While hacking on ape, I came to a situation where I need to pass some arguments to a custom defined slot. The slot is being called from different signals, one where the argument is passed by PyQt itself and a second one where I need to programmatically pass the argument to the slot.

First I tried with something like:

action = QAction("My action", parent)
action.triggered.connect(my_slot(my_argument))

which ended in an error: TypeError: connect() slot argument should be a callable or a signal, not ‘NoneType’

After a bit of poking around I passed a lambda function to the connect() method:

action = QAction("My action", parent)
action.triggered.connect(lambda arg=my_argument: my_slot(arg))

Works like a charm.

Also this is my first try to use github gists as a way to embed/highlight code. Hope it’ll work out.

Happy hackin’!

While working on ape I had a problem with figuring out how to properly connect a signal to a slot, where the signal is emitted by a QTreeView widget. As this is not my first app with python and pyqt, I was doing something like (this is, btw, the “old style”):

self.connect(widget, SIGNAL("emitted_signal()"), self.my_slot)

but it simply didn’t work. Nothing happened. I was trying all different of connect/signal/slot combinations but everything was just dead silent. Google gave only pretty much old posts talking about QT3. Then I figured that, because the QTreeView is “sitting” inside a QDockWidget, maybe that dock widget thingy is somehow intercepting/taking over the signals. Nope. Wth? Wtf is going on? Current pyqt version is (on my machine) 4.6. Last time I used pyqt it was something like 4.2 or 4.3. Something must’ve been changed in the mean time. Off to the pyqt docs I go (btw, I use the official QT docs, the C++ version, there isn’t really a big difference from pyqt): PyQt reference, chapter 7 – “New-style Signal and Slot Support”. A-ha! They changed it! Here is an example of the “new style”:

widget.emmited_signal.connect(self.my_slot)

Oh my, isn’t that just beautiful?! Much more readable and simpler, for me at least. And it works! Yay! The QTreeView signals are happily connected to slots, thus, I’m happy too.

A few paragraphs later, turns out that the “old style” isn’t thrown out, it should still work. Why it didn’t work for me escapes me at the moment, but honestly, I don’t really care as long as the new style is working.

Happy hackin’!

P.S.: The syntax highlighter is a bit out dated thus breaking python code. Will fix it. Some day.

A week ago I started working on a simple editor/IDE for PHP called ape. That’s my weak try on creating a reverse acronym as ape stands for – ape is a PHP editor. This is kind of an introductory post into the whole developing process of it, as my intention is to blog about it a bit more :)

Why?

First, to answer the question everyone is giving me when I mention I’m writing ape:
“Why the hell do you do that (to yourself)?”

Programming is fun. Programming is interesting. Programming makes me learn new things. I like having fun and I do this to learn more about programming and having even more fun. I’m writing web applications each and every day, so writing a desktop app requires a different way of thinking and leaving my “comfort zone” (altho, I’m quite comfortable in front of the keyboard hackin’ away code). ape is written in python and pyqt, but again, it’s not about the language used, for me it is about programming.

The idea

Netbeans is my main IDE for quite some time now and I love it. I know my way around vim, too. But, netbeans has too many features for my taste – I use SVN, git, (on rare occasions I write them) run unit tests from the console. As for vim, maybe I just don’t get it enough, but I feel less productive with it. Debugging PHP apps ends up var_dump-ing things all over the place. So, basically what I want/need from an editor is grouping files into projects, regex search/replace, code coloring & completion and, of course, file editing.

I plan to write a feature a day. On my personal projects I usually want to push out as much code as I can during one day as I’m highly motivated, but this time want to try a different approach. So far I didn’t got far, figured out syntax highlighting, opening files from a file browser widget thingy and things like that, but more on that in other posts.

If anyone wants to take a look, the source code is up on github. It is licensed under GNU GPL v2, as pyqt is licensed under it and I don’t want to waste my time on figuring out could I use MIT or some other license.

Happy hackin’!

It’s been a while since I last wrote something; didn’t have anything smart or interesting to say. Not that I do have this time. It’s 4AM and I can’t sleep. Can’t really find the inspiration for work and writing (if you can consider these scribblings as writing). Lots of ssss… stuff happened which had a great impact on my mood and my ability to do something useful. And I just didn’t felt like doing something about it. Until recently…

I was having a couple of beers with a friend of mine, with whom I go to college. After the 3rd beer or so, we came to an idea of submitting a paper to this year’s SISY conference. All I will say for now, that it will include Python, Assembly, microcontrollers, electric motors and lots of other geeky stuff. This project, even while the idea is still only in my head, got my mind running again and might be the way out of this state of indifference. Why? Well, to be able to start this project, I first need to finish my current project, my graduate work. To finish my grad work, I needed to start working on it again (which I did, honest!). I’ll even spend my whole Saturday this week in the college to write/test/debug my app there. If all goes well, the app will be finished this week and I can go onto writing the documentation for the grad work. Everything will go fine, right?

I installed Ubuntu 9.04 on my laptop a few days ago. Loving it! Had only 2 minor issues with the hardware upon the installation. First, the graphic card was messing around, it didn’t want to enable all those funky visual effects. That got sorted out, thanks to @firusvg who suggested to install compiz and @ivan86 who pointed me to this article. Second, when plugged in the headphones, the sound was still coming out on the speakers. @Asgrim sent me this link which helped me to sort this out. Apart from this, everything else works out-of-box. Even the wifi!

OK, enough for now. Here’s to hoping that the bad times are over and the good times are coming. Cheers!

I wrote a Python script for automating the steps required to setup a web project environment on my local dev machine that runs on Ubuntu. Called it pywst: Python, Web, Svn, Trac. That’s the best I could do, sorry :P

The main steps for setting up a new project are:

• Create a virtual host
• Add it to /etc/hosts
• Enable the virtual host
• Import the new project to the SVN repository
• Checkout the project to /var/www
• Create a TRAC environment for the project
• Restart Apache

After these steps I have http://projectName.lh/ which points to /var/www/projectName/public/, SVN repo under http://localhost/repos/projectName/ and the TRAC environment under http://localhost/trac/projectName/.

As I have this ability to forget things, I always forget a step or 2 of this process. Thus, I wrote pywst (note, this is a txt file, to use it, save it to your HDD and rename it to pywst.py). It’s not the best and nicest Python script ever wrote, but gets the job done. All that is need to be done to setup a project with pywst is:

sudo ./pywst.py projectName

2 things are required: to run it with sudo powers and to provide a name for the project.

Future improvements

The first, and the most important is to finish the rollback() method. Now, it only exits pywst when an error occurs, but it should undo all the steps made prior to the error.

Second, to make it work on other distros, not only on Ubuntu. That would require for me getting those other distros, set them up, look where they store Apache and stuff, where’s the default document root, etc. Hmm… This will take a while :)

Third, support PHP frameworks – Zend Framework, CodeIgniter and CakePHP — ZF is a must :P Under support I mean to create the basic file structure for them automagically.

Cheers!