.so sli-item \c{

The $item$ class

The canvas widget allows the programmer to create a number of built-in graphic items. Items are given a numerical index when created and, in addition, they may be given a (string) tag. Tags allow items to be manipulated in a group-wise fashion. To deal with items in a C++ context, the hush library contains a class item of which the functionality is shown in slide class-item. } \c{ Instances of item may not be created directly by the user, but instead are created by the canvas widget. For an item, its index may be obtained by casting the item to int. If the index does not identify an existing item, it will be zero. Existing items may be moved, in a relative way, by the move function. } \c{ In a similar way as for widgets, items may be associated with events, either explicitly by using item::bind, or implicitly by using item::handler. The default bindings for items are identical to the default bindings for the canvas widget, but these may be overridden by descendant classes. Similar to the widget class, the item class is derived from the handler class. This allows the user to define possibly compound shapes defining their own handler. }