After switchig to a notebook with higher resolution monitor, I noticed, that the FLTK based ICC Examin application looked way too small. Having worked in the last months much with pixel independent resolutions in QML, it was a pain to see the non adapted FLTK GUI. I had the impression, that despite of several years of a very appreciated advancement of monitor technology, some parts of graphics stacks did not move and take advantage. So I became curious on how to solve high DPI support the hard way.

First of all a bit of introduction to my environment, which is openSUSE Linux and KDE-5 with KF5 5.5.3. Xorg use many times a hardcoded default of 96 dpi, which is very unfortune or just a bug? Anyway, KDE follows X11. So the desktop on the high resolution monitor looks initially as bad as any application. All windows, icons and text are way too small to be useable. In KDE’s system settings, I had to set Force Font with DPI and doubled its size from 96 to 192. In the kscreen module I had to set scale 2.0 and then increased the KDE task bars width. Out of the box useability is bad with so many inconsistent manual user intervention. In comparision with the as well tested Unity DE, I had to set a single display scaling factor to 2.0 and everything worked fine and instantly, icons, fonts and window sizes. It would be cool if DE’s and Xorg understand screen resolution. In the tested OS X 10.10 even different screen resolutions of multiple monitors are scaled correctly, so moving a window from a high DPI monitor screen to a traditional low resolution external monitor gives reasonable physical GUI rendering. Apples OS X provides that good behaviour initially, without manual user intervention. It would be interessting how GNOME behaves with regards to display scaling.

Back to FLTK. As FLTK appears to define itself as pixel based, DPI detecion or settings have no effect in FLTK. As a app developer I want to improve user experience and modified first ICC Examin to initially render physically reasonably. First I looked at the FL::screen_dpi() function. It is only a helper for detecting DPI values. FL::screen_dpi() has has in FLTK-1.3.3 hardcoded values of 96DPI under Linux. I noticed XRandR provides correct milimeter based screen dimensions. Together with the XRandR provided screen resolution, it is easy to calculate the DPI values. ICC Examin renderd much better with that XRandR based DPI’s instead of FLTK’s 96DPI. But ICC Examin looked slightly too big. The 192DPI set in KDE are lower than the XRandR detected 227 DPI of my notebooks monitor. KDE provides its forced DPI setting to applications by setting Xft.dpi in XResources. That way all Xft based applications should have the same basic font scaling. KDE and Mozilla apps do use Xft. So add parsing of a Xlib XResources solved that for ICC Examin. The remainder of programing was to programatically scale FLTK’s default font size from 14 pixels with: FL_NORMAL_SIZE = scale(14) . Some more widget sizes, the FtGl font sizes for OpenGL, drawing line widths and graphics scaling where needed. After all those changes, ICC Examin takes now advantage of high resolution rendering inside KDE. Testing under Windows and OS X must follow.

The way to program high DPI support into a FLTK application was basically the same as in QML. However Qt’s QML takes off more tasks by providing a relative font unit, much like CSS em sizes. For FLTK, I would like to see some relative based API’s, in addition to the pixel based API’s. That would be helpful to write more elegant code and integrate with FLTK’s GUI layout program fluid. Computer times point more and more toward W3C technology. FLTK would be helpful to follow.

BITA IT Show, the biggest IT exhibition in western India is coming to town on 24-26 January, We will be there promoting Li-f-e. If you are in this part of the world, drop in to check it out.

Fosscomm is the annual conference of the Greek Free Software communities. This year the event took place on November 7 & 8 at the Technological Educational Institute(TEI) of Athens. This time around openSUSE had quite the strong presence in the conference with 3 talks and a booth.

openSUSE-el

The Booth itself always had at least 3 persons busy answering questions with old time and some new contributors to the project and local community handling the organization and distribution of the swag in the booth and explaining the merits of our current structure, projects and releases.

Enlightening Lizards

Although i haven’t had time to really contribute to this project in a while, it’s still one i really hold dear/close to heart so made sure to do this presentation again this year but with updated stats to spread the word about this awesome window manager and its foundation libraries and the stellar packaging work done by simon lees.

Automated Testing With openQA

My second and I believe most important presentation, this year, was about the excellent QA tool actually used to build our distro, “openQA”. As said by it’s motto, “Life is too short for manual testing!”, thus openQA is used to automate testing of the whole distribution (either as a collection or in individual package basis). You can see some test case examples on it’s homepage, you can also fetch the presentation from my github repo (FOSSCOMM_2015 directory) linked in the blog sidebar.

