldoc(1) or even less(1) in your \$PATH\n" .
      "The documentation can be found at the end of $0\n";
    exit 1
  }
}

# ----------------------------------------------------------------------

#2# args

my $name;

while (@ARGV) {
  $_ = shift;
  perldoc() if /^-+(man|h)/;
  $name = $_;
  last;
}

# ----------------------------------------------------------------------

#3# screen size

my %screen;

my $main = MainWindow->new;

if (defined $name && $name =~ /(\d+)x(\d+)/) {
  %screen = (
    width => $1,
    height => $2
  ) if $1 > 0 && $2 > 0;
}

%screen = (
  width => $main->screenwidth,
  height => $main->screenheight
) unless %screen;

$name = $cmd . '_' . $screen{width} . 'x' . $screen{height}
  unless defined $name;

# ----------------------------------------------------------------------

#4# fonts

my %font;
my %bold;

$font{5} = '-*-*-*-*-*-*-10-*-*-*-*-50-*-*';
$bold{5} = '-*-*-*-*-*-*-10-*-*-*-*-50-*-*';
$font{6} = '-*-*-medium-r-*--13-*-*-*-c-60-iso10646-*';
$bold{6} = '-*-*-bold-r-*--13-*-*-*-c-60-iso10646-*';

# ----------------------------------------------------------------------

#5# xterm

my %inc;
my %base;
my %wm;

for my $f (5, 6) {

  my $xy = $f == 5 ? '+0+0' : '-0-0';

  system qq(
    xterm -geometry 80x24$xy -fn $font{$f} \\
      -e sh -c 'echo \$\$ \$WINDOWID >/tmp/$cmd$$; sleep 10' &
  );

  sleep 3; # 1 too short for Gateway 2000
  $_ = `cat /tmp/$cmd$$`;
  my ($pid, $windowid) = split;
  my $xprop = `xprop -id $windowid`;
  my $xwininfo = `xwininfo -id $windowid`;
  kill 15, $pid;

  ($inc{$f}{width}, $inc{$f}{height}) =
    $xprop =~ /program specified resize increment: (\d+) by (\d+)/;
  ($base{$f}{width}, $base{$f}{height}) =
    $xprop =~ /program specified base size: (\d+) by (\d+)/;

  if ($f == 5) {
    ($wm{left}, $wm{top}) =
      $xwininfo =~ /Corners:\s+\+(\d+)\+(\d+)/;
  } else {
    ($wm{right}, $wm{bottom}) =
      $xwininfo =~ /Corners:\s+\S+\s+\S+\s+-(\d+)-(\d+)/;
  }
}

# ----------------------------------------------------------------------

#6# decide widths

# number of columns of 80+ @ 6
my $i = int(
  $screen{width} /
    ($wm{left} + 80 * $inc{6}{width} + $base{6}{width} + $wm{right})
);

quit("can't fit an 80 column xterm with font 6 pixels wide") if $i == 0;

my $remains = $screen{width};
$remains -= $i *
   ($wm{left} + 80 * $inc{6}{width} + $base{6}{width} + $wm{right});

# number of columns of 72+ @ 6
my $j = int(
  $remains /
    ($wm{left} + 72 * $inc{6}{width} + $base{6}{width} + $wm{right})
);

# number of columns of 72+ @ 5
my $k = 0;
if ($j == 0) {
  $k = int(
    $remains /
      ($wm{left} + 72 * $inc{5}{width} + $base{5}{width} + $wm{right})
  );
}

# print "\$i=$i, \$j=$j, \$k=$k\n";

# ----------------------------------------------------------------------

#7# store widths

my @widths;
my @fonts;

$widths[$_] = 80 for 0 .. $i - 1;
$fonts[$_] = 6 for 0 .. $i - 1;

if ($j == 0 && $k == 0) { # extend last 80
  $widths[$i - 1] += int($remains / $inc{6}{width});
} elsif ($k == 0) { # extend 72 @ 6
  $widths[$i] = int($remains / $inc{6}{width});
  $fonts[$i] = 6;
} elsif ($j == 0) { # extend 72 @ 5
  $widths[$i] = int($remains / $inc{5}{width});
  $fonts[$i] = 5;
} else {
  quit("\$j=$j,\$k=$k");
}

