I’ve had some minor upgrade issues with the blog lately, and I am only about halfway through updating everything. In the meantime, I’m afraid things will look a bit messy. (Syntax highlighting is currently broken, and there are probably other formatting / data issues as well. I think I have to restore the uploads directory, for one, so there probably won’t be any images in the posts for a while.)
I started writing for another blog this week:
Brewed, Bottled, Cultured and Sweetened is a blog about beer, coffee, wine, cheese, chocolate, etc… that I’m writing with an old friend from Dagit.o
Update: updated the script with improved (functional) error output. added notes about xhost.
There is an annoying bug in the sequence of code that manages the wacom rotation / sleep / resume and stylus calibration right now. (Where “right now” is Ubuntu Intrepid, with the 0.8.2-1 wacom drivers.)
This is a document bug over at the ubuntu launchpad, and the poster there does a fine job of describing the intricacies of reproducing the bug, so I’ll only give a brief explanation here to help get indexed.
If you rotate the screen any amount, even returning to the original rotation, and then sleep the machine, when it wakes up, the stylus will not be calibrated properly — the cursor will be off to the side of the stylus point. It doesn’t seem to matter how it was calibrated when the machine slept, nor does it matter what rotation you’re in when you put the machine to sleep.
There is one straightforward workaround: When you wake the machine, run wacomcpl, click on stylus, click calibrate (the mouse should now be under the stylus again), and exit wacomcpl. This is incredibly cumbersome, but at least it’s better than restarting X, which is what I have been doing.
Further inspection (based largely on the thread of comments on that launchpad bug) reveals that the problem is actually related to bad values for the TopX, TopY, BottomX and BottomY settings on the wacom devices after a resume. By resetting these to their proper values for the current rotation, we can reestablish the proper calibration. First off, we need to know the proper values, and the easiest way to get them is with xsetwacom:
Now, we’ll run this for each rotation, and save the results. You should end up with something like the following:
(Note that my bash prompt looks like & command lines above are indented, and the output is left-aligned)
That gives us enough information to script the calibration when we resume. For example, when resuming to a “normal” rotation, I need to run:
(Wrap that in a bash script and give it a shot!)
Here’s the full script that gets the current orientation and then calibrates the common wacom devices:
Stick that in /etc/pm/sleep.d/40wacomCalibrate (or some similarly named file), make it executable by all (chmod a+x /etc/pm/sleep.d/40wacomCalibrate) and it should be run when the system resumes.
Update: I found that the logging of the old script didn’t work, so I’ve updated the script to reflect that. There were also some problems with how I was testing the first script, and the actions I was taking didn’t actually trigger the bug. (The bug seems to be quite state-dependent, and markovian assumption was wrong.) To get this to work, root will need to have access to the display that xsetwacom uses. The simplest way to do this is to add xhost + to you x startup. (I put it in my ~/.xsession just before exec enlightenment-start).
Ubuntu 8.10 configured most everything properly, as mentioned in the previous post in this series, but it did not result in a functional pen.
The tablet screen is a wacom digitizer with a pen that has two buttons (eraser and a finger button), and the tablet can differentiate between touching and hovering. The linux wacom driver & tools are necessary to get this all working. While I didn’t find a single page with instructions that worked flawlessly, I was able to figure it out from a collection of links:
First off, you will need the latest version of the linux Wacom driver (8.2.1 at the time of this writing). The driver versions seem to be tied to your kernel versions, so this is quite important. The wacom-tools package that comes with Ubuntu is not sufficient (in fact, you’ll want to uninstall it if you have it already).
Once you have the wacom package downloaded, follow the directions for installing it in the howto (linked above). The wacom package uses a typical configure, make, make install process but there are a few kinks:
uname -r/kernel/drivers/usb/input/ directory manually (creating subdirs if necessary), before running make install. (This is outlined in the mini-howto.)Once wacom is installed, you can begin working with the X.org configuration. This is fairly clearly explained at the aliencam blog linked above, or you can use my xorg.conf here.
