#!/usr/bin/wish -f
##+###########################################################################
##
## SCRIPT: make_BASE64data_fromTkPhotoIMAGEfile.tk
##
## PURPOSE: This script is designed to select an image file supported by
##          the Tk create 'photo' function (such as a GIF,PGM,PPM, or PNG file)
##          and invoke the 'base64' command (available on Linux/Unix/BSD)
##          to create base64 data --- which is shown in a popup window,
##          such as a text-editor window or the window of a text file
##          browser such as 'xpg'.
##
##          For 8.5.x (or some earlier) versions of the 'wish' interpreter,
##          the image file selected may be a GIF file. The image file selected
##          may be a PNG file, when using 8.6.x versions of the 'wish'
##          interpreter.
##
## THE GUI:
##          This script provides a Tk GUI with the following widgets.
##
##         0) There are some BUTTONS such as 'Exit', 'Help' and 'GenBASE64data'.
##
##         1) There is a FILENAME-ENTRY FIELD and 'Browse ...' BUTTON with
##            which to get an image file, from which to generate the
##            'base64' data.
##
##         2) There is a (scrollable) CANVAS widget on which the image
##            may be shown (previewed).
##
##+#######################################################################
## 'CANONICAL' STRUCTURE OF THIS CODE:
##
##  0) Set general window and widget parms (win-name, win-position,
##     win-color-scheme, fonts, win-min-size, text-array-for-labels-etc).
##  1a) Define ALL frames (and sub-frames, if any).
##  1b) Pack   all the frames.
##  2) Define & pack all widgets in the frames, frame by frame.
##
##  3) Define BINDINGS for key and mouse/touchpad/touch-screen 'events',
##     if needed.
##  4) Define PROCS, if needed.
##  5) Additional GUI initialization (typically with one or more of
##     the procs), if needed.
##
##+#################################
## Some detail of the code structure of this particular script:
##
##  1a) Define ALL frames:
## 
##      Top-level :
##       'fRbuttons'  - to contain 'Exit' and 'Help' buttons.
##       'fRfile'     - to contain a triplet: label-entry-button widgets
##       'fRcanvas'   - to contain a canvas widget, with scrollbars
##
##      Sub-frames: none
##
##  1b) Pack ALL frames.
##
##  2) Define & pack all widgets in the frames -- basically going through
##     frames & their interiors in left-to-right and/or top-to-bottom order.
##
##  3) Define bindings:
##         - Button1-release  on the filename entry field
##         - Return key press on the filename entry widget
##
##  4) Define procs:
##        - a proc to get the image filename
##        - a proc to call the 'base64' command and put the output in
##                             a text-editor or text-browser window
##        - a proc to present the help text
##
##  5) Additional GUI initialization: none needed
##
##+#######################################################################
## DEVELOPED WITH: Tcl-Tk 8.5 on Ubuntu 9.10 (2009-october, 'Karmic Koala')
##
##   $ wish
##   % puts "$tcl_version $tk_version"
##
## showed
##     8.5 8.5
## but this script should work in most previous 8.x versions, and probably
## even in some 7.x versions (if font handling is made 'old-style').
##+#######################################################################
## MAINTENANCE HISTORY:
## Started by: Blaise Montandon 2013aug14 Started development, on Ubuntu 9.10,
##                                        based on a couple of my other
##                                        scripts that
##                                        a) get an image file and put its
##                                           image on a scrollable canvas
##                                        b) 'exec' a command and put its
##                                           text output in a text editor.
## Changed by: Blaise Montandon 2013aug21 Added the proc to show $HELPtext. 
##                                        Added 'labelIMGSIZE' label.
##+########################################################################

##+#######################################################################
## Set WINDOW TITLE and POSITION.
##+#######################################################################

wm title    . "Generate BASE64 data from a Tk 'photo' image file (GIF,PNG,...)"
wm iconname . "BASE64data"

wm geometry . +15+30


##+######################################################
## Set the COLOR SCHEME for the window and its widgets ---
## such as entry field background color.
##+######################################################

tk_setPalette "#e0e0e0"

set entryBKGD "#ffffff"
# set listboxBKGD "#ffffff"


##+########################################################
## Set (temp) FONT NAMES.
##
## We use a VARIABLE-WIDTH font for text on LABEL and
## BUTTON widgets.
##
## We use a FIXED-WIDTH font for the text in ENTRY, LISTBOX,
## and TEXT (or MESSAGE) widgets.
##+########################################################

font create fontTEMP_varwidth \
   -family {comic sans ms} \
   -size -14 \
   -weight bold \
   -slant roman

font create fontTEMP_SMALL_varwidth \
   -family {comic sans ms} \
   -size -12 \
   -weight bold \
   -slant roman

