NAME

       Clipboard - manages a list of graphical component subjects

SYNOPSIS

       #include <Unidraw/clipboard.h>

DESCRIPTION

       A  Clipboard  maintains  a list of GraphicComp objects and provides operations for manipulating the list.
       Catalog and Command classes use clipboards to store graphical components they affect.

PUBLIC OPERATIONS

       Clipboard(GraphicComp* = nil)
              Construct a new clipboard object, optionally with a GraphicComp that should  appear  initially  on
              the list.

       virtual ~Clipboard()
              Delete the clipboard.  Deleting the clipboard does not delete the GraphicComp objects it contains.

       void Init(Selection*)
       void CopyInit(Selection*)
              Init  initializes  the  clipboard  with the subjects belonging to the graphical views in the given
              selection object.  CopyInit initializes it with copies of the subjects.

       void Clear()
              Remove all GraphicComp objects from the clipboard.  The objects are not deleted.

       void DeleteComps()
              Delete each GraphicComp in the clipboard.  This operation does not delete the list itself; thus it
              will still be possible to iterate through the list afterwards.  DeleteComps  is  generally  called
              just before the clipboard is destroyed.

       void Append(GraphicComp*)
       void Prepend(GraphicComp*)
       void InsertAfter(Iterator, GraphicComp*)
       void InsertBefore(Iterator, GraphicComp*)
       void Remove(GraphicComp*)
       void Remove(Iterator&)
              Operations  for  adding  and  removing  GraphicComp  objects  from the clipboard.  InsertAfter and
              InsertBefore take an iterator that specifies the point before or after which the given GraphicComp
              should be inserted.  Remove(Iterator&) removes the GraphicComp to which the  iterator  refers  and
              increments the iterator to point to the following GraphicComp.

       GraphicComp* GetComp(Iterator)
       void SetComp(GraphicComp*, Iterator&)
              GetComp  effectively  dereferences  an  iterator,  returning  the  GraphicComp to which it points.
              SetComp initializes an iterator to point to the given GraphicComp object, assuming the  object  is
              in the clipboard.

       void First(Iterator&)
       void Last(Iterator&)
       void Next(Iterator&)
       void Prev(Iterator&)
       boolean Done(Iterator&)
              Operations  for  iterating  through  the GraphicComps in the clipboard.  First and Last modify the
              iterator to point to the first and last GraphicComp objects.  Next  and  Prev  make  the  iterator
              point  to  the  succeeding  and  preceding GraphicComp objects.  Done returns whether the iterator
              points to the sentinel object on the list, which marks the beginning and the end of list.

       boolean IsEmpty()
       boolean Includes(GraphicComp*)
              Return whether or not the clipboard is empty or whether it includes the given GraphicComp object.

       virtual Clipboard* Copy()
       virtual Clipboard* DeepCopy()
              Copy creates a new clipboard with a list of  the  same  GraphicComp  objects  as  this.   DeepCopy
              creates a new clipboard containing copies of the objects in this.

PROTECTED OPERATIONS

       UList* Elem(Iterator)
       GraphicComp* Comp(UList*)
              The  Clipboard  class  stores  its  GraphicComp  objects  in a UList.  These convenience functions
              convert an iterator into a UList element and dereference a UList element to obtain  a  GraphicComp
              object, respectively.

SEE ALSO

       Catalog(3U), Command(3U), GraphicComp(3U), Iterator(3U), Selection(3U), UList(3U)

Unidraw                                           12 June 1990                                     Clipboard(3U)