NAME

Tk::ObjScanner - Tk data scanner

SYNOPSIS

  use Tk::ObjScanner;
  
  my $scanner = $mw->ObjScanner( caller => $object, 
                                 title=>"windows") -> pack ;
                                 
  my $mw -> ObjScanner
  (
   caller                   => $object,
   title                    => 'demo setting the scanner options',
   background       => 'white',
   selectbackground => 'beige',
   foldImage            => $mw->Photo(-file => Tk->findINC('folder.xpm')),
   openImage            => $mw->Photo(-file => Tk->findINC('openfolder.xpm')),
   itemImage            => $mw->Photo(-file => Tk->findINC('textfile.xpm')),
  )
  -> pack(expand => 1, fill => 'both') ;

DESCRIPTION

The scanner provides a GUI to scan the attributes of an object. It can also be used to scan the elements of a hash or an array.

The scanner is a composite widget made of a Tk::HList and a text window (actually a TK::ROText). This widget acts as a scanner to the object (or hash ref) passed with the 'caller' parameter. The scanner will retrieve all keys of the hash/object and insert them in the HList.

When the user double clicks on a key, the corresponding value will be added in the HList.

If the value is a scalar, the scalar will be displayed in the text window. (Which is handy if the value is a multi-line string)

Constructor parameters

• caller: The ref of the object or hash or array to scan (mandatory).

• title: the title of the menu created by the scanner (optional)

• destroyable: If set, a menu entry will allow the user to destroy the scanner widget. (optional, default 1) . You may want to set this parameter to 0 if the destroy can be managed by a higher level object.

• background: the background color for subwidgets (optional)

• selectbackground: the select background color for HList (optional)

• itemImage: the image for a scalar item (optional, default 'file.xbm')

• foldImage: the image for a composite item (array or hash) when closed (optional, default 'folder.xbm')

• openImage: the image for a composite item (array or hash) when open (optional, default 'openfolder.xbm')

WIDGET-SPECIFIC METHODS

updateListBox

Update the keys of the listbox. This method may be handy if the scanned object wants to update the listbox of the scanner when the scanned object gets new attributes.

CAVEATS

The name of the widget is misleading as any data (not only object) may be scanned. This widget is in fact a DataScanner.

ObjScanner may fail if an object involves a lot of internal perl magic. In this case, I'd be glad to hear about and I'll try to fix the problem.

ObjScanner does not detect recursive data structures. It will just keep on displaying the tree until the user gets tired of clicking on the HList items.

There's no sure way to detect if a reference is a pseudo-hash or not. When a reference is believed to be a pseudo-hash, ObjScanner will display the content of the reference like a hash. If the reference is should not be displayed like a pseudo-hash, you can turn off the pseudo-hash view with the check button on the top right of the widget.

THANKS

To Rudi Farkas for all the improvements provided to ObjScanner.

To Slaven Rezic for the propotype code of the pseudo-hash viewer.

AUTHOR

Dominique Dumont, Dominique_Dumont@grenoble.hp.com

Copyright (c) 1997-2001 Dominique Dumont. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

SEE ALSO

perl(1), Tk(3), Tk::HList(3)