basewidget(3) User Contributed Perl Documentation basewidget(3)NAME
Gimp::basewidget - pragma to declare the superclass of a gtk widget
SYNOPSIS
use Gimp::basewidget 'superclass';
e.g.
use Gimp::basewidget Gtk::Button;
DESCRIPTION
This pragma can (but does not need to) be used to declare the current package as a childclass of an existing Gtk widget class. The only
"import tag" must be the name of the existing superclass.
The module automatically registers a subtype, calls a special callback at gtk initialization time and provides default implementations for
some common methods (the list might grow in the future to enhance settor/gettor functionality).
The following methods are provided. All of them can be overriden in your package.
new A simple generic new constructor is provided. It will simply call "Gtk::Object::new" with all the provided arguments.
GTK_INIT
This callback is called as early as possible after gtk was initialized, but not before. This can be used to register additional sub-
types, argument types etc. It is similar to GTK_CLASS_INIT.
GTK_CLASS_INIT
Unlike the standard Gtk-callback of the same name, this method can be omitted in your package (while still being a valid Widget).
GTK_OBJECT_INIT
This callback can also be omitted, but this rarely makes sense ;)
BUGS
This was a pain to implement, you will not believe this when looking at the code, though.
AUTHOR
Marc Lehmann <pcg@goof.com>.
SEE ALSO perl(1), Gimp, Gimp::UI, Gtk.
perl v5.8.0 2001-12-06 basewidget(3)
Check Out this Related Man Page
OO(1) User Contributed Perl Documentation OO(1)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.
perl v5.8.0 1999-08-02 OO(1)