Write and edit source code

When you work with code, MPS ensures that your work is stress-free. It offers various shortcuts and features to help you add, select, copy, move, edit, fold, find occurrences, and save code.

Find action

If you do not remember a shortcut for the action you want to use, press Ctrl+Shift+A to find any action by name.

Configure tabs and indents

In the Settings/Preferences dialog Ctrl+Alt+S , go to Editor | Code Style.
Select a language for which you want to configure the indentation.
From the options on the right, on the Tabs and Indents, select the Use tab character for the editor to use tabs when you press Tab, indent, or reformat code. You can also configure the tab size if you need. If you don't select this option, MPS will use spaces.

Copy and paste code

You can use the standard shortcuts to copy Ctrl+C and paste Ctrl+V any selected code fragment. If nothing is selected, MPS automatically copies as is the whole line where the caret is located.

By default, when you paste anything in the editor, MPS performs "smart" paste, for example, pasting multiple lines in comments will automatically add the appropriate markers to the lines you are pasting. If you need to paste just plain text, press Ctrl+Alt+Shift+V.

Place the caret at a line or a symbol, right-click to open the context menu, select Copy/Paste Special | Copy Reference. When you select the Copy Reference (Ctrl+Alt+Shift+C) option, MPS creates a reference string that includes the line number of the selected line or symbol. You can press Ctrl+V to paste the copied reference anywhere.
MPS keeps track of everything you copy to the clipboard. To paste from history, in the editor, from the context menu, select Copy/Paste Special | Paste from History (Ctrl+Shift+V). In the dialog that opens, select your entry and click Paste.
The default number of items stored in the clipboard history is 100.

Lines of code

MPS offers several useful shortcuts for manipulating code lines.

To add a line after the current one, press Shift+Enter. MPS moves the caret to the next line.
To add a line before the current one, press Ctrl+Alt+Enter. MPS moves the caret to the previous line.
To duplicate a line, press Ctrl+D.
To sort lines alphabetically in the whole file or in a code selection, from the main menu, select Edit | Sort Lines or Edit | Reverse Lines. These actions might be helpful when you work with property files, data sets, text files, log files, and so on. If you need to assign shortcuts to those actions, refer to Configuring keyboard shortcuts for more information.
To delete a line, place the caret at the line you need and press Ctrl+Y.
To split string literals into two parts, press Enter.

MPS splits the string and provides the correct syntax. You can also use the Break string on '\n' intention to split string literals. Press Alt+Enter or click to select this intention.
To comment a line of code, place the caret at the appropriate line and press Ctrl+/.

Code statements

Move statements

In the editor, place the caret at the needed statement and press Ctrl+Shift+Up to move a statement up or Ctrl+Shift+Down to move a statement down. MPS moves the selected statement performing a syntax check.

Complete current statement

In the editor, press Ctrl+Shift+Enter or from the main menu select Code | Complete Current Statement. MPS inserts the required trailing comma automatically in structs, slices, and other composite literals. The caret is moved to the position where you can start typing the next statement.

Code fragments

Move and copy code fragments by dragging them in the editor.
- To move a code fragment, select it and drag the selection to the target location.
- To copy a code selection, keeping Ctrl pressed, drag it to the target location.
  
  The copy action might not be available in macOS since it can conflict with global OS shortcuts.
To toggle between the upper and lower case for the selected code fragment, press Ctrl+Shift+U.

Note that when you apply the toggle case action to the CamelCase name format, MPS converts the name to the lower case.

Code folding

Folded code fragments are shown as shaded ellipses (). If a folded code fragment contains errors, MPS highlights the fragment in red.

Expand or collapse code elements

To fold or unfold a code fragment, press Ctrl+NumPad -/Ctrl+NumPad +. MPS folds or unfolds the current code fragment, for example, a single method.
To collapse or expand all code fragments, press Ctrl+Shift+NumPad -/Ctrl+Shift+NumPad +.

MPS collapses or expands all fragments within the selection, or, if nothing is selected, all fragments in the current file, for example, all methods in a file.
To fold blocks of code, press Ctrl+Shift+.. This action collapses the code fragment between the matched pair of curly braces {}, creates a custom folding region for that fragment, and makes it "foldable".
To collapse or expand a custom code selection, press Ctrl+..

You can fold or unfold any manually selected regions in code.

Fold or unfold nested fragments

To expand the current fragment and all the nested fragments, press Ctrl+NumPad *, 1. You can expand the current fragment up to the specified nesting level (from 1 to 5).
To expand all the collapsed fragments in the file, press Ctrl+Shift+NumPad *, 1. You can expand the collapsed fragments up to the specified nesting level (from 1 to 5).

Use the Surround With action

You can collapse or expand code using the Surround With action.

In the editor, select a code fragment and press Ctrl+Alt+T.
In the popup menu, select <editor-fold...> Comments or region...endregion Comments.
If you need, name your custom region and collapse or expand the created region as usual Ctrl+NumPad -/Ctrl+NumPad +.
Press Ctrl+Alt+. to navigate to the created custom region.

Disable code folding outline

You can disable the code folding outline that appears on the left gutter.

In the Settings/Preferences dialog Ctrl+Alt+S, go to Editor | General | Code Folding.
Clear the Show code folding outline checkbox.

Autosave

MPS automatically saves changes that you make in your files. Saving is triggered by various events, such as compiling, running, debugging, performing version control operations, closing a file or a project, or quitting the IDE. Most of the actual events are predefined and cannot be configured, but you can be sure that changes will not be lost as you work.

Configure autosave behavior

In the Settings/Preferences dialog Ctrl+Alt+S, go to Appearance and Behavior | System Settings.
Under Autosave, configure the following options:
- Save files when switching to a different application
- Save files is the IDE is idle for N seconds

If you use version control integration, names of all modified files will be marked with a dedicated color on the file tab. But you can also mark unsaved files with an asterisk (*) on the file tab.

Mark files with unsaved changes

In the Settings/Preferences dialog Ctrl+Alt+S, go to Editor | General | Editor Tabs.
Select the Mark modified tabs with asterisk checkbox.

Revert changes

For the most recent changes, press Ctrl+Z or choose Edit | Undo from the menu.
For the most robust tracking of all changes,use a version control system.

Last modified: 14 September 2020