Gtk3::ImageView(3)

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.