Using overlays, it is possible to set up dictionaries that are local to specific regions of text. The predictive mode support for a number of major modes makes use of this feature (see Major Modes). Configuring region-local dictionaries is, however, beyond the scope of this user manual. See Region-Local Dictionaries.
Predictive mode provides an auxilliary minor-mode,
predictive-which-dict-mode, which displays the name of the
currently active dictionary in the mode-line, i.e. the dictionary that
is active at the point. If the active dictionary is in fact a list of
dictionaries, the name of the first dictionary in the list is displayed,
followed by ‘...’. Positioning the mouse over the dictionary name
displays the names of the other dictionaries, either in the echo-area
(if tooltip-mode is disabled, or in a terminal) or in a
tooltip. However, for this to work, you have to customize part of the
mode-line-modes variable, as the default setting clobbers this
functionality. Find the part that refers to the minor-mode-alist
variable, and delete the help-echo property, i.e. change that
part to:
(:propertize ("" minor-mode-alist)
mouse-face mode-line-highlight local-map
(keymap (header-line keymap (down-mouse-3 . mode-line-mode-menu-1))
(mode-line keymap (down-mouse-3 . mode-line-mode-menu-1)
(mouse-2 . mode-line-minor-mode-help)
(down-mouse-1 . mouse-minor-mode-menu))))