dot/xinitrc: Overhaul the Emacs/terminal allocation algorithm.

[profile] / dot / xinitrc

#! /bin/bash
###
### X startup script

###--------------------------------------------------------------------------
### Utility functions.

## Progress indicators.
info=yes
info () {
  case $info in yes) echo "- $*" >&2 ;; esac
}

run=yes
run () {
  local what=$1; shift
  local bg=no

  case $what in bg*) bg=yes what=${what#bg} ;; esac
  info "run $what: $*"

  case "$run,$bg" in
    yes,no) "$@" ;;
    yes,yes) "$@" & ;;
  esac
}

manage () {
  local when=$(date +%s) now
  local fail=0 rc report

  while :; do
    "$@"; rc=$?
    case $rc in
      0) info "manage $1: successful exit"; break ;;
      143) info "manage $1: terminated"; break ;;
    esac
    now=$(date +%s)
    report="rc = $rc"
    if (( $now - $when > 5 )); then
      fail=0
    else
      report="$report, early failure"
      fail=$(( $fail + 1 ))
      if (( $fail >= 5 )); then
	info "manage $1: exit ($report), giving up after $fail failures"
	break
      fi
    fi
    info "manage $1: exit ($report), restarting"
    when=$now
  done
}

## Program choice
pick_program () {
  local what=$1; shift
  local choice=false
  for i in "$@"; do
    if type -t >/dev/null "$i"; then choice=$i; break; fi
  done
  info "pick $what = $choice"
  echo "$choice"
}

###--------------------------------------------------------------------------
### Parse arguments.

vnc=no
atomtag=
start=yes
wait=yes

for opt; do
  case "$opt" in
    help)
      cat <<EOF
Options:
  tag=TAG
  [no]trace
  [no]info
  [no]run
  [no]start
  [no]wait
  [no]vnc
EOF
      exit
      ;;

    tag=*) atomtag=/${opt#tag=} ;;
    trace) set -x ;;
    notrace) set +x ;;
    info | run | start | wait | vnc) eval "$opt=yes" ;;
    noinfo | norun | nostart | nowait | novnc) eval "${opt#no}=no" ;;

    *) echo "unknown option $opt" >&2; exit 1 ;;
  esac
done

###--------------------------------------------------------------------------
### Preliminary hook.

if [ -r $HOME/.xinitrc-prehook ]; then
  . $HOME/.xinitrc-prehook
fi

###--------------------------------------------------------------------------
### Iniitial settings.

## Assume X sessions are secure.
export __mdw_sechost="`hostname`"

## Obtain the screen dimensions.
case ",$XWIDTH,$XHEIGHT," in
  *,,*) eval $(xscsize -bx; xscsize -bmx) ;;
esac
case ",$XNSCR," in
  ,,)
    XNSCR=1 XSCR0_X=0 XSCR0_Y=0 XSCR0_WIDTH=$XWIDTH XSCR0_HEIGHT=XHEIGHT
    ;;
esac
i=0; while (( i < XNSCR )); do
  eval "x=\$XSCR${i}_X y=\$XSCR${i}_Y
	wd=\$XSCR${i}_WIDTH ht=\$XSCR${i}_HEIGHT"
  info "screen #$i = ${wd}x${ht}+${x}+${y}"
  i=$(( i + 1 ))
done

initialize () {
  ## Load the X resource database.
  run init xrdb -override $HOME/.Xdefaults

  ## Random xsettery.
  run init xset b 5 2000 50
  run init xset r rate 500 50
  run init xset m 2 1

  ## Key mappings.
  xmodmap $HOME/.xmodmap
  if [ -r $HOME/.xmodmap-local ]; then
    xmodmap $HOME/.xmodmap-local
  fi
}

###--------------------------------------------------------------------------
### Start a window manager.

wm=$(pick_program window-manager e16 compiz enlightenment e17 twm)
wmopts=""
case "$wm,$vnc" in
  enlightenment,yes | e16,yes)
    wmopts="$eopts -econfdir $HOME/.enlightenment-vnc"
    ;;
esac

start-e16 () {
  run bginit manage $wm $wmopts
  win=nil
  for i in $(seq 10); do
    sleep 1
    if eesh version >/dev/null 2>&1; then
      win=t
      break
    fi
  done
  case $win in
    t)
      info "$wm started ok"
      run init xsetroot -cursor_name left_ptr
      ;;
    nil)
      info "$wm failed to start!"
      ;;
  esac
}

start-window-manager () {
  case $(type -t start-$wm || echo "not-found") in
    function)
      start-$wm $wmopts
      ;;
    *)
      run bginit manage $wm $wmopts
      ;;
  esac
}

###--------------------------------------------------------------------------
### Random useful clients.

start-clients-local () { :; }

start-clients () {

  ## Gnome session.
  case "$vnc,$(xfce4-session --version 2>&1),$(gnome-session --version 2>&1)"
  in
    no,xfce4-session*)
      run bginit xfce4-session
      ;;
    no,*,gnome-session\ 2.3[2-9].* | \
    no,*,gnome-session\ 2.4[0-9].* | \
    no,*,gnome-session\ 2.[1-9][0-9][0-9]*)
      run bginit gnome-session --session mdw
      ;;
    no,*,gnome-session*)
      run bginit gnome-session
      ;;
  esac

  ## Local clients.
  start-clients-local
}

###--------------------------------------------------------------------------
### Main screen layout.

