Shallow Thoughts

Akkana's Musings on Open Source, Science, and Nature.

Wed, 16 Jul 2008

Running a second X: Xnest, Xephyr and xinit

I had a silly problem: I needed to make some screenshots, but my window borders were too pretty.

The problem isn't actually that they're pretty; it's that the theme I wrote for openbox is very different from the much simpler theme I used to use in fvwm, and I needed new screenshots that matched the old fvwm look. Preferably without actually going back to using fvwm -- I'm quite happy with openbox these days.

Anyway, the obvious solution is to run a second X. I had done that in the past (when I needed to test something repeatedly, like a wacom tablet, and didn't want to be restarting X all the time) so I knew that was possible. But then someone told me about Xnest. It's a way to run an X server embedded in a window of the current X session. What a neat idea! I wanted to try it.

I made a simple .xinitrc.xnest file that starts fvwm after loading .Xdefaults. It took some fiddling to find a combination of arguments that worked. In the end, this was it:
xinit ~/.xinitrc.xnest -- /usr/bin/Xnest -ac :1 -geometry 1024x768
And indeed, a 1024x768 window popped up with an fvwm running inside it. Cool! Except it turned out to be not so cool -- because as soon as I switched desktops, I found that the Xnest window wouldn't repaint itself. Not even after being covered with another window then uncovered -- it just didn't seem to get any expose events. Bummer!

Next I tried Xephyr -- I heard that it was similar to Xnest, a little more heavyweight but a little more reliable. It turned out the arguments were just the same, so I ran it exactly like Xnest:
xinit ~/.xinitrc.xnest -- /usr/bin/Xephyr -ac :1 -geometry 1024x768
but Xephyr was even worse about window redrawing, plus it had some problems with the mouse pointer, which kept jumping to random places.

Too bad! They both sounded fun, and I'm sure they'll improve and will eventually become usable. But for now, I'm back to the simpler solution, running a second X server. Here's how that works: first I have to log in on console 2 (ctl-alt-F2). For some reason, I can't run a second X except from there. Then I run:
startx ~/.xinitrc.xnest -- :1 and I get a new X session, on ctl-alt-F8 (with my regular session still accessible on ctl-alt-F7).

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[ 20:01 Jul 16, 2008    More linux | permalink to this entry ]

Fri, 11 Jul 2008

Paving notice

They're repaving the streets where I live.

[Repavng notice with no time, date or contact info] They left this flyer on our door to alert us. It's good of them to keep us informed.

I guess they don't want us to ask any questions. It's helpful to know where the cars will be safe.

I wonder when we should start parking somewhere else?

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[ 13:49 Jul 11, 2008    More humor | permalink to this entry ]

Fri, 04 Jul 2008

Learning about Firefox 3 extensions

Oops! Right after I posted that last entry, I discovered that my little kitfox extension wasn't working as well as I'd thought. And the more I hacked it, the less well it worked, and the more I discovered was missing, like a chrome.manifest file (which firefox 2 hadn't seemed to need).

Eventually some very helpful folks on #extdev pointed me to Ted Mielczarek's excellent Extension Wizard. Give it some details about your extension (its name and version, your name, and a couple things you might want like a toolbar button, a prefs panel and a context menu) and it generates a zipped directory containing a bare bones extension, even including niceties like internationalized strings.

Even better, your new extension skeleton includes a readme that tells you how to leave the extension expanded while you work on it. That's quite a bit easier than building the XPI file and installing it each time.

So kitfox has a 0.3 version (in the unlikely event that anybody besides me wants it).

There's a project called fizzypop to develop and extend useful Mozilla dev tools like the Extension Wizard ... watch that space for more details.

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[ 20:12 Jul 04, 2008    More tech/web | permalink to this entry ]

Making Firefox 3 livable

I finally broke down and spent the time to get Firefox 3 working properly for me ... meaning, mostly, finding replacement extensions for the bare minimum of what I need in a browser: control over cookies (specifically, enabling/disabling them for specific sites), flashblock, and blocking of animated images. I'd downloaded extensions for all those a few weeks ago, but I found that although Firefox 3.0 said the FF3 extensions were active, and Firefox 2 said the old ones were, neither set actually worked.

I decided to start from scratch: remove all extensions -- rm -rf .mozilla/firefox/extensions/* .mozilla/firefox/extensions.* plus apt-get remove firefox-2-dom-inspector -- then install a new set of Firefox 3 add-ons.

After much hunting (I sure wish addons.mozilla.org would offer a way to limit the view to only extensions that work with Firefox 3! Combing through 15 pages of extensions looking for the handful that will actually install gets old fast) I found the replacements I needed: CS Lite for the cookie controls, a newer Flashblock, and Custom Toolbar Buttons as a stopgap for image animation (though I suspect updating anidisable will be a better solution in the long run). This time, with the old firefox 2 extensions purged, the new ones took hold and worked.

I also added a nice extension called OpenBook that fixes the horrible Firefox "Add bookmark" dialog. You know: the one that has two nearly identical dropdown category menus side by side, with the bigger one giving you only a tiny subset of your bookmark categories, and the smaller one being the real one. The one that doesn't offer a space for keyword, so to set up a bookmarklet you have to Add Bookmark, OK, Organize Bookmarks, find the bookmark you just added, Ctrl-I to get the Bookmark info dialog, and finally you can add your keyword. OpenBook gives you a dialog where you can set the keyword to begin with, and it only gives you one menu to list categories so you aren't constantly tempted to click on the wrong one.

Now for the urlbar -- that new firefox 3 "smarter" urlbar that slows down typing in the middle of a word so it can pop up a big fancy window full of guesses (all wrong) about where I might be trying to go. Actually, even if the guesses were right, it wouldn't help, because I'd have to stop typing, search the list visually, then if one of the suggestions was right, move my hand to the mouse or the arrow keys to choose that suggestion. That takes way longer than just typing the url.

But I guess I don't mind unhelpful suggestions popping up as long as it doesn't mess up focus (preventing me from clicking or tabbing to other apps on my screen) or slow down typing. Firefox 3 seems to be handling the focus issue better than firefox 2 did, but the slowdown was quite noticeable on the poor old laptop. So I wanted a way to disable the behavior. A little googling revealed that the Firefox crew immodestly calls their new urlbar the "awesomebar", which aside from giggle factor also proves quite useful in googling: a search on firefox disable awesomebar reveals that I'm not the only one who doesn't like it, and got me several preferences I could tweak in about:config plus a couple of extensions to turn it off entirely. I won't try to summarize, since the best settings depend on your machine's spec, plus personal preference.

Making progress! Now the only issue was getting my urlbar tweaks working, so that typing <Ctrl-Return> after typing a URL opened the URL in a new tab instead of tacking on various silly extensions (oh, yes, of course I wanted to go to http://www.firefox disable awesomebar.com rather than googling for those terms in a new tab). Fortunately, it turned out that the javascript that runs the urlbar has changed very little since firefox 2, and I hardly needed to change anything to get my kitfox extension (v. 0.2) working in Firefox 3.

Only one more issue: this blog. The CSS that handles the right sidebar wasn't displaying right. Seems that Firefox 2 has changed something about its interpretation of CSS, so it was floating the right sidebar way down to the bottom of the page below the last content line. Eventually (after adding firefox-3.0-dom-inspector, another extension that had stopped working in the transition) I discovered the problem: the #content was set to width: 77% while the #rightsidebar's left-margin was at 76%. Apparently Firefox 2 rounded up as needed, whereas Firefox 3 just ignores the left-margin if it would overlap the content, and then floats the sidebar anywhere it thinks it can fit it. Fixing those percentages helped quite a bit, and I added an overflow-x: hidden (on a tip from a helpful person in #firefox) so that wide calendar doesn't hurt layout for narrow windows. I think it's working now ... any readers having problems with the layout in any browser, by all means let me know.