## Some other possible (similar) variable width fonts:
##  Arial
##  Bitstream Vera Sans
##  DejaVu Sans
##  Droid Sans
##  FreeSans
##  Liberation Sans
##  Nimbus Sans L
##  Trebuchet MS
##  Verdana


font create fontTEMP_fixedwidth  \
   -family {liberation mono} \
   -size -14 \
   -weight bold \
   -slant roman

font create fontTEMP_SMALL_fixedwidth  \
   -family {liberation mono} \
   -size -12 \
   -weight bold \
   -slant roman

## Some other possible fixed width fonts (esp. on Linux):
##  Andale Mono
##  Bitstream Vera Sans Mono
##  Courier 10 Pitch
##  DejaVu Sans Mono
##  Droid Sans Mono
##  FreeMono
##  Nimbus Mono L
##  TlwgMono


##+###########################################################
## Set variables for GEOMETRIC attributes of various widgets.
## (e.g. width and height of canvas, and padding for Buttons)
##+###########################################################

set initCanWidthPx  300
set initCanHeightPx 300

set minCanWidthPx  24
set minCanHeightPx 24

# set BDwidthPx_canvas 2
  set BDwidthPx_canvas 0


## BUTTON widget geom settings:

set PADXpx_button 0
set PADYpx_button 0
set BDwidthPx_button 2


## LABEL widget geom settings:

set PADXpx_label 0
set PADYpx_label 0
set BDwidthPx_label 2


## ENTRY widget geom settings:

set BDwidthPx_entry 2
set initEntryWidthChars 20


## LISTBOX geom settings:

# set BDwidthPx_listbox 2
# set initListboxWidthChars 30
# set initListboxHeightChars 8


##+######################################################
## Set a MIN-SIZE of the window (roughly).
##
## We set approx MIN WIDTH of the window based on a width
## allowance for the label-entry-button widgets that
## prompt for the image file.
##
## We set the approx MIN HEIGHT of the window based on
## allowance for
##     1 char   high for the 'fRbuttons' frame
##     1 char   high for the 'fRfile'    frame
##    24 pixels high for the 'fRcanvas' frame.
##+######################################################

set minWinWidthPx [font measure fontTEMP_fixedwidth \
   "Img filename (GIF,PNG,...):  a-filename-goes-here  Browse..."]

## Add some pixels to account for right-left-size of window-manager
## decoration (about 8 pixels) --- and add some pixels for 
## frame/widget borders (about 3 widgets x 4 pixels/widget):

set minWinWidthPx [expr {20 + $minWinWidthPx}]

## Get approx min-HEIGHT for the window allowing
##     1 char   high for the 'fRbuttons' frame
##     1 char   high for the 'fRfile'    frame
##    24 pixels high for the 'fRcanvas' frame.
##
## Add about 20 pixels for top-bottom window decoration --
## and about 3 frames x 4 pixels/frame for frame/widget borders.

set charHeightPx [font metrics fontTEMP_fixedwidth -linespace]

set minWinHeightPx [expr {( 2 * $charHeightPx ) + 24 + 32 }]

## FOR TESTING:
#   puts "minWinWidthPx = $minWinWidthPx"
#   puts "minWinHeightPx = $minWinHeightPx"

wm minsize . $minWinWidthPx $minWinHeightPx

## We allow the window to be resizable and we pack the canvas with
## '-fill both' so that the canvas can be enlarged by enlarging the
## window.

## If you want to make the window un-resizable, 
## you can use the following statement.
#  wm resizable . 0 0


##+####################################################################
## Set a TEXT-ARRAY to hold text for buttons & labels on the GUI.
##     NOTE: This can aid INTERNATIONALIZATION. This array can
##           be set according to a nation/region parameter.
##+####################################################################

## if { "$VARlocale" == "en"}

set aRtext(buttonEXIT)    "Exit"
set aRtext(buttonHELP)    "Help"
set aRtext(buttonBASE64)  "GenBASE64data"

set aRtext(labelFILE)     "Img filename (GIF,PNG,...) :"
set aRtext(buttonBROWSE)  "Browse..."

