Get copy and paste working

[blippy]

1. The copy accelerator key should be Ctrl-c, the paste accelerator key should be Ctrl-v, and both menu items should be enabled.
2. Get copying working.
3. Get pasting working.

[blippy]

ITEM 1 - MENU KEYS

fallback.c should now be changed to read:

//      "*copy.sensitive:               no",
//      "*paste.sensitive:              no",
        "*copy.accelerator:            Ctrl<Key>c",
        "*paste.accelerator:            Ctrl<Key>v",
        "*copy.acceleratorText:         Ctrl-c",
        "*paste.acceleratorText:         Ctrl-v",

ITEM 2 - COPYING

Changes needed to be made in CopyCB(). Use the function decomp() to obtain a pointer to the formula expressed as a string. The functions XmClipboardStartCopy(), XmClipboardCopy(), XmClipboardEndCopy() and a number of other Motif functions are used to affect the copy to clipboard.

In the line long private_id = 0x01E0;, 01E0 is a "magic number" identifying oleo. It looks like the word "OLEO".

Most of the code was cribbed from http://www.oreilly.com/openbook/motif/vol6a/Vol6a_html/ch17.html. In a call to XmClipboardStartCopy(), the parameter CurrentTime was passed in, as per the afrorementioned webpage. However man XmClipboardStartCopy says:

A valid timestamp must be supplied; it is not sufficient to use CurrentTime.

There does not appear to be an issue with its use, however.

ITEM 3 - PASTING

XmClipboardRetrieve() was called to retrieve the contents of the clipboard into a buffer of size 80. Motif has an ability to read in the clipboard in chunks, but I think the simple solution I have adopted is sufficient.

Setting this string - which may actually be a formula - into the cell is straigtforward:

                new_value(curow, cucol, buf);

[blippy]

Closing, as issue has been implemented.