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Customizing Calva

Don't like the defaults? On this page we can collect some of the customizations that people have done, and maybe write a thing or two about it some day.

Tip for VS Code newcomers: The search box in Settings is your friend. Also, some Calva settings are more complex than the Settings UI can handle. VS Code will then show you a link to settings.json. And VS Code's built-in json extension is awesome. To add settings for Calva's Pretty Printing, for example, search for ”prettyprint” in VS Code Settings and follow the link to settings.json. Start typing ”calvapretty” until auto-complete suggests calva.prettyPrintingOptions. Press ENTER and VS Code will fill in these defaults:

    "calva.prettyPrintingOptions": {
        "enabled": true,
        "printEngine": "pprint",
        "width": 40
    },

Clojure Defaults

Calva sets some VS Code settings for all Clojure files. Some of these are needed for Calva to function correctly, which should not be tampered with unless you really know what you are doing, and some of them are convenient defaults. If you add a setting to your settings.json and accept the snippet help you get when you type "[clojure]", you will get the Calva defaults pasted:

    "[clojure]": {
        "editor.wordSeparators": "\t ()\"':,;~@#$%^&{}[]`",
        "editor.autoClosingBrackets": "always",
        "editor.autoClosingQuotes": "always",
        "editor.formatOnType": true,
        "editor.autoIndent": "full",
        "editor.formatOnPaste": true,
        "files.trimTrailingWhitespace": false,
        "editor.matchBrackets": "never",
        "editor.renderIndentGuides": false,
        "editor.parameterHints.enabled": false
    }

Note

The above editor.wordSeparators setting establish Clojure word boundaries. E.g - is considered to be part of words. This affects what happens when double-clicking symbols and other things. If you want to include - or something else as a word boundary, just add it to the setting.

Pretty Printing

Calva's pretty printing mode can be configured a bit. See Pretty Printing.

Calva Highlight

Calva takes care of syntax highlighting, and also provides some features not available through VS Code's highlighting mechanism. These extras include rainbow parens, sane bracket matching, and comment form dimming/highlighting.

You are in charge of how brackets and comments are highlighted via the calva.highlight.<setting> settings:

Setting Meaning Example
enableBracketColors Enable rainbow colors true
rainbowIndentGuides Enable rainbow indent guides true
highlightActiveIndent Highlight the active indent guide true
bracketColors Which colors to use ["#000", "#999"]
cycleBracketColors Whether same colors should be
reused for deeply nested brackets
true
misplacedBracketStyle Style of misplaced bracket { "border": "2px solid #c33" }
matchedBracketStyle Style of bracket pair highlight {"backgroundColor": "#E0E0E0"}
ignoredFormStyle Style of #_... form {"textDecoration": "none; opacity: 0.5"}
commentFormStyle Style of (comment ...) form {"fontStyle": "italic"}

Note

The VS Code built-in settings editor.renderIndentGuides and editor.highlightActiveIndent do not have any effect, since the former is switched off by the Clojure Defaults, mentioned above. Use Calva Highlight's rainbowIndentGuides and highlightActiveIndent instead. They are different from the built in ones in that they are independent, meaning you can choose to have active indent highlighted while the guides generally are not rendered (this is the default, even).

Automatic Parameter Hints Poppup

Calva has helpful parameter hints to aid when typing function calls. They look like so:

image

To have the hints automatically pop up when you are typing, set editor.parameterHints.enabled to true in the above [clojure] scoped setting. (To call them up on demand the default VS Code keybindings are cmd+shift+space on Mac and ctrl+shift+space on Linux/Windows.)

Code Formatting

See Formatting for information on how to configure this.

Jack-in and Connect Sequences

Jack-in and Connect are very customizable through Custom Connect Sequences.

Jack-in Dependency Versions

The versions of the dependencies Calva Jack-in injects in order for the REPL session to support IDE features are configurable via the VS Code settings calva.jackInDependencyVersions. At the time of this writing the default versions are:

Dependency Version Description
nrepl 0.8.3 nREPL is the wonderful piece of software that gives Calva a structured and extensible connection to the REPL in your Clojure and ClojureScript projects.
cider-nrepl 0.25.8 cider-nrepl is middleware that extends the nREPL connection with all sorts of nice stuff that Calva uses to give you a delightful IDE experience.
cider/piggieback 0.5.2 Piggieback is used to create nREPL sessions in ClojureScript projects. (Not with shadow-cljs projects though, which provides its own middleware for this.)

