A simple-pane with scrollbar(s).
A cursor specification or
end-pane-drag-operation together implement a simple dragging operation, which means that
scrolls as much as the user move the cursor. The scrolling happens by a call to scroll with the appropriate parameters, in the dimension(s) for which
start-pane-drag-operation initializes the dragging operation on
cursor is non-nil, the overriding cursor is set internally (not affecting the value that
pane-drag-operation-update performs the dragging operation and calls scroll with the appropriate arguments to scroll
(in the direction(s) that the pane has scrollbar(s)).
is scrolled based on the difference between
in the calls to
end-pane-drag-operation are called without a preceding call to
start-pane-drag-operation or after a call to
end-pane-drag-operation without following call to
start-pane-drag-operation they do nothing.
CAPI User Guide and Reference Manual (Macintosh version) - 3 Aug 2017