XmClipboardStartCopy --- A clipboard function that sets up a storage and data structure
SYNOPSIS
#include <Xm/CutPaste.h>
int XmClipboardStartCopy (display, window, clip_label,
timestamp, widget, callback, item_id)
Display * display;
Window window;
XmString clip_label;
Time timestamp;
Widget widget;
XmCutPasteProc callback;
long * item_id;
(void)
DESCRIPTION
XmClipboardStartCopy
sets up storage and data structures to receive clipboard data.
An application calls this function during a cut or copy operation.
The data item that these structures receive then becomes
the next data item in the clipboard.
Copying a large piece of data to the clipboard can take a long time.
It is possible that, once the data is copied, no application will ever
request that data. The Motif Toolkit provides a mechanism so that an
application does not need to actually pass data to the clipboard until
the data has been requested by some application.
Instead, the application passes format and length information in
XmClipboardCopy to the clipboard functions, along with a widget
ID and a callback function address that is passed in
XmClipboardStartCopy. The widget ID is necessary for
communications between the clipboard functions in the application that
owns the data and the clipboard functions in the application that
requests the data.
The callback functions are responsible for copying the actual data to
the clipboard through XmClipboardCopyByName. The callback
function is also called if the data item is removed from the clipboard
and the actual data is no longer needed.
display
Specifies a pointer to the Display structure that was returned in a
previous call to XOpenDisplay or XtDisplay.
window
Specifies the window ID of a widget that relates the application window to the
clipboard. The widget's window ID can be obtained through
XtWindow.
The same application instance should pass the same window ID to each of the
clipboard functions that it calls.
clip_label
Specifies the label to be associated with the data item.
This argument
is used to identify the data item, as in a clipboard viewer.
An example of a label is the name of the application that places the
data in the clipboard.
timestamp
Specifies the time of the event that triggered the copy.
A valid timestamp must be supplied; it is not sufficient to use
CurrentTime.
widget
Specifies the ID of the widget that receives messages requesting data
previously passed by name. This argument must be present in order to
pass data by name. Any valid widget ID in your application can be
used for this purpose and all the message handling is taken care of by
the cut and paste functions.
callback
Specifies the address of the callback function that is called when the
clipboard needs data that was originally passed by name. This is also
the callback to receive the delete message for items that were
originally passed by name. This argument must be present in order to
pass data by name.
item_id
Specifies the number assigned to this data item.
The application uses this number in calls to
XmClipboardCopy, XmClipboardEndCopy, and
XmClipboardCancelCopy.
The widget and callback arguments must be present in order to
pass data by name. The callback format is as follows:
void (*callback) (widget, data_id, private, reason)
Widget widget;
long *data_id;
long *private;
int *reason;
(void)
widget
Specifies the ID of the widget passed to this function.
data_id
Specifies the identifying number returned by
XmClipboardCopy, which identifies the pass-by-name data.
private
Specifies the private information passed to
XmClipboardCopy.
reason
Specifies the reason. XmCR_CLIPBOARD_DATA_DELETE
or XmCR_CLIPBOARD_DATA_REQUEST
are the possible values.
RETURN
XmClipboardSuccess
The function was successful.
XmClipboardLocked
The function failed because the clipboard was locked by another
application. The application can continue to call the function again with
the same parameters until the lock goes away. This gives the application
the opportunity to ask if the user wants to keep trying or to give up
on the operation.