The editor uses the Tab key to increase or decrease the indentation level. The indentation size can be altered in the editor's Language Properties window.

###### Changing indentation size

To change the indentation size, do the following:

- Select the Properties Window.
- Select the Language Properties pane.
- Set the Indent Size property for the required language.

The editor can optionally use tab characters to fill whitespace when indenting. The use of tabs for filling whitespace can be selected in the editor's Language Properties window.

###### Selecting tab or space fill when indenting

To enable or disable the use of tab characters when indenting, do the following:

- Select the Properties Window.
- Select the Language Properties pane.
- Set the Use Tabs property for the required language. Note that changing this setting does not add or remove existing tabs from files, the change will only effect new indents.

The editor can provide assistance with source code indentation while inserting text. There are three levels of indentation assistance:

- None The indentation of the source code is left to the user.
- Indent This is the default. The editor maintains the current indentation level. When Return or Enter is pressed, the editor automatically moves the cursor to the indentation level of the previous line.
- Smart The editor analyses the source code to compute the appropriate indentation level for the line. The number of lines before the current cursor position that are analysed for context can be altered. The smart indent mode can be configured to either indent open and closing braces or the lines following the braces.

###### Changing indentation options

To change the indentation mode, do the following:

- Select the Properties Window.
- Select the Language Properties pane.
- Set the Indent Mode property for the required language.

To change whether opening braces are indented in smart indent mode, do the following:

- Select the Properties Window.
- Select the Language Properties pane.
- Set the Indent Opening Brace property for the required language.

To change whether closing braces are indented in smart indent mode, do the following:

- Select the Properties Window.
- Select the Language Properties pane.
- Set the Indent Closing Brace property for the required language.

###### Changing indentation context

To change number of previous line used for context in smart indent mode, do the following:

- Select the Properties Window.
- Select the Language Properties pane.
- Set the Indent Context Lines property for the required language.