NAME

       Tk::ObjScanner - a GUI to scan any perl data structure or object

SYNOPSIS

           # regular use
           use Tk::ObjScanner;

           my $mw  = MainWindow->new;

           my $scanner1 = $mw->ObjScanner(
               -caller => $object,
               -title=>"windows"
           )->pack;

           my $scanner2 = $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' ) ;

           # non-intrusive scan style

           # user code to produce data
           Tk::ObjScanner::scan_object($mydata) ;
           # resume user code

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.

       This widget can be used as a regular widget in a Tk application or can be used as an
       autonomous popup widget that will display the content of a data structure. The latter is
       like a call to a graphical Data::Dumper. The scanner can be used in an autonomous way with
       the "scan_object" function.

       The scanner is a composite widget made of a menubar and Tk::HList.  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 multi-line scalar, the scalar will be displayed in a popup text window.
       Code ref will be deparsed and shown also in the pop-up window.

       Tied scalar, hash or array internal can also be scanned by clicking on the middle button
       to open them.

       Weak references are recognized (See WeakRef for details)

Autonomous widget

   scan_object( data )
       This function is not exported and must be called this way:

         Tk::ObjScanner::scan_object($data);

       This function will load Tk and pop up a scanner widget. When the user destroy the widget
       (with "File -" destroy> menu), the user code is resumed.

Constructor parameters

       "caller"
           The ref of the object or hash or array to scan (mandatory). (you can also use
           '"-caller"')

       "-title"
           The title of the menu created by the scanner (optional)

       "-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')

       "-show_menu"
           ObjScanner can feature a menu with 'reload' button, 'show tied info', 'view
           pseudo-hash' check box. (optional default 0).

       "-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. This parameter is ignored if show_menu is unset.

       "-view_pseudo"
           If set, will interpret pseudo hashes as hash (default 0). This option is disabled for
           Perl 5.09 and later.

       "-show_tied"
           If set, will indicate if a variable is a tied variable. You can see the internal data
           of the tied variable by double clicking on the middle button. (default 1)

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.

       Aynway, pseudo-hashes are deprecated from perl 5.8.0. Hence they are also deprecated in
       ObjScanner.

       The icon used for tied scalar changes from scalar icon to folder icon when opening the
       object hidden behind the tied scalar (using the middle button). I sure could use a better
       icon for tied items. (hint hint)

THANKS

       To Rudi Farkas for all the improvements provided to ObjScanner.

       To Slaven Rezic for:

       •   The propotype code of the pseudo-hash viewer.

       •   The idea to use B::Deparse to view code ref.

CONTRIBUTORS

       Many thanks to Achim Bohnet for all the tests, patches (and reports) he made. Many
       improvements were made thanks to his efforts.

       Thanks to Rudi Farkas for the 'watch' patch.

       Thanks to Slavec Rezic for the pseudo-hash prototype.

       Thanks to heytitle for the documentation fixes

AUTHOR

       Dominique Dumont, ddumont@cpan.org

       Copyright (c) 1997-2004,2007,2014,2017 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, Tk, Tk::HList, B::Deparse