Scroll to navigation

Gtk2::ImageView(3pm) User Contributed Perl Documentation Gtk2::ImageView(3pm)

NAME

Gtk2::ImageView - General purpose image viewer for Gtk+

SYNOPSIS

 use Gtk2::ImageView;
 Gtk2->init;
 $window = Gtk2::Window->new();
 $view = Gtk2::ImageView->new;
 $view->set_pixbuf($pixbuf, TRUE);
 $window->add($view);
 $window->show_all;

DESCRIPTION

GtkImageView is a full-featured general purpose image viewer widget for GTK. It provides a scrollable, zoomable pane in which a pixbuf can be displayed.

The Gtk2::ImageView module allows a perl developer to use the GtkImageView Widget.

HIERARCHY

  Glib::Object
  +----Glib::InitiallyUnowned
       +----Gtk2::Object
            +----Gtk2::Widget
                 +----Gtk2::ImageView

INTERFACES

  Glib::Object::_Unregistered::AtkImplementorIface
  Gtk2::Buildable

METHODS

widget or undef = Gtk2::ImageView->new

Returns a new Gtk2::ImageView with the following default values.

boolean = $view->get_black_bg

Returns TRUE if the view renders the widget on a black background, otherwise FALSE.

$view->set_black_bg ($black_bg)

•
$black_bg (boolean)

If TRUE, the view uses a black background. If FALSE, the view uses the default (normally gray) background.

The default value is FALSE.

list = $view->get_check_colors

Reads the two colors used to draw transparent parts of images with an alpha channel. Note that if the transp setting of the view is GTK_IMAGE_TRANSP_BACKGROUND or GTK_IMAGE_TRANSP_COLOR, then both colors will be equal.

$view->damage_pixels ($rect)

•
$rect (Gtk2::Gdk::Rectangle)

Mark the pixels in the rectangle as damaged. That the pixels are damaged means that they have been modified and that the view must redraw them to ensure that the visible part of the image corresponds to the pixels in that image. Calling this method emits the ::pixbuf-changed signal.

This method must be used when modifying the image data:

    // Drawing something cool in the area 20,20 - 60,60 here...
    ...
    // And force an update
    $view->damage_pixels (Gtk2::Gdk::Rectangle->new(20, 20, 40, 40);

If the whole pixbuf has been modified then rect should be NULL to indicate that a total update is needed.

See also gtk_image_view_set_pixbuf().

rectangle = $view->get_draw_rect

Get the rectangle in the widget where the pixbuf is painted, or undef if the view is not allocated or has no pixbuf.

For example, if the widgets allocated size is 100, 100 and the pixbufs size is 50, 50 and the zoom factor is 1.0, then the pixbuf will be drawn centered on the widget. rect will then be (25,25)-[50,50].

This method is useful when converting from widget to image or zoom space coordinates.

boolean = $view->get_fitting

Returns TRUE if the view fits the image, FALSE otherwise.

$view->set_fitting ($fitting)

•
$fitting (boolean)

Sets whether to fit or not. If TRUE, then the view will adapt the zoom so that the whole pixbuf is visible.

Setting the fitting causes the widget to immediately repaint itself.

Fitting is by default TRUE.

rectangle = $view->image_to_widget_rect ($rect_in)

•
$rect_in (Gtk2::Gdk::Rectangle)

Converts a rectangle in image space coordinates to widget space coordinates. If the view is not realized, or if it contains no pixbuf, then the conversion was unsuccessful, FALSE is returned and rect_out is left unmodified.

Note that this function may return a rectangle that is not visible on the widget.

interptype = $view->get_interpolation

Returns the current interpolation mode of the view.

$view->set_interpolation ($interp)

•
$interp (Gtk2::Gdk::InterpType)

Sets the interpolation mode of how the view. GDK_INTERP_HYPER is the slowest, but produces the best results. GDK_INTERP_NEAREST is the fastest, but provides bad rendering quality. GDK_INTERP_BILINEAR is a good compromise.

Setting the interpolation mode causes the widget to immidiately repaint itself.

