PlainMD

A simple and elegant Markdown Viewer built with Qt6.

PlainMD is partially vibe-coded with OpenCode: Kimi K2.5 Turbo / Kimi K2.6 🤖

Features

• Native Qt6 markdown rendering - Fast, native rendering without external dependencies
• File browser sidebar - Browse and open markdown files with a tree view
• Multiple format support - Markdown (.md), MDX (.mdx), and plain text (.txt)
• Drag and drop support - Open files and folders by dragging them into the window
• Recent files & folders - Quick access to recently opened files and folders with separate history and privacy toggles
• Auto-reload on file change - Detects external file modifications and prompts to reload
• Manual reload - Force a refresh of the current file with F5 (useful when auto-reload is missed or you want to clear caches)
• File tree / Sidebar - Show/hide sidebar with F9 or status bar button. Right-click any file to copy its path or reveal it in Explorer/File Manager. Right-click any folder to copy its path or open it in Explorer
• Zen Mode - Distraction-free reading at the press of F11. Hides sidebar, toolbar, status bar, and menu bar for a pure document view. Press F11 again or Escape to restore everything exactly as it was
• Navigation History - Go back and forward through recently viewed files with Alt+← / Alt+→ or toolbar buttons. Session-only (never saved to disk). Optional privacy toggle in Preferences
• Document Outline - Left QTabWidget (tabs at bottom) with Files/Outline panes. Outline scans headings from the rendered document and shows them hierarchically; click any heading to jump to it in the document
• Minimap - Document overview with color-coded content types (images, headings, lists, links, code blocks) and viewport highlight; toggle with F10 or status bar button. Plain text (.txt) and MDX files show simplified minimap without markdown-specific coloring
• Status bar - Shows word count, zoom level, file type, encoding (auto-detected UTF-8 or ANSI), line endings (CRLF/LF), word wrap toggle, and quick-toggle buttons for file tree and minimap
• Zoom controls - Zoom in/out with Ctrl++ and Ctrl+-
• Word wrap toggle - Toggle line wrapping with Ctrl+W or status bar button
• Find/Search - Search within documents with Ctrl+F, find next with F3
• Search in Files - Search across all markdown files in the loaded folder with Ctrl+Shift+F. Shows match count per file, snippet preview, and highlights first occurrence when opened
• Print & Export - Print to physical printer or export directly to PDF (with better emoji support)
• Copy File/Folder Path - Right-click any file or folder in the sidebar to copy its full path to the clipboard (with native path separators)
• Copy Code - Right-click on code blocks or inline code to copy to clipboard with custom context menu
• Customizable fonts - Configure editor font and emoji print font
• Window title format - Choose between filename only or full path in window title
• Privacy options - Toggle external image loading, recent files/folders history, last opened file, and last opened folder memory independently
• Folder protection - Blocks opening root drives and system folders (Windows, Program Files, /usr, etc.) to prevent UI freezing; warns when opening empty folders; shows progress indicator while scanning
• URL tooltips - Hover over links to see the resolved absolute path
• YAML frontmatter display - Shows frontmatter as a code block

Screenshots

System Requirements

Windows

• Windows 10 or later (64-bit)
• Visual C++ Redistributable 2022 (most systems already have this installed)

Note: If PlainMD fails to start with a missing DLL error, install the Visual C++ Redistributable from the link above. This is a one-time system requirement.

Linux

• Qt 6.x runtime libraries
• Standard desktop environment (X11 or Wayland)

Building from Source

Prerequisites

• Qt 6.x (with Qt6Core, Qt6Gui, Qt6Widgets, Qt6Network, Qt6PrintSupport)
• C++17 compatible compiler

Windows (Visual Studio 2022)

Quick build using provided scripts:

:: Build
build.bat

:: Clean build artifacts
clean.bat

:: Deploy Qt dependencies (after building)
windeployqt release\plainmd.exe

Manual build:

:: Setup MSVC environment (or run vcvarsall.bat x64 directly)
setenv.bat

:: Generate build files and build
qmake plainmd.pro && nmake

:: Deploy Qt dependencies
windeployqt release\plainmd.exe

:: Create installer (optional, requires Inno Setup)
:: Output: dist\plainmd-<version>-x64-setup.exe
build-installer.bat

:: Create portable ZIP (optional)
:: Output: dist\plainmd-<version>-x64-portable.zip
build-zip.bat

:: All-in-one release build (optional)
:: Output: dist\plainmd-<version>-release.zip
build-release.bat

Editor integration: Build tasks are configured for Zed (.zed/tasks.json) and VS Code (.vscode/tasks.json) for integrated development.

