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Gtk2::Gdk::Pixbuf::Draw::Cache.3pm

NAME

Gtk2::Gdk::Pixbuf::Draw::Cache - Cache for drawing scaled pixbufs

HIERARCHY

   Glib::Boxed
   +----Gtk2::Gdk::Pixbuf::Draw::Cache
 
 

DESCRIPTION

Gtk2::Gdk::Pixbuf::Draw::Cache provides a cache that should be used by the Gtk2::ImageView::Tool when redrawing the Gtk2::ImageView.

METHODS

cache = Gtk2::Gdk::Pixbuf::Draw::Cache->new

Creates a new pixbuf draw cache.

Returns

a new Gtk2::Gdk::Pixbuf::Draw::Cache

$cache->draw ($opts, $drawable)

*

$opts (Gtk2::Gdk::Pixbuf::Draw::Opts)

*

$drawable (Gtk2::Gdk::Drawable)

Redraws the area specified in the pixbuf draw options in an efficient way by using caching.

cache : a GdkPixbufDrawCache

opts : the Gtk2::Gdk::Pixbuf::Draw::Opts to use in this draw

drawable : a GdkDrawable to draw on

$cache->free

Deallocates a pixbuf draw cache and all its data.

$cache->invalidate

Force the pixbuf draw cache to scale the pixbuf at the next draw.
Gtk2::Gdk::Pixbuf::Draw::Cache tries to minimize the number of scale operations needed by caching the last drawn pixbuf. It would be inefficient to check the individual pixels inside the pixbuf so it assumes that if the memory address of the pixbuf has not changed, then the cache is good to use.
However, when the image data is modified, this assumtion breaks, which is why this method must be used to tell draw cache about it.

method = Gtk2::Gdk::Pixbuf::Draw::Cache->get_method ($old, $new)

*

$old (Gtk2::Gdk::Pixbuf::Draw::Opts)

*

$new (Gtk2::Gdk::Pixbuf::Draw::Opts)

Gets the fastest method to draw the specified draw options. old is assumed to be the last PixbufDrawOpts used and new is the one to use this time.

old : the last draw options used

new : the current draw options

Returns

the best draw method to use to draw

ENUMS AND FLAGS

enum Gtk2::Gdk::Pixbuf::Draw::Method

*

'scale' / 'GDK_PIXBUF_DRAW_METHOD_SCALE'

*

'contains' / 'GDK_PIXBUF_DRAW_METHOD_CONTAINS'

*

'scroll' / 'GDK_PIXBUF_DRAW_METHOD_SCROLL'

SEE ALSO

Gtk2::ImageView, Glib::Boxed

COPYRIGHT

Copyright (C) 2007 by Jeffrey Ratcliffe.

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

POD ERRORS

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