## END OF  if { "$VARlocale" == "en"}


##+################################################################
## DEFINE *ALL* THE FRAMES:
##
##   Top-level : '.fRbuttons'  '.fRfile'  'fRcanvas'
##
##   Sub-frames: none
##+################################################################

## FOR TESTING: (of resizing of frames during window resizing):
# set feRELIEF_frame raised
# set feBDwidth_frame 2

set RELIEF_frame flat
set BDwidth_frame 0

frame .fRbuttons   -relief $RELIEF_frame  -bd $BDwidth_frame
frame .fRfile      -relief $RELIEF_frame  -bd $BDwidth_frame
frame .fRcanvas    -relief raised         -bd 2


##+##############################
## PACK ALL the FRAMES. 
##+##############################

pack .fRbuttons \
   -side top \
   -anchor nw \
   -fill x \
   -expand 0

pack .fRfile \
   -side top \
   -anchor nw \
   -fill x \
   -expand 0

pack .fRcanvas \
   -side top \
   -anchor nw \
   -fill both \
   -expand 1


##+#################################
## In FRAME '.fRbuttons' -
## DEFINE-and-PACK BUTTON widgets
## --- 'Exit','Help'.
##+#################################

button .fRbuttons.buttEXIT \
   -text "$aRtext(buttonEXIT)" \
   -font fontTEMP_varwidth \
   -padx $PADXpx_button \
   -pady $PADYpx_button \
   -relief raised \
   -bd $BDwidthPx_button \
   -command {exit}

button .fRbuttons.buttHELP \
   -text "$aRtext(buttonHELP)" \
   -font fontTEMP_varwidth \
   -padx $PADXpx_button \
   -pady $PADYpx_button \
   -relief raised \
   -bd $BDwidthPx_button \
   -command {popup_msgVarWithScroll .topHelp $HELPtext}

button .fRbuttons.buttBASE64 \
   -text "$aRtext(buttonBASE64)" \
   -font fontTEMP_varwidth \
   -padx $PADXpx_button \
   -pady $PADYpx_button \
   -relief raised \
   -bd $BDwidthPx_button \
   -command {gen_base64_data}

## The text for this label will be provided
## by the 'put_img_on_canvas' proc.

label .fRbuttons.labelIMGSIZE \
   -text "" \
   -font fontTEMP_varwidth \
   -justify left \
   -anchor w \
   -relief  flat \
   -bd 0

## Pack the widgets of frame 'fRbuttons'.

pack .fRbuttons.buttEXIT \
     .fRbuttons.buttHELP \
     .fRbuttons.buttBASE64 \
     .fRbuttons.labelIMGSIZE \
   -side left \
   -anchor w \
   -fill none \
   -expand 0


##+###############################
## In FRAME '.fRfile' -
## DEFINE-and-PACK 3 widgets -
## LABEL, ENTRY, BUTTON:
##+###############################

label .fRfile.labelFILE \
   -text "$aRtext(labelFILE)" \
   -font fontTEMP_varwidth \
   -justify left \
   -anchor w \
   -relief flat \
   -bd 0

set ENTRYfilename ""

entry .fRfile.entFILENAME \
   -textvariable ENTRYfilename \
   -bg $entryBKGD \
   -font fontTEMP_fixedwidth \
   -width $initEntryWidthChars \
   -relief sunken \
   -bd $BDwidthPx_entry

button .fRfile.buttBROWSE \
   -text "Browse ..." \
   -font fontTEMP_varwidth \
   -padx $PADXpx_button \
   -pady $PADYpx_button \
   -relief raised \
   -bd $BDwidthPx_button \
   -command {get_img_filename}

## Pack the widgets in frame 'fRfile'.

pack .fRfile.labelFILE \
   -side left \
   -anchor w \
   -fill none \
   -expand 0

pack .fRfile.entFILENAME \
   -side left \
   -anchor w \
   -fill x \
   -expand 1

pack .fRfile.buttBROWSE \
   -side left \
   -anchor w \
   -fill none \
   -expand 0


##+###############################
## In FRAME '.fRcanvas' -
## DEFINE-and-PACK a CANVAS widget,
## with SCROLLBARS.
##+###############################
## We set highlightthickness & borderwidth of the canvas to
## zero, as suggested on page 558, Chapter 37, 'The Canvas
## Widget', in the 4th edition of the book 'Practical
## Programming in Tcl and Tk'.
##+######################################################

canvas .fRcanvas.can \
   -width $initCanWidthPx \
   -height $initCanHeightPx \
   -relief flat \
   -highlightthickness 0 \
   -borderwidth 0 \
   -yscrollcommand ".fRcanvas.scrbary set" \
   -xscrollcommand ".fRcanvas.scrbarx set"

scrollbar .fRcanvas.scrbary \
   -orient vertical -command ".fRcanvas.can yview"

scrollbar .fRcanvas.scrbarx \
   -orient horizontal -command ".fRcanvas.can xview"