Leaping Ahead

Alex Vennos another community member had a presentation about the latest stable release “Leap 42.1”, unfortunately i couldn’t attend it but heard that it was well received even though people showed some confusion about the sudden “Leap” to a version like 42.1 from the previous 13.2

The rest

I spent the rest of the conference at our booth helping people, answering questions and generally socializing and talking with old & new friends.

Congratulations to the people from the TEI of Athens for the organization! :)

Update minor (mostly grammar/typo fixes)

Da der offizielle Support für openSUSE 13.1 am 5.1.2015 endet war es höchste Zeit meine Workstation mal auf openSUSE Leap 42.1 zu migrieren. Solche Migrationen mache ich mit SUSE schon seit es noch einstellige Versionsnummern hatte. Diesmal war die Migration allerdings ungewohnt holprig.

Meine Workstation nutzt ein vermutlich nicht ganz gewöhnliches Set-Up. OpenSUSE ist parallel zu Windows 10 installiert, und beides wird per UEFI Secure Boot gestartet. Den UEFI-Boot habe ich dann auch gleich mal genutzt um mir mit Anlauf selbst in den Fuß zu schießen: OpenSUSE unterstützt es zwar schon seit Ewigkeiten eine Upgrade aus dem laufenden System durchzuführen, da es mir aber immer als der sauberere Ansatz vorkam – und sicher auch aus Nostalgie – mache ich solche Updates immer noch ganz altmodisch per DVD. Allerdings bietet mein ASUS-EFI in der Bootmedienauswahl das Blu-Ray-Laufwerk immer zwei mal an. Einmal ganz oben in der Liste als BIOS-Boot, und einmal ganz unten als echten UEFI-Boot. Natürlich habe ich – wollte ja nur schnell mal das Update starten – den oberen Eintrag genommen und mein EFI-System dann mal schön im BIOS-Modus aktualisiert. Leider fängt openSUSE diesen PEBKAC aktuell nicht ab und hat mir dann mal schön die Bootloaderkonfiguration kaputtgeschrieben. Zum Glück ist der Fehler – wenn man erst mal verstanden hat, was man falsch gemacht hat – trivial zu korrigieren. Einfach nochmal das Upgrade im UEFI-Modus starten, von Leap 42.1 auf Leap 42.1 aktualisieren (ja, das geht). Danach ist der Bootloader korrekt geschrieben.

Leider tritt einem beim Versuch die DVD mit openSUSE Leap 42.1 per UEFI zu booten Bug 950569 in den Weg. Der Bootcode auf der DVD ist nicht korrekt signiert, was auf meinem System zufolge hat, dass der Bildschirm einfach schwarz bleibt. Das Problem lässt sich lösen, indem man Secure Boot im BIOS temporär deaktiviert. Zum Glück installiert openSUSE Leap 42.1 bei der Installation bzw. dem Upgrade bereits die aktuellsten Version aller Pakete. So bleibt Nachzüglern wie mir nicht nur die Updateorgie nach der Installation erspart, sondern es landet auch korrekt signierter Code auf der Platte, so dass Secure Boot nach dem Update gleich wieder aktiviert werden kann.

Ein weiteres Problem bei openSUSE Leap 42.1 ist, dass es zumindest bei Upgrades nicht korrekt mit verschlüsselten Root-Partitionen umgehen kann. Beim Boot „vergisst“ das System nach der Passphrase zu fragen. Wechselt man durch die Konsolen findet zeigt sich folgende Fehlermeldung: Failed to start systemd-cryptsetup@luks<codierte ID>.service:. Ich habe die ID in der Fehlermeldung mal gekürzt ;). Wie in Bug 904987 lässt sich das Problem lösen, indem man dem Kernel explizit sagt, dass er die entsprechende Partition entschlüsseln soll, indem man ihm die ID des LUKS-Containers per Kernelparameter rd.luks.uuid mitgibt.

Die ID des LUKS-Containers lässt sich mit Cryptsetup herausfinden. Liegt die Root-Partition z.B. auf /dev/sda2, so lässt sich die ID wie folgt herausfinden.

> cryptsetup luksUUID /dev/sda2
07246af2-915a-bd54-6a5s-6a5c35d15f45

Der Bootparameter muss dann in /etc/sysconfig/bootloader zum Wert DEFAULT_APPEND hinzugefügt werden. Dieser sollte dann z.B. wie folgt aussehen:

DEFAULT_APPEND="splash=silent quiet showopts rd.luks.uuid=07246af2-915a-bd54-6a5s-6a5c35d15f45"

Anschließend einmal den Bootloader neu schreiben lassen und das System fragt wieder nach dem Passwort. Idealerweise wird dieser Workaround schon vor dem Update implementiert. Nicht, weil dann der Bootloader sowieso neu geschrieben wird, sondern weil man sich dann das Herumgewurschtel mit einem Recovery-System spart.

