Untabify
Untabify (Alt+Ctrl+O)
Untabifies the indentation of the selection by replacing leading Tabs with Spaces on each line
according to the current Tab Size setting. See chapter Edit page of the Settings dialog for more details.
If Tabs and Spaces are mixed together on the beginning of a line, the total visual white-space
extent is calculated first, and only then Spaces are used to fill the space of the original indentation.
Note: Using this tool should not generate any visible changes to the indentation, when used with a fixed-width font. However, some proportional fonts do not use the average character width for Spaces, thus Tabs may seem to be longer than a set of Spaces. This is a visual inconvenience only and should not be considered incorrect.
Note: This tool does not modify any other white-spaces
than the leading ones.
See also Tabify tool.