# ----------------------------------------------------------------------

#8# decide heights

# 2 dimensional array ...
my %n; # number of xterms in a column, key = column font width
my %lines_per_xterm;
my %lines_remaining;
my $min = 20;

# 1 dimensional array ...
my %lines_per_screen;

for my $f (5, 6) {
  $n{$f} = int(
    $screen{height} /
      ($wm{top} + $base{$f}{height} +
        $min * $inc{$f}{height} + $wm{bottom})
  );

  # 1 dimensional array ...
  $lines_per_screen{$f} = int(
    ($screen{height} - ($wm{top} + $base{$f}{height} + $wm{bottom})) /
      $inc{$f}{height}
  );

  # 2 dimensional array ...
  my $pixels_for_lines =
    $screen{height} -
      $n{$f} * ($wm{top} + $base{$f}{height} + $wm{bottom});
  $lines_per_xterm{$f} = int(
    $pixels_for_lines / ($n{$f} * $inc{$f}{height})
  );
  $lines_remaining{$f} = int(
    ($pixels_for_lines -
        $n{$f} * $inc{$f}{height} * $lines_per_xterm{$f}) /
      $inc{$f}{height}
  );
}

# ----------------------------------------------------------------------

#9# output/1

print "# example ~/.xscreens file for xchar system\n";
print "# generated by $0 " . `date`;
print "\n";

print "{\n";

$name = "'$name'" if $name =~ /\W|^\d/;
print ' ' x 2, "$name => {\n";
print ' ' x 4, "width => $screen{width},\n";
print ' ' x 4, "height => $screen{height},\n";

# ----------------------------------------------------------------------

#10# output/2

# full height xterms

print ' ' x 4, "clients => {\n";

{ my $m = 1;
  my $x = 0;

  for my $I (0 .. $#widths) {
    my $f = $fonts[$I]; # 5 or 6
    next if $n{$f} == 1;
    my %w;
    $w{chars} = $widths[$I];
    $w{pixels} = $widths[$I] * $inc{$f}{width} + $base{$f}{width};
    my $y = 0;
    my %h;
    $h{chars} = $lines_per_screen{$f};
    $h{pixels} = $h{chars} * $inc{$f}{height} + $base{$f}{height};
    my %geometry;
    $geometry{chars} = "$w{chars}x$h{chars}+$x+$y";
    $geometry{pixels} = "$w{pixels}x$h{pixels}+$x+$y";
    print ' ' x 6, "$m => {\n";
    print ' ' x 8,
      "geometry => ['$geometry{chars}', '$geometry{pixels}'],\n";
    print ' ' x 8, "normal => '$font{$f}',\n";
    print ' ' x 8, "bold => '$bold{$f}',\n";
    print ' ' x 6, "},\n";
    $m++;
    $x += $w{pixels} + $wm{left} + $wm{right};
  }
}

# ----------------------------------------------------------------------

#11# output/3

# 2-dim array of xterms

{ my $c = 'a';
  my $x = 0;

  for my $I (0 .. $#widths) {
    my $f = $fonts[$I]; # 5 or 6
    my %w;
    $w{chars} = $widths[$I];
    $w{pixels} = $widths[$I] * $inc{$f}{width} + $base{$f}{width};
    my $y = 0;
    for my $J (0 .. $n{$f} - 1) {
      my %h;
      $h{chars} = $lines_per_xterm{$f};
      $h{chars}++ if $n{$f} - $J <= $lines_remaining{$f};
      $h{pixels} = $h{chars} * $inc{$f}{height} + $base{$f}{height};
      my %geometry;
      $geometry{chars} = "$w{chars}x$h{chars}+$x+$y";
      $geometry{pixels} = "$w{pixels}x$h{pixels}+$x+$y";
      print ' ' x 6, "$c => {\n";
      print ' ' x 8,
        "geometry => ['$geometry{chars}', '$geometry{pixels}'],\n";
      print ' ' x 8, "normal => '$font{$f}',\n";
      print ' ' x 8, "bold => '$bold{$f}',\n";
      print ' ' x 6, "},\n";
      $c++;
      $y += $h{pixels} + $wm{top} + $wm{bottom};
    }
    $x += $w{pixels} + $wm{left} + $wm{right};
  }
}

print ' ' x 4, "},\n";