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[ 11:04 Jul 04, 2008    More tech/web | permalink to this entry ]

Wed, 02 Jul 2008

Not a combination I'd think of

There's a store down the road from me that offers an unusual combination of items. It always makes me stop and wonder when I pass by.

[CIGARETTES & PURE WATER]

It must be my naivety and lack of marketing accumen, but it never would have occurred to me that cigarettes and pure water were two products that ought to be sold side by side.

The most amazing part is that another store just a few blocks away has started offering the same combination! (Though their sign is much less striking.)

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[ 22:56 Jul 02, 2008    More humor | permalink to this entry ]

Nature updates

Part of my reason for keeping this blog is keeping records of when particular events happen. If there's no story attached, that doesn't necessarily make for interesting reading. So I'll be brief, and just mention that last weekend the mysterious chlorine smell (Dave calls it a bleach smell) was fairly strong up on Skyline near Castle Rock; but it was not noticable at all the previous super-hot week. There goes the theory that it's temperature related.

And the bullfrogs are back at Walden West pond, though they're not croaking very actively. We even managed to spot a (huge!) tadpole, and the feet of something that looked like a crab but was probably a crayfish.

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[ 22:55 Jul 02, 2008    More nature | permalink to this entry ]

Sun, 22 Jun 2008

Custom ringtones on a Motorola phone, from Linux

I decided to stick a tentative toe into the current millennium and get myself a cellphone.

I sense your shock and amazement -- from people who know me, that I would do such a thing, and from everybody else at the concept that there's anybody in 2008 who didn't already have one.

I really don't think cellphones are evil, honest! (Except in the hands of someone driving a car -- wouldja please just put the phone down and pay attention to the friggin' road?) The truth is that I just don't much like talking on the phone, and generally manage fine with email. The land-line phone works fine for the scant time I spend on the phone, and I have to have the land line anyway (as part of the DSL package) so why pay another monthly bill for a second phone?

Prepaid plans looked like just the ticket, and that's what I got. With a cute little Motorola V195s. New toy! Rock! It can take custom MP3 ringtones and Java games ... but of course I don't want theirs, I want to make my own. So I wanted to talk to the phone from Linux.

The charger plug was a familiar shape -- looked a lot like a standard mini USB connector. Could the hardware be that easy? Sure enough, it's a standard mini USB. Kudos to Motorola for making that so easy! Now what about software?

My initial web searches led me down a false trail paved with programs like wammu and gnokii. I learned that I needed to enable ACM in my kernel (that's the modem protocol most cellphones use over USB), so as long as I was building a new kernel anyway, I grabbed the latest tarball from kernel.org (2.6.25.7). With that done, I was able to talk to the phone with gnokii, but the heavily Nokia-oriented program didn't show me much that looked useful.

Moto4lin is the answer

I set the project aside for a while. But half a week later while looking for something else, I stumbled across moto4lin, which turned out to be exactly what I needed. I had to run as root, or else when I try to connect, it prints on stderr:

sendControl Error:[error sending control message: Operation not permitted]
) but I'm sure that can be solved somehow.

So run as root, click Connect, click File Manager if you're not already in that mode, then click Update List and it reads the files. Once they're there, you can click around in the folder list on the left looking for the audio files (on my phone, they're in a directory called audio somewhere under C, not A). Excellent!

Creating a ringtone leads to a kernel debugging digression

Okay, now I needed a ringtone. I wanted to use a bit of birdsong, so I loaded one of the tracks I use for tweet into Audacity and fiddled semi-randomly until I figured out how to cut and save a short clip. It would only save as WAV, but lame clip.wav clip.mp3 solved that just fine.

(Update: the easiest way is to select the clip you want, then do File->Export Selection...)

Except ... somewhere along the way, the clips stopped playing. I couldn't even play the original ogg track from tweet. It *looked* like it was playing ... it found the track, printed information about it, showed a running time-counter for the appropriate amount of time ... but made no sound.