## Choose appropriate clients.
emacs=$(pick_program emacs emacs23 emacs24 emacs22 emacs21 emacs)
term=$(pick_program terminal pterm Eterm xterm)

## Emacs window measurements.
##
## e_colwd = basic width of a column in pixels
## e_hextra = extra horizontal width in pixels
##	Width of an N-column Emacs frame in pixels will be
##	N*e_colwd + e_hextra
## e_colchars = width of a column in Emacs `-geometry' units
## e_cextra = extra horizontal width in Emacs `-geometry' units
##	So an N-column frame should be reported to Emacs as being
##	N*e_colchars + e_cextra geometry units wide
## e_lineht = height of a character line in pixels
## e_vextra = number of additional vertical cruft pixels
##	So an N-line Emacs frame takes N*e_lineht + e_vextra pixels
case "$emacs" in
  emacs21 | emacs)
    e_colwd=492 e_hextra=34
    e_colchars=82 e_cextra=-2
    e_lineht=13 e_vextra=52
    ;;
  emacs22 | emacs23)
    e_colwd=492 e_hextra=8
    e_colchars=82 e_cextra=-6
    e_lineht=13 e_vextra=46
    ;;
  emacs24)
    e_colwd=492 e_hextra=5
    e_colchars=82 e_cextra=-6
    e_lineht=13 e_vextra=42
    ;;
esac

## Terminal window measurements.
##
## t_wd = the window width, in pixels
## t_lineht, t_vextra = height parameters: if the window is N lines high,
##	then it will be N*t_lineht + t_vextra pixels high
case "$term" in
  pterm) t_wd=504 t_lineht=13 t_vextra=23 geom=-geometry;;
  Eterm) t_wd=504 t_lineht=13 t_vextra=23 geom=-g;;
  xterm) t_wd=507 t_lineht=13 t_vextra=27 geom=-geometry;;
esac

## GNOME stuff measurements.
declare -i panelwd=64 xbound=$(( XWIDTH - panelwd ))

## Choose a width for Emacs.
##
## We're going to make a single frame of Emacs, which will be automatically
## divvied into columns; the rest of the space will be tiled with xterms.  If
## we have multiple screens, then Emacs can have the first screen and we'll
## fill the rest with terminals.  Otherwise, we'll try to have N columns of
## Emacs, and N - 1 columns of xterms; if that doesn't work, we'll make do
## with N - 2 columns of xterms.
##
## So, let W be the available width; let E and T be the widths of an Emacs
## column (e_colwd) and terminal (t_wd), respectively, and let E0 be the
## additive width of Emacs's existence (e_hextra).  If we have more than one
## screen, then instead, let T be zero.  To start out, then, we let N = 1 +
## floor((W - E - E0)/(E + T)).  If W - E0 - (N + 1) E - (N - 1)*T >= 0, then
## we increase N by one.
declare -i lim=XSCR0_WIDTH
if (( lim > xbound )); then lim=xbound; fi
declare -i twd=t_wd; if (( XNSCR > 1 )); then twd=0; fi
declare -i ecols=$(( (lim - e_colwd - e_hextra)/(e_colwd + twd) + 1 ))
if (( lim - e_hextra - (ecols + 1)*e_colwd - (ecols - 1)*twd >= 0 )); then
  ecols=$(( ecols + 1 ))
fi

declare -i \
  emacsx=$(( ecols*e_colchars + e_cextra )) \
  emacsy=$(( (XHEIGHT - e_vextra)/e_lineht ))

start-emacs () {
  GDK_NATIVE_WINDOWS=1 run bgclients noip \
    $emacs -bg black -geometry ${emacsx}x${emacsy}+${XSCR0_X}+${XSCR0_Y}
}

## Now place some xterms.
##
## A few smaller xterms are in general better than one great big one.  35
## lines is a good height for most terminals.  25 lines is a minimum.  The
## strategy for doling out xterms into a column is to make as many 35-liners
## as we can, until the remaining space would be too small for a 25-liner.
## If we can get two 25s out of that then we do (largest first); otherwise
## just make one big one.  We stop at the end of a page, once we've made
## three xterms.

start-xterms () {

  ## Initialize some parameters.
  declare -i x=$(( ecols*e_colwd + e_hextra + XSCR0_X )) xb=xbound
  declare -i n=0 pgx=0 l h y ht scr=0 ll=lim
  declare -i hstd=$(( 35*t_lineht + t_vextra ))
  declare -i hmin=$(( 25*t_lineht + t_vextra ))
  declare -i scrx scry scrwd scrht

  eval "scrx=\$XSCR${scr}_X scry=\$XSCR${scr}_Y
	scrwd=\$XSCR${scr}_WIDTH scrht=\$XSCR${scr}_HEIGHT"