# ----------------------------------------------------------------------

#12# output/4

# distances from right edges of xterms to right side of screen

{ my @x;
  my $x = $screen{width};

  for my $I (0 .. $#widths) {
    my $f = $fonts[$I]; # 5 or 6
    my %w;
    $x -=
      $wm{left} + $widths[$I] * $inc{$f}{width} + 
        $base{$f}{width} + $wm{right};
    push @x, $x;
  }

  print ' ' x 4, 'x => [', join(', ', @x), "],\n";
}

# ----------------------------------------------------------------------

#13# output/5

print ' ' x 4, "font => '$font{6}',\n";
print ' ' x 4, "root => 'steelblue',\n";

print ' ' x 2, "},\n";
print "}\n";

__END__

# ----------------------------------------------------------------------

#14# notes

# +xwin/config3 +taskbar9

# 1.16
#   renamed from mkscreens to mkxscreens
# 1.17
#   renamed from mkxscreens to mk.xscreens
# 1.22
#   stopped being mean with borders ... no longer overlap
#   because ugly with default (wide) side & bottom fvwm borders

# $Revision: 1.24 $

# ----------------------------------------------------------------------

#15# pod

# Sorry, there's no perldoc in your $PATH, so here's the raw pod

=head1 NAME

mk.xscreens - generate an X11::Screens configfile

=head1 SYNOPSIS

 mk.xscreens [name]

 mk.xscreens > ~/.xscreens

=head1 DESCRIPTION

See the references below for the role of the X11::Screens configfile
~/.xscreens.  Briefly, it contains an entry for each screen size you
use.  Each entry defines a set of what could be simply X geometries,
each keyed by a character (see xchar(1)).  In general they might contain
two X geometries, one in character units & one in pixel units, and two
font names (normal and bold).  The extra information allows the
configfile to be used by terminal launchers (eg xterms(1)) as well as by
xmv(1) & GUI launchers.  With mk.xscreens all are given two geometries &
two fonts.

mk.xscreens is an X client.  It creates a configfile with one entry.
This entry is suitable for the current screen ($DISPLAY or :0.0).

The entry divides the screen into columns (2 or 3 for most screens).  It
creates 2 arrays of geometries based on these columns.  One array is
just the 1 dimensional array of columns.  The other is 2 dimensional,
each column being divided into rows.  The geometries in the 1
dimensional array are assigned characters '1', '2', etc.  The geometries
in the 2 dimensional array are assigned characters 'a', 'b', etc, going
down the 1st column, then down the 2nd, etc.

mk.xscreens tries to use a 13-pixel font, falling back to a 10-pixel
font if needed to get reasonably wide or high windows (this sometimes
results in different columns having different numbers of rows).

If the entry's key is not specified on the command line, it's
constructed from the screen size (something like
'mk.xscreens_1280x960').  The name isn't important in getting started
with xchar(1).

mk.xscreens runs 2 xterms for a few seconds, to get the relation between
pixel-relative & character-relative geometries, and the size of the
window manager decorations (titlebar & other borders).  It uses xprop(1)
& xwininfo(1) for this.

The fonts used are old fashioned server-side fonts:

        -*-*-medium-r-*--13-*-*-*-c-60-iso10646-*
        -*-*-*-*-*-*-10-*-*-*-*-50-*-*

=head1 BUGS

With mk.xscreens in it's current form, creating an X11::Screens
configfile can still easily be too much work for the user.  In
particular, many people won't be able to read 10-pixel fonts, & have to
adjust the configfile by trial & error, or learn more than they want to
about the relation between character-relative geometries, pixel-relative
geometries, & font metrics.

=head1 SEE ALSO

X11::Screens(3), xscreens(1), xchar(1)

=head1 AUTHOR

Brian Keck E<lt>bwkeck@gmail.comE<gt>

=head1 VERSION

 $Source: /home/keck/gen/RCS/mk.xscreens,v $
 $Revision: 1.24 $
 $Date: 2007/07/06 14:24:10 $
 xchar 0.2

=cut