Between Linux and Anime

So there are a good number of threads for zypper/yast hanging up in the middle of various actions, but none were relevant to my particular problem, so throwing this out into the googlespace for the next person who might end up facing my problem.

The Symptoms: Yast Software Manager and Zypper would randomly freeze and stay frozen apparently indefinitely – at least for hours. The freeze occurs seemingly randomly in the midst of any action that may require downloading – including refreshing repositories and actually downloading packages/updates.

What is happening: Staring at zypper output on -vv I began noticing that it always hangs up when trying to download something from download.opensuse.org. It doesn’t do so consistently: most of the time the download happens, but sometimes it doesn’t and it freezes forever – but always when attempting to download from download.opensuse.org. With some research I found out that download.opensuse.org isn’t actually a centralized download repository but uses something called mirrorbrain that transparently redirects you to a chosen download mirror. So it would appear that one of those mirrors were having trouble with me – perhaps my IP is somehow blacklisted by that server. What’s confounding is that it doesn’t seem to be able to flag an error or at least timeout so I can be served another mirror or simply retry – it just goes on staying stuck forever.

Solution: With the hypothesis that one of the mirrors is somehow rejecting me in this inexplicable way, a direct solution would be to simply find a mirror that is happy with me, and force zypper/yast to use it. For core OpenSUSE packages (distribution and update), a list of mirros is available here. For the repositories at http://download.opensuse.org/repositories/ though, I couldn’t find a mirror list. Instead, I discovered that when you open the listing of packages on a browser, for eg here, you can click on ‘details’ next to any package and that shows a list of mirrors you can get the package from.

So armed with this knowledge, I simply went through all my enabled repositories, looked for all repositories that have download.opensuse.org as source, and replaced the url with that of a specific mirror. After that zypper and yast operated without problems.

Of course, this is a non-optimal set up, so after a while you might consider switching back to download.opensuse.org and see if the problem has gone away.

Or not.

Recent versions of Chromium (and, presumably, Google Chrome) appear to be capable of differentiating between input from a touch screen, and input from a mouse. The problem is, on Linux, you’ll often find the capability a counter-productive one, since chromium sometimes outright IGNORES all touch input, rendering chromium utterly inoperable with a touchscreen. Mouse and touchpad operates chromium okay? Touchscreen operates other applications okay but you can’t so much as click a link on Chromium? You’re probably experiencing what I’m talking about.

There’s a report here, but it doesn’t seem to be going anywhere at the moment. Apparently Ubuntu carries a patch that tries to fix this, and I’m not sure how well it works, but at least on OpenSUSE we appear to be on our own. Fortunately, it’s possible to workaround, based on a suggestion in the comments.

First, on the terminal, type

xinput list

You should get a listing that looks like

⎡ Virtual core pointer                          id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ Atmel Atmel maXTouch Digitizer            id=10   [slave  pointer  (2)]
⎜   ↳ SynPS/2 Synaptics TouchPad                id=13   [slave  pointer  (2)]
⎣ Virtual core keyboard                         id=3    [master keyboard (2)]
    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
    ↳ Power Button                              id=6    [slave  keyboard (3)]
    ↳ Video Bus                                 id=7    [slave  keyboard (3)]
    ↳ Power Button                              id=8    [slave  keyboard (3)]
    ↳ Lenovo EasyCamera                         id=9    [slave  keyboard (3)]
    ↳ Ideapad extra buttons                     id=11   [slave  keyboard (3)]
    ↳ AT Translated Set 2 keyboard              id=12   [slave  keyboard (3)]

You need to look for the name of your touch screen hardware. In the above case, that is “Atmel Atmel maXTouch Digitizer”. Note the id number for the hardware on the right, 10 in the above case.

What you need to do is pass this id as a parameter to Chromium/Chrome. Like so:

chromium --touch-devices=10

Replace 10 of course with the id of your device. Launched this way, touch input should actually work reasonably on Chromium. In particular – you can switch tabs with touch, touch links to visit them, and even touch-scroll.

Of course, it’s a little tedious to do this every time you want to start Chromium. Fortunately, it’s not hard to put it all in a script. Like so:

#!/bin/bash
SCREEN=`xinput list | awk '/maXTouch/ { gsub(".*id=",""); print $1 }'`
exec chromium --touch-devices=$SCREEN

Of course, you’ll need to change ‘maXTouch’ above to a suitable identifier for your particular device, but running the script should start Chromium in touch-usable state. If you want, you can even modify your application menu entry to call this script instead of the Chromium binary directly.

UPDATE

It seems the above doesn’t quite work anymore on recent versions of Chromium. On my own box I’ve found that I now need to use the id of the parent item – ie “Virtual Core Pointer”, id=2 in the listing above. The rest of the procedure is basically the same, and if you use the script above you’ll need to make a minor adjustment to look for Virtual Core Pointer instead.

If you find, like I did for my box, that the id for Virtual Core Pointer stays the same all the time, instead of making a script you could just add the command line flag to the Chromium default settings config file. On OpenSUSE 13.2 this is at /etc/default/chromium, though I hear it can also be at /etc/chromium/default on some platforms. Simply add the following to the file:

CHROMIUM_FLAGS="--touch-devices=2"

This is cleaner and would probably also live across version updates :)