pmuellr is Patrick Mueller

other pmuellr thangs: home page, twitter, flickr, github

Friday, December 17, 2010

weinre at GitHub

I finally pushed my weinre project up to GitHub last night:

weinre - web inspector remote - pronounced "winery"

It's a debugger for mobile web apps. Uses the Web Inspector debug front-end from WebKit (implemented in HTML/CSS/JS), plugged up to some plain old JavaScript running in your web page. There's an HTTP server in there somewhere.

It's early days - it may not be the easiest thing to set up and run - and there's a lot of function not implemented (showing all the CSS style info, for instance). But it's something.

I intend to continue enhancing it over the next while. First order of business will be to get it back, function-wise, to where my earlier prototype was, as shown in this video. I've been spending more time on infrastructure stuff than adding debug function lately - it'll be fun to dive back into the innards of Web Inspector again.

My intention is for this work to eventually be folded into the PhoneGap project. PhoneGap (wisely IMO) requires a Contributor Agreement in place before accepting contributions, so I won't be able to accept any contributions into my repo unless you've signed up.

If you have questions, feature requests, etc, create an issue at GitHub. I also hang out on #phonegap on freenode during business hours (US east).

Tasty Innards Too!

Besides this project's subject matter being a fun thing to work on (building a working debugger), I've had a lot of fun building and using smaller thingees. If I can get my blogging going again, hopefully I'll write more about some of these goodies, soon:

  • All my JavaScript code is structured as CommonJS modules, using modjewel.

  • All my JavaScript is written in a pidgin dialect of JavaScript called scoop. Basically just a lexically simpler way to define classes, methods, etc in JavaScript (if you didn't know already, I'm an old Smalltalk dude). Here's an example - the implementation of the Console class used by the debug target.

  • The interface between the large grained components of weinre is specified in a subset-but-extended bastardization of WebIDL. The Web Inspector code already does this itself (because WebKit in general does this also), and it worked out well for me. I wrote a WebIDL-to-JSON compiler, and the runtime makes use of the JSON to create proxies, etc. Lots more interesting stuff can be done here, I'm sure.

Tuesday, December 14, 2010

tech books on the Kindle

Three images from David Flanagan's JQuery Pocket Reference, as they look on my 3rd generation (latest) 6" (not the big one) Kindle.

The first image below is from the PDF version of the book.

The font size is a little too small for me, and I would assume, most people. It also wastes a lot of space on the left and right margins in general, on the indentation of the code sample, and the footer information.

Note that PDFs are not "resizable" in the same way a web page is; you can't make the font larger. What you see is what you get.

The next image below is from the Mobi version of the book. Mobi is a publishing format that has been used by various reader software over the years, and is the "native" format for the Kindle.

What I'm showing here is the text at the smallest font size supported. I typically read at one font size up from that. There are 8 font sizes available when you're reading Mobi files, along with being able to tweak the line spacing a bit, etc.

I'm showing the smallest font size because it shows one of the biggest problems with using Mobi for tech documents - the code sample is too big for this font size (the smallest!) and it wraps. It just looks terrible.

I have some experience with the Mobi format, converting HTML documents to Mobi using Calibre. It appears the Mobi format is pretty limited. I've tried all sorts of styling of <pre> elements, and the best you can do is force some vertical whitespace (not the default!) in front of your code samples. It's just awful.

What's a boy to do? Turns out O'Reilly also offers an ePub version of their eBooks. You can easily turn your ePub into a Mobi with Calibre, but you're not going to be able to do much better than the image above.

So I did something different:

  • unzip the ePub - ePub files are zip files with an .epub file extension

  • concatenate all the .html files in the epub together, into one file - ePub files are XHTML files for their main text content

    cat ch*.html > combined.html
  • remove the <head> sections with a find/replace regex pattern, etc

  • add a simple <style> section:

        h1.title {
            page-break-before:  always;
        body {
            font-size:          200%;
            font-family:        Georgia;
        pre {
            font-size:          70%;
            background-color:   #EEE;
            padding:            0.5em;
            overflow:           hidden;
            border-radius:      0.5em;
            -moz-border-radius: 0.5em;
        .sidebar {
            padding:            0.0em 0.5em;
            overflow:           hidden;
            border-radius:      0.5em;
            -moz-border-radius: 0.5em;
            background-color:   #EEE;
        .sidebar p.title {
            font-weight:        bold;
  • bring the resulting file up in FireFox

  • print, but save to PDF instead of actually print (I'm on a Mac)

  • copy the PDF to the Kindle

Here's the result. Not perfect, but much better than the other two files. The font is larger, and the code sample is readable and well separated from the other text.

Note: FireFox is not my day-to-day web browser, but is the only browser that produces usable PDF files for files like this. PDFs produced from both Safari and Chrome only last about 30 pages or so before the text disappears, when viewed on the Kindle. Who knows.

Update on 2010/12/14 at 1:20pm - the images aren't working from flickr, so put on dropbox