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clipboard(3tk) Tk Built-In Commands clipboard(3tk) 





NAME


clipboard - Manipulate Tk clipboard






SYNOPSIS


clipboard option ?arg arg ...?










DESCRIPTION


This command provides a Tcl interface to the Tk clipboard, which
    stores data for later retrieval using the selection mechanism (via the
    -selection CLIPBOARD option). In order to copy data into the
    clipboard, clipboard clear must be called, followed by a sequence of
    one or more calls to clipboard append. To ensure that the
    clipboard is updated atomically, all appends should be completed before
    returning to the event loop.


The first argument to clipboard determines the format of
    the rest of the arguments and the behavior of the command. The following
    forms are currently supported:



  

  
Claims ownership of the clipboard on window's display and removes
      any previous contents. Window defaults to “.”.
      Returns an empty string.

  

  
Appends data to the clipboard on window's display in the
      form given by type with the representation given by format
      and claims ownership of the clipboard on window's display.






Type specifies the form in which the selection is to be
    returned (the desired “target” for conversion, in ICCCM
    terminology), and should be an atom name such as STRING or FILE_NAME; see
    the Inter-Client Communication Conventions Manual for complete details.
    Type defaults to STRING.


The format argument specifies the representation that
    should be used to transmit the selection to the requester (the second column
    of Table 2 of the ICCCM), and defaults to STRING. If format is
    STRING, the selection is transmitted as 8-bit ASCII characters. If
    format is ATOM, then the data is divided into fields separated
    by white space; each field is converted to its atom value, and the 32-bit
    atom value is transmitted instead of the atom name. For any other
    format, data is divided into fields separated by white space
    and each field is converted to a 32-bit integer; an array of integers is
    transmitted to the selection requester. Note that strings passed to
    clipboard append are concatenated before conversion, so the caller
    must take care to ensure appropriate spacing across string boundaries. All
    items appended to the clipboard with the same type must have the same
    format.


The format argument is needed only for compatibility with
    clipboard requesters that do not use Tk. If the Tk toolkit is being used to
    retrieve the CLIPBOARD selection then the value is converted back to a
    string at the requesting end, so format is irrelevant.


A -- argument may be specified to mark the end of options:
    the next argument will always be used as data. This feature may be
    convenient if, for example, data starts with a -.





  

  
Retrieve data from the clipboard on window's display. Window
      defaults to “.”. Type specifies the form in which the
      data is to be returned and should be an atom name such as STRING or
      FILE_NAME. Type defaults to STRING. This command is equivalent to
      “selection get -selection CLIPBOARD”.






Note that on modern X11 systems, the most useful type to retrieve
    for transferred strings is not STRING, but rather
  UTF8_STRING.








EXAMPLES


Get the current contents of the clipboard.




if {[catch {clipboard get} contents]} {


    # There were no clipboard contents at all
}




Set the clipboard to contain a fixed string.




clipboard clear
clipboard append "some fixed string"




You can put custom data into the clipboard by using a custom
    -type option. This is not necessarily portable, but can be very
    useful. The method of passing Tcl scripts this way is effective, but should
    be mixed with safe interpreters in production code.




# This is a very simple canvas serializer;
# it produces a script that recreates the item(s) when executed
proc getItemConfig {canvas tag} {


   set script {}


   foreach item [$canvas find withtag $tag] {


      append script {$canvas create } [$canvas type $item]


      append script { } [$canvas coords $item] { }


      foreach config [$canvas itemconf $item] {


         lassign $config name - - - value


         append script [list $name $value] { }


      }


      append script \n


   }


   return [string trim $script]
}
# Set up a binding on a canvas to cut and paste an item
set c [canvas .c]
pack $c
$c create text 150 30 -text "cut and paste me"
bind $c <<Cut>> {


   clipboard clear


   clipboard append -type TkCanvasItem \


         [getItemConfig %W current]


   # Delete because this is cut, not copy.


   %W delete current
}
bind $c <<Paste>> {


   catch {


      set canvas %W


      eval [clipboard get -type TkCanvasItem]


   }
}










SEE ALSO


interp(3tcl), selection(3tk)








KEYWORDS


clear, format, clipboard, append, selection, type







  

    8.4
    Tk