Test::Weaken::Gtk2 -- Gtk2 helpers for Test::Weaken


 use Test::Weaken::Gtk2;


This is a few functions to help Test::Weaken leak checking on Gtk2 widgets etc. The functions can be used individually, or combined into larger application-specific contents etc handlers.

This module doesn't load Gtk2. If Gtk2 is not loaded then the functions simply return empty, false, or do nothing, as appropriate. This module also doesn't load Test::Weaken, that's left to a test script.


Contents Functions

@widgets = Test::Weaken::Gtk2::contents_container ($ref)

If $ref is a Gtk2::Container or subclass then return its widget children per $container->get_children(). If $ref is not a container, or Gtk2 is not loaded, then return an empty list.

Container children are held in C structures (unless the container is implemented in Perl) and so generally not reached by the traversal Test::Weaken does.

@widgets = Test::Weaken::Gtk2::contents_submenu ($ref)

If $ref is a Gtk2::MenuItem then return its submenu per $item->get_submenu(), or if it's a Gtk2::MenuToolButton then per $item->get_menu(). If there's no menu, or $ref is not such a widget, then return an empty list.

The submenu in both cases is held in the item's C structure and is not otherwise reached by the traversal Test::Weaken does.

Only the MenuItem and MenuToolButton classes are acted on currently, just in case a get_submenu() / get_menu() on some other Gtk class isn't a simple property fetch but perhaps some kind of constructor. Other classes which are a simple fetch could be added here in the future.

@widgets = Test::Weaken::Gtk2::contents_cell_renderers ($ref)

If $ref is a widget with the Gtk2::CellLayout interface then return its Gtk2::CellRenderer objects from get_cells(). Or if $ref is a Gtk2::TreeViewColumn or Gtk2::CellView then get_cell_renderers(). For anything else the return is an empty list.

get_cells is new in Gtk 2.12. get_cell_renderers() is the previous style. The renderers in a C code viewer widget are held in C structures and are not otherwise reached by the traversal Test::Weaken does.

Gtk2::CellView as of Gtk 2.20.1 has a bug or severe misfeature where it gives a g_assert() failure on attempting get cells when there's no display row set, including when no model. The returned cells are correct, there's just an assert logged. contents_cell_renderers() suppresses that warning so as to help leak checking of CellViews not yet displaying anything.

When a C-code widget has sub-widgets or renderers as part of its implementation, those children will end up extracted and leak checked by the functions above. This is usually desirable in as much as it notices leaks, even though they may not relate to Perl level code.

Destructor Functions

Test::Weaken::Gtk2::destructor_destroy ($top)

Call $top->destroy(), or if $top is an arrayref then call destroy() on its first element. This can be used when a constructed widget or object requires an explicit destroy(). For example,

    my $leaks = leaks({
      constructor => sub { Gtk2::Window->new('toplevel') },
      destructor => \&Test::Weaken::Gtk2::destructor_destroy,

The arrayref case is designed for multiple widgets etc returned from a constructor, the first of which is a toplevel window or similar needing a destroy(),

    my $leaks = leaks({
      constructor => sub {
        my $toplevel = Gtk2::Window->new('toplevel');
        my $label = Gtk2::Label->new('Hello World');
        return [ $toplevel, $label ];
      destructor => \&Test::Weaken::Gtk2::destructor_destroy,

All Gtk2::Objects support destroy() but most don't need it for garbage collection. Gtk2::Window is the most common which does. Another is a MenuItem which has an AccelLabel and is not in a menu (see notes in Gtk2::MenuItem).

Test::Weaken::Gtk2::destructor_destroy_and_iterate ($top)

The same as destructor_destroy() above, but in addition run Gtk2->main_iteration_do() for queued main loop actions. There's a limit on the number of iterations done, so as to protect against a runaway main loop.

This is good if some finalizations are only done in an idle handler, or perhaps under a timer which has now expired. Currently queued events from the X server are run, but there's no read or wait for further events.

Ignore Functions

$bool = Test::Weaken::Gtk2::ignore_default_display ($ref)
$bool = Test::Weaken::Gtk2::ignore_default_screen ($ref)
$bool = Test::Weaken::Gtk2::ignore_default_root_window ($ref)

Return true if $ref is respectively the default display, screen or root window, as per


If there's no respective default then return false. This happens if Gtk2 is not loaded yet, or Gtk2->init() not called yet, and under Gtk 2.0.x there's no Gtk2::Gdk::Display class and Gtk2::Gdk::Screen classes at all (only a default root window).

    my $leaks = leaks({
      constructor => sub { make_something },
      ignore => \&Test::Weaken::Gtk2::ignore_default_display,

These default objects are generally permanent, existing across a test, and on that basis will not normally be tracked for leaking. Usually they're not seen by leaks() anyway, since they're only in the C structures of widgets, windows, etc. These ignores can be used if operating on the root window, or holding a display or screen in Perl code.


Nothing is exported by default, but the functions can be requested in usual Exporter style.

    use Test::Weaken::Gtk2 'contents_container';

There's no :all tag since new functions are likely to be added in the future and an import of all would risk name clashes with application functions etc.


Test::Weaken, Gtk2::Container, Gtk2::MenuItem, Gtk2::Object, Gtk2::Window, Gtk2::Gdk::Display



Copyright 2008, 2009, 2010, 2011, 2012 Kevin Ryde

Gtk2-Ex-WidgetBits is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version.

Gtk2-Ex-WidgetBits is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

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