I am not a filesystem expert

Dear fsck

I am not a filesystem expert so when you said to me “filesystem has errors, please run me without -a -p options” I did that. But then you gave me some numbers asked question which I did not had a chance to understand (even Google query did not helped) so I dig for my dusted normal user hat and pressed “Enter” key. Then again and again and again and then I just looked for something heavy and put it on keyboard so you will stop interrupting and just do your work.

So can you just do what you can next time instead of asking me to keep “Enter” key like any other monkey? That heavy object was hedgehog made by my lovely daughter and I prefer to not use for things like that.

Sincerely yours, Marcin

Is designing UI simple with Qt?

I use Qt on my devices since my first LinuxPDA: Sharp Zaurus SL5000 on which I used OpenZaurus with OPIE as primary environment. It was based on Qt/Embedded 2.3.x and was looking ok. UI of most applications work properly in both portrait and landscape modes, adapted to size of fonts (I used smaller then default ones).

Then Zaurus c760 arrived at my place and I did some UI code tweaks to make everything looking better on VGA screen (not that it looked wrong — I just improved few things). At that time I had nearly every Zaurus model in hands and took care to make all looks proper in both orientations.

From time to time I was also playing with 3rdparty applications to adapt them to resolutions higher then QVGA (which was sort of standard in palmtops of that era). Usually loading UI files into Qt Designer and reordering them or adding layouts helped. One of them was Mileage which required adding huge amount of layout elements just to make it look properly (all elements were put as X,Y positions originally).

Some time later I moved to GTK/X11 based environments on portable devices and later my cellphones took PDA place.

But with Nokia N900 I decided to go back to programming with Qt – 4.6 version this time. First was my module player (which I probably never end) and some time later I decided to play a bit with Vexed released by
Paul Romanchenko (rmrfchik on #maemo) where I reorganized UI a bit, added portrait support and did few other tweaks.

But then I switched to ApMeFo and while idea of application is good the UI is disaster:

  • tabs in main window
  • lack of portrait support
  • unusable UI when forced to portrait mode
  • use of non standard button sizes
  • use of non standard font sizes

And sources lacked UI files… So one day I decided that it will be good occasion to learn something new. Author was not responding to my sources request so I launched Qt Designer and started to recreate UI from scratch — using existing sources as information what kind of widgets were used. Took me some time but I got new, a bit improved UI which even worked in portrait mode:

But it still was not what I wanted. It still had tabs and small buttons… First I got rid of tabs:

Rest of functionality was moved to menu and separate window:

I was not too proud of it. OK, it looked better, I even changed some non-UI code but it still was not what I wanted to achieve. But at least I had something what I could give to users for testing.

How does it look now? Let me show not yet published version:

First main window — all buttons are finger friendly. I also grouped them a bit — it is visible in portrait mode which is also great when user want to re-order items.

Dialog to select applications to add got some changes too. It is maybe not conform with UI style guide (OK not under but on right) but it gave me extra line in list widget. Think of multi selection…

As you see (de)activation and folders are now in menu. (De)Activation has also Yes/No requesters 🙂

Folders window is place which needs lot of work. Only delete works now (also with Yes/No requester).

List of things to do is long as users suggested many things. I probably will not add most of them because so far I did not checked how exactly ApMeFo works but once I will read rest of source code I think that something good will come from it.

And is designing UI simple with Qt? I think that it is — developer does not have to worry what kind of paddings are needed to be used, how to place widgets to make UI conform to style guide rules etc. Once you do design with layout elements application adapts itself to what is available.

Few hints for chroot users

During last months I used chroot functionality many times — mostly to test my cross compilers in clean environment. In that time I collected list of hints for having less work.

  • Use APT proxy. I am using APT-Cacher NG for all my machines and chroots. This allows for APT lines like http://localhost:3142/pl.archive.ubuntu.com/ubuntu and gives 30MB/s download speed when I need to install something.
  • Disable installing of recommended packages. Most of time I do not need those and installing “texlive-extra-doc” takes precious megabytes. Just create /etc/apt/apt.conf.d/99-no-extra file with:

APT::Install-Recommends “0”;
APT::Install-Suggests “0”;

  • Mount /proc, /dev, /dev/pts filesystems — some packages depend on them during installation.
  • Set locale to “C” — simple export LC_ALL=C is enough. Otherwise applications will complain about missing l18n informations.
  • Create user with same UID/GID as your host one and use it for any work — will allow to use editors from host system to edit files.
  • Kill each daemon which started after installation — who needs several Samba daemons on one machine?

Ubuntu cross compilers – part 2

Two months ago I wrote about cross compilers for Ubuntu. Lot of things changes since then:

  1. I am able to bootstrap ARM targeting cross compiler using Ubuntu build machines (so no manual steps).
  2. Packages are now available in my Armel cross compilers PPA repository. My repository at people.canonical.com is still operational but will not be updated anymore.
  3. Source of my packages with whole history is available in GIT repository.
  4. Bug was filled to get those packages imported into Ubuntu archive. And it got accepted by Ubuntu Release Team! So expect ARM cross compiler packages soon in Maverick 🙂

What next? Improvements of course. Recently Al Viro got Debian/Ubuntu gcc packages working for biarch/triarch architectures (think: powerpc, mips, s390) so in free time I will take a look to make powerpc cross compiler (require some work).

Other thing will be merging my packages into Debian. This will take more time because kernel recipes needs to be changed for it and Debian is not only Linux…

UPDATE: armel cross-compiler packages are available in Ubuntu 10.10 ‘maverick’ and newer. To install them you need to run apt-get install gcc-arm-linux-gnueabi (substitute ‘gcc’ with ‘g++’ or ‘gfortran’ or ‘gobjc’ or ‘gobcj++’ if needed). Other repositories were taken down and will not return.