How to expand/collapse a diff sections in Vimdiff?

Question

I've started using vimdiff today, and wanted to do some of the things that I've taken for granted on Windows based diff editors (like expand/collapse a diff section, have full file expansion/only diffs with 3 context lines above or below, etc.). I currently know only the following commands :

Keyboard Shortcuts:

• do - Get changes from other window into the current window.

• dp - Put the changes from current window into the other window.

• ]c - Jump to the next change.

• [c - Jump to the previous change.

• CTRL+W, w - Switch to the other split window (CTRL+W, CTRL+W does the same thing, in case you let go of the CTRL key a bit later)

Could someone point me to the right direction so I could replicate similar features?

It would be nice if I could expand/collapse lines around the diffs, for example.

Answer 1

Aside from the ones you mention, I only use frequently when diffing the following:

• :diffupdate :diffu -> recalculate the diff, useful when after making several changes vim's isn't showing minimal changes anymore. Note that it only works if the files have been modified inside vimdiff. Otherwise, use:
  • :e to reload the files if they have been modified outside of vimdiff.
• :set noscrollbind -> temporarily disable simultaneous scrolling on both buffers, reenable by :set scrollbind and scrolling.

Most of what you asked for is folding: vim user manual's chapter on folding. Outside of diffs I sometime use:

• zo -> open fold.
• zc -> close fold.

But you'll probably be better served by:

• zr -> reducing folding level.
• zm -> one more folding level, please.

or even:

• zR -> Reduce completely the folding, I said!.
• zM -> fold Most!.

The other thing you asked for, use n lines of folding, can be found at the vim reference manual section on options, via the section on diff:

• set diffopt=<TAB>, then update or add context:n.

You should also take a look at the user manual section on diff.