unity8-team

In previous posts I’ve alluded to the ecosystem of projects developed to support Unity8. While I have come across most of them during my time with Canonical I wouldn’t be confident of creating a complete list.

But some of the Unity8 developers (mostly Pete Woods) have been working to make it easy to identify these projects. They have been copied onto github:

https://github.com/unity8-team

This is simply a snapshot for easy reference, not the start of another fork.

The end of a dream?

We read in the press that Canonical has pulled out of the dream of “convergence”. With that the current support for a whole family of related projects dies.

That doesn’t mean that the dream has to die, but it does mean changes.

I hope the dream doesn’t die, because Canonical has done a lot of the “heavy lifting” – the foundations are laid, the walls are up, we have windows, plumbing and power. But we’re lacking the paintwork and there’s no buyer.

My expertise is developing working software and I’m going to donate some of that to the dream.

Stable Intermediate Forms is an important principle – keep things working while making changes. If you throw away a large chunk intending to replace it you’ll find re-integration really, really hard. Do things gradually!

So, don’t simply fork Unity8 and plan to get it working on Wayland. You’ll end up with a single wall that falls over before you’ve replaced the rest of the building. (Sorry, I went back to “metaphor”.)

Take the whole infrastructure etc. and keep it in place until any replacements are demonstrably ready.

The Elephant in the room

Many have issues with the way Mir has been presented to the community, but in the opinion of the developers it is a good piece of software and not inherently incompatible with Wayland. (Just look at what the developers have written about it especially the early posts that addressed this directly.)

There are two plausible evolutions of the dream that reconcile Mir with Wayland.

Plan 1: (my recommendation) Add support to libmirserver for Wayland clients in parallel to the existing protocol. Once this is working this either junk libmirclient or rework its interaction with libmirserver.

Plan 2: Implement an analog of QtMir/MirAL on your choice of Wayland server. Then transition Unity8 to these and junk Mir.

I can’t guarantee that my recommendation of “plan 1” isn’t biased by my history with the Mir project, clearly I know its potential better than that of competing projects and I would find developing these easier than someone new to the code. In then end, the choice will depend on who takes on the work and what they can achieve most effectively.

MirAL 1.3.2

There’s a bugfix MirAL release (1.3.2) available in ‘Zesty Zapus’ (Ubuntu 17.04) and the so-called “stable phone overlay” ppa for ‘Xenial Xerus’ (Ubuntu 16.04LTS). MirAL is a project aimed at simplifying the development of Mir servers and particularly providing a stable ABI and sensible default behaviors.

The bugfixes in 1.3.2 are:

In libmiral a couple of “fails to build from source” fixes:

Fix FTBFS against Mir < 0.26 (Xenial, Yakkety)

Update to fix FTBFS against lp:mir (and clang)

In the miral-shell example, a crash fixed:

With latest zesty’s libstdc++-6-dev miral-shell will crash when trying to draw its background text. (LP: #1677550)

Some of the launch scripts have been updated to reflect a change to the way GDK chooses the graphics backend:

change the server and client launch scripts to avoid using the default Mir socket (LP: #1675794)

Update miral-xrun to match GDK changes (LP: #1675115)

In addition a misspelling of “management” has been corrected:

miral/set_window_management_policy.h

miral gets cut & paste

For some time now I’ve been intending to investigate the cut & paste mechanisms in the Unity8/Mir stack with the intention of ensuring they are supported in MirAL.

I’ve never had the time to do this, so I was surprised to discover that cut & paste is now working! (At least on Zesty.)

I assume that this is piggy-backing off the support being added to enable the “experimental” Unity8 desktop session, so I hope that this “magic” continues to work.

MirAL 1.3.1

There’s a bugfix MirAL release (1.3.1) available in ‘Zesty Zapus’ (Ubuntu 17.04) and the so-called “stable phone overlay” ppa for ‘Xenial Xerus’ (Ubuntu 16.04LTS). MirAL is a project aimed at simplifying the development of Mir servers and particularly providing a stable ABI and sensible default behaviors.

Unsurprisingly, given the project’s original goal, the ABI is unchanged.

The bugfixes in 1.3.1 are:

In libmiral a focus management fix:

When a dialog is hidden ensure that the active window focus goes to the parent. (LP: #1671072)

In the miral-shell example, two crashes fixed:

If a surface is deleted before its decoration is painted miral-shell can crash, or hang on exit (LP: #1673038)

If the specified “titlebar” font doesn’t exist the server crashes (LP: #1671028)

In addition a misspelling of “management” has been corrected:

SetWindowManagmentPolicy => SetWindowManagementPolicy

MirAL 1.3

There’s a new MirAL release (1.3.0) available in ‘Zesty Zapus’ (Ubuntu 17.04) and the so-called “stable phone overlay” ppa for ‘Xenial Xerus’ (Ubuntu 16.04LTS). MirAL is a project aimed at simplifying the development of Mir servers and particularly providing a stable ABI and sensible default behaviors.

Unsurprisingly, given the project’s original goal, the ABI is unchanged.

The changes in 1.3.0 fall are:

Support for “workspaces”

This is part of the enabling “workspaces” for Unity8 desktop. MirAL doesn’t provide fancy transitions and spreads, but you can see some basic workspace switching in the miral-shell example program:

$ apt install miral-examples
$ miral-app

There are four workspaces (corresponding to F1-F4) and you can switch using Meta-Alt-[F1|F2|F3|F4], or switch taking the active application to the new workspace using Meta-Ctrl-[F1|F2|F3|F4].

