bug#9054: 24.0.50; show source in other window

[Juri Linkov]

>> But what to do with long symbols?  For example, this won't fit to any menu:
>>
>>    Describe `display-fill-column-indicator-character'
>>    Lookup `display-fill-column-indicator-character' in Manuals
>>    Show Definition of `display-fill-column-indicator-character'
>>    Show References for `display-fill-column-indicator-character'
>
> We could abbreviate such monsters in the menu entry and show the full
> identifier in the tooltip of the menu entry.

I'm not sure if this would be more useful:

  Describe `display-...'
  Lookup `display-...' in Manuals
  Show Definition of `display-...'
  Show References for `display-...'

>> There is the menu “Describe” in the submenu “Help” on the manu-bar,
>> but I don't see “Describe Character” in it.
>
> Describe Character makes most sense when the user "is right at that
> character".

Generally, I agree, but the problem is that "Describe Character"
is not specific to the currently discussed emacs-lisp-mode.
Should the context menu always contain "Describe Character"
in all buffers?

> Thus I'd say that "Select All" has no place in the "Context Menu" but
> I'm not very sure where to put it instead: Maybe in a sub-menu where we
> offer to select symbol, s-expression, containing function and the entire
> buffer around the mouse position.  Then we could also add a search
> sub-menu that would allow to search for the symbol near the mouse
> cursor.  But the place where "Select All" should really go to is the
> mode line.

The "Select" sub-menu is a good idea.  For example, LibreOffice has
a sub-menu "Selection Mode" with "Standard" and "Rectangle Selection".
Gimp even has the top-level menu "Select", etc.  But this means that
region-related part of the context menu doesn't need to be the same
as region-related part of the Edit sub-menu of the menu-bar?

>>> BTW: Show/Hide in the Options menu should allow to toggle context menu
>>> mode.
>>
>> Maybe in the next version context menu mode will be enabled by default.
>
> Then we need an entry that allows to toggle it off.

Maybe not in Show/Hide sub-menu that is related only to visible parts
of the screen.