I recently contributed some introduction to the Gerrit
Project. This included some
screenshots and understandably the project maintainers are concerned
about the overhead of keeping these screenshots up to date. So just for
my own interest I've started looking in to how to automate the
generation of these screenshots. This is not a working solution yet,
just a collection of the ideas I'm playing with.
This first thing I started looking at was how I could automatically
create a screenshots of the browser. After a bit of googling these seem
to be two broad techniques. There are a few tools that given a URL will
generate an image. Khtml2png and
webkit2png seem to be good
examples of these tools. While these are fine tools I really want to be
able to capture pictures of the application as I modify it, so they
don't quite serve my purpose.
The second technique seems rather more promising, starting a headless X
Server using xvfb, starting firefox
in it and then creating an image of this virtual screen using the
ImageMagick's import tool.
This is really much simpler than it sounds, it looks something like
$ Xvfb :2 -screen 0 800x600x24 & -- Start the virtual frame buffer
$ DISPLAY=:2 icewm & -- Start ice window manager so we get chrome
$ DISPLAY=:2 firefox &
$ DISPLAY=:2 import -window root snapshot.png
Simple enough really, I think it's quite a neat trick myself. Of course
it could be any X server, I'm using Xvfb to make it completely
standalone, but it also works with
Xvnc if you
want to interact with the applications you've started. Jordan Sissel has
a script which finds a free display number and starts Xvfb for this.
Next, attempts to automate the browser session so I can actually take
the screenshots I need.
There are comments.