DOKK / manpages / debian 12 / libgoocanvas2-perl / GooCanvas2.3pm.en
GooCanvas2(3pm) User Contributed Perl Documentation GooCanvas2(3pm)

GooCanvas2 - Perl binding for GooCanvas2 widget using Glib::Object::Introspection

        #!/usr/bin/perl -w
        use strict;
        use warnings;
        use Gtk3 -init;
        use GooCanvas2;
        
        my $window = Gtk3::Window->new();
        $window->set_default_size(640, 600);
        $window->signal_connect('destroy' => sub {Gtk3->main_quit()});
        my $scrolled_win = Gtk3::ScrolledWindow->new();
        $scrolled_win->set_shadow_type('in');
        my $canvas = GooCanvas2::Canvas->new();
        $canvas->set_size_request(600,450);
        $canvas->set_bounds(0,0,1000,1000);
        $scrolled_win->add($canvas);
        my $root = $canvas->get_root_item();
        # Add a few simple items
        my $rect_item = GooCanvas2::CanvasRect->new('parent' => $root,
                                                'x' => 100,
                                                'y' => 100,
                                                'width' => 300,
                                                'height' => 300,
                                                'line_width' => 10.0,
                                                'radius-x' => 20.0,
                                                'radius-y' => 10.0,
                                                'stroke-color' => 'yellow',
                                                'fill-color' => 'red');
        my $text_item = GooCanvas2::CanvasText->new('parent' => $root,
                                                'text' => 'Hello World',
                                                'x' => 300, 'y' => 300, 
                                                'width' => -1,
                                                'anchor' => 'center',
                                                'font' => 'Sans 24');
        $text_item->rotate(45, 300, 300);
        # Connect a signal handler for the rectangle item.
        $rect_item->signal_connect('button_press_event' => \&on_rect_button_press);
        $window->add($scrolled_win);
        $window->show_all;
        # Pass control to the Gtk3 main event loop
        Gtk3->main();
        # This handles button presses in item views. 
        #We simply output a message to the console
        sub on_rect_button_press {
                my ($item, $target, $event) = @_;
                print "rect item received button press event \n";
                return 1;
        }

You need to install the typelib file for GooCanvas-2.0. For example on Debian/Ubuntu it should be necessary to install the following package:

        sudo apt-get install gir1.2-goocanvas-2.0

On Mageia for example you have to install:

        urpmi lib64goocanvas-gir2.0

GooCanvas2 is a new canvas widget for use with Gtk3 that uses the Cairo 2d library for drawing. This is a simple and basic implementation of this wonderful Canvas widget.

For more information see <https://wiki.gnome.org/action/show/Projects/GooCanvas>

For instructions, how to use GooCanvas2, please study the API reference at <https://developer.gnome.org/goocanvas/unstable/> for now. A perl-specific documentation will perhaps come in later versions. But applying the C documentation should be no problem.

OBJECTS, ITEMS, MODELS

The GooCanvas2 module provides the following objects, items and models. For more details see <https://wiki.gnome.org/action/show/Projects/GooCanvas>.

Core Objects

  • GooCanvas2::Canvas - the main canvas widget
  • GooCanvas2::CanvasItem - the interface for canvas items
  • GooCanvas2::CanvasItemModel - the interface for canvas item models.
  • GooCanvas2::CanvasItemSimple - the base class for the standard canvas items.
  • GooCanvas2::CanvasItemModelSimple - the base class for the standard canvas item models.
  • GooCanvas2::CanvasStyle - support for cascading style properties for canvas items.

Standard Canvas Items

  • GooCanvas2::CanvasGroup - a group of items.
  • GooCanvas2::CanvasEllipse - an ellipse item.
  • GooCanvas2::CanvasGrid - a grid item.
  • GooCanvas2::CanvasImage - an image item.
  • GooCanvas2::CanvasPath - a path item (a series of lines and curves).
  • GooCanvas2::CanvasPolyline - a polyline item (a series of lines with optional arrows).
  • GooCanvas2::CanvasRect - a rectangle item.
  • GooCanvas2::CanvasText - a text item.
  • GooCanvas2::CanvasWidget - an embedded widget item.
  • GooCanvas2::CanvasTable - a table container to layout items.

Standard Canvas Item Models

  • GooCanvas2::CanvasGroupModel - a model for a group of items.
  • GooCanvas2::CanvasEllipseModel - a model for ellipse items.
  • GooCanvas2::CanvasGridModel - a model for grid items.
  • GooCanvas2::CanvasImageModel - a model for image items.
  • GooCanvas2::CanvasPathModel - a model for path items (a series of lines and curves).
  • GooCanvas2::CanvasPolylineModel - a model for polyline items (a series of lines with optional arrows).
  • GooCanvas2::CanvasRectModel - a model for rectangle items.
  • GooCanvas2::CanvasTextModel - a model for text items.
  • GooCanvas2::CanvasTableModel - a model for a table container to layout items.

Customizations and overrides

In order to make things more Perlish, GooCanvas2 customizes the API generated by Glib::Object::Introspection in a few spots:

•
The array ref normally returned by the following functions is flattened into a list:

  • GooCanvas Homepage at <https://wiki.gnome.org/action/show/Projects/GooCanvas>
  • GooCanvas2 API Reference <https://developer.gnome.org/goocanvas/unstable/>
  • Gtk3
  • Glib::Object::Introspection

Maximilian Lika, <Maximilian-Lika@gmx.de>

Copyright (C) 2017 by Maximilian Lika

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.22.3 or, at your option, any later version of Perl 5 you may have available.

2022-06-30 perl v5.34.0