## Pack the widgets in frame 'fRcanvas'.
## (Pack the scrollbars before the canvas so that
##  the canvas does not fill the available area first.)

pack .fRcanvas.scrbary \
   -side right \
   -anchor e \
   -fill y \
   -expand 0

pack .fRcanvas.scrbarx \
   -side bottom \
   -anchor sw \
   -fill x \
   -expand 0

pack .fRcanvas.can \
   -side top \
   -anchor nw \
   -fill both \
   -expand 1


##+##################################################
## END OF DEFINITION of the GUI widgets.
##+##################################################
## Start of BINDINGS, PROCS, Added-GUI-INIT sections.
##+##################################################

##+#######################################################################
##+#######################################################################
##  BINDINGS SECTION:
##
##   - For MB1-release in the image filename entry field,
##         use the ENTRYfilename to create a Tk 'photo' image structure
##         and put it on the canvas.
##
##   - For Enter-key-press when focus is in the image filename entry field,
##         use the ENTRYfilename to create a Tk 'photo' image structure
##         and put it on the canvas.            
##
## These 2 bindings are DEACTIVATED. We put the create-img-on-canvas
## function in the 'get_img_filename' proc, which is called by the
## 'Browse...' button.
##+#######################################################################


##COMMENTED for now:
if {0} {

bind .fRfile.entFILENAME <ButtonRelease-1>  {
   put_img_on_canvas
}

bind .fRfile.entFILENAME <Return>  {
   put_img_on_canvas
}

}
## END OF if {0} --- to DEACIVATE these bindings.


##+#####################################################################
##+#####################################################################
## DEFINE PROCS SECTION:
##
##   'get_img_filename' - called by the 'Browse...' button,
##                        to get the filename of an image (GIF,PNG,...) file
##                        and 
##                        then place the image on the canvas.
##
##   'put_img_on_canvas' - called by proc 'get_img_filename' (and perhaps
##                         by some bindings), to place the image on
##                         canvas, for the current filename
##
##  'gen_base64_data'   - called by the 'GenBASE64data' button,
##                        to run the 'base64' command on the file and
##                        show the text output in a popup GUI (a
##                        text-file editor or browser).
##
##  'popup_msgWithScroll' - called by the 'Help' button,
##                          to show text in var $HELPtext
##
##+#####################################################################


##+#####################################################################
## proc 'get_img_filename'
##
## PURPOSE: To get the name of an image file (GIF/PNG) and put the
##          filename into global var 'ENTRYfilename'. Then
##          create a Tk 'photo' structure from the image file,
##          and put the image on the canvas.
##
## CALLED BY: the '-command' option of the 'Browse ...' button.
##+#####################################################################

# set curDIR "$env(HOME)"
  set curDIR [pwd]

proc get_img_filename {} {

   global ENTRYfilename env curDIR img1 aRtext

   ## Load data from an OBJ file

   set fName [tk_getOpenFile -parent . -title "$aRtext(labelFILE)" \
      -initialdir "$curDIR" ]

   ## FOR TESTING:
   #   puts "fName : $fName"

   if {"$fName" == ""} {return}

   if {[file exists "$fName"]} {
      set ENTRYfilename "$fName"
      set curDIR [ get_chars_before_last / in "$ENTRYfilename" ]
      
      put_img_on_canvas
   }
   ## END OF if file-exists

}
## END OF proc 'get_img_filename'


##+#####################################################################
## proc 'put_img_on_canvas'
##
## PURPOSE: From the filename in var 'ENTRYfilename',
##          create a Tk 'photo' structure from the image file,
##          and put the image on the canvas.
##
## CALLED BY: the proc 'get_img_filename'
##+#####################################################################

proc put_img_on_canvas {} {

   global ENTRYfilename img1
   # global env curDIR

   # image create photo img1 -file "$ENTRYfilename"
   set img1 [image create photo -file "$ENTRYfilename"]

   ## FOR TESTING:
   #  puts "get_img_filename - img1: $img1"

   .fRcanvas.can delete all

   # .fRcanvas.can create image 0 0 -anchor nw -image img1
   .fRcanvas.can create image 0 0 -anchor nw -image $img1

   set imgWIDTHpx  [image width $img1]
   set imgHEIGHTpx [image height $img1]
   .fRbuttons.labelIMGSIZE configure \
      -text "ImgSize (pixels): ${imgWIDTHpx}x$imgHEIGHTpx"

