fce-enhanced

An enhanced Flet CodeEditor control with file I/O, search/replace, syntax highlighting, and theme selection.

Built on top of flet-code-editor, adding a full-featured editing experience you can drop into any Flet app or run standalone. This project was created to explore and showcase what's possible with Flet — building a desktop-quality code editor entirely in Python.

Install

pip install fce-enhanced

Or with uv:

uv add fce-enhanced

Development setup

git clone https://github.com/oktl/flet-fce-enhanced.git
cd flet-fce-enhanced
uv sync
source .venv/bin/activate
pre-commit install  # optional, for development

Usage

Run as a standalone app

uvx fce-enhanced                     # open with an empty editor
uvx fce-enhanced path/to/file.py     # open a specific file on launch

During development:

flet run src/fce_enhanced/editor.py                     # open with an empty editor
flet run src/fce_enhanced/editor.py path/to/file.py     # open a specific file on launch

Embed in your own Flet app

EnhancedCodeEditor is a standard ft.Column subclass — add it to any Flet page or layout just like any other control.

Minimal example

import flet as ft
from fce_enhanced import EnhancedCodeEditor


def main(page: ft.Page):
    page.title = "My Editor"
    editor = EnhancedCodeEditor(expand=True)
    page.add(editor)


ft.run(main)

With configuration

import flet as ft
import flet_code_editor as fce
from fce_enhanced import EnhancedCodeEditor


def main(page: ft.Page):
    page.title = "My Editor"

    def on_title_change(display_path, name, is_dirty):
        page.title = f"{name}{'*' if is_dirty else ''} — My Editor"
        page.update()

    editor = EnhancedCodeEditor(
        language=fce.CodeLanguage.JAVASCRIPT,
        value="console.log('hello');",
        code_theme=fce.CodeTheme.MONOKAI,
        on_title_change=on_title_change,
        ruff_on_save=False,  # disable ruff (only applies to Python files)
        expand=True,
    )
    page.add(editor)


ft.run(main)

Constructor parameters

Parameter	Type	Default	Description
language	CodeLanguage	PLAINTEXT	Initial syntax highlighting language
value	str	"# New file\n"	Initial editor content
show_toolbar	bool	True	Show the file I/O toolbar
show_status_bar	bool	True	Show the line/column status bar
show_gutter	bool	True	Show the line-number gutter
register_keyboard_shortcuts	bool	True	Register global keyboard shortcuts
autocomplete	bool	True	Enable autocomplete
autocomplete_words	list[str]	None	Custom autocomplete suggestions
code_theme	CodeTheme	ATOM_ONE_DARK	Syntax highlighting theme
text_style	TextStyle	None	Text style for editor content
gutter_style	GutterStyle	None	Style for the line number gutter
on_title_change	callable	None	Callback (display_path, name, is_dirty) — fires on file open/close, save, and dirty-state changes. display_path is the home-relative path (e.g. ~/projects/foo.py) or "untitled".
ruff_on_save	bool	True	Auto-format Python files with ruff on save

Any additional keyword arguments are passed through to ft.Column.

Useful properties

editor.value           # current editor content (str)
editor.current_path    # path of open file, or None
editor.dirty           # True if there are unsaved changes
editor.language        # current CodeLanguage
editor.code_editor     # the underlying fce.CodeEditor control
editor.search_bar      # the SearchReplaceBar control

Other public exports

The package also exports these utilities from fce_enhanced:

Export	Description
SearchReplaceBar	Reusable search/replace control
open_file() / save_file()	Async platform-aware file dialogs
language_for_path()	Detect CodeLanguage from a file path
EXTENSION_TO_LANGUAGE	Dict mapping file extensions to CodeLanguage
THEMES / DEFAULT_THEME / theme_display_name()	Theme utilities
main() / run()	Entry points for standalone mode

Features

• File operations — Open, Save, Save As, Close, and Revert to Saved with unsaved-changes confirmation
• Native file dialogs — AppleScript dialogs on macOS (with extension filtering), Flet's built-in FilePicker on other platforms
• Search & Replace — Find toolbar with match counting, case sensitivity toggle, whole word matching, prev/next navigation (Enter navigates to next match), Replace and Replace All
• Command Palette — Searchable list of all available commands; type to filter (Cmd+Shift+P / Ctrl+Shift+P)
• Theme Selector — 80+ built-in syntax highlighting themes via a searchable dialog (type to filter)
• Go to Line — Jump to a specific line number (Cmd+G / Ctrl+G)
• Read-Only Mode — Toggle editing lock (Cmd+L / Ctrl+L)
• Font Size Controls — Increase/decrease font size (Cmd+= / Cmd+-)
• Language Selector — Choose syntax highlighting language from a searchable dialog (type to filter); auto-detected on file open, and Save As defaults to the matching file extension
• Language Detection — Automatic syntax highlighting for 40+ file extensions
• Dirty-File Tracking — Visual indicator for unsaved changes
• Diff Pane — Toggleable unified diff view showing changes since last save, with green/red syntax coloring (Cmd+D / Ctrl+D)
• Gutter Toggle — Show or hide the line-number gutter (Shift+Cmd+G / Ctrl+Shift+G)
• Ruff on Save — Auto-runs ruff check --fix and ruff format on .py files; silently skips if ruff is not installed (no error). Remaining lint warnings are shown in a snackbar, and the editor auto-reloads the formatted content. Toggleable from the toolbar
• Status Bar — Line, column, language, and selection info

Keyboard shortcuts

Action	macOS	Windows / Linux
Open File	⌘O	Ctrl+O
Save	⌘S	Ctrl+S
Save As	⇧⌘S	Ctrl+Shift+S
Close File	⌘W	Ctrl+W
Revert to Saved	⇧⌘R	Ctrl+Shift+R
Find	⌘F	Ctrl+F
Find and Replace	⌥⌘F	Ctrl+H
Toggle Diff	⌘D	Ctrl+D
Toggle Gutter	⇧⌘G	Ctrl+Shift+G
Go to Line	⌘G	Ctrl+G
Toggle Read-Only	⌘L	Ctrl+L
Increase Font Size	⌘+	Ctrl++
Decrease Font Size	⌘-	Ctrl+-
Command Palette	⇧⌘P	Ctrl+Shift+P
Help	F1	F1
Close Search Bar	Esc	Esc

Contributing

Contributions are welcome! See CONTRIBUTING.md for guidelines.

License

MIT

Development

Code style is enforced with ruff via pre-commit hooks:

pre-commit run --all-files

Run tests:

pytest

Built With

• Flet — Build multi-platform apps in Python powered by Flutter
• flet-code-editor — Code editor control for Flet with syntax highlighting
• ruff — Fast Python linter and formatter