The default interpolation mode is GDK_INTERP_BILINEAR.

string = Gtk2::ImageView->library_version

Returns the version of the underlying GtkImageView C library

$view->set_offset ($x, $y, $invalidate=FALSE)

  • $x (double)
  • $y (double)
  • $invalidate (boolean)

Sets the offset of where in the image the GtkImageView should begin displaying image data.

The offset is clamped so that it will never cause the GtkImageView to display pixels outside the pixbuf. Setting this attribute causes the widget to repaint itself if it is realized.

If invalidate is TRUE, the views entire area will be invalidated instead of redrawn immidiately. The view is then queued for redraw, which means that additional operations can be performed on it before it is redrawn.

The difference can sometimes be important like when you are overlaying data and get flicker or artifacts when setting the offset. If that happens, setting invalidate to TRUE could fix the problem. See the source code to GtkImageToolSelector for an example.

Normally, invalidate should always be FALSE because it is much faster to repaint immidately than invalidating.

pixbuf or undef = $view->get_pixbuf

Returns the pixbuf this view shows.

$view->set_pixbuf ($pixbuf, $reset_fit=TRUE)

  • $pixbuf (Gtk2::Gdk::Pixbuf or undef)
  • $reset_fit (boolean)

Sets the pixbuf to display, or NULL to not display any pixbuf. Normally, reset_fit should be TRUE which enables fitting. Which means that, initially, the whole pixbuf will be shown.

Sometimes, the fit mode should not be reset. For example, if GtkImageView is showing an animation, it would be bad to reset the fit mode for each new frame. The parameter should then be FALSE which leaves the fit mode of the view untouched.

This method should not be used if merely the contents of the pixbuf has changed. See gtk_image_view_damage_pixels() for that.

If reset_fit is TRUE, the zoom-changed signal is emitted, otherwise not. The pixbuf-changed signal is also emitted.

The default pixbuf is NULL.

boolean = $view->get_show_cursor

Returns TRUE if the cursor is shown when the mouse is over the widget, otherwise FALSE.

$view->set_show_cursor ($show_cursor)

•
$show_cursor (boolean)

Sets whether to show the mouse cursor when the mouse is over the widget or not. Hiding the cursor is useful when the widget is fullscreened.

The default value is TRUE.

boolean = $view->get_show_frame

Returns TRUE if a one pixel frame is drawn around the pixbuf, otherwise FALSE.

$view->set_show_frame ($show_frame)

•
$show_frame (boolean)

Sets whether to draw a frame around the image or not. When TRUE, a one pixel wide frame is shown around the image. Setting this attribute causes the widget to immediately repaint itself.

The default value is TRUE.

tool = $view->get_tool

Returns the currently bound image tool

$view->set_tool ($tool)

•
$tool (Gtk2::ImageView::Tool)

Set the image tool to use. If the new tool is the same as the current tool, then nothing will be done. Otherwise Gtk2::ImageView::Tool::pixbuf_changed() is called so that the tool has a chance to generate initial data for the pixbuf.

Setting the tool causes the widget to immediately repaint itself.

The default image tool is a Gtk2::ImageView::Tool::Dragger instance. See also Gtk2::ImageView::Tool.

$view->set_transp ($transp, $transp_color=0x000000)

  • $transp (Gtk2::ImageView::Transp)
  • $transp_color (integer)

Sets how the view should draw transparent parts of images with an alpha channel. If transp is GTK_IMAGE_TRANSP_COLOR, the specified color will be used. Otherwise the transp_color argument is ignored. If it is GTK_IMAGE_TRANSP_BACKGROUND, the background color of the widget will be used. If it is GTK_IMAGE_TRANSP_GRID, then a grid with light and dark gray boxes will be drawn on the transparent parts.

Calling this method causes the widget to immediately repaint. It also causes the pixbuf-changed signal to be emitted. This is done so that other widgets (such as GtkImageNav) will have a chance to render a view of the pixbuf with the new transparency settings.

rectangle = $view->get_viewport

Returns a rectangle with the current viewport. If pixbuf is NULL or there is no viewport, undef is returned.