   ## Make the canvas scrollbars usable for large images.

   .fRcanvas.can configure -scrollregion "0 0 $imgWIDTHpx $imgHEIGHTpx"
}

## END OF proc 'put_img_on_canvas'


######################################################################
## Proc 'get_chars_before_last' -
######################################################################
## INPUT:  A character and a string.
##         Note: The "in" parameter is there only for clarity.
##
## OUTPUT: Returns all of the characters in the string "strng" that
##         are BEFORE the last occurence of the characater "char".
##
## CALLED BY: proc 'get_img_filename'
##
#####################################################################

proc get_chars_before_last { char in strng } {

   set endIDX [ expr [string last $char $strng ] - 1 ]
   set output [ string range $strng 0 $endIDX ]

   ## FOR TESTING:
   # puts "From 'get_chars_before_last' proc:"
   # puts "STRING: $strng"
   # puts "CHAR: $char"
   # puts "RANGE up to LAST CHAR - start: 0   endIDX: $endIDX"

   return $output

}
## END OF 'get_chars_before_last' PROCEDURE


##+###################################################################
## Proc 'gen_base64_data'
##
## PURPOSE: Run a script that applies the 'base64' command to the
##          image file and shows the resulting text in a popup GUI
##          text-editor or text-browser window.
##
## CALLED BY: the '-command' option of the '...BASE64...' button.
##+###################################################################

proc gen_base64_data {} {

   global ENTRYfilename curDIR

   if {"$ENTRYfilename" == ""} {return}

   exec ./sho_base64_data_from_imgfile.sh $ENTRYfilename &

}
## END OF proc 'gen_base64_data'


##+########################################################################
## PROC 'popup_msgVarWithScroll'
##+########################################################################
## PURPOSE: Report help or error conditions to the user.
##
##       We do not use focus,grab,tkwait in this proc,
##       because we use it to show help when the GUI is idle,
##       and we may want the user to be able to keep the Help
##       window open while doing some other things with the GUI
##       such as putting a filename in the filename entry field
##       or clicking on a radiobutton.
##
##       For a similar proc with focus-grab-tkwait added,
##       see the proc 'popup_msgVarWithScroll_wait' in a
##       3DterrainGeneratorExaminer Tk script.
##
## REFERENCE: page 602 of 'Practical Programming in Tcl and Tk',
##            4th edition, by Welch, Jones, Hobbs.
##
## ARGUMENTS: A toplevel frame name (such as .fRhelp or .fRerrmsg)
##            and a variable holding text (many lines, if needed).
##
## CALLED BY: 'help' button
##+########################################################################
## To have more control over the formatting of the message (esp.
## words per line), we use this 'toplevel-text' method, 
## rather than the 'tk_dialog' method -- like on page 574 of the book 
## by Hattie Schroeder & Mike Doyel,'Interactive Web Applications
## with Tcl/Tk', Appendix A "ED, the Tcl Code Editor".
##+########################################################################

proc popup_msgVarWithScroll { toplevName VARtext } {

   ## global fontTEMP_varwidth #; Not needed. 'wish' makes this global.
   ## global env

   # bell
   # bell
  
   #################################################
   ## Set VARwidth & VARheight from $VARtext.
   #################################################
   ## To get VARheight,
   ##    split at '\n' (newlines) and count 'lines'.
   #################################################
 
   set VARlist [ split $VARtext "\n" ]

   ## For testing:
   #  puts "VARlist: $VARlist"

   set VARheight [ llength $VARlist ]

   ## For testing:
   #  puts "VARheight: $VARheight"


   #################################################
   ## To get VARwidth,
   ##    loop through the 'lines' getting length
   ##     of each; save max.
   #################################################

   set VARwidth 0

   #############################################
   ## LOOK AT EACH LINE IN THE LIST.
   #############################################
   foreach line $VARlist {

