What is a droplet?

It is a way to drag and drop a file(s) or directory(ies) onto a tcl program which can then pick up the file/directory names using the standard [argc] and [argv] command line argument variables.

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[ET] Here is how one goes about this on windows (w2k and up, not w9x):

Create a text file with a .bat extention, and prefix the tcl code with

 ::if 0 {
 start wish "%~f0" %* 
 exit
 }
 
 Tcl/tk code follows....

Note: This assumes you have '''wish''' in your path. If you install ActiveState's tcl/tk, this should set the path for you.

[AET] 12apr06 If you want to use '''TclKit.exe''' instead of '''wish''', a little jiggery pokery is required, because you cannot use
 tclkit myScript myArguments
the myArguments are simply lost.  I save the list to an environment variable, then pick it up again within Tcl. For example;
 ::if 0 {FIRST THE BATCH SCRIPT
   @echo off
   if not {%1}=={} (
     set myFiles=%*
     start /min tclkit "%~f0"
     exit
   ) else (
     echo No arguments supplied; You probably didn't drop any files onto the batch file.
     pause & exit
   )
 }
 # NOW TCL STARTS
 wm wi .
 foreach f [string map {\\ \/} $env(MYFILES)] {append fileList "\n" $f}
 tk_messageBox -message "You dropped these files: $fileList"
 exit
NOTES:

The batch script sets an environment variable (only within it's own shell) which is lost when it closes.  The variable is a space delimited list (quoted to preserve spaces) of dropped files.  Another shell is started within this shell before it closes, so inherits the environment.  Tclkit - started within this child shell - can read it with $env(MYFILES).  Note that the variable name '''must''' be capitalised, regardless of the case in the saved variable. 

Of course, a minimal script only needs lines 4,5,6; I prefer the minimal;
  if not {%1}=={} @echo off & set myFiles=%* & start /min tclkit "%~f0" & exit

The /min switch tends to minimise the ugly DOS box that briefly appears.  

Note the exit at the end of Tcl.  if you leave this out, the instance of tcl will not close.  You will see see them accumulate in your process list in Task Manager.  

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Here are 2 examples, 
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2clip.bat


This simply lets one drag/drop a file onto the batch file and the full path to the file is placed into the clipboard. It will put up a dialog box because the clipboard gets cleared when the program exits. It will also just quit in 30 seconds as well. So, before the 30 seconds are up, you can paste the full name of the file into, say, a console windows.


 ::if 0 {
 start wish "%~f0" %* & exit
 }
 wm wi .
 if {$argc > 0} {
	 clipboard clear
	 set f [lindex $argv 0]
	 clipboard append $f
	 after 30000 exit
	 tk_messageBox -message "Clipboard:\n$f" 
 }
 exit

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pic2tcl.bat

Drag/drop a .gif or .jpg file(s) onto the batch file and it will create a file of the same path and name but with a .tcl extension that can be used as an inline image.



 ::if 0 {
 start wish "%~f0" %* & exit
 }
   package require base64
   proc trans {arg} {

     set file $arg

     set fd [open $file r]
     fconfigure $fd -translation binary
     set rawdata [read $fd]
     close $fd
     set fd [open [file root $arg].tcl w]
     set b64data [base64::encode $rawdata]
     puts $fd "image create photo -data {\n$b64data\n}"
     close $fd
   }


  wm wi .
  
  if {$argc > 0} {
    foreach f $argv {
      set f [file normalize $f]
      #tk_messageBox -message "Doing something with \n$f"
      trans $f
    }
  }
  tk_messageBox -message Done.
  exit
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[Category Windows]