/ 
Tk-ObjScanner-2.018
River stage one • 3 direct dependents • 3 total dependents
/ Tk::ObjScanner

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'. (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.

-destroy_label

Label to be used for destroy menu entry.

-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.

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 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 heytitle for the documentation fixes

AUTHOR

Dominique Dumont, ddumont@cpan.org

SEE ALSO

perl, Tk, Tk::HList, B::Deparse, data_viewer