Homepage: https://www.gnu.org/software/emacs
Author: Kevin Broadey
Folding extensions for outline-mode and outline-minor-mode
This file provides folding editor extensions for outline-mode and
outline-minor-mode buffers. What's a "folding editor"? Read on...
Imagine you're in an outline-mode buffer and you've hidden all the text and
subheadings under your level-1 headings. You now want to look at the stuff
hidden under one of these headings. Normally you'd do C-c C-e (show-entry)
to expose the body or C-c C-i to expose the child (level-2) headings.
With foldout, you do C-c C-z (`foldout-zoom-subtree'). This exposes the body
and child subheadings and narrows the buffer so that only the level-1
heading, the body and the level-2 headings are visible. If you now want to
look under one of the level-2 headings, position the cursor on it and do C-c
C-z again. This exposes the level-2 body and its level-3 child subheadings
and narrows the buffer again. You can keep on zooming in on successive
subheadings as much as you like. A string in the mode line tells you how
deep you've gone.
When zooming in on a heading you might only want to see the child
subheadings. You do this by specifying a numeric argument: C-u C-c C-z.
You can specify the number of levels of children too (c.f. show-children):
e.g. M-2 C-c C-z exposes two levels of child subheadings. Alternatively,
you might only be interested in the body. You do this by specifying a
negative argument: M-- C-c C-z. You can also cause the whole subtree to be
expanded, similar to C-c C-s (show-subtree), by specifying a zero argument:
M-0 C-c C-z.
While you're zoomed in you can still use outline-mode's exposure and hiding
functions. It won't upset foldout at all. Also, since the buffer is
narrowed, "global" editing actions will only affect the stuff under the
zoomed-in heading. This is useful for restricting changes to a particular
chapter or section of your document.
You unzoom (exit) a fold by doing C-c C-x (`foldout-exit-fold'). This hides
all the text and subheadings under the top-level heading and returns you to
the previous view of the buffer. Specifying a numeric argument exits that
many folds. Specifying a zero argument exits *all* folds.
You might want to exit a fold *without* hiding the text and subheadings.
You do this by specifying a negative argument. For example, M--2 C-c C-x
exits two folds and leaves the text and subheadings exposed.
Foldout also provides mouse bindings for entering and exiting folds and for
showing and hiding text. Hold down Meta and Control, then click a mouse
button as follows:-
mouse-1 (foldout-mouse-zoom) zooms in on the heading clicked on:-
single click expose body
double click expose subheadings
triple click expose body and subheadings
quad click expose entire subtree
mouse-2 (foldout-mouse-show) exposes text under the heading clicked on:-
single click expose body
double click expose subheadings
triple click expose body and subheadings
quad click expose entire subtree
mouse-3 (foldout-mouse-hide-or-exit) hides text under the heading clicked
on or exits the fold:-
single click hide subtree
double click exit fold and hide text
triple click exit fold without hiding text
quad click exit all folds and hide text
You can change the modifier keys used by setting `foldout-mouse-modifiers'.