Architecture

Overview

DWN is written in ANSI C (C99) and follows a modular single-responsibility architecture. A global DWNState singleton manages all state, and the main event loop dispatches X11 events to specialized modules.

Directory Structure

dwn/
├── src/                  # Source files (.c)
│   ├── main.c           # Entry point, event loop
│   ├── client.c         # Window management
│   ├── workspace.c      # Virtual desktops
│   ├── layout.c         # Tiling algorithms
│   ├── decorations.c    # Title bars, borders
│   ├── panel.c          # Top/bottom panels
│   ├── systray.c        # System tray widgets
│   ├── notifications.c  # D-Bus notifications
│   ├── atoms.c          # X11 atoms (EWMH/ICCCM)
│   ├── keys.c           # Keyboard handling
│   ├── config.c         # INI parser
│   ├── ai.c             # AI integration
│   └── util.c           # Utilities
├── include/             # Header files (.h)
├── site/                # Documentation website
├── Makefile             # Build system
├── CLAUDE.md            # AI assistant context
└── README.md            # Project readme

Core Modules

Module Dependencies

main.c (orchestrator)
    ├── client.c
    │   ├── decorations.c
    │   ├── config.c
    │   └── atoms.c
    ├── workspace.c
    │   ├── client.c
    │   ├── layout.c
    │   └── atoms.c
    ├── panel.c
    │   ├── client.c
    │   └── config.c
    ├── systray.c
    │   └── config.c
    ├── notifications.c (independent)
    ├── ai.c (independent)
    ├── autostart.c
    │   └── config.c
    └── keys.c
        └── config.c

Global State (DWNState)

All window manager state is centralized in a single DWNState structure. This simplifies state management and makes the codebase easier to understand.

typedef struct {
    Display *display;           // X11 connection
    Window root;                // Root window
    int screen;                 // Default screen
    Client *clients[MAX_CLIENTS];   // All managed windows
    int client_count;
    Workspace workspaces[MAX_WORKSPACES];  // Virtual desktops
    int current_workspace;
    Panel top_panel;
    Panel bottom_panel;
    Config config;              // User configuration
    KeyBinding keys[MAX_KEYBINDINGS];
    // EWMH atoms
    Atom atoms[ATOM_COUNT];
} DWNState;
extern DWNState *dwn;  // Global singleton

Event Loop

DWN uses a traditional X11 event loop with XNextEvent. Events are dispatched to appropriate handlers based on type.

int main(int argc, char *argv[]) {
    dwn_init();           // Initialize X11, atoms, config
    setup_keybindings();  // Register keyboard shortcuts
    setup_panels();       // Create panel windows
    XEvent event;
    while (running) {
        XNextEvent(dwn->display, &event);
        switch (event.type) {
            case MapRequest:
                handle_map_request(&event.xmaprequest);
                break;
            case UnmapNotify:
                handle_unmap_notify(&event.xunmap);
                break;
            case KeyPress:
                handle_key_press(&event.xkey);
                break;
            case ButtonPress:
                handle_button_press(&event.xbutton);
                break;
            case ConfigureRequest:
                handle_configure_request(&event.xconfigurerequest);
                break;
            // ... more event types
        }
    }
    dwn_cleanup();
    return 0;
}

Key Constants

Coding Conventions

void client_focus(Client *c) {
    if (!c) return;
    // Unfocus previous
    if (dwn->focused && dwn->focused != c) {
        client_unfocus(dwn->focused);
    }
    dwn->focused = c;
    XSetInputFocus(dwn->display, c->window, RevertToPointerRoot, CurrentTime);
    XRaiseWindow(dwn->display, c->frame);
    decorations_update(c);
    atoms_set_active_window(c->window);
}

EWMH/ICCCM Support

DWN implements key Extended Window Manager Hints and ICCCM protocols for compatibility with modern applications.

Build System

DWN uses a simple Makefile-based build system with pkg-config for dependency detection.

Contributing

Contributions are welcome! Here's how to get started: