XtSelectionDoneProc() XtSelectionDoneProc()
Name
XtSelectionDoneProc - interface definition for procedure called after selection transfer is completed.
Synopsis
typedef void (*XtSelectionDoneProc)(Widget, Atom *, Atom *);
Widget w;
Atom *selection;
Atom *target;
Inputs
w Specifies the widget that owns the converted selection.
selection Specifies the atom that names the selection that was transferred.
target Specifies the target type to which the conversion was done.
Description
An XtSelectionDoneProc is optionally registered in a call to XtOwnSelection(), and is called by the Intrinsics after the corresponding
XtConvertSelectionProc has been called and the data it returns is transferred to the requestor.
An XtSelectionDoneProc should free the memory returned by the XtConvertSelectionProc and any other memory or resources allocated by that
procedure to convert the selection value. If no XtSelectionDoneProc is registered with XtOwnSelection(), then the Intrinsics will automat-
ically free the memory returned by the XtConvertSelectionProc by calling XtFree().
Usage
Most XtConvertSelectionProc procedures will allocate a single block of memory with XtMalloc() and can simply rely on the Intrinsics to free
that block with XtFree(). In this case, there is no need for an XtSelectionDoneProc.
Note that an XtSelectionDoneProc is not passed a client_data argument, nor is it passed a pointer to the memory that was returned by the
XtConvertSelectionProc. In a widget, the widget structure can point to the memory that must be freed, but in an application, you will
probably have to rely on a global variable, as in the example below.
The XtSelectionDoneProc and XtOwnSelection() are part of the Intrinsics atomic selection transfer mechanism. For some selection values, it
may be more convenient to transfer the selection value in pieces. This can be done with the incremental transfer mechanism; see XtOwnSe-
lectionIncremental(1).
Example
The xcalc client uses a static character string to store the selection value. Because this is not allocated memory, it should not be
freed, so xcalc provides a XtSelectionDoneProc which simply sets the static buffer to contain the empty string:
static char selstr[LCD_STR_LEN]; /* storage for selections from the LCD */
/*ARGSUSED*/
void done(w, selection, target)
Widget w;
Atom *selection;
Atom *target;
{
selstr[0] = ' ';
}
This XtSelectionDoneProc is registered with this call:
XtOwnSelection(LCD, XA_PRIMARY, time, convert, lose, done);
See Also
XtDisownSelection(1), XtGetSelectionValue(1), XtGetSelectionValues(1), XtOwnSelection(1), XtOwnSelectionIncremental(1),
XtConvertSelectionProc(2).
Xt - Selections XtSelectionDoneProc()
