Tag Archives: gnome 3

Changing font size in GNOME 3.4 on Fedora 17.

Someone asked me a few weeks ago whether I knew how to change the default font size in GNOME 3 on Fedora. I have all my boxes on Fedora 17 since before the release, with GNOME 3.4. I had to admit that I’d never looked for how to change the font size in GNOME, but it seemed like something you might want to do, especially on extremely small or large displays. I hadn’t bothered to write this up, but I thought given a news story this morning that it might be useful to others.

I had no clue where to start. So how did I find it? I went to the Overview mode by hitting the super key (you could also use the Activities hot spot or Alt+F1). Then I started typing: f o n t. The first thing that comes up in the menu is the Universal Access setting. I opened it up (I just hit Enter, but you could mouse to it just as easily), and sure enough, under the “Seeing” tab there’s a setting for the default font size!

Enrichment day 4.

This week was the last enrichment class for my group of fifth graders.  As I reported in the last installment, the syllabus ended up changing a bit to adapt for the unexpected difficulty of some of the concepts.  Variables in particular were difficult, but eventually the students started to understand them pretty well.

This week built on variables to teach the concepts of conditionals and loops, using the if and while statements in Python.  It was at this point that I could tell that most of the students had really grasped the concept.  One of our exercises was to follow the logic of a simple counting/printing loop.  The kids seemed to like putting themselves in the role of the computer.

It was also at this point that the kids started to understand the power of booleans (True and False).  We tried a number of additional comparisons to understand cases where conditions evaluated to each.  The emphasis on True and False paid off in the section where we discussed conditionals and loops because we could pay more attention to the actual branching operation, as opposed to getting stuck on figuring out why the branch happened.

This week I also discovered what I think was a good way to increase the idea of collaboration in the class.  Obviously there wasn’t time to check every child’s work at every step of the way.  But I could make things easier and less pressured on the kids by rotating a “look and see” duty around the class.

Since the class was relatively small (only six kids), I could have all of them gather around one person’s console to see the results of a program or exercise.  We could even figure out what went wrong together in some cases.  Hopefully this removed a little of the pressure of having the instructor point out something that was wrong — a friend could point it out and even help fix it.

Of course, it wouldn’t be a last class without some bonus for the kids!  Thanks to the fine people at the Fedora Project, I had stickers, temporary tattoos, and buttons for the kids, which they loved.  They also got to take their Fedora Live USB keys home, which several of them had been waiting for since the first class.

Speaking of keys, I sent home an information sheet for the parents to go with the keys, so they’d understand what was on it, how to use it, and where to find more information and help.  The keys also had two complete electronic books (both CC BY-SA licensed, check them out here and here) included that are specifically aimed at teaching Python to kids, so if the kids want to go further they can.  A couple of the students demonstrated really serious aptitude, so I think chances were good the class ignited the imagination of a future computer genius!

I’ve posted the last lesson (and miscellaneous resources) in my fedorapeople space, and as with previous lessons, it’s all licensed as CC BY-SA 3.0 so it can be reused by others.  I hope you got something out of reading about the class.  I had a great time teaching it and I think the kids enjoyed it too. Thanks again to my employer, Red Hat, for lending me a few hours this month to give back to some kids in my community.

Enrichment days 2 and 3.

I’m sorry I got behind in posting about the enrichment class last week. After week 1 went so well, I thought I’d easily be able to post updates weekly, but alas, it was not to be. However, this wasn’t just because of other workload. The week 2 class actually didn’t go as quickly as the week 1 class. The lesson plan I thought would be light enough to cover in one session has actually taken up the hours for both weeks 2 and 3. I’ve posted the lesson in my Fedora People space.

It turns out that one of the most difficult things for the kids to grasp has been return values. That is, understanding that when you run a function in Python, a value is often generated as a result. Python can either do something with it, or not. This is deeply tied to understanding the usefulness (if not the concept) of variables as a way of holding on to those results for later use.

This concept is inherently difficult for fifth graders who haven’t yet been exposed to concepts of algebra or the unknown. Math and science up to this point in their education are decidedly concrete, and focus strictly on known quantities. I underestimated the difficulty of introducing the concept of an unknown, indeterminate object like a variable.