After doing that, you should be able to reboot and the pen should be working. You can do things like configure the buttons with xsetwacom (and you’ll need that when it comes time to rotate the screen), but I kept getting this error when I tried to run xsetwacom:
I made a lucky guess, and fixed the problem with a quick ldconfig:
Update: There were some issues with the wacom calibration after a sleep/resume cycle if the laptop screen had been rotated during that prior wake cycle (this happens a lot more than it seems, given how complex that description is.) I’ve written up a workaround here.
I finally broke down and bought a Lenovo X61 tablet (with SXGA+ screen!), and it arrived this week. This is the first of a series of posts about getting it up and running with Linux.
First off, some specs:
I’ll flesh that list out more as I can find the details (eg: wireless chipset, video, etc..)
First off, I blew some time poking around in Vista of course :). The handwriting input app is phenomenal in a lot of ways. It works very well, training is well integrated, and it has worked with every input area I’ve tried. It could be better if it had contextual clues, and could tie into things like Eclipse’s intellisense. Overall, though, it is amazing how simple it is to use, and how aesthetically pleasing the handwriting actually is. There is a lot to be said for using a couple extra pixels to make the strokes taper off as you pull the pen away. It has QWAN.
That done, I started to move on to installing Linux. I’m giving Ubuntu 8.10 the first chance, and I thought I’d try using a USB-based install so I wouldn’t have to monkey around with the Ultrabase & drive. If you have an 8.10 system already, you can easily create a bootable usb ubuntu drive with usb-creator and an ubuntu iso. This takes perhaps 45min – 1 hour.
Booting was as simple as going into the ibm bios-like page (by hitting the ThinkVantage button on boot) and telling it to boot from another device, then selecting the usb drive (that I had already inserted). I split the existing 200gb partition in two with the ubuntu installer, keeping Vista in it’s 100 gig sandbox, and leaving the remaining ~100 gigs for Ubuntu to partition further (which it did, as two partitions: one for / and one for swap. /dev/sda5 and /dev/sda6).
I do wish it had said how much space was being allocated to each of those partitions though. The installer didn’t give any indication.
Installation from booting the installer from usb to booting into the installed system took right about 30min. I’m impressed :)
Out of the box:
More information as I figure it out :)
I desperately needed to find out why the tutorials I’ve been following for an Eclipse PDE task today kept referencing a startup.jar file that I could not locate.
A couple google searches later turned up this link:
http://dev.eclipse.org/newslists/news.eclipse.platform/msg62159.html
The poster in that thread had the same problem (back in Feb. 2007), and found the answer, but none of the content in that thread makes it trivial to locate the answer again.
The responder (with the answer) simply included a link to another mailing list:
http://dev.eclipse.org/mhonarc/lists/cross-project-issues-dev/maillist.html
Notice that that page is not constant. Today, it shows the most recent posts as of October 31st, 2008. In order to figure out what had happened to startup.jar, I had to take into account the OP’s response (“Ok so this is very recent.”), the timestamp on the messages (Mon, 12 Feb 2007) and then navigate the mailing list archives to find that time period, and start reading.
Please don’t put people through this sort of crap. It’s generally not difficult to find permlinks to a given email, or include a quick note with the actual answer. I have the answer now (startup.jar was replaced with org.eclipse.equinox.launcher in 3.3), but there is no way that I can tie that answer to the conversation I’ve linked to above.
For the purposes of Google:
If you’re having this problem:
I’m trying to do some automation, but I’m running into a problem with the 3.3 integration build.
java -cp plugins\org.eclipse.platform_3.2.100.v20070126\startup.jar org.eclipse.core.launcher.Main
doesn’t do anything. It doesn’t say anything. The only information I’m getting is an exit status of 13.
Then you need to use “java -jar plugins/org.eclipse.equinox.launcher_1.0.0.v20070207.jar” (adjusting the version numbers for your installation).
