Manpages

Manpage of OO

OO

Section: User Contributed Perl Documentation (1)
Updated: 1999-08-03
Index
Return to Main Contents
 

NAME

Gimp::OO - Pseudo-OO for Gimp functions.  

SYNOPSIS

  use Gimp;             # Gimp::OO is now part of Gimp.


 

DESCRIPTION

As you might have noticed, you can sort most gimp functions fall into three groups, depending on the name-prefix: "gimp_", "plug_in_", "extension_" etc..

Whats more, there are functions groups like "gimp_image_" or "gimp_selection_", operating on a common object, Images and Selection in this case.

If you only had the plain syntax, your scripts would quickly aquire the ``vertical gimp syndrome'':

 gimp_palette_set_foreground(...)
 gimp_layer_new(...)
 gimp_palette_set_background(...)
 gimp_image_add_layer(...)


etc. Of course, your fingers will suffer from severe injuries as well.

A solution to this situation is to use OO-syntax. Gimp plays some (very) dirty tricks and provides a number of classes, like "Gimp::Image" and "Gimp::Palette" that allow shorter identifiers to be used (all these appear with the "Gimp::" prefix as well as without, i.e. "Gimp::Palette" is the same class as "Palette").

If you call a method, "Gimp" tries to find a gimp function by prepending a number of prefixes until it finds a valid function:

 $image = Gimp->image_new(...); # calls gimp_image_new(...)
 $image = Image->new(...);      # calls gimp_image_new as well
 $image = new Image(...);       # the same in green
 Palette->set_foreground(...)   # calls gimp_palette_set_foreground(..)


Return values from functions are automatically blessed (through The Magic Autobless feature ;) to their corresponding classes, i.e.

 $image = new Image(...);       # $image is now blessed to Gimp::Image
 $image->height;                # calls gimp_image_height($image)
 $image->flatten;               # likewise gimp_flatten($image)
 $image->histogram(...);        # calls gimp_histogram($image,...), since
                                # gimp_image_histogram does not exist


The class argument ($image in the above examples) is prepended to the argument list.

Another shortcut: many functions want a (redundant) image argument, like

 $image->shear ($layer, ...)


Since all you want is to shear the $layer, not the $image, this is confusing as well. In cases like this, Gimp allows you to write:

 $layer->shear (...)


And automatically infers the additional IMAGE-type argument.

As the (currently) last goodie, if the first argument is of type INT32, its name is ``run_mode'' and there are no other ambiguties, you can omit it, i.e. these three calls are equivalent:

 plug_in_gauss_rle (RUN_NONINTERACTIVE, $image, $layer, 8, 1, 1);
 plug_in_gauss_rle ($image, $layer, 8, 1, 1);
 plug_in_gauss_rle ($layer, 8, 1, 1);


You can call all sorts of sensible and not-so-sensible functions, so this feature can be abused:

 patterns_list Image;           # will call gimp_patterns_list
 quit Plugin;                   # will quit the Gimp, not an Plugin.


there is no image involved here whatsoever...  

AVAILABLE CLASSES

The following classes (with and without Gimp::) are available. The prefixes that are checked are shown as well (the null prefix "" is implicit).
Gimp (there is no Gimp::Gimp, only Gimp::)
 gimp_


Layer
 gimp_layer_
 gimp_drawable_
 gimp_floating_sel_
 gimp_image_
 gimp_
 plug_in_
 perl_fu_


Image
 gimp_image_
 gimp_drawable_
 gimp_
 plug_in_
 perl_fu_


Drawable
 gimp_drawable_
 gimp_layer_
 gimp_image_
 gimp_
 plug_in_
 perl_fu_


Selection
 gimp_selection_


Channel
 gimp_channel_
 gimp_drawable_
 gimp_selection_
 gimp_image_
 gimp_
 plug_in_
 perl_fu_


Display
 gimp_display_
 gimp_


Palette
 gimp_palette_


Plugin
 plug_in_


Gradients
 gimp_gradients_


Edit
 gimp_edit_


Progress
 gimp_progress_


Region
(none except the implicit null prefix)
Tile
 gimp_tile_


PixelRgn
 gimp_pixel_rgn_


GDrawable
 gimp_gdrawable_


Brushes
 gimp_brushes_


Patterns
 gimp_patterns_


 

AUTHOR

Marc Lehmann <pcg@goof.com>  

SEE ALSO

perl(1), Gimp.


 

Index

NAME
SYNOPSIS
DESCRIPTION
AVAILABLE CLASSES
AUTHOR
SEE ALSO

This document was created by man2html, using the manual pages.
Time: 15:31:11 GMT, April 25, 2024