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)