      #############################################
      ## Get the length of the line.
      #############################################
      set LINEwidth [ string length $line ]

      if { $LINEwidth > $VARwidth } {
         set VARwidth $LINEwidth 
      }

   }
   ## END OF foreach line $VARlist

   ## For testing:
   #   puts "VARwidth: $VARwidth"


   ###############################################################
   ## NOTE: VARwidth works for a fixed-width font used for the
   ##       text widget ... BUT the programmer may need to be
   ##       careful that the contents of VARtext are all
   ##       countable characters by the 'string length' command.
   ###############################################################


   #####################################
   ## SETUP 'TOP LEVEL' HELP WINDOW.
   #####################################

   catch {destroy $toplevName}
   toplevel  $toplevName

   # wm geometry $toplevName 600x400+100+50

   wm geometry $toplevName +100+50

   wm title     $toplevName "Note"
   # wm title   $toplevName "Note to $env(USER)"

   wm iconname  $toplevName "Note"


   #####################################
   ## In the frame '$toplevName' -
   ## DEFINE THE TEXT WIDGET and
   ## its two scrollbars --- and
   ## DEFINE an OK BUTTON widget.
   #####################################

   if {$VARheight > 10} {
      text $toplevName.text \
         -wrap none \
         -font fontTEMP_varwidth \
         -width  $VARwidth \
         -height $VARheight \
         -bg "#f0f0f0" \
         -relief raised \
         -bd 2 \
         -yscrollcommand "$toplevName.scrolly set" \
         -xscrollcommand "$toplevName.scrollx set"

      scrollbar $toplevName.scrolly \
         -orient vertical \
         -command "$toplevName.text yview"

      scrollbar $toplevName.scrollx \
         -orient horizontal \
         -command "$toplevName.text xview"
   } else {
      text $toplevName.text \
         -wrap none \
         -font fontTEMP_varwidth \
         -width  $VARwidth \
         -height $VARheight \
         -bg "#f0f0f0" \
         -relief raised \
         -bd 2 
   }

   button $toplevName.butt \
      -text "OK" \
      -font fontTEMP_varwidth \
      -command  "destroy $toplevName"

   ###############################################
   ## PACK *ALL* the widgets in frame '$toplevName'.
   ###############################################

   ## Pack the bottom button BEFORE the
   ## bottom x-scrollbar widget,

   pack  $toplevName.butt \
      -side bottom \
      -anchor center \
      -fill none \
      -expand 0


   if {$VARheight > 10} {
      ## Pack the scrollbars BEFORE the text widget,
      ## so that the text does not monopolize the space.

      pack $toplevName.scrolly \
         -side right \
         -anchor center \
         -fill y \
         -expand 0

      ## DO NOT USE '-expand 1' HERE on the Y-scrollbar.
      ## THAT ALLOWS Y-SCROLLBAR TO EXPAND AND PUTS
      ## BLANK SPACE BETWEEN Y-SCROLLBAR & THE TEXT AREA.
                
      pack $toplevName.scrollx \
         -side bottom \
         -anchor center \
         -fill x  \
         -expand 0

      ## DO NOT USE '-expand 1' HERE on the X-scrollbar.
      ## THAT KEEPS THE TEXT AREA FROM EXPANDING.

      pack $toplevName.text \
         -side top \
         -anchor center \
         -fill both \
         -expand 1
   } else {
      pack $toplevName.text \
         -side top \
         -anchor center \
         -fill both \
         -expand 1
   }


   #####################################
   ## LOAD MSG INTO TEXT WIDGET.
   #####################################

   ##  $toplevName.text delete 1.0 end
 
   $toplevName.text insert end $VARtext
   
   $toplevName.text configure -state disabled
  
}
## END OF PROC 'popup_msgVarWithScroll'


##+########################
## END of PROC definitions.
##+########################
## Set HELPtext variable.
##+########################

set HELPtext "\
*** HELP for this utility to make BASE64 data from a Tk 'photo' image file ***

This utility script is designed to select an image file supported by the
Tk create 'photo' function (such as a GIF or PGM or PPM or PNG file)
and invoke the 'base64' command (available on Linux/Unix/BSD)
to create base64 data.

The 'base64' data is shown in a popup window, such as a text-editor
window or the window of a text file browser such as 'xpg'.

---------

For 8.5.x (or some earlier) versions of the 'wish' interpreter,
the image file selected may be a GIF (or PGM or PPM) file.

The image file selected may be a PNG file, when using 8.6.x versions
of the 'wish' interpreter.

