mode-line major and minor mode help text and bindings

[Drew Adams]

emacs -Q

C-x d <some directory>
M-x outline-minor-mode  ; or any other minor mode

Help echo (tool tip) in mode line, with pointer over lighter "Outl":
"mouse-2: help for minor modes, mouse-3: minor mode menu". However, with
pointer over a major mode name, such as "Dired by name", is this: "mouse-1:
major-mode-menu, mouse-2: help for current major mode".

There is a lack of symmetry here, and a few sources of confusion.

1. "major-mode-menu": This should be "major-mode menu" (or "major mode
menu", depending on the hyphenation convention used by Emacs).

2. "minor mode menu": This looks just like the major-mode case, but in this
case it is not a menu for the indicated minor mode but a menu to turn on/off
*any* minor modes. This should be called something like "menu to change
minor modes" or "menu of minor modes".

3. Why is the menu for the major mode on mouse-1 and the menu for the minor
modes on mouse-3? Why not put them both on mouse-3 (but see #6, below, for a
better suggestion).

4. "help for minor modes" (with an `s') is apparently not correct. The
mouse-3 minor-modes menu shows that these minor modes are all turned on:
font lock, line number, and outline. However, mouse-2 over the minor-mode
lighter gives only the help for outline-minor-mode (perhaps since that is
the only lighter?); it does not give "help for [all] minor modes". If only
one mode is described then this should be called "help for this minor mode".

5. Enhancement suggestion: Have mouse-1 toggle the minor mode (of that
lighter). This is a shortcut for using the minor-modes menu and choosing the
corresponding menu item.

6. Enhancement suggestion: It seems a bit silly to have the same menu be on
each of the minor-mode lighters - a waste of the mouse-3 binding.
Suggestion: Instead, add this minor-modes menu to the major-mode menu as a
submenu, "Choose Minor Modes". Bonus: if the minor mode (for that lighter)
has, itself, a menu, that could be on mouse-3.

7. Unrelated question: Why do we call the mode-line name of the mode a
"lighter" (and use the keyword ":lighter" for `define-minor-mode')? Where
does this term come from - is it perhaps a translation? Why don't we call it
the "mode-line name" of the mode (and use keyword :mode-line-name)? Who will
understand "lighter" for this without an explanation? Who will look for that
term in the Emacs Lisp-manual index? (BTW - Foldoc has no definition for
"lighter", so I suspect it is not a previously used computing term:
http://foldoc.org/foldoc.cgi?query=lighter&action=Search.)