* @defgroup Elm_Slideshow Slideshow
* @ingroup Elementary
* @image html slideshow_inheritance_tree.png
* @image latex slideshow_inheritance_tree.eps
* @image html img/widget/slideshow/preview-00.png
* @image latex img/widget/slideshow/preview-00.eps
* This widget, as the name indicates, is a pre-made image
* slideshow panel, with API functions acting on (child) image
* items presentation. Between those actions, are:
* - advance to next/previous image
* - select the style of image transition animation
* - set the exhibition time for each image
* - start/stop the slideshow
* The transition animations are defined in the widget's theme,
* consequently new animations can be added without having to
* update the widget's code.
* @section Slideshow_Items Slideshow items
* For slideshow items, just like for @ref Genlist "genlist" ones,
* the user defines a @b classes, specifying functions that will be
* called on the item's creation and deletion times.
* The #Elm_Slideshow_Item_Class structure contains the following
* - @c func.get - When an item is displayed, this function is
* called, and it's where one should create the item object, de
* facto. For example, the object can be a pure Evas image object
* or an Elementary @ref Photocam "photocam" widget.
* See #SlideshowItemGetFunc.
* - @c func.del - When an item is no more displayed, this function
* is called, where the user must delete any data associated to
* the item. See #SlideshowItemDelFunc.
* @section Slideshow_Caching Slideshow caching
* The slideshow provides facilities to have items adjacent to the
* one being displayed <b>already "realized"</b> (i.e. loaded) for
* you, so that the system does not have to decode image data
* anymore at the time it has to actually switch images on its
* viewport. The user is able to set the numbers of items to be
* cached @b before and @b after the current item, in the widget's
* item list.
* This widget inherits from the @ref Layout one, so that all the
* functions acting on it also work for slideshow objects.
* This widget emits the following signals, besides the ones sent from
* @ref Layout:
* - @c "changed" - when the slideshow switches its view to a new
* item. event_info parameter in callback contains the current visible item
* - @c "transition,end" - when a slide transition ends. event_info parameter
* in callback contains the current visible item
* - @c "focused" - When the slideshow has received focus. (since 1.8)
* - @c "unfocused" - When the slideshow has lost focus. (since 1.8)
* - @c "language,changed" - the program's language changed (since 1.9)
* Supported @c elm_object_item common APIs.
* @li @ref elm_object_item_del
* List of examples for the slideshow widget:
* @li @ref slideshow_example
* @addtogroup Elm_Slideshow