Key bindings

Most of Calva's commands have default keybindings. They are only defaults, though, and you can change keybindings as you wish. To facilitate precision in binding keys Calva keeps some when clause contexts updated.

When Clause Contexts

The following contexts are available with Calva:

  • calva:keybindingsEnabled: a master switch that you find in the settings
  • paredit:keyMap: strict, original, or none from the corresponding Calva setting (see Paredit)
  • calva:connected: true when Calva is connected to a REPL (there is also calva:connecting || calva:launching)
  • calva:outputWindowActive: true when the Output/REPL window has input focus
  • calva:replHistoryCommandsActive: true when the cursor is in the Output/REPL window at the top level after the last prompt
  • calva:outputWindowSubmitOnEnter: true when the cursor is adjacent after the last top level form in the Output/REPL window
  • calva:cursorInString: true when the cursor/caret is in a string or a regexp
  • calva:cursorInComment: true when the cursor is in, or adjacent to a line comment
  • calva:cursorBeforeComment: true when the cursor is adjacent before a line comment
  • calva:cursorAfterComment: true when the cursor is adjacent after a line comment
  • calva:cursorAtStartOfLine: true when the cursor is at the start of a line including any leading whitespace
  • calva:cursorAtEndOfLine: true when the cursor is at the end of a line including any trailing whitespace
  • calva:showReplUi: false when Calva's REPL UI is disabled through the corresponding setting

Some Custom Bindings

Here is a collection of custom keybindings from here and there.

Are you a vim extension user? See: Using with VIM extension.

Move by word

By default Calva changes the move-by-word key bindings to move by sexpr/form when the cursor is in structural Clojure code. Within line comments the editor default word movement is active.

If you want the VS Code default word movement shortcuts, use these settings:

    {
        "key": "ctrl+right",
        "win": "ctrl+right",
        "mac": "alt+right",
        "command": "cursorWordRight"
    },
    {
        "key": "ctrl+left",
        "win": "ctrl+left",
        "mac": "alt+left",
        "command": "cursorWordLeft"
    },
    {
        "key": "ctrl+right",
        "mac": "ctrl+right",
        "win": "alt+right",
        "command": "paredit.forwardSexp",
        "when": "calva:keybindingsEnabled && editorTextFocus && editorLangId == 'clojure' && paredit:keyMap =~ /original|strict/"
    },
    {
        "key": "ctrl+left",
        "mac": "ctrl+left",
        "win": "alt+left",
        "command": "paredit.backwardSexp",
        "when": "calva:keybindingsEnabled && editorTextFocus && editorLangId == 'clojure' && paredit:keyMap =~ /original|strict/"
    }

Use it as an inspiration for customizing things to your own liking. 😄

Wrap using (, [, { (like Cursive)

Something I use in IntelliJ/Cursive is the ability to select an expression and hit one of (, [, { to wrap it. And after wrapping the expression I don't want the selection anymore, so if I were wrapping (foo) then I would want to get ( | (foo)) where | would be my cursor.

Here's how you can make this work with Calva Paredit: Update all of the Paredit: Wrap Around ... commands so that their respective shortcuts are the wrappers themselves and update the when clause to include editorHasSelection (otherwise when you open a paren the next expression would get slurped in).

The change would look like this in your keybindings.json:

    {
        "key": "shift+9",
        "command": "paredit.wrapAroundParens",
        "when": "editorTextFocus && editorHasSelection && !editorReadOnly && editorLangId =~ /clojure|scheme|lisp/ && paredit:keyMap =~ /original|strict/"
    },
    {
        "key": "[",
        "command": "paredit.wrapAroundSquare",
        "when": "editorHasSelection && editorTextFocus && !editorReadOnly && editorLangId =~ /clojure|scheme|lisp/ && paredit:keyMap =~ /original|strict/"
    },
    {
        "key": "shift+[",
        "command": "paredit.wrapAroundCurly",
        "when": "editorHasSelection && editorTextFocus && !editorReadOnly && editorLangId =~ /clojure|scheme|lisp/ && paredit:keyMap =~ /original|strict/"
    }