Support for “previous window in application”

You can now use Alt-Shift-` to switch to the previous in an application.

miral-shell adds a background

miral-shell now uses its background for a handy guide to the available keyboard shortcuts.

Bug fixes

Two bug fixes related to shutdown problems: one deals with a possible race in libmiral code, the other works around a bug in Mir.

  • [libmiral] Join internal client threads before server shutdown (LP: #1668651)
  • [miral-shell] Workaround for crash on exit (LP: #1667645)

miral-workspaces

“Workspaces” have arrived on MirAL trunk (lp:miral).

We won’t be releasing 1.3 with this feature just yet (as we want some experience with this internally first). But if you build from source there’s an example to play with (bin/miral-app).

As always, bug reports and other suggestions are welcome.

Note that the miral-shell doesn’t have transitions and other effects like fully featured desktop environments.

MirAL 1.2

There’s a new MirAL release (1.2.0) available in ‘Zesty Zapus’ (Ubuntu 17.04) and the so-called “stable phone overlay” ppa for ‘Xenial Xerus’ (Ubuntu 16.04LTS). MirAL is a project aimed at simplifying the development of Mir servers and particularly providing a stable ABI and sensible default behaviors.

Unsurprisingly, given the project’s original goal, the ABI is unchanged.

Since my last update the integration of libmiral into QtMir has progressed and libmiral has been used in the latest updates to Unity8.

The changes in 1.2.0 fall are:

A new libmirclientcpp-dev package

This is a “C++ wrapper for libmirclient” and has been split
from libmiral-dev.

Currently it comprises RAII wrappers for some Mir client library types: MirConnection, MirWindowSpec, MirWindow and MirWindowId. In addition, the WindowSpec wrapper provides named constructors and function chaining to enable code like the following:

auto const window = mir::client::WindowSpec::
    for_normal_window(connection, 50, 50, mir_pixel_format_argb_8888)
    .set_buffer_usage(mir_buffer_usage_software)
    .set_name(a_window.c_str())
    .create_window();

Refresh the “Building and Using MirAL” doc

This has been rewritten (and renamed) to reflect the presence of MirAL in the Ubuntu archives and make installation (rather than “build it yourself”) the default approach.

Bug fixes

  • [libmiral] Chrome-less shell hint does not work any more (LP: #1658117)
  • “$ miral-app -kiosk” fails with “Unknown command line options:
    –desktop_file_hint=miral-shell.desktop” (LP: #1660933)
  • [libmiral] Fix focus and movement rules for Input Method and Satellite
    windows. (LP: #1660691)
  • [libmirclientcpp-dev] WindowSpec::set_state() wrapper for mir_window_spec_set_state()
    (LP: #1661256)

mircade-snap

mircade, miral-kiosk and snapcraft.io

mircade is a proof-of-concept game launcher for use with miral-kiosk. It looks for installed games, works out if they use a toolkit supported by Mir and allows the user to play them.

miral-kiosk is a proof-of-concept Mir server for kiosk style use. It has very basic window management designed to support a single fullscreen application.

snapcraft.io is a packaging system that allows you to package applications (as “snaps”) in a way that runs on multiple linux distributions. You first need to have snapcraft installed on your target system (I used a dragonboard with Ubuntu Core as described in my previous article).

The mircade snap takes mircade and a few open games from the Ubuntu archive to create an “arcade style” snap for playing these games.

Setting up the Mir snaps

The mircade snap is based on the “Mir Kiosk Snaps” described here.

Mir support on Ubuntu Core is currently work in progress so the exact incantations for installing the mir-libs and mir-kiosk snaps to work with mircade varies slightly from the referenced articles (to work around bugs) and will (hopefully) change in the near future. Here’s what I found works at the time of writing:

$ snap install mir-libs --channel edge
$ snap install mir-kiosk --channel edge --devmode
$ snap connect mir-kiosk:mir-libs mir-libs:mir-libs
$ sudo reboot

Installing the mircade-snap

I found that installing the mircade snap sometimes ran out of space on the dragonboard /tmp filesystem. So…

$ TMPDIR=/writable/ snap install mircade --devmode --channel=edge
$ snap connect mircade:mir-libs mir-libs:mir-libs
$ snap disconnect mircade:mir;snap connect mircade:mir mir-kiosk:mir
$ snap disable mircade;sudo /usr/lib/snapd/snap-discard-ns mircade;snap enable mircade

Using mircade on the dragonboard

At this point you should see an orange screen with the name of a game. You can change the game by touching/clicking the top or bottom of the screen (or using the arrow keys). Start the current game by touching/clicking the middle of the screen or pressing enter.

MirAL 1.0

There’s a new MirAL release (1.0.0) available in ‘Zesty Zapus’ (Ubuntu 17.04) and the so-called “stable phone overlay” ppa for ‘Xenial Xerus’ (Ubuntu 16.04LTS). MirAL is a project aimed at simplifying the development of Mir servers and particularly providing a stable ABI and sensible default behaviors.

Surprisingly, given the project’s original goal, the ABI is changed. This allowed us to address a couple of minor issues and the timing seemed good as downstreams are faced with Mir-0.25 moving some necessary APIs from libmircommon to the more ABI stable libmircore.

The changes in 1.0.0 are:

  1. The default movement of child windows can be overridden by the window management policy;
  2. A new “miral-app” script that runs the miral example servers as an application on an existing desktop;
  3. Bug fix LP: #1646431 “Examples fail to start under Unity8”;
  4. Bug fix LP: #1646735 “[miral-shell –window-manager tiling] windows are not correctly constrained to tiles”; and
  5. A couple of deprecated APIs have been removed.