--- name: "Gimp::OO" section: "3pm" platform: "linux" package: "libgimp-perl" version: "2.0.dfsg+2.2pre1.dfsg-5" release: "Debian 5.0 (Lenny)" platforms: ["linux"] url: "https://new.carta.tech/Gimp::OO" --- # Gimp::OO(3pm) Pseudo-OO for Gimp functions. ## 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 \ ## SEE ALSO [*perl*(1)](/perl/1.md), Gimp.