therning.org/ magnus

With Python being dropped as a language for extensions in epiphany 2.28 I needed to replace epilicious. I tried writing it in JavaScript (seed was integrated in 2.28), but I gave up due to hitting too many hurdles on the way. Instead I decided to rewrite epilicious using Vala and a minimal layer of C.

It turned out to be very doable, despite epiphany’s extension API lacking Vala bindings (Cosimo Cecchi, I’m looking at you ). Basically I did the following setup:

1. Add the extension following the instructions in Writing Epiphany Extensions by Adam Hooper.
2. Add a check for valac in configure.ac.
3. Add a rule in the extension’s Makefile.am to generate a C header file for all the Vala code, for use from C.

Then I started writing the actual extension. I did the minimal amount of work in C, trying to escape as soon as possible into Vala. In the few places I needed to call from Vala into C I would declare a delegate in Vala, and pass a function from Cⁱ.

I call this new version BMS, for bookmark synchronisation. I have a patch for BMS that applies to epiphany 2.28.1. (The file also contain a PKGBUILD in order to delight Arch users )

I should probably point out that while epilicious never could be called polished, BMS is even less so. I might find the time to make it multi-threaded, so that it’s possible to do some sort of progress dialogue, but don’t hold your breath. In the back of my mind is also the thought of rewriting it yet again, in JavaScript/seed.

1. The format of .vapi files are unknown to me, and I haven’t managed to find much documentation. Using function pointers seemed like an easier way, especially given that I needed this in exactly 3 places.[back]

Since the Python extensions to Epiphany have been removed from the repository I thought it was high time to start playing with what seems to be the replacement to Python extensions: Seed extensions. The first step is of course to get a version of Epiphany that supports Seed extensions. After a few emails on the mailing list I’ve come to a recipe (I’ve done this twice now on different machines to I’m fairly confident it works). I should probably preface this by saying that I run an up-to-date Arch system, if you run something else you might need to do a bit more, or less if you’re lucky

1. Make sure the following packages are installedⁱ: libsoup, libwebkit, gnome-common, intltool, libffi
2. Clone the following Git repositories from git.gnome.org: epiphany-extensions, epiphany, seed, gobject-inspection, gnome-js-common, gir-repository

3. Decide on a $prefix, i.e. where you want it all installed (I use ~/opt/gnome-trunk). Then export the following environment variables:

   export PATH=$prefix/bin:$PATH
   export PKG_CONFIG_PATH=$prefix/lib/pkgconfig
   

4. Then configure, build and install everything. Use the autogen.sh script to create the configuration, and make sure to pass it prefix=$prefix each time. Some of the modules need extra arguments as well. This is the order and extra arguments I used:

   1. gnome-js-common (--disable-seed --disable-gjs)
   2. seed
   3. gnome-js-common (--disable-gjs)
   4. gobject-introspection
   5. gir-repository
   6. epiphany (--enable-introspection --enable-seed)
   7. epiphany-extensions

After that you can put your extensions in ~/.gnome2/epiphany/extensions/. I have two instances of Epiphany installed, a stable from my distro, and the dev version I built myself. I haven’t managed to run them both side by side, but beyond that there seems to be no bad interaction between them.

1. You might need a few more packages depending on what desktop environment you use. Those were the packages I needed to add to my machine where I run Gnome and do regular non-Gnome development[back]