#!/bin/sh

#
# cde-backdrop
# Copyright © 2002 Thomas A. Fine
# License is hereby granted to redistribute for any use (commercial or
# otherwise), in whole or in part, provided only that this copyright and
# license are preserved.
#
# Version 1.0 Fri Sep  6 15:24:49 EDT 2002
#
# For the latest version and additional information:
#    http://hea-www.harvard.edu/~fine/Tech/cde-backdrop.html
#
# To Install:
#    1. stick this file in your path
#    2. edit the PATH line below to add additional directories needed
#       to find xprop, xloadimage, xwininfo, djpeg, or tifftopnm
#    3. Make sure the file is executable
#
PATH=/soft/netpbm/bin:/usr/local/bin:$PATH

if [ $# -eq 1 ]
then
  targetws=""
  image=$1
elif [ $# -eq 2 ]
then
  targetws=$1
  image=$2
else
  echo "usage: $0 "'[ workspace | -select ] image-file'
  echo '    "workspace" can be the name shown on the front panel button or'
  echo '    a string of the form ws<N>, where <N> is a number starting at 0.'
  echo '    If "-select" is chosen, you must click the mouse on the background.'
  echo '    If no workspace is given, the current workspace is used.'
  echo "  $0 "'-list'
  echo '    List all available workspaces (for use with other programs).'
  echo "  $0 "'[ workspace | -select ] -id'
  echo '    Show the window id of the cde backdrop for the selected workspace.'
  exit 1
fi


setvalues() {
  tmpws=$1
  shift
  eval ${tmpws}_backdrop="$7"
  eval ${tmpws}_name=\""$1"\"
}

name2ws() {
  for ws in $WS_list
  do
    eval tmp_name=\$${ws}_name
    if [ "$tmp_name" = "$1" ]
    then
      echo $ws
      return 0
    fi
  done
  return 1
}

name2backdrop() {
  for ws in $WS_list
  do
    eval tmp_name=\$${ws}_name
    if [ "$tmp_name" = "$1" ]
    then
      eval echo \$${ws}_backdrop
      return 0
    fi
  done
  return 1
}


find_ws_backdrop() {
  # The _MOTIF_WM_INFO property of the root window points to another
  # window where we can find workspace info
  # Similar but less complete info can be found by checking the props from
  # the window referred to by _SUN_SdtWmCommPropWindow
  win=`xprop -notype -root _MOTIF_WM_INFO | awk '{ print $4 }'`
  # Now we get the properties of this new window
  info="`xprop -notype -id $win`"
  # Extract the current workspace id from the appropriate property
  WS_current=`echo "$info" | grep _DT_WORKSPACE_CURRENT | awk '{ print $3 }'`
  # Extract a list of all workspaces from the appropriate property
  WS_list=`echo "$info" | grep _DT_WORKSPACE_LIST | sed 's/^.* = //' | sed 's/,//g'`

  # The _DT_WORKSPACE_INFO_ws0 property contains information on workspace
  # ws0, including the name, and the backdrop window id.  The setvalues
  # function (above) parses this property into the needed fields.
  for ws in $WS_list
  do
    tmp_info="`echo "$info" | grep _DT_WORKSPACE_INFO_$ws | sed 's/^.* = //' | sed 's/,//g'`"
    eval ${ws}_info=\'"$tmp_info"\'
    eval setvalues $ws "$tmp_info"
  done

  if [ $# -eq 0 -o "$1" = "current" -o "$1" = "" ]
  then
    eval backdrop=\$${WS_current}_backdrop
  else
    backdrop=`name2backdrop "$1"`
    if [ "$backdrop" = "" ]
    then
      case $1 in
	ws[0-9])
	  eval backdrop=\$${1}_backdrop
	  ;;
	*)
	  backdrop=""
	  ;;
      esac
    fi
  fi
  echo $backdrop
}

list_backdrops() {
  # see comments in find_ws_backdrop()
  win=`xprop -notype -root _MOTIF_WM_INFO | awk '{ print $4 }'`
  info="`xprop -notype -id $win`"
  echo "$info" | grep _DT_WORKSPACE_LIST | sed 's/^.* = //' | sed 's/,//g'
}


if [ "$image" = "-list" ]
then
  list_backdrops
  exit 0
fi

if [ "$targetws" = "-select" ]
then
  echo Please click on the background...

  #xwininfo: Window id: 0x3400028 (has no name)
  winid=`xwininfo | grep 'Window id:' | sed 's/^.*Window id: //' | sed 's/ .*$//'`
else
  winid=`find_ws_backdrop $targetws`
  if [ "$winid" = "" ]
  then
    echo "Can't find workspace called $targetws"
    exit 1
  fi
fi

if [ "$image" = "-id" ]
then
  echo $winid
  exit 0
fi

case $image in
  *.ppm | *.PPM | *.pgm | *.PGM | *.pbm | *.PBM )
    CONVERT_COMMAND=cat
    ;;
  *.gif | *.GIF)
    CONVERT_COMMAND=cat
    ;;
  *.jpg | *.JPG | *.jpeg | *.JPEG)
    #latest xloadimage might handle JPEG directly (e.g. try using "cat")
    CONVERT_COMMAND="djpeg -pnm"
    ;;
  *.tif | *.tiff | *.TIF | *.TIFF | *.Tiff)
    #latest xloadimage might handle TIFF directly (e.g. try using "cat")
    CONVERT_COMMAND=tifftopnm
    ;;
  *)
    echo unrecognized file type, lets hope xloadimage supports it
    CONVERT_COMMAND=cat
    ;;
esac

$CONVERT_COMMAND $image | xloadimage -windowid $winid stdin


## Also tried dtksh, but could only figure out how to get the current backdrop
## window:
##!/usr/dt/bin/dtksh
#
#textDISPLAY=$DISPLAY
#
#XtInitialize WIDGET wsInfo wsInfo
#XtScreen SCREEN $WIDGET
#XtDisplay DISPLAY $WIDGET
#XRootWindowOfScreen ROOTWIN $SCREEN
#
#DtWsmGetWorkspaceList $DISPLAY $ROOTWIN WSLIST
#DtWsmGetCurrentBackdropWindow $DISPLAY $ROOTWIN BDWIN
#
## workspace list (WSLIST) is a list of atoms, to get the names use:
##XmGetAtomName tmp $DISPLAY $atom
## to go in the other direction, use (example below for workspace 2)
##XmInternAtom tmp $DISPLAY ws2 True
#
##This doesn't work - causes a core dump
##DtWsmSetCurrentWorkspace $WIDGET $tmp