(Edit: If you’re reading this after OSGi R4.2, then there is almost certainly a better way to accomplish the same thing)
I’ve been digging into OSGi a bit over the last week or so inorder to create some Eclipse plugins that will automatically discover eachother, and I’ve been generally impressed with the framework on the whole. The documentation is a bit lacking, but there are some good blog posts about it. (Specifically [Neil Bartlett's introduction to OSGi][intro].)
One thing that bugged me is the repetition needed when you implement the CommandProvider interface to add commands to the OSGi console. CommandProvider defines one method you must supply:
OSGi then uses reflection to extract each of the methods that starts
with an underscore, and supplies those methods to the command environment as
new commands. (The underscore is trimmed, and the name of the method becomes
the command name.) General practice is to include the name of the
method in the return value of getHelp(), along with a description of
what the method does, eg:
This seems like a pain to maintain, so I took a quick look at annotations, and propose a new syntax:
Here we’ve extracted the getHelp() method into a new superclass, so
our SampleCommandProvider now extends an abstract class instead of
implementing an interface. It also makes use of an Annotation, which
we need to define:
Finally, we just need to define the superclass that implements
getHelp():
Note that the actual reflection on the class only happens once — all
subsequent calls to getHelp() use a cached copy of the documentation.
[intro]: http://neilbartlett.name/blog/osgi-articles/
The venerable Joel Spolsky asked recently why someone hasn’t made a device that clips to the back of a desk and:
* It’s a power strip
* It’s a network hub
* It’s a USB hub
* You clamp it onto the back of any desk
The idea being that:
This would make it easy to plug in laptops, USB peripherals, and all your rechargers at your desk without crawling around on the floor.
He links to a device that does some of this, and runs ~$150/device. At that price, I think a better solution is a docking station–when you get down to it, I don’t want to plug in 4 things every time I sit down even if it doesn’t involve crawling under the desk (power, video, usb, ethernet and possibly audio). I think it’s unlikely that all the features needed above are really necessary when you just show up for a meeting, or hop over to your coworker’s office for a short hacking session. Many conference rooms these days already have tables wired for ethernet / power and svga video to a projector.
Joel Spolsky and Jeff Atwood just launched the public beta of Stackoverflow today, with the intent of building a community for high-quality technical questions and answers. I’ve been using the site for about three weeks now, during the closed beta, and I’ve noticed a disturbing trend that was outlined in Joel’s announcement post today:
Want to know an easy way to earn reputation? Find a question somewhere with several good, but incomplete, answers. Steal all the answers and write one long, complete, detailed answer which is better than the incomplete ones.
The site presents an interface where much of the functionality is hidden from new users. You can’t comment on posts, for example, until you’ve earned 50 “rep”. Voting up takes 15 rep, voting down takes 100 rep, and each downvote you place will cost you one rep. You gain rep by posting questions and answers that other users vote up, or accept. The result is an addictive system that, in theory, prevents “Griefing” (the system does NOT prevent griefing, by the way. It is extremely easy to game.)
Because of this, it is tempting to re-post successful content from other sources, and nothing the creators (Atwood and Spolsky) have incorporated into the site, or the recent announcements, has indicated that this is objectionable. Afterall, good content on Stackoverflow will improve their service, regardless of where it came from, and regardless of whether it is properly credited.
After using stackoverflow for a couple weeks, I think that they have created a useful service, but I also want to call them out for providing an environment that is encouraging plagiarism. Duplication/copying of content within stackoverflow does not set easy with me, but I’m willing to accept that the content I create for stackoverflow is public domain, and is free to be copied at will. However these posts are not.
The ‘proper’ way to do user interface design is hotly contested in the OSS software development world, and the discussions usually boil down to three suggestions:
I don’t agree with any of these — (1) is completely unreasonable. Some people may be able to hack out a UI in their favorite language quickly, but when you suddenly need to move half the UI into a new dialog, or out of a dialog and into the main window, and change the tabs into a check list, with sample data, you’re screwed. Once you finish manhandling your code to account for that change, you’ll need to add a component that is shaped like a septahedron with 7 distinct clickable areas and a tooltip that includes the latest stock quotes, and that tooltip needs to be scrollable. The widget set places unreasonable restrictions on the design phase of your project.