  ## Do the placement.
  while :; do

    ## Start a new iteration.
    if (( x + t_wd > ll )); then
      scr=$(( scr + 1 ))
      if (( scr >= XNSCR )); then
	if (( n >= 3 )); then break; fi
	pgx=$(( pgx + XWIDTH )) xb=$(( xb + XWIDTH ))
	scr=0
      fi
      eval "scrx=\$XSCR${scr}_X scry=\$XSCR${scr}_Y
	    scrwd=\$XSCR${scr}_WIDTH scrht=\$XSCR${scr}_HEIGHT"
      x=$(( pgx + scrx ))
      ll=$(( x + scrwd ))
      if (( ll > xb )); then ll=xb; fi
    fi

    ## Make large xterms.
    y=scry ht=scrht
    while (( ht - hstd >= hmin )); do
      run bgclients $term $geom 80x35+$x+$y
      y=$(( y + hstd )) ht=$(( ht - hstd )) n=$(( n + 1 ))
    done

    ## Fill the remaining space.
    if (( ht >= 2*hmin )); then h=$(( ht - hmin )); else h=ht; fi
    l=$(( (h - t_vextra)/t_lineht )) h=$(( l*t_lineht + t_vextra ))
    run bgclients $term $geom 80x$l+$x+$y
    y=$(( y + h )) ht=$(( ht - h )) n=$(( n + 1 ))
    if ((ht >= hmin)); then
      run bgclients $term $geom 80x25+$x+$y
      n=$(( n + 1 ))
    fi
    x=$(( x + t_wd ))
  done
}

###--------------------------------------------------------------------------
### Requesters.

req () {
  declare title=$1 hist=$2; shift 2
  cmd=$(xgetline -t "$title" -p "_Command:" -Hl "$HOME/$hist") &&
  exec "$@" "$cmd"
}

###--------------------------------------------------------------------------
### Final waiting.

atom=XINIT_COMMAND$atomtag

xwait () {
  while :; do
    xatom delete $atom
    info "waiting on $atom"
    line=$(xatom wait $atom)
    info "xatom: $line"

    case "$line" in
      :help)
	xmsg -I -t "xinitrc help" -d "xinitrc commands" - <<EOF &
:help
:emacs :xterms :window-manager :clients
:ask-run :ask-command
:init
:terminal
! SHELL-COMMAND
CLIENT
EOF
	;;
      :emacs | :xterms | :window-manager | :clients)
	start-${line#:}
	;;
      :terminal)
	run bgclients $term
	;;
      :init)
	initialize
	;;
      :exec)
	info "restarting xinitrc"
	exec "$0" wait nostart
	;;
      :ask-run)
	req "Shell command" .cmd.hist xcatch -F"Fixed 13" -- sh -c&
	;;
      :ask-command)
	req "xinit command" .xinit.hist xatom set XINIT_COMMAND$atomtag&
	;;
      :*)
	xmsg -E -t "xinitrc error" "Unknown command \`$line'" &
	;;
      !*)
	eval "${line#!}"
	;;
      *)
	set -- $line
	run bgclients "$@"
	;;
    esac
  done
}

###--------------------------------------------------------------------------
### Gnome session care and feeding.

session-running-p () {
  dbus-send --session --print-reply --dest=org.freedesktop.DBus / \
    org.freedesktop.DBus.GetNameOwner string:org.gnome.SessionManager \
    >/dev/null 2>&1
}

dbus-service-running-p () {
  dbus-send >/dev/null 2>&1 --session --print-reply \
    --dest=org.freedesktop.DBus / \
    org.freedesktop.DBus.GetNameOwner string:$1
}

kill-gnome-session () {
  win=nil
  while read service object logout; do
    if dbus-service-running-p $service; then win=t; break; fi
  done <<EOF
org.xfce.SessionManager /org/xfce/SessionManager org.xfce.Session.Manager.Shutdown uint32:1 boolean:false
org.gnome.SessionManager /org/gnome/SessionManager org.gnome.SessionManager.Logout uint32:2
EOF
  case $win in nil) return ;; esac
  info "killing session manager"
  dbus-send --session --dest=$service $object $logout
  for i in 1 2 3 4 5; do
    sleep 1
    if ! dbus-service-running-p $service; then break; fi
  done
}

###--------------------------------------------------------------------------
### Actually start things up.

if [ -f $HOME/.xinitrc-local ]; then
  . $HOME/.xinitrc-local
fi

case "$start" in
  yes)
    info "starting standard clients"
    initialize
    start-window-manager
    start-clients
    start-emacs
    start-xterms
    ;;
  no)
    info "not starting standard clients"
    ;;
esac

case "$wait" in
  yes)
    xwait
    kill-gnome-session
    ;;
  no)
    info "not waiting before exit"
    ;;
esac

###----- That's all, folks --------------------------------------------------