copy in editor<%>
Copies items into the clipboard.
The system may execute a copy (in response to other method calls)
without calling this method. To extend or re-implement copying,
override the
do-copy in text% or
do-copy in pasteboard% method of an editor.
( -> void
send an-editor copy extend? time)
extend? = : boolean
#f
time = : exact integer0
Copies the selected items into the clipboard. If extend? is not
#f, the old clipboard contents are appended.
See Cut and Paste for a discussion of the time argument. If
time is outside the platform-specific range of times,
an exn:application:mismatch exception is raised.