Creating a window manager for Linux

25
votes

I want to create a simple stacking window manager (in C) for private use, mainly for the purpose of learning and challenging myself.

I've looked through twm's source code which has relatively few bells and whistles but it seems very low level since it's not based on a widget toolkit.1 Would using a toolkit such as GTK+ be preferable? I'm afraid that some of the code and libraries in twm might be too antiquated (edit: deprecated) and I want the window manager to use relatively modern libraries. For the sake of understanding I would also be interested in suggestions how to start a window manager from scratch — there aren't many tutorials for this purpose.

Update: For those thinking of similar projects: I ended up using Common Lisp and the CLX library. tinywm-lisp served as a basis and the brilliant CLFSWM and Stumpwm were a great help. For reference I used the CLX — Common LISP X Interface (PDF warning) and #xlib on Freenode.

8
clinuxx11window-managerswindow-management
Widgets basically live inside windows, so most of what a window manager does can't depend on widgets. – Jerry Coffin
I though so, that's why I referenced Wikipedia that; “[twm is] written in C directly against Xlib rather than based on a widget toolkit.” I assumed that meant more modern window managers are based on widget toolkits. – Iceland_jack
For some reason this question made me think of this... – Brian Nixon

8 Answers

24
votes

Whatever you do, use XCB and not Xlib. It' modern, asynchronous, simpler and gives you direct access to the X11 protocol.

9
votes

I've written an in-depth tutorial series that shows you how to write an X11 window manager in C++:

In addition, you can check out a simple example window manager, basic_wm, at

It's heavily commented for pedagogical purposes.

On Xlib vs XCB - I would recommend Xlib over XCB if you're first starting out. XCB is more efficient, but it's much more low-level and much more verbose (think assembly language for the GUI). You don't want to burden yourself with premature optimization until you already have a prototype working.

6
votes

A very minimalistic WM is wm2. I haven't read the source code and hence I don't know if it is a teaching example. Of course you can use libraries that already do much of the abstraction and drawing work for you like gdk and gtk. But since this project is only for personal learning, I'd go the hard way and use Xlib directly.

Here are some links that might be useful for you:

6
votes

Have a look at the code for dwm. The codebase is beautiful and easy to understand. The entire thing is about 2000 lines.

2
votes

http://code.google.com/p/partiwm/ is an attempt to write a window manager (tiling, not stacking) from scratch, it might be useful to you to read through the code.

2
votes

metacity uses gtk for certain UI elements. See its HACKING and README.

see also Where are some good Xlib programming guides?

2
votes

For the sake of understanding I would also be interested in suggestions how to start a window manager from scratch

You may want to have a look at the aewm window manager. The code is small and it does the basics quite well. It's written in C and uses Xlib.

http://www.red-bean.com/decklin/aewm/

0
votes

Xmonad might be a good place to start.