kryndex / swc

A library for making a simple Wayland compositor

swc

swc is a small Wayland compositor implemented as a library.

It has been designed primary with tiling window managers in mind. Additionally, notable features include:

• Easy to follow code base
• XWayland support
• Can place borders around windows

Dependencies

• wayland
• wayland-protocols
• libdrm
• libinput (see my libinput repository if you don't want the libudev dependency)
• libxkbcommon
• pixman
• wld
• linux[>=3.12] (for EVIOCREVOKE)

For input hotplugging, the following is also required:

• libudev

For XWayland support, the following are also required:

• libxcb
• xcb-util-wm

Implementing a window manager using swc

You must implement two callback functions, new_window and new_screen, which get called when a new window or screen is created. In new_window, you should allocate your own window window structure, and register a listener for the window's event signal. More information can be found in swc.h.

static void new_window(struct swc_window * window)
{
    /* TODO: Implement */
}

static void new_screen(struct swc_screen * screen)
{
    /* TODO: Implement */
}

Create a struct swc_manager containing pointers to these functions.

static const struct swc_manager manager = { &new_screen, &new_window };

In your startup code, you must create a Wayland display.

display = wl_display_create();

Then call swc_initialize.

swc_initialize(display, NULL, &manager);

Finally, run the main event loop.

wl_display_run(display);

An example window manager that arranges it's windows in a grid can be found in example/, and can be built with make example.

Why not write a Weston shell plugin?

In my opinion the goals of Weston and swc are rather orthogonal. Weston seeks to demonstrate many of the features possible with the Wayland protocol, with various types of backends and shells supported, while swc aims to provide only what's necessary to get windows displayed on the screen.

I've seen several people look at Wayland, and ask "How can I implement a tiling window manager using the Wayland protocol?", only to be turned off by the response "Write a weston shell plugin". Hopefully it is less intimidating to implement a window manager using swc.

How can I try out swc?

If you are not interested in developing your own window manager, check out my swc-based window manager, velox.

TODO

• XWayland copy-paste integration.
• Better multi-screen support, including mirroring and screen arrangement.
• DPMS support.
• Floating window Z-ordering.
• Full-screen composite bypass.
• Atomic modesetting support.

Contact

If you have questions or want to discuss swc feel free to join #swc on freenode.

Related projects

Since swc's creation, several other projects with similar goals have been created.

• wlc and loliwm
• waysome