Fortunately, Python has made it simple for the kids to try smaller steps on their way to understanding this concept. Python’s particular style of input/output at the interpreter allows them to see how return values are generated. Then it becomes a matter of understanding the concept of variables, and assigning that return value to a variable. This is not as easy as it sounds for fifth-graders, but by the middle of week 3’s class light bulbs were switching on!

Regardless of the difficulty of the class, the students in general have loved the class, and are excited when they show up each day. I wish I had more time with them, but alas, the class only lasts for four weeks.

We have one more class coming up on the Monday afternoon after Thanksgiving. Based on the experience thus far, I expect we’ll spend the majority of the last class on conditionals, and understanding the if statement. Courtesy of the Fedora Project, I have some wonderful swag items to give out which I think the kids will love, like buttons, stickers, and temporary tattoos. Also I plan to give them their Live USB keys, as well as a note for their parents on what the keys contain and information on how to use them.

I will try like mad to have a blog post up sooner after next week’s class!

Enrichment day 1.

Yesterday was day 1 of the enrichment class I’m teaching at my daughter’s elementary school. The class is elementary computer programming using Python, and has a total of six students, all fifth-graders. Actually, the first class only had five, because one went home on the bus by accident instead of staying at school for the extra class.

The first day is never the best day, because there are a lot of introductory things to get out of the way. In our case, I needed to show the kids some essentials for how to open programs, write and save files, find them again, and start up the Python program. This might sound really easy to you and me, but for fifth graders one needs to adjust the expectations. Not every child is comfortable with a keyboard, for example, and I couldn’t assume that every child had ever typed a document before just because my child had.

As it turns out, we really needed every minute of class to cover our material, which made me glad I didn’t overschedule the tasks in the class. We started with some basic information about what software is and why it’s important — that without software computers are basically as dumb as a box of hair.

The kids enjoyed this explanation; I demonstrated the difference between instructions for computers and humans by having one of the students walk down to the end of the room and back. I didn’t explain to him, of course, how to get up from his chair step by step, push his chair in, turn to the left, put one foot in front of the other, etc., etc. So that made a great example for how computers have to be told everything explicitly. This made it easier, later in the class, to have the kids understand why the computer gave them an error in certain examples I set up.

I was impressed with how quickly the kids picked up the GNOME 3 interface, even though it’s somewhat different than the computers they’re probably used to.  Most of them figured out the overview and how to find applications very quickly — so I had to get them back on track once they found the games! They also had no problem moving, resizing, and closing windows.

The computers in the school lab need to be powered off at night according to school policy. It was a little tricky to show the kids how to shut down the systems, but other than that the transition was pretty smooth for most of them.

One child was uncomfortable enough at the computer that I suspect she hadn’t much experience at all. She seemed worried about doing things wrong or breaking the computer, so I tried to go a little out of my way to give her some positive feedback and tell her she was doing a good job!

We got all the way through the ending exercise, which was to let the kids fire up Python 3 and have the computer do some math problems for them. I even managed to tie into one of the kids’ current math lessons, which is on order of operations. They were really impressed the computer knew how to do their homework for them!

I’ve put the day 1 labs in my Fedora People space in case you’re interested in seeing what we covered. I would also be remiss if I failed to thank my employer, Red Hat, for giving me the flexibility to take on this extramural project.

Enrichment class.

Lately, as an extramural project I’ve been preparing an enrichment class I’ll be teaching at my kids’ elementary school in November. The class is for fifth graders, a very light introduction to software and programming concepts. The kids elect their enrichment class, which is a fantastic way to put together an audience because you know they’ll already be interested in the subject. The classes are held for one hour each Monday after school for four weeks — so there are four hours of class in total.

The first question was, would we use a language? I felt strongly the answer was yes, because I wanted the kids to have a hands-on learning experience. In addition, I believe fast feedback is very important for younger kids. It helps them feel more confident while they get comfortable with the material. So it was important to pick a language that was interpreted.

I ultimately decided on Python, not just because I’m comfortable with it and it meets the criteria, but also because it’s widely in use running things the kids have heard of (Google, Facebook, NASA), widely recognized as a good first language for learning, and is eminently readable for any of the kids who decide to pursue it further after class is over.

