Skip to main content

Dead to Me! Trapdoor, Prototyping web-based desktop applications

This is the inaugural post in my Dead to Me! series which I announced.

I’m not gonna lie. I’m pretty proud of this one. To say Trapdoor was ahead of the times might be a stretch, but really only a small stretch.


My project README explains


Trapdoor is a web-based desktop framework. Confused yet? The idea is to leverage how much energy is put into the web today and make developing a desktop application fun again. Again? For the first time?


Trapdoor was an exploration of how to utilize web development skillsets to build desktop tools. I wanted to experiment with how this idea would play out and if it really made any sense. I was never planning Trapdoor to become are solution. I just wanted to play with the idea, but I do think I played with the idea pretty early on and that it was an extremely successful experiment.


At the time I was still a KDE user and had been learning a little bit of Qt via the Python bindings PyQt4. I knew that Qt had a WebKit widget and quickly found that PyQt4 exposed this pretty easily.





This was a simple demo I built with Trapdoor. We have a web-app built, for this simple example, all in Javascript dumping a few simple controls to the DOM. The JS is responsible for window creation and gets access to the DOM in the new window, where it can construct an interface in HTML and use jQuery to wire it up.


What I was most proud of is that, recognizing this would only be useful if the desktop applications being built could do anything a normal desktop app could do, I made it really easy to extend the Javascript APIs with new things.


The Calculator class defined in the above calculator.py file above and registered in the manifest is able to expose methods to the Javascript API it injects into the application. Otherwise, it is just regular everyday Python and can do anything and can use any Python libraries.


I only worked on Trapdoor for three days. Vaguely I recall wondering if I could write an extension that used PyOpenGL to render 3D graphics in my web-based desktop application, a good year before the WebGL spec landed and three and a half years before work would begin on Node Webkit. Trapdoor won’t be worked on by me and shouldn’t be picked up by anyone else, probably. It will continue to sit in my Github for a while, but it stay forever among my favorite personal projects.

Check it out, if you’re curious.

Comments

Anonymous said…
How to run examples?

trapdoor$ ./run-trapdoor demos.helloworld

just hangs
Calvin Spealman said…
Sorry I have not touched this code in 4 years, and I don't have an environment with the dependencies right now (I only ever tested it on Linux and I use Mac/Windows mostly now). I am really happy to see someone trying to use it, but I can't say why it would be hanging. I have not tried it on any modern version of Qt, either.

Popular posts from this blog

Why I Switched From Git to Microsoft OneDrive

I made the unexpected move with a string of recent projects to drop Git to sync between my different computers in favor of OneDrive, the file sync offering from Microsoft. Its like Dropbox, but "enterprise."

Feeling a little ashamed at what I previously would have scoffed at should I hear of it from another developer, I felt a little write up of the why and the experience could be a good idea. Now, I should emphasize that I'm not dropping Git for all my projects, just specific kinds of projects. I've been making this change in habit for projects that are just for me, not shared with anyone else. It has been especially helpful in projects I work on sporadically. More on why a little later.

So, what drove me away from Git, exactly?

On the smallest projects, like game jam hacks, I just wanted to code. I didn't want to think about revisions and commit messages. I didn't need branching or merges. I didn't even need to rollback to another version, ever. I just …

CARDIAC: The Cardboard Computer

I am just so excited about this.


CARDIAC. The Cardboard Computer. How cool is that? This piece of history is amazing and better than that: it is extremely accessible. This fantastic design was built in 1969 by David Hagelbarger at Bell Labs to explain what computers were to those who would otherwise have no exposure to them. Miraculously, the CARDIAC (CARDboard Interactive Aid to Computation) was able to actually function as a slow and rudimentary computer. 
One of the most fascinating aspects of this gem is that at the time of its publication the scope it was able to demonstrate was actually useful in explaining what a computer was. Could you imagine trying to explain computers today with anything close to the CARDIAC?

It had 100 memory locations and only ten instructions. The memory held signed 3-digit numbers (-999 through 999) and instructions could be encoded such that the first digit was the instruction and the second two digits were the address of memory to operate on. The only re…

On Pruning Your Passions

We live in a hobby-rich world. There is no shortage of pastimes to grow a passion for. There is a shortage of one thing: time to indulge those passions. If you're someone who pours your heart into that one thing that makes your life worthwhile, that's a great deal. But, what if you've got no shortage of interests that draw your attention and you realize you will never have the time for all of them?

If I look at all the things I'd love to do with my life as a rose bush I'm tending, I realize that careful pruning is essential for the best outcome. This is a hard lesson to learn, because it can mean cutting beautiful flowers and watching the petals fall to the ground to wither. It has to be done.

I have a full time job that takes a lot of my mental energy. I have a wife and a son and family time is very important in my house. I try to read more, and I want to keep up with new developments in my career, and I'm trying to make time for simple, intentional relaxing t…