 









  


On December 5, 2015 openSUSE.Asia Summit 2015 was open, and off course there are many DVD and stickers :-D


Michal Hrusecky, openSUSE Board, give a keynote speech about what's been going on in openSUSE lately.


And after the break it was my turn. I put my presentation on slideshare in case any of you want to read.










It is an honor for me to attend to this event and hope Indonesia can be the host of the next openSUSE.Asia Summit 2016. See you all next year!



Most of photographs are taken from:

https://www.flickr.com/photos/vanmalay/
https://www.flickr.com/groups/opensuse-asia-summit-2015/

Thanks to:
Utian Ayuba, Estu Fardani - You both are great travel companion
Al Cho, Joey Lee, openSUSE Taiwan - Thanks for invitation
Sakana Max - You should come next time :-D
Franklin Weng, Erick - You make me always remember that I have friends in Taiwan
Rijal, Rosi, Pak Pur, LC - The video rock!
openSUSE Indonesia Community - Thanks for great support
openSUSE - Thanks for the great distro and TSP :-D 

Earlier tool live-fat-stick uses syslinux to create multiboot USB stick/hdd on a vfat parition without having to format the stick preserving existing data and copying whole ISO so the same stick can serve as demo as well as to copy ISOs for distributing. However the disadvantages are all of them that comes from using vfat.

Grub2 has come a long way and almost all major distributions now support booting from the iso image via loopback. So here is live-grub-stick script that uses grub in place of syslinux bringing in all the advantages of using grub2.

Currently live images of openSUSE, Ubuntu, Fedora and all their clones are supported. Go ahead and fork it if you would like to add support for your distribution.

Ya lo he contado por aquí alguna vez, mi entorno de trabajo en el ordenador me gusta con tendencia minimalista. En general, pero en especial en el trabajo gráfico, me parece fundamental eliminar todos los menúes y botoneras posibles y manejar la aplicación a base accesos directos/métodos abreviados. Me da mucho coraje que lo fundamental, el trabajo que se está realizando, se pierda en una selva de menúes desplegables, solapas, botoneras, barras de herramientas, de progreso, at infinitum.
Lo puedo entender si eres el programador que ha desarrollado el programa y está encantado disfrutando con el panorama de funciones y órdenes que eres de capaz de desplegar para ayudar al usuario… pero si eres el usuario final, pasártela contemplando la interfaz, es poco recomendable (por decirlo con suavidad).

Pues el otro día descubrí como minimalizar la konsola de KDE a su expresión más simple y dejándola más bonita que la original. Muy sencillo y en dos cómodos pasos:
– Sobre el borde de una konsola de KDE pulsamos botón derecho y elegimos “Preferencia específicas de ventana“. Nos vamos a la solapa “Apariencia y fijados” activamos la casilla “Sin barra de título y marco“. Aceptar.
Con esto eliminamos toda la decoración y bordes, pero entonces se nos queda todavía muy fea.
– Lo siguiente es aplicar una hoja de estilos personalizada (stylesheet) a la konsola en el momento de abrirla. Así es que en Kate creamos un archivo de texto con el siguiente contenidoQFrame {border:1px solid #AAAAAA; }
y lo guardais en ~/.konsole.qss
Ahora lo único que tenéis que hacer es cambiar las llamadas a ejecutar konsole añadiendo la opción konsole −−stylesheet /home/tu-usuario/.konsole.qss

La hoja de estilo funciona casi igual que CSS de HTML, obviamente cambian las clases y los elementos. Investigadlo, podéis empezar probando con los elementos QFrame, QListview, QScrollBar, QTabBar…

The best Linux distribution for education got a whole lot better, your Li-f-e(Linux for Education) takes a “Leap” to 42.1. openSUSE Education community is proud to present this latest edition based on openSUSE 42.1 with all the features, updates and bug fixes available on it till date. This effectively makes it the only enterprise grade long term supported(LTS) distribution for Education.

As with previous releases we have bundled a ton of softwares on this live DVD/USB specially packaged for education, along with the Plasma, GNOME and Mate Desktop Environments, full multimedia experience is also provided out of the box thanks to the Packman repositories. Only x86_64 architecture is supported, if you have a lot of machines that only support x86 then read on to find out how you can extend their Li-f-e.

You can of course very easily turn Li-f-e to full-fledged LTSP server to PXE boot machines in your local network. Booting both i686 and x86_64 architectures is supported. In case you need to PXE boot machines below i686 then you would have to install this package.

Happy holidays!

Get Li-f-e from here: Direct Download | md5sum | Alternate download and mirrors

我在 Google+ 上看到有人問關於 dock 的喜好問題