Linux

Quick build using provided scripts:

# Build release binary
./build.sh

# Clean build artifacts
./clean.sh

Manual build:

# Install dependencies (Debian/Ubuntu)
sudo apt install qt6-base-dev build-essential

# Generate build files and build
qmake plainmd.pro && make

# Output: release/plainmd

# Create .deb package (Debian/Ubuntu, optional)
# Output: dist/plainmd_<version>_amd64.deb
./build-deb.sh

# Create AppImage (universal Linux, optional)
# Output: dist/plainmd-<version>-x86_64.AppImage
./build-appimage.sh

# Create Flatpak (optional, requires flatpak-builder)
# Output: dist/plainmd-<version>-<arch>.flatpak
./build-flatpak.sh

# All-in-one release build (optional)
# Output: dist/plainmd-<version>-linux-release.zip
./build-release.sh

Usage

Opening Files

• File Menu → Open File (Ctrl+O) or Open Folder (Ctrl+Shift+O)
• Drag and drop files or folders into the window
• Command line: plainmd <file.md> or plainmd <folder/>
• Double-click .md files (after file association on Windows)

Navigation

• File tree on the left shows all markdown files in the current folder
• Recent files in the File menu for quick access
• Click any file in the tree to view it instantly

Keyboard Shortcuts

Shortcut	Action
Ctrl+O	Open file
Ctrl+Shift+O	Open folder
Ctrl+F	Find in document
F3	Find next
Ctrl+Shift+F	Search in files
F5	Reload current file
F9	Toggle file tree
F10	Toggle minimap
Ctrl+W	Toggle word wrap
Ctrl+P	Print
Ctrl+Shift+P	Export to PDF
Ctrl+,	Preferences
Ctrl++	Zoom in
Ctrl+-	Zoom out
Ctrl+0	Reset zoom
Esc	Clear search highlight

Configuration

Access preferences via View → Preferences (Ctrl+,):

• Editor Font - Main text font
• Emoji Print Font - Font for emoji characters when printing (use a Nerd Font for best results)
• External Editor - Path to your preferred external editor
• Window Title - Choose between filename only or full path format
• Privacy - Toggle external image preview, recent files/folders history, last opened file, and last opened folder memory independently

Emoji Printing on Windows (Experimental)

Color emoji fonts (like Segoe UI Emoji) may not render correctly when printing to PDF. To fix this:

1. Install a Nerd Font (e.g., "CaskaydiaCove Nerd Font", "JetBrainsMono Nerd Font")
2. Open Preferences → Editor
3. Set "Emoji Print Font" to your Nerd Font
4. Check "Use for emoji printing"
5. Now emojis will print correctly as monochrome glyphs

Architecture

• Single-window desktop app - Entry: src/main.cpp → MainWindow
• Qt6 native rendering - Uses QTextEdit::setMarkdown() for rendering (no external parser)
• File system model - QFileSystemModel wrapped with FilterProxyModel for file tree
• Auto-reload - QFileSystemWatcher monitors loaded files for external changes; manual reload via F5 unconditionally re-runs loadFile()
• Document outline - Left QTabWidget (tabs at bottom) with Files/Outline panes. Outline deferred via QTimer::singleShot after setMarkdown() so Qt's async heading format assignment finishes before scanning
• Settings - QSettings (IniFormat) for preferences persistence

Project Structure

PlainMD/
├── src/                    # Source code
│   ├── main.cpp
│   ├── mainwindow.cpp/h    # Main window and UI
│   ├── preferencesdialog.cpp/h/ui # Preferences dialog
│   ├── finddialog.cpp/h/ui         # Find in document dialog
│   ├── searchindialog.cpp/h/ui       # Search in files dialog
│   ├── aboutdialog.cpp/h/ui        # About dialog with license viewer
│   ├── licensedialog.cpp/h/ui      # License viewer dialog
│   ├── minimap.cpp/h       # Document minimap widget
│   └── filterproxymodel.cpp/h      # File tree filtering
├── images/                 # Application icons (Tabler Icons)
├── samples/                # Sample markdown files
├── .zed/                   # Zed Editor configuration
│   └── tasks.json          # Build tasks for Zed
├── .vscode/                # VS Code configuration
│   └── tasks.json          # Build tasks for VS Code
├── plainmd.pro             # qmake project file
├── plainmd.qrc             # Qt resources
├── plainmd.rc              # Windows resources
├── build.sh                # Linux build script
├── clean.sh                # Linux clean script
├── build-deb.sh            # Debian package builder (outputs to dist/)
├── install-deb.sh          # Debian install helper
├── uninstall-deb.sh        # Debian uninstall helper
├── build-appimage.sh       # AppImage builder (outputs to dist/)
├── build-flatpak.sh        # Flatpak builder (outputs to dist/)
├── uninstall-flatpak.sh    # Remove Flatpak from system
├── build-release.sh        # Linux all-in-one release pipeline
├── make-checksums.sh       # Generate SHA256 checksums (Linux)
├── archive-release.sh      # Create versioned archive of dist/ (Linux)
├── build.bat               # Windows build script
├── clean.bat               # Windows clean script
├── setenv.bat              # Set up MSVC environment
├── build-installer.bat     # Windows installer builder (outputs to dist/)
├── build-zip.bat           # Windows portable ZIP builder (outputs to dist/)
├── build-release.bat       # Windows all-in-one release pipeline
├── make-checksums.bat      # Generate SHA256 checksums (Windows)
├── archive-release.bat     # Create versioned archive of dist/ (Windows)
├── dist/                   # Distribution packages (.exe, .zip, .deb, .AppImage, .flatpak, .sha256)
├── installer.iss           # Inno Setup installer script
├── eu.brainbytez.plainmd.yaml # Flatpak manifest
├── .gitattributes          # Git line ending rules (for WSL/cross-platform dev)
├── README.md               # User documentation
└── AGENTS.md               # Developer documentation

License

GPLv3 License - See LICENSE file for details.

Acknowledgments

• Icons by Tabler Icons (MIT License)
• Built with Qt6

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Happy markdown viewing! 📄✨