It eventually turned out that the problem was that shiny new 2.6.25.7 kernel I'd downloaded. A bug introduced in 2.6.24 to the ymfpci sound card driver makes Yamaha sound cards unable to play anything with a bitrate of 44100 (which happens to be the typical CD bitrate). After a lot of debugging I eventually filed bug 10963 with a patch that reverts the old, working code from 2.6.23.17.

Ringtone success

Okay, a typical open source digression. But while I was still trying to track down the kernel bug, I meanwhile found this Razr page that tipped me off that I might need a different bitrate for ringtones anyway. So I converted it with:

lame -b 40 mock.wav mock.mp3
(which also made it playable on the new kernel.) I also found some useful information in the lengthy Ubuntu forums discussion of moto4lin.

In the end, I was able to transfer the file easily to the motorola phone, and to use it as my nifty new ringtone. Success! Too bad nobody ever calls me and this phone is mostly for outgoing calls ...

Now to look for some fun Java apps.

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[ 19:27 Jun 22, 2008    More linux | permalink to this entry ]

Thu, 12 Jun 2008

Making Firefox default to Portrait printing

I discovered a handy tip for Linux Firefox' printing Page Setup today.

Normal web page printing uses "Portrait" mode: you read the page with the paper oriented so that it's taller than it is wide.

Once a week, I need to print a form from a club web site to bring to the meetings. It's a table that's much wider than it is tall, so I want to print it that way: in "Landscape" mode.

In Firefox 2 (at least on Linux), you can't do that from the Print dialog -- there's no Portrait/Landscape option. So you have to use a separate dialog, Page Setup, following these steps:

  1. Run Page Setup
  2. Change Portrait to Landscape
  3. Click OK
  4. Print (bring up the Print dialog and click OK)
  5. Run Page Setup
  6. Change Landscape to Portrait
  7. Click OK
Kind of a lot of steps just to print one landscape page! But if you forget, the next page you print from Firefox will be printed in Landscape mode and will take twice as many pages as it should (if you don't notice what's happening and dive for the printer's OFF switch in time, that being the only way to cancel a printing job once it hits the printer).

This morning, it finally occurred to me that Firefox was storing this setting somehow, most likely in prefs.js. If I could find the setting and force it in user.js (which takes precedence over prefs.js and is not updated by Firefox), I could make Firefox set itself back to Portrait every time it starts up. (prefs.js and user.js are both generally found in $HOME/.mozilla/firefox/).

Some greppery-pokery revealed the solution. I needed only to add a line in user.js that looks like this:

user_pref("print.printer_CUPS/Epson.print_orientation", 0);
and presto! my problem was solved.

Oddly, it's set separately for every printer you have defined, even though there's no way to set one printer to Landscape while another one is still on Portrait (the Page Setup dialog is global, and applies to every printer Firefox knows about). "Epson" is the CUPS name of my primary printer; replace that with your printer's name (as set in CUPS), and add a similar line for each printer you have. For the printers I've used, 0 is Portrait and 1 is Landscape, but you can verify that by typing:

grep orientation prefs.js | grep name

That command will also help you if you're not sure what printers you have defined, or you don't use CUPS but want to try this under a different print spooler. (Don't be misled by all the orientation prefs with "tmp" in the name.)

As a minor digression, there's actually a secret pref that's supposed to give another way around the problem:

user_pref("print.whileInPrintPreview", true);
This lets you do all your printing from the Print Preview window, which offers its own Portrait and Landscape buttons. That would be a nice solution. Alas, the Portrait and Landscape buttons in that dialog currently don't work, and since this preference is undocumented and unmaintained, filing more bugs isn't likely to help.

(I should mention that this all pertains to Firefox 2. I haven't switched to Firefox 3 yet, so I don't know the state of its printing UI, or whether this preference is either helpful or effective there.)

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[ 20:07 Jun 12, 2008    More tech/web | permalink to this entry ]