egmde: a project that uses Mir
by Alan Griffiths on 19 November 2018
Display servers solve a large and complex problem. Mir provides a broad and powerful library to solve those problems, but there is a learning curve to use Mir effectively. It is really helpful to have a step-by-step example that covers enough of the issues to get a decent start.
To address this need there’s a set of blog posts based around the development of “egmde” [Example Mir Desktop Environment]: a very simple shell that can either form the basis of further development or provide a platform for experimentation. Note that egmde is not a complete desktop: the tutorials (and the code in egmde) don’t cover aspects of a desktop environment that are not related to using Mir. Missing functionality includes: integrating into the system for screen locking & suspend, policy kit integration, internationalization, etc.
Usage of egmde
There are currently five articles based around egmde:
- Wayland reboot: a Mir server that supports Wayland client apps.
- Keymap and wallpaper: getting the correct keymap and adding “wallpaper”.
- Integrating a launcher: adds a launcher to select and start apps.
- Desktop session: install and use as an alternative desktop.
- A touch of touch support: adds support for touch-only operation.
After following these tutorials you should have a good idea how to use the Mir libraries to develop your own desktop.
Egmde uses Mir
Mir simplifies the complexity that shell authors need to deal with. It provides a stable, well tested and performant platform with touch, mouse and tablet input, multi-display capability and secure client-server communications based on Wayland.
Mir deals with the bringup and configuration of a broad array of graphics and input hardware. It abstracts hardware differences away from shell authors (transparently dealing with hardware quirks) and integrates with system components such as greeters.
Mir window management is integrated and yet extremely customizable by shell authors using a simple high-level API.
Egmde accepts the Mir window management defaults and does the minimum needed to show how to build on that. It adds identifying the user’s keymap (from gsettings), painting a desktop background, a simple “launcher” and registering with the greeter to provide an “egmde” desktop session.