3 While editing, it happens that you apply an unintended change, or make
4 a choice one that you later decide was wrong. All changes to the
5 arrangement of session components (regions, control points) along the
6 timeline can be <dfn>undone</dfn> (and <dfn>redone</dfn> if necessary).
9 The default keybindings are <kbd class="mod1">Z</kbd> for Undo and
10 <kbd class="mod1">R</kbd> for Redo. These match the conventions of most
11 other applications that provide undo/redo.
14 Changes are also saved to the <dfn>session history</dfn> file, so that
15 undo/redo is possible even if you close the session and reopen it later,
16 even if you quit Ardour in between.
19 The maximum number of changes that can be undone can be configured under
20 <kbd class="menu">Edit > Preferences > Misc > Undo</kbd>.
21 The maximum number of changes stored in the history file is a separate
22 parameter, and can also be set in the same place.
26 In addition to the normal undo (which works only on actions that change
27 the timeline), there is a <dfn>visual undo</dfn> which will revert any
28 command that affects the display of the editor window. Its shortcut is
29 <kbd class="mod3">Z</kbd>.
30 There is also an undo for selection. See
31 <a href="@@selection-techniques">Selection Techniques</a> for more information.