[GPS] May 27, 2002: I wanted an extended entry box that provides by default copy, paste, cut, and append options via a popup menu.  I also wanted the ability to restrict the data entered to a RE pattern.  The solution below provides a modified entry widget that does all of the above.  It is standalone, but does use one of the binding procs from the [Inheriting Widget Binding Classes] page.
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  #Updated Aug 7, 2002 to fix minor bugs and introduce paste primary

 ''GPS is editing!''
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  #BEGIN test code
  proc checkIP {win clientData} {
    set RE {[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}}
  
    set data [$win get]
  
    set result 1
    if {[regexp $RE $data] > 0} {
      foreach num [split $data .] {
        if {$num < 0 || $num > 255} {
          set result 0
          break
        }
      }
    } else {
      set result 0
    }
  
    eval [concat $clientData $result]
  }
  
  proc main {} {
    pack [widget:entry .e -inputregexp {[0-9\.]} -width 20]
    .e insert end abc ;#should fail
    pack [frame .info] -side left -fill x
    pack [label .info.valid -text "Valid: "] -side left
    pack [label .info.bool -text 0] -side left
    #I could use a textvariable but this works
    pack [button .checkIP -text "Check IP" -command "checkIP .e {.info.bool config -text}"]
    pack [button .exit -text Exit -command exit]
  }
  main
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