SimpleText

A lightweight, native macOS plaintext editor. No rich formatting — just fast, clean text editing.

Features

• Tabs — Cmd+T new tab, Cmd+W close tab, File → Close All Tabs; drag to reorder; right-click for "Close Tabs to the Right" / "Close Other Tabs"; closing the last tab opens a fresh blank tab (window stays open)
• Line numbers with automatic gutter width
• Dark / light mode toggle (Cmd+Shift+D) — independent of system setting
• Remove blank lines (Edit menu)
• Syntax highlighting — VS Code Dark+/Light+ color scheme for Swift, Python, JavaScript, TypeScript, JSON, HTML, CSS, Bash, Go, Rust, Java, Ruby, YAML, PowerShell, and more; Markdown uses a dedicated regex highlighter for accurate inline rendering
• Native find bar with Next / Previous / case-sensitive / Replace (Cmd+F)
• Font size zoom (Cmd+= / Cmd+-) — persists across launches
• Status bar — version number (bottom-left), live line/column/word/character count (bottom-right)
• Print (Cmd+P)
• Undo / Redo — word-boundary granularity (one undo step per word), isolated per tab
• Session recovery — all open tabs (unsaved or modified) persist between app launches, restoring your exact tab layout and content
• Window position & size memory — remembers your window layout on relaunch
• Background mode — closing the window hides the app instead of quitting
• Opens files via command-line arguments, Finder (double-click / "Open With…"), drag onto Dock icon, or drag-and-drop directly into the app window

Keyboard Shortcuts

Action	Shortcut
New Tab	Cmd+T
Open…	Cmd+O
Save	Cmd+S
Save As…	Cmd+Shift+S
Close Tab	Cmd+W
Undo	Cmd+Z
Redo	Cmd+Shift+Z
Cut	Cmd+X
Copy	Cmd+C
Paste	Cmd+V
Select All	Cmd+A
Find…	Cmd+F
Find Next	Cmd+G
Find Previous	Cmd+Shift+G
Toggle Dark Mode	Cmd+Shift+D
Zoom In	Cmd+=
Zoom Out	Cmd+-
Reset Zoom	Cmd+0
Print…	Cmd+P
Quit	Cmd+Q

Usage Notes

Background mode: Clicking the red X hides the window — the app keeps running in the Dock. To fully quit, use Cmd+Q or SimpleText → Quit SimpleText.

Session recovery: All tabs (saved and unsaved) are automatically persisted to ~/Library/Application Support/SimpleText/session.json and restored on next launch. The selected tab index is also restored. Use Edit → "Clear Unsaved Buffer" to wipe the recovery state if needed.

Save prompts: When closing a tab (Cmd+W) or using "Close Tabs to the Right" / "Close Other Tabs", you'll be prompted to save if the tab has a named file with unsaved changes, or if an untitled tab has content. Empty or clean tabs close without a prompt. Cmd+Q prompts for all unsaved named files before quitting.

Undo: Each tab has its own isolated undo stack. Undo steps at word boundaries — each word is a single undo step, matching TextEdit behavior.

Installation

1. Download SimpleText.app.zip from the latest release, or build from source
2. Unzip and drag SimpleText.app to /Applications
3. Launch from Finder or Spotlight

Note: Because SimpleText is not notarized, macOS may show "cannot be opened because it is from an unidentified developer." Right-click (or Ctrl-click) the app and choose Open to bypass this once.

Requirements

• macOS 13+
• Xcode Command Line Tools (xcode-select --install) — for building from source only

Building from Source

Run directly (development)

swift run
swift run SimpleText /path/to/file.txt   # open a specific file

Build a .app bundle

./build.sh
open build/SimpleText.app

The .app is written to build/SimpleText.app. You can drag it to /Applications.

Open in Xcode

open Package.swift

Architecture

Built with Swift + AppKit, structured for future cross-platform portability:

File	Role
TextEngine.swift	Pure Swift text logic — no AppKit, portable to other platforms
RecoveryBuffer.swift	Auto-saves full session (all tabs) to ~/Library/Application Support/SimpleText/session.json
EditorView.swift	NSScrollView + NSTextView with LineNumberRulerView as a sibling view; StatusBarView anchored at the bottom; intercepts file-URL drags to open in a new tab instead of inserting text
LineNumberRulerView.swift	Custom NSView line number gutter with dynamic width; sibling to the scroll view
TabBarView.swift	Chrome-style tab bar with pill-shaped active tabs; drag-to-reorder with animation; right-click context menu
TabController.swift	Manages multiple editor tabs; routes Finder file opens without losing current work; prompts to save on close (named files and untitled buffers with content); bulk close ("Close Tabs to the Right" / "Close Other Tabs") processes tabs one at a time
DocumentController.swift	File I/O (open, save, new) and recovery buffer integration
AppearanceManager.swift	Dark / light mode toggle via window.appearance override
EditorViewController.swift	Central coordinator; owns UI subviews and handles menu actions
WindowController.swift	Window lifecycle; hides on close (background mode)
AppDelegate.swift	App lifecycle and programmatic menu bar construction
SyntaxHighlighter.swift	Markdown syntax highlighting (regex-based, VS Code–matched colors); uses NSLayoutManager temporary attributes (not undo-tracked)
HighlightCoordinator.swift	Wraps Neon's TextViewHighlighter for Tree-sitter–based syntax highlighting of all non-Markdown languages
LanguageRegistry.swift	Maps file extensions to lazily-loaded LanguageConfiguration objects (15+ languages)
HighlightTheme.swift	Maps tree-sitter capture names to VS Code Dark+/Light+ colors