Of course I plan to spend a couple minutes to explain to them the awesomeness of free software, and how they can share it with others. I hope that’s a tiny nugget of learning they can take away even if they never touch Python again.

I also knew I’d need some good self-directed learning resources for kids in this age group, so they could keep going when class ends. There are at least two good books out there the kids can use if they want to continue on their own:

Both these books are available for Python 3, which is what I’ll be using for the class. I’ll be providing electronic copies of both for the kids to enjoy and learn more later.

Now, how would I make Python available for the kids? As it turns out, the school has brand-new HP desktop machines that were purchased this past year, and the resulting lab is completely homogeneous. This is fantastic because it means I have to worry a lot less about a student having a problem specific to their computer. If things work OK on one, they should be OK for all, modulo some low risk of sudden hardware problems.

But this didn’t mean I can necessarily install Python on all the computers. Nor would I want the kids to go through that process; it would be a waste of time as well as frought with all sorts of chances for human error that would lessen the learning experience. Although I have full support from the school administration, that doesn’t mean I should be installing stuff on their computers’ hard disks, or putting the onus on the computer resource teacher to do it.

Obviously, what I needed was a bootable operating system that wouldn’t touch the lab systems’ hard drives. This called for a Fedora Live USB key! I decided to go with Fedora 15 since the class is coming up before the release date of Fedora 16. And thanks to the livecd-tools package, and the spin-kickstarts repository on Fedora Hosted, this was relatively easy to handle as well. With a couple quick customizations, I could provide the kids with a safe, friendly, and powerful environment in which to learn.

After creating this boffo live image, I needed to try it out at the actual lab environment. I did that this afternoon, just as school was letting out for the kids, since the lab was free. There were no problems at all — the free software X video drivers worked spectacularly, NetworkManager connected kids to the classroom network with zero fuss, and the new GNOME 3 environment was ready to use. I tried a number of lab systems and gloriously, they were all configured homogeneously as well. The systems were even set to boot from USB first; all I have to do is make the keys, and before class, just insert them and power on!

I know I shouldn’t be elated that the software works just like it should, but I still love to think about how far we’ve come from the days when Linux could only be used by tinkerers. And of course I have to give huge props to all the people who work on the kernel and plumbing, GNOME 3, and Python. Without their hard work there’s no way I could provide the class to the kids. And the best part is, the zero cost and freedom of Fedora means all the kids can keep the keys and continue learning even after class ends.

I also want to thank Máirín Duffy for the inspiration, and her thoughts as I started putting the class together. She ran an amazing Inkscape class for some young people not long ago, which you should definitely check out! Just as Máirín did, I’m going to provide all my materials under a Creative Commons license, and blogging the class progress here. I can’t promise to provide lots of photos to go along with everything (terminals make dull subjects!), but I hope it’ll be fun and maybe even interesting to read.

A fun day… for some hacking.

Over the course of the day, I:

  • Tweaked the package complement on my workstation where last night I did an installation of the Fedora 15 pre-release tree
  • Identified some weirdness in my local Eclipse environment and got things in better shape for later work
  • Got a good start on some user documentation for PulseCaster
  • Took my daughter to the skate rink, and managed to skate for at least a little while before realizing I was having a rough time because my kingpin bolts are just way too freakin’ tight
  • Figured out how to adjust said kingpin bolts and made a note to take care of that before next week
  • Took my son out for some errands and lunch — a nice trip and a good chance to exercise my patience muscles
  • As a reward, bought some beer and a couple decent malbecs
  • After returning home, cleared out some obsolete packages hanging around in Bodhi and begging for death
  • Built and pushed a new update of PulseCaster to fix some bugs
  • Built and pushed a refreshed upstream version of xmlstarlet
  • Played with the dog
  • Came back and turned up a French trance station I got into recently (for some reason, monotonous, non-vocal electronica seems to help me work more efficiently… probably since there are few lyrics to listen to and digest mentally)
  • Went through some email to reduce backlog for Monday
  • Triaged a crummy gnome-system-monitor bug affecting people with more than 4 CPU cores (like me)
  • Had dinner with the family (Eleya made a fabulous corned beef, first timer but it was pretty much perfect!)
  • Came back to the desk to find that the superhuman Matthias Clasen had fixed the gnome-system-monitor bug in question, and built and pushed an update out
  • Installed said update with many thanks to Matthias, tested, and provided feedback

So of course, my definition of hacking is not nearly what some of my colleagues manage daily. But I feel like attacking some of this stuff on weekends and working on my own GNOME-ish projects are starting to give me a better fundamental understanding of some of the plumbing at work in the desktop. And of course, it gives me a wh0le new appreciation for it as well. I’m now rocking GNOME 3.0 pre-releases on both my main systems here at home, my laptop and my big workstation, and loving it.

