* @defgroup Elm_Clock Clock
* @ingroup Elementary
* @image html clock_inheritance_tree.png
* @image latex clock_inheritance_tree.eps
* @image html img/widget/clock/preview-00.png
* @image latex img/widget/clock/preview-00.eps
* This is a @b digital clock widget. In its default theme, it has a
* vintage "flipping numbers clock" appearance, which will animate
* sheets of individual algorisms individually as time goes by.
* A newly created clock will fetch system's time (already
* considering local time adjustments) to start with, and will tick
* accordingly. It may or may not show seconds.
* Clocks have an @b edition mode. When in it, the sheets will
* display extra arrow indications on the top and bottom and the
* user may click on them to raise or lower the time values. After
* it's told to exit edition mode, it will keep ticking with that
* new time set (it keeps the difference from local time).
* Also, when under edition mode, user clicks on the cited arrows
* which are @b held for some time will make the clock to flip the
* sheet, thus editing the time, continuously and automatically for
* the user. The interval between sheet flips will keep reducing in
* time, so that it helps the user to reach a time which is distant
* from the one set.
* The time display is, by default, in military mode (24h), but an
* am/pm indicator may be optionally shown, too, when it will
* switch to 12h.
* This widget inherits from the @ref Layout one, so that all the
* functions acting on it also work for clock objects.
* This widget emits the following signals, besides the ones sent from
* @ref Layout:
* - @c "changed" - the clock's user changed the time
* - @c "focused" - When the clock ehas received focus. (since 1.8)
* - @c "unfocused" - When the clock has lost focus. (since 1.8)
* - @c "language,changed" - the program's language changed (since 1.9)
* Supported elm_object common APIs.
* @li @ref elm_object_signal_emit
* @li @ref elm_object_signal_callback_add
* @li @ref elm_object_signal_callback_del
* Here is an example on its usage:
* @li @ref clock_example
* @addtogroup Elm_Clock