October 15th, 2012
I’ve been playing with drawing on your own widgets in PyGTK on Windows, and I found it incredibly difficult to figure out how to draw something in color on a gtk.gdk.Drawable object using draw_line, draw_rectangle, etc. You can’t just set the color using the semi-obvious mechanism:
gc = widget.window.new_gc()
I think the reason it doesn’t work is because if the color isn’t in the device-specific colormap, then GTK will ignore whatever color you set without bothering to warn you that something is wrong. However, I’ve finally hit on something that works. In your expose event (or elsewhere), you can put in something like the following:
def on_expose_event(self, widget, event):
gc = widget.window.new_gc()
colormap = self.gc.get_colormap()
color = colormap.alloc_color('yellow')
# whatever gtk.gdk.Drawable draw_* functions you call here
# will use that color
Hope you find this useful!
October 10th, 2012
Apparently at some point my anti-spam plugin decided to stop working. No wonder I haven’t had any comments in a really long time…. should be working now!
October 6th, 2012
Well, I haven’t blogged here in quite awhile, but it’s been a pretty busy year! One project I’ve been spending a fair amount of time on is Exaile, a cross platform music player for GTK+ (its free and works on Windows, Linux, and even OSX — though, the installation for OSX is rather tricky). I’ve been DJ’ing Lindy Hop dances for almost a year now, and I’ve been fixing up Exaile to be an awesome music player for DJing — adding a BPM counter, secondary output device support (sometimes called pre-listening), and other things that I’ve found to be useful.
One feature in particular I want to highlight is a plugin I’ve created called GroupTagger. This super-useful plugin is distributed with the latest stable version of Exaile. This plugin allows you to easily and rapidly organize your music using the ‘Grouping’ tag in your audio files. The best part about this is that the data is stored in your MP3/OGG/FLAC/whatever audio files, so you can use the data with your favorite audio player if it supports it (Winamp, iTunes, others already do). A lot of people already categorize their music using this tag, and this plugin can manage music that is already tagged this way. To illustrate how useful this is, here are some screenshots and a mini-tutorial.
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October 3rd, 2011
I’ve been starting to use my desktop machine at home a lot lately, so I’ve been looking for a cross-platform audio player that I can use that doesn’t annoy me. After a long search (and discarding most of the linux audio players: amarok, banshee, etc as too annoying or not the right features or whatever) I finally stumbled across Exaile, which not only doesn’t annoy me greatly, but it’s written in python so its way easy to modify and figure out what it does
I’ve been doing a bit of swing dancing lately (in particular Lindy Hop), so I’ve been gathering music together to listen to, and I need BPM for the music… one thing Exaile did not already have was a BPM counter, so I wrote a manual beat counter for it. You can write plugins for Exaile, though the documentation is rather sparse. I must say though, using the GLADE widget editor thing has to be the most annoying GUI design tool ever…
Download it at my usual software site.
PS: In case anyone asks, I’m not interested in writing an automated beat counter… this works well enough for me
January 11th, 2011
I’m really excited about the idea of using python on our FIRST Robotics Team’s Robot this year, and one of the first things that got really annoying was the lack of debugging capability, since vxWorks doesn’t really have a console (I mean it does, but in the way that FRC has it setup, its not really a console in the traditional sense of the word). So I searched around and found Winpdb, a pretty neat remote debugger for python. So after playing with it for a bit, I’ve got it working on RobotPy and it seems to do the trick so far.
I’ll be creating some other tools as needed, so watch for more python in the future!
November 12th, 2010
The FIRST Robotics Competition uses the NI-cRio platform for the controller for the robots in the competition. There is a bit of functionality called ‘NetConsole’ which sends the stdout from vxWorks out to a waiting client (refer to the WPI FIRST website for instructions to enable this). It turns out that the protocol used to implement the NetConsole for the cRio is incredibly simple… it just sends the raw output data as a bunch of UDP packets out to the broadcast address on port 6666 (which I suppose is slightly amusing). Here’s a dirt-simple python script that catches the output (TODO: need to send it input… haven’t gotten around to looking at that yet).
sock = socket.socket( socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP )
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
sock.bind( ('',UDP_PORT) )
result = select.select( [sock], ,  )
msg = result.recv( 8196 )
May 23rd, 2010
So my dad tends to have a lot of really dumb computer problems that are either caused by him or some random virus/malware that he somehow manages to get on his system. And of course, I get to be ‘Mr. Helpdesk’ and help him fix them (sometimes), even though I’m 900 miles always from him.
His latest dumb computer trick involved some weird bug where he created a partition while Windows was running, formatted it, *moved* (not copied, but *moved*) a bunch of data to it, and then managed to get a blue screen without rebooting the system. For whatever reason, Windows decided that it didn’t want to write the partition or boot sectors for the hard drive correctly, and so he temporarily lost his data. In the past when I’ve had these kinds of problems with partition layouts, I’ve done things like manually recreating the MBR (a very long time ago) or using something like linux’s fdisk to set the parameters manually. However, the ‘easy’ tricks didn’t work for his problem this time, but I found this marvelous software that seems to do the trick:
So hopefully it’s useful for you too!
March 24th, 2010
I’ve become a fan of the obsidian theme for notepad++ (even though I know it comes from other locations as well), because I feel like the theme is a lot easier on my eyes. So I’ve had to start using Visual Studio a bit more lately, and I adjusted the fonts/colors to match the notepad++ obsidian theme (with some variation, of course). I’ve exported the settings, and you can use them as you wish. I haven’t fully explored the settings yet, but this seems to do it for much of the stuff I run into. If you have adjustments for this that makes it better, let me know!
January 23rd, 2010
This is a better packaged version of WebDMA, with a few feature improvements. Of particular interest to FRC teams, I have released an installer that installs the object files for WebDMA on your robot, and copies the header files to the needed locations for Wind River. There is also a sample program installed for Wind River as well that allows you to control two motors on your robot with the web interface as a demo. All you need to do to use WebDMA on your robot is install the install package to your development computer, and then run the install program to copy the necessary object files to your robot.
While this is very easy and painfree for beginners to install and use, of course I must give you this disclaimer since a program installed by the installer writes directly to the robot to install the object file:
WARNING: The provided installer will WRITE DIRECTLY TO YOUR ROBOT and modify files on it via FTP.
While I have tested this and this works just fine for our team on our cRio with no ill effects, I cannot be held responsible for your robot. This installer is not sanctioned or associated with National Instruments, Wind River, or FIRST Robotics. In particular, this may void your warranty, render your cRio useless, and COST YOUR TEAM A LOT OF MONEY.
If you are a student: DO NOT DOWNLOAD AND INSTALL THIS ON YOUR ROBOT WITHOUT ASKING THE ADULT LEADER OF YOUR TEAM.
But seriously, it works just fine for me though. And if you have problems, let me know.
November 24th, 2009
I gave a presentation at work about Boost.Asio, and it came out reasonably well, so I figured I would post the slides here. Its a brief introduction to Asio and what one might use it for. Also has some basic concepts and patterns one might use while programming with Asio. Aimed for a technical audience, but nothing too detailed though.
Boost.Asio Tech Talk Slides (PDF)