NAME

       Gtk3::ImageView - Image viewer widget for Gtk3

VERSION

       9

SYNOPSIS

        use Gtk3::ImageView;
        Gtk3->init;

        $window = Gtk3::Window->new();

        $view = Gtk3::ImageView->new;
        $view->set_pixbuf($pixbuf, TRUE);
        $window->add($view);

        $window->show_all;

DESCRIPTION

       The Gtk3::ImageView widget allows the user to zoom, pan and select the specified image and
       provides hooks to allow additional tools, e.g. painter, to be created and used.

       Gtk3::ImageView is a Gtk3 port of Gtk2::ImageView.

       To discuss Gtk3::ImageView or gtk3-perl, ask questions and flame/praise the authors, join
       gtk-perl-list@gnome.org at lists.gnome.org.

SUBROUTINES/METHODS

   $view->set_pixbuf( $pixbuf, $zoom_to_fit )
       Defines the image to view. The optional zoom_to_fit parameter specifies whether to zoom to
       fit the image or not.

   $view->get_pixbuf
       Returns the image currently being viewed.

   $view->get_pixbuf_size
       Returns a hash of containing the size of the current image in width and height keys.

   $view->set_zoom($zoom)
       Specifies the zoom level.

   $view->get_zoom
       Returns the current zoom level.

   $view->set_zoom_to_fit($zoom_to_fit, $limit)
       Specifies whether to zoom to fit or not. If limit is defined, such automatic zoom will not
       zoom more than it. If the limit is undefined, the previously set limit is used, initially
       it's unlimited.

   $view->zoom_to_box( $box, $additional_factor )
       Specifies a box to zoom to, including an additional zoom factor

   $view->zoom_to_selection($context_factor)
       Zooms to the current selection, plus an addition zoom factor. Shortcut for

        $view->zoom_to_box( $view->get_selection, $context_factor );

   $view->get_zoom_to_fit
       Returns whether the view is currently zoom to fit or not.

   $view->zoom_in
       Increases the current zoom by "zoom-step" times (defaults to 2).

   $view->zoom_out
       Decreases the current zoom by "zoom-step" times (defaults to 2).

   $view->zoom_to_fit
       Shortcut for

        $view->set_zoom_to_fit(TRUE);

   $view->set_fitting( $value )
       Shortcut for

        $view->set_zoom_to_fit($value, 1);

       which means that it won't stretch a small image to a large window. Provided (despite the
       ambiguous name) for compatibility with Gtk2::ImageView.

   $view->set_offset( $x, $y )
       Set the current view offset (i.e. pan position).

   $view->set_offset
       Returns the current view offset (i.e. pan position).

   $view->get_viewport
       Returns a hash containing the position and size of the current viewport.

   $view->set_tool
       Set the current tool (i.e. mode) - an object of a subclass of "Gtk3::ImageView::Tool".

       Here are some known subclasses of it:

       •
        "Gtk3::ImageView::Tool::Dragger" allows the image to be dragged when zoomed.

       •
        "Gtk3::ImageView::Tool::Selector" allows the user to select a rectangular area of the
        image.

       •
        "Gtk3::ImageView::Tool::SelectorDragger" selects or drags with different mouse buttons.

       Don't rely too much on how Tool currently interacts with ImageView.

   $view->get_tool
       Returns the current tool (i.e. mode).

   $view->set_selection($selection)
       Set the current selection as a hash of position and size.

   $view->get_selection
       Returns the current selection as a hash of position and size.

   $view->set_resolution_ratio($ratio)
       Set the ratio of the resolutions in the x and y directions, allowing images with non-
       square pixels to be correctly displayed.

   $view->get_resolution_ratio
       Returns the current resolution ratio.

   $view->set_interpolation
       The interpolation method to use, from "cairo_filter_t"
       <https://www.cairographics.org/manual/cairo-cairo-pattern-t.html#cairo-filter-t> type.
       Possible values are lowercase strings like "nearest". To use different interpolation
       depending on zoom, set it in the "zoom-changed" signal.

   $view->get_interpolation
       Returns the current interpolation method.

DIAGNOSTICS

CONFIGURATION AND ENVIRONMENT

DEPENDENCIES

INCOMPATIBILITIES

   Porting from Gtk2::ImageView
       •
        "set_from_pixbuf()" was renamed to "set_pixbuf()" and now its second argument means
        "zoom_to_fit()" instead of "set_fitting()".

       •
        "set_fitting(TRUE)" used to be the default, now you need to call it explicitly if you
        want that behavior. However, once it's called, new calls to "set_from_pixbuf()" won't
        reset it, see "set_zoom_to_fit()" for more details..

       •
        Drag and drop now can be triggered by subscribing to "dnd-start" signal, and calling
        "$view->drag_begin_with_coordinates()" from the handler. "drag_source_set()" won't work.

       •
        "Gtk2::ImageView::ScrollWin" replacement is not yet implemented.

       •
        "set_transp()" is now available through CSS
        <https://developer.gnome.org/gtk3/stable/chap-css-overview.html> instead, e.g. via

         .imageview.transparent {
             background-image: url('checkers.svg');
         }

       •
        "set_interpolation()" now accepts "cairo_filter_t"
        <https://www.cairographics.org/manual/cairo-cairo-pattern-t.html#cairo-filter-t> instead
        of "GdkInterpType" <https://developer.gnome.org/gdk-pixbuf/stable/gdk-pixbuf-
        Scaling.html#GdkInterpType>.

BUGS AND LIMITATIONS

       This should be rewritten on C, and Perl bindings should be provided via Glib Object
       Introspection.

AUTHOR

       Jeffrey Ratcliffe, <jffry@posteo.net>

       Alexey Sokolov <sokolov@google.com>

LICENSE AND COPYRIGHT

       Copyright (C) 2018--2020 by Jeffrey Ratcliffe

       Copyright (C) 2020 by Google LLC

       Modelled after the GtkImageView C widget by Björn Lindqvist <bjourne@gmail.com>

       This library is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself, either Perl version 5.8.5 or, at your option, any later version of
       Perl 5 you may have available.