I’ve contributed a few bug reports and to a small portion of the GNOME 3.0 user documentation for this release. It was lots of fun and made me feel connected with the release process for something I use every day that will be an intrinsic part of Fedora 15 when it arrives. It’s a great feeling to be just cranking on some little bits to help others, and just as much as ever, I know that if everyone does the same, free software has a future that is even brighter than the (already well-lit) present.

Eager beaver, no. 38.

I was really eager to get my laptop onto the branch that will become Fedora 15. A recently uncovered bug (possibly in glibc), along with another unrelated problem (in pygobject?), are preventing installs via the nightly composed ISO images of the pre-release. So if you’re on Fedora 14, and want to get on the new branch, you could do this:

  1. Back up your data and at least your /etc directory. You never know what you might wish you’d kept!
  2. Also run the following command to save the names of your installed packages: rpm -qa –qf ‘%{NAME}\n’ > /home/rpmnames-old.txt
  3. Download the Fedora 15 Alpha release, Desktop Live spin, in your choice of 32- or 64-bit, and install. In a moment you’ll update everything.
  4. After you start up and run through the normal setups, don’t bother logging in at the GUI yet. Hit Ctrl+Alt+F2 to switch to a text terminal. Login as root, or else use sudo with the following commands.
  5. Install any -release type repository RPMs you may want. I keep copies of these hanging around for just such occasions.
  6. Get the names of the newly installed packages: rpm -qa –qf ‘%{NAME}\n’ > /home/rpmnames-new.txt
  7. Run: yum –skip-broken install `diff -u /home/rpmnames-old.txt /home/rpmnames-new.txt | tail -n +4 | grep ‘^-‘ | cut -c 2-`

Note this is not a perfect solution. Releases change, and some packages may not be available in the new release that were in the old one. You may want to rerun steps 6 and 7 a couple days later if there are any broken dependencies that foil you from installing everything you wanted. Or alternately, you might want to stick in a step 6.5, which runs a few yum groupinstall commands to make step 7 shorter. This isn’t a panacea, it’s just a quick way to get up and running if you want to try out the new hotness but are stymied by the bugs listed above.

And of course, you could just download the entire Alpha DVD and point it at  so you won’t have to twiddle as much afterward; quite a few services that run by default in a DVD install, like sshd, aren’t necessarily enabled by default in an installation from the Live image. The above is just a quick way to get started if you know you’ll be doing further installation testing or other hackery later anyway. And it will give you a good flavor for the awesome new GNOME environment.

What if you want recapture your user account and password? Just refer back to your backup you made. Do not simply restore it over the new /etc files. You could really get hosed that way. Instead do something like this. I’m going to assume you only have a couple of users on your system, starting with userid 500 per normal:

mkdir /tmp/restore && cd /tmp/restore
tar xf /path/to/etc-backup.tar.gz   # Got backup?
for i in $(grep ':50[0-9]:' etc/passwd | cut -d: -f1); do
  for f in passwd shadow group gshadow; do
    grep ^$i etc/$f >> /etc/$f

Here’s something I also recommend: move your user’s ~/.gconf directory to a backup before you login the first time. Try the spiffy new GNOME 3 out in its default settings. If you need to tweak or restore, you still have the old settings to which you can refer. But it’s worth trying everything as it was intended out of the box. I’m totally excited to run the pre-release so I can rock the new GNOME Shell. Pretty soon I’ll start working on a new branch of PulseCaster that will use the new PyGObject available in Fedora 15, and maybe a few of the cool new GTK+ 3 bits I’ve seen might be helpful in the  new UI.