no titlebar for maximized windows - map this script to Alt+F10 (and Super+Up in Gnome 3) and use it for window maximization

max_no_titlebar.sh

#!/bin/sh

missing_command=0
hash xprop 2>/dev/null || { echo "${0##*/}: please install xprop" >&2; missing_command=1; }
hash wmctrl 2>/dev/null || { echo "${0##*/}: please install wmctrl" >&2; missing_command=1; }
[ "$missing_command" -eq 1 ] && exit 1

case "$1" in
  res*)
    wmctrl -r :ACTIVE: -b remove,maximized_vert,maximized_horz
    exit 0
    ;;
  max*)
    todo=max
    ;;
  *)
    todo=toggle
    ;;
esac

window_props() {
  cardinal=_GTK_HIDE_TITLEBAR_WHEN_MAXIMIZED
  retval=0

  # get id of active window
  xprop_out="$(xprop -root _NET_ACTIVE_WINDOW)"
  [ -n "$xprop_out" ] && window="${xprop_out#*# }"
  [ -z "$window" ] && return "$retval"

  # check if the cardinal is set
  if [ "$(xprop -id "$window" "$cardinal")" != "${cardinal}(CARDINAL) = 1" ]; then
    # cardinal is not set: set the cardinal
    # and indicate that the window needs to be (re-)maximized
    xprop -id "$window" -f "$cardinal" 32c -set "$cardinal" 0x1 && retval=1
  fi
  return "$retval"
}

window_props
[ "$?" -eq 1 ] && todo=remax

case "$todo" in
  'remax')
    # re-maximize the window to take effect
    wmctrl -r :ACTIVE: -b remove,maximized_vert,maximized_horz
    wmctrl -r :ACTIVE: -b add,maximized_vert,maximized_horz
    ;;
  'max')
    wmctrl -r :ACTIVE: -b add,maximized_vert,maximized_horz
    ;;
  'toggle')
    wmctrl -r :ACTIVE: -b toggle,maximized_vert,maximized_horz
    ;;
esac