**********************
AUXILIARY SHELL SCRIPT:

When the user clicks on the '$aRtext(buttonBASE64)' button,
a shell script named

        sho_base64_data_from_imgfile.sh

(in a directory with this Tk GUI script) executes to run the 'base64'
Linux/Unix/BSD command on the selected image file and show the text
output from 'base64' in a popup GUI (a text-file editor or text-file browser).

That shell script can be edited to change the text-editor/browser 
that is used --- and to change the location and/or name of the
temporary text file that is created.

**************************************************
SOME SOURCES OF Tk 'photo' FILES (PGM,PPM,GIF,PNG):

In case you are looking for files to test this utility --- or to
convert for use in Tk apps ...

Here are some typical directories of *PGM* files on Linux installations:

   /usr/share/gimp/2.0/gimpressionist/Brushes/
   /usr/lib/pymodules/python2.5/openshot/transitions/
   /usr/share/kde4/apps/kdenlive/lumas/

These directories may be available if you have the GIMP image editor
and/or the OpenShot and Kdenlive movie editors installed.

---

For *PPM* files, you can try directories like

   /usr/share/doc/tk8.5/examples/images/
   /usr/share/gimp/2.0/gimpressionist/Brushes/

---

For *GIF* files, you can try directories like

   /usr/share/doc/tk8.5/examples/images/
   /usr/share/tcltk/tk8.5/images/

   as well as

   /usr/lib/firefox-3.6.16/res/
   /usr/lib/openoffice/basis3.1/share/config/wizard/web/images/
   /usr/lib/openoffice/basis3.1/share/gallery/
   /usr/lib/openoffice/basis3.1/share/template/en-US/wizard/bitmap/
   /usr/lib/python2.4/idlelib/Icons/
   /usr/lib/seamonkey-2.0.11/res/
   /usr/lib/xulrunner-1.9.1.16/res/
   /usr/share/apps/ksgmltools2/docbook/xsl/images/
   /usr/share/couchdb/www/image/
   /usr/share/cups/doc-root/images/
   /usr/share/doc/dvd+rw-tools/
   /usr/share/doc/kbd/dvorak/
   /usr/share/doc/perlmagick/examples/demo/
   /usr/share/gthumb/albumthemes/
   /usr/share/kde4/apps/ksgmltools2/docbook/xsl/images/
   /usr/share/sunbird/res/
   /usr/share/thunderbird/res/
   /usr/share/webkit-1.0/webinspector/Images/
   /usr/share/zenmap/pixmaps/