Option (2) suffers from the same issues as (1) — you’re constrained by the widgets available, although this is less of an issue because it’s generally easier to add images, and the images can look like the widgets you’re missing. However, since GUI UI development tools are, well, for development, they require you to do lots of irrelevant (at this stage) tasks, like specifying how objects will behave when they’re resized, and dealing with layout managers.
(3) is the closest fit for my needs, and I do do lots of paper/whiteboard prototyping, but eventually, I need to show something that looks real, and sketches don’t cut it. There simply isn’t enough resolution there to convey everything that needs to be included in the mock-ups I create.
Hm.. perhaps I should go into what I do need, since my needs may be pretty esoteric. If you’ve made it this far, you’re probably seething with anger, or you’ve got some idea of where I’m coming from. I’m frequently in need of electronic versions of UI prototypes for remote collaboration, “wizard of oz” testing, or for inclusion in presentations and reports. These mock-ups need to look “real” or the is a substantial risk of biasing any experiments, and there is an expectation of polish that can’t be reached with hand-drawn interfaces. Since a lot of what I create is to solve novel problems in (at times) esoteric domains, we often need to use a mix of existing and novel widgets.
Generally, we use Visio to create these interfaces. It offers a good balance between vector drawing capabilities and shape templates for common UI widgets / forms / etc. You are also able to import images, which is fairly critical when updating or adding to the UI of an existing tool. (It’s easy to take a screenshot, clear out the details with the Gimp, and import as a background layer in Visio.)
Unfortunately, I’ve been unable to find any OSS tools that can fill this niche as well as visio. There are a few, as recent posts from slashdot and the old Joel on Software forums show:
None of these, on their own, do the job. However, with nothing else looking bright, I’ve been digging into Inkscape more over the last few days, and I think I’ve figured out a workflow that will do.
First off, the YUI stencils are critical — but they are not in a format that can be easily imported and used as “widgets”. Ideally, Inkscape would let me define custom shapes, complete with constraints on the sub-components of those shapes to influence resize and translation behaviors, but that isn’t yet available (to my knowledge). You can get around this, somewhat, by using the open dialog as a pallet of sorts:
“If you have a number of small SVG files whose contents you often reuse in other documents, you can conveniently use the Open dialog as a palette. Add the directory with your SVG sources into the bookmarks list so you can open it quickly. Then browse that directory looking at the previews. Once you found the file you need, simply drag it to the canvas and it will be imported into your current document.” (From the *Tips and Tricks* tutorial in Inkscape)
This would work reasonably well, if the open dialog were not modal! (Ranting about modal dialog is another post, or two, at least.) Thankfully, you can drag from the dialog into an inkscape instance even if they are running on different processes :). Therefore, you can start up two inkscape processes (NOT via the “new document” option on the toolbar or file menu — you have to actually start up two instances separately or the dialog’s modality will still interfere with your work). Once you have the processes going, and two inkscape windows, open the open dialog on one of them, go to the directory with your widgets, minimize the (now useless) inkscape window you opened the dialog from, and rock on with the YUI stencils & whatever other tools you need to hack out your UI in the other inkscape instance.
There are a couple of things to keep in mind:
The drag-and-drop action from the open dialog will include everything in the dragged svg file — so the YUI stencils (or any custom shapes you make) need to be broken out into separate files. (I’ve done this for some of the components, and you can download those files here: (Broken out YUI stencils). They are released under a Creative Commons Attribution 2.5 License.
Pencil (or one of the other options) may work better for you — many people have complained that their clients think an app is nearly finished because the UI looks “real”, and there are numerous ways to address that. (eg: NapkinLAF for Swing apps.) I haven’t had this problem, and something like NapkinLAF doesn’t address the problems I have, which are all related to pre-coding UI design.