The current viewport is defined as the rectangle, in zoomspace coordinates as the area of the loaded pixbuf the Gtk2::ImageView is currently showing.

double = $view->get_zoom

Get the current zoom factor of the view.

$view->zoom_in

Zoom in the view one step. Calling this method causes the widget to immediately repaint itself.

$view->zoom_out

Zoom out the view one step. Calling this method causes the widget to immediately repaint itself.

$view->set_zoom ($zoom)

•
$zoom (double)

Sets the zoom of the view.

Fitting is always disabled after this method has run. The zoom-changed signal is unconditionally emitted.

SIGNALS

ENUMS AND FLAGS

enum Gtk2::Gdk::InterpType

  • 'nearest' / 'GDK_INTERP_NEAREST'
  • 'tiles' / 'GDK_INTERP_TILES'
  • 'bilinear' / 'GDK_INTERP_BILINEAR'
  • 'hyper' / 'GDK_INTERP_HYPER'

enum Gtk2::Gdk::ScrollDirection

  • 'up' / 'GDK_SCROLL_UP'
  • 'down' / 'GDK_SCROLL_DOWN'
  • 'left' / 'GDK_SCROLL_LEFT'
  • 'right' / 'GDK_SCROLL_RIGHT'

enum Gtk2::ImageView::Transp

  • 'color' / 'GTK_IMAGE_TRANSP_COLOR'
  • 'background' / 'GTK_IMAGE_TRANSP_BACKGROUND'
  • 'grid' / 'GTK_IMAGE_TRANSP_GRID'

enum Gtk2::ScrollType

  • 'none' / 'GTK_SCROLL_NONE'
  • 'jump' / 'GTK_SCROLL_JUMP'
  • 'step-backward' / 'GTK_SCROLL_STEP_BACKWARD'
  • 'step-forward' / 'GTK_SCROLL_STEP_FORWARD'
  • 'page-backward' / 'GTK_SCROLL_PAGE_BACKWARD'
  • 'page-forward' / 'GTK_SCROLL_PAGE_FORWARD'
  • 'step-up' / 'GTK_SCROLL_STEP_UP'
  • 'step-down' / 'GTK_SCROLL_STEP_DOWN'
  • 'page-up' / 'GTK_SCROLL_PAGE_UP'
  • 'page-down' / 'GTK_SCROLL_PAGE_DOWN'
  • 'step-left' / 'GTK_SCROLL_STEP_LEFT'
  • 'step-right' / 'GTK_SCROLL_STEP_RIGHT'
  • 'page-left' / 'GTK_SCROLL_PAGE_LEFT'
  • 'page-right' / 'GTK_SCROLL_PAGE_RIGHT'
  • 'start' / 'GTK_SCROLL_START'
  • 'end' / 'GTK_SCROLL_END'

SEE ALSO

GtkImageView Reference Manual at http://trac.bjourne.webfactional.com/

perl(1), Glib(3pm), Gtk2(3pm), Gtk2::ImageViewer - an alternative image viewer widget.

AUTHOR

Jeffrey Ratcliffe <Jeffrey dot Ratcliffe at gmail dot com>, with patches from muppet <scott at asofyet dot org>, Torsten Schoenfeld <kaffetisch at web dot de> and Emanuele Bassi <ebassi at gmail dot com> Kevin Ryde <user42 at zip.com.au>

The DESCRIPTION section of this page is adapted from the documentation of GtkImageView.

COPYRIGHT AND LICENSE

Copyright (c) 2007 -- 2008 by Jeffrey Ratcliffe <Jeffrey.Ratcliffe@gmail.com> see AUTHORS for complete list of contributors

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

This library 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 Library General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this program. If not, see <http://www.gnu.org/licenses/>.

COPYRIGHT

Copyright (C) 2007 by Jeffrey Ratcliffe.

This software is licensed under the GPL-3; see Gtk2::ImageView for a full notice.

2017-07-23 perl v5.26.0