---

For *PNG* files, you can try a Tk 8.6 directory or directories like


   /usr/lib/erlang/lib/wings-1.0.1/textures/
   /usr/lib/firefox-3.6.16/icons/
   /usr/lib/firefox-3.6.16/res/
   /usr/lib/firefox-addons/extensions/
   /usr/lib/openoffice/basis3.1/share/gallery/htmlexpo/
   /usr/lib/pymodules/python2.6/openshot/blender/icons/
   /usr/lib/pymodules/python2.6/openshot/effects/icons/
   /usr/lib/pymodules/python2.6/openshot/images/
   /usr/lib/pymodules/python2.6/openshot/themes/
   /usr/lib/pymodules/python2.6/openshot/transitions/
   /usr/lib/pymodules/python2.6/openshot/uploads/logos/
   /usr/lib/pymodules/python2.6/openshot/windows/ui/icons/
   /usr/lib/seamonkey-2.0.11/chrome/icons/
   /usr/lib/seamonkey-2.0.11/extensions/
   /usr/lib/seamonkey-2.0.11/res/html/
   /usr/lib/seamonkey-2.0.11/searchplugins/
   /usr/lib/xulrunner-1.9.2.16/chrome/icons/default/
   /usr/lib/xulrunner-1.9.2.16/icons/
   /usr/lib/xulrunner-1.9.2.16/res/
   /usr/local/share/icons/hicolor/128x128/apps/
   /usr/local/share/icons/hicolor/128x128/mimetypes/
   /usr/share/abiword-2.6/clipart/
   /usr/share/aeskulap/images/
   /usr/share/agave/pixmaps/
   /usr/share/app-install/icons/  (many hundreds)
   /usr/share/apps/guarddog/pics/
   /usr/share/apps/karbon/icons/
   /usr/share/apps/kchart/icons/
   /usr/share/apps/kchart/pics/
   /usr/share/apps/kdeprint/icons/
   /usr/share/apps/kdeprint/pics/
   /usr/share/apps/kdeprint/
   /usr/share/apps/kdeui/about/
   /usr/share/apps/kdeui/pics/
   /usr/share/apps/kdewidgets/pics/
   /usr/share/apps/kexi/icons/
   /usr/share/apps/khtml/icons/
   /usr/share/apps/kivio/icons/
   /usr/share/apps/kivio/pics/
   /usr/share/apps/kivio/stencils/
   /usr/share/apps/kmfsystray/icons/
   /usr/share/apps/kmfsystray/pics/
   /usr/share/apps/kmyfirewall/icons/
   /usr/share/apps/kmyfirewall/pics/
   /usr/share/apps/koffice/icons/
   /usr/share/apps/koffice/pics/
   /usr/share/apps/kpresenter/...
   /usr/share/apps/krita/...
   /usr/share/apps/ksgmltools2/docbook/xsl/images/
   /usr/share/apps/kspread/...
   /usr/share/apps/kstyle/pixmaps/riscos/
   /usr/share/apps/kudesigner/icons/
   /usr/share/apps/kword/icons/
   /usr/share/ardour2/icons/
   /usr/share/brasero/icons/hicolor/
   /usr/share/cheese/...
   /usr/share/compiz/...
   /usr/share/couchdb/www/image/
   /usr/share/cups/doc-root/images/
   /usr/share/decibel-audio-player/pix/
   /usr/share/devede/
   /usr/share/diff-ext/icons/diff-ext/
   /usr/share/doc/bless/user/figures/
   ...
   ...
   /usr/share/filezilla/resources/...
   ...
   /usr/share/gimp/2.0/images/
   /usr/share/gimp/2.0/themes/Default/images/preferences/
   ...
   /usr/share/gnome-about/...
   /usr/share/gnome-applets/...
   /usr/share/gnome-control-center/pixmaps/
   /usr/share/gnome-doc-utils/...
   /usr/share/gnome-games/...
   /usr/share/gnome-media/icons/...
   /usr/share/gnome-nettool/pixmaps/
   /usr/share/gnome-panel/pixmaps/
   /usr/share/gnome-power-manager/icons/...
   ...
   /usr/share/gnome/help/...  (many hundreds)
   ...
   /usr/share/gthumb/albumthemes/
   /usr/share/gthumb/glade/
   /usr/share/gtk-doc/html/...
   /usr/share/gtkhtml-3.14/icons/
   /usr/share/hplip/data/images/
   /usr/share/icons/...      (many, many hundreds)
   /usr/share/inkscape/tutorials/
   /usr/share/k3d/icons/
   /usr/share/k3d/ngui/pixmap/
   /usr/share/k3d/ngui/rasterized/
   ...
   /usr/share/kde4/apps/...  (many)
   /usr/share/ktoon/themes/default/...
   ...
   /usr/share/libindicator/icons/hicolor/
   /usr/share/lives/icons/
   /usr/share/locale/l10n/...
   /usr/share/m17n/icons/...
   ...
   /usr/share/mplayer/skins/
   /usr/share/nautilus/icons/
   /usr/share/nautilus/patterns/
   ...
   /usr/share/pixmaps/...  (many)
   ...
   /usr/share/povray/...
   /usr/share/pyshared/openshot/...
   /usr/share/python-wxgtk2.8/Editra/pixmaps/
   /usr/share/qt4/doc/src/images/    (many hundreds)
   /usr/share/rhythmbox/icons/hicolor/...
   ...
   /usr/share/scribus/...
   /usr/share/skype/avatars/
   /usr/share/smplayer/themes/... (many)
   /usr/share/synaptic/...
   /usr/share/themes/...  (many)
   ...
   /usr/share/tomboy/icons/hicolor/...
   ...
   /usr/share/transmission/web/images/...
   ...
   /usr/share/ubuntu-docs/libs/...
   /usr/share/vlc/http/images/
   /usr/share/vlc/lua/http/images/
   /usr/share/vlc/osdmenu/default/...
   ...
   /usr/share/webkit-1.0/...
   ...
   /usr/share/zenity/...
   /usr/share/zenmap/pixmaps/...

So you see that there are many more PNG files available than
PGM, PPM, and even GIF files on the typical computer installation,
circa 2013.

And there are even more JPEG files --- from the Internet and from 
digital cameras, iPhones, Android-Phones, iPads, Android-Pads, etc.

But, unfortunately, the Tk 8.6 (and before) 'image create photo'
command does not support JPEG files. Tcl-Tk extensions are necessary.
"

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## Additional GUI INITIALIZATION: not needed
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