RE: Help buffer key bindings

["Drew Adams" <drew.adams@oracle.com>]

    > I was going to suggest the same thing, without the smiley.
    > There should be a command to go forward, and it should be bound,
    > like `l'.  And it should be bound to `mouse-5' (as `mouse-4'
    > should be bound to `help-go-back').

    Isn't that mouse scroll?

See earlier in this thread.

Yes, mouse-4 and mouse-5 are currently co-opted by X11 for interpretation of
the mouse wheel (hence, mouse scroll). Emacs is currently aligned to X11 in
this regard, which wastes the 4th and 5th mouse buttons for platforms other
than X11.

Emacs treats key sequences mouse-4 and mouse-5 as the 4th and 5th mouse
buttons for platforms other than X11, however. For example, on Windows,
mouse-4 represents the 4th mouse button. Users on non-X11 platforms can thus
bind mouse-4 and mouse-5 to capture the 4th and 5th button events. However,
we have shied away from assigning any standard Emacs behavior for the 4th
and 5th buttons, because of the special treatment for X11.

Note that Emacs does not, for example, reserve mouse-4 and mouse-5 for the
mouse wheel in all cases, and assign, say, keys mouse-6 and mouse-7 to the
4th and 5th buttons.

I argue that Emacs should not limit itself in this way. It is OK that Emacs
respect the X11 limitation when the platform is X11, but it shouldn't do so
otherwise.

Emacs should go ahead and bind the 4th and 5th mouse buttons to standard
behaviors (e.g. Back and Forward in Info and Help). There are at least two
ways to do this:

1. Use, say, mouse-6 and mouse-7 for the 4th and 5th mouse buttons
systematically, for all platforms (because X11 co-opts mouse-4 and mouse-5).

2. Use mouse-4 and mouse-5 for the 4th and 5th mouse buttons for platforms
other than X11.