Themes and Syntaxes

The list of selectable themes and language modes comes from two places:

1. The theme_list and syntax_list maps in ace_editor.settings, which drive the Theme and Syntax select lists in every settings form.
2. The actual theme-*.js and mode-*.js files present in your Ace library, which are auto-discovered as Drupal libraries (ace_editor/theme.<name> and ace_editor/mode.<name>) by hook_library_info_build().

At render time the module checks whether the chosen theme.<name> / mode.<name> library exists; if not, it falls back to the default theme/syntax from configuration. So selecting a theme that isn't present in your library build degrades gracefully rather than breaking the editor.

Themes (examples)

Cobalt, Ambiance, Chaos, Chrome, Clouds, Crimson Editor, Dawn, Dreamweaver, Eclipse, GitHub, Idle Fingers, Katzenmilch, Kuroir, Merbivore, Mono Industrial, Monokai, Pastel On Dark, Solarized Dark, Solarized Light, SQL Server, Terminal, TextMate, Tomorrow Night (and variants), Twilight, Vibrant Ink, Xcode, …

Syntaxes (examples)

HTML, PHP, JavaScript, JSON, CSS, SCSS, LESS, YAML, Twig, Markdown, SQL, Bash, C/C++, C#, Java, Python, Ruby, Rust, Go, TypeScript, JSX/TSX, XML, Dockerfile, Diff, INI, Properties, Plain Text, … and many more.

The complete shipped lists are defined in config/install/ace_editor.settings.yml. To expose additional themes/modes, ensure the corresponding theme-*.js / mode-*.js files exist in your Ace library and that the name appears in the relevant list.