As of Friday night, I am now on a two month unpaid leave. There are a few reasons I want to do this. It’s getting towards the 3-year point at Mozilla, and that’s usually the sort of time I get itchy feet to try something new. I also think I may have been getting a bit close to burn-out, which is obviously no good. I love my job at Mozilla and I think they’ve spoiled me too much for me to easily work elsewhere even if that wasn’t the case, so that’s one reason to take an extended break.

I still think Mozilla is a great place to work, where there are always opportunities to learn, to expand your horizons and to meet new people. An unfortunate consequence of that, though, is that I think it’s also quite high-stress. Not the kind of obvious stress you get from tight deadlines and other external pressures, but a more subtle, internal stress that you get from constantly striving to keep up and be the best you can be. Mozilla’s big enough now that it’s not uncommon to see people leave, but it does seem that a disproportionate amount of them cite stress or needing time to deal with life issues as part of the reason for moving on. Maybe we need to get better at recognising that, or at encouraging people to take more personal time?

Another reason though, and the primary reason, is that I want to spend some serious time working on creating a game. Those who know me know that I’m quite an avid gamer, and I’ve always had an interest in games development (I even spoke about it at Guadec some years back). Pre-employment, a lot of my spare time was spent developing games. Mostly embarrassingly poor efforts when I view them now, but it’s something I used to be quite passionate about. At some point, I think I decided that I preferred app development to games development, and went down that route. Given that I haven’t really been doing app development since joining Mozilla, it feels like a good time to revisit games development. If you’re interested in hearing about that, you may want to follow this Twitter account. We’ve started already, and I like to think that what we have planned, though very highly influenced by existing games, provides some fun, original twists. Let’s see how this goes

I’ve never really considered myself an unhealthy person. I exercise quite regularly and keep up with a reasonable amount of active hobbies (climbing, squash, tennis). That’s not really lapsed much, except for the time the London Mozilla office wasn’t ready and I worked at home – I think I climbed less during that period. Apparently though, that isn’t enough… After EdgeConf, I noticed in the recording of the session I participated in that I was looking a bit more plump than the mental image I had of myself. I weighed myself, and came to the shocking realisation that I was almost 14 stone (89kg). This put me well into the ‘overweight’ category, and was at least a stone heavier than I thought I was.

I’d long been considering changing my diet. I found Paul Rouget’s post particularly inspiring, and discussing diet with colleagues at various work-weeks had put ideas in my head. You could say that I was somewhat of a diet sceptic; I’d always thought that exercise was the key to maintaining a particular weight, especially cardiovascular exercise, and that with an active lifestyle you could get away with eating what you like. I’ve discovered that, for the most part, this was just plain wrong.

Before I go into the details of what I’ve done over the past 5 months, let me present some data:

I started my new diet on February 10th, and as of today (July 13th), I’ve lost 3 stone/~19kg and am well in the ‘ideal’ weight range. Of course, BMI is a pretty rough measure of anything, but I feel better, I’m in much better shape and I find physical activity far more enjoyable than I used to. So how did I do it?

One of the things that really intrigued me about Paul’s diet was that he said that all he did to lose the weight was change what he ate. Nothing else. This was a pretty enticing idea. I never thought I’d be able to give up things like pasta and bread, but if it really meant your weight would just start decreasing with no further effort, it almost seems silly not to give it a try… So I gave it a try. I cut out the major sources of carbohydrate in my diet (potato, pasta, rice, bread, snacks) and indeed my weight, as you can see, immediately started dropping. If you have the weight to lose, the results are pretty dramatic, and much faster than you’d expect. At this point, I was doing no extra exercise, and although I was snacking much less, my portion sizes for meals were unchanged.

I found some nice alternatives for the things I missed. Pasta and rice are quite nicely replaced by steamed, crushed cauliflower. Steamed aubergine makes a nice filler too. For potato, sweet potato is pretty much just better as far as I’m concerned, and celeriac is also a nice alternative. I never really found an alternative to bread, so I still have breakfast with my parents on the weekends and eat my mum’s home-made wholemeal bread. In moderation, I’ve not found it to interrupt my weight-loss at all. I still have porridge for breakfast, and I’m not strict about keeping to any particular amount of carbs in a day. If I gain weight on a day, I just try to be a bit more careful the next day.

The first two stone just dropped off. I did no extra exercise, I didn’t count my calories. The only thing I did was avoid high-carbohydrate foods and weight myself every day. There seem to be mixed opinions on weigh-in frequency, but being able to see the numbers go up and down was pretty significant motivation for me. Your mileage, as ever, may vary. After getting to about 12 stone, my fellow London Mozillian Jonathan Watt challenged me to beat him to 70kg. I’m very grateful for that, as at that time I was pretty happy with 12 stone (it’s in the ideal range and it felt and looked noticeable to me).

The next stone, though still reasonably easy, didn’t come without effort. However, this increased effort was enjoyable, and is now a part of my life (and I intend that to continue). It ends up that carrying 12kg less weight while climbing makes it much more enjoyable, so I was able to climb longer and more frequently. Similarly, I started running with another colleague, Ryan Watson. The weight continued to come off, if anything at an increased rate now, and I was reaching weights I hadn’t been since my early teens.

The last few pounds has been difficult though. I wanted to hit 10 stone 12 to say that I lost 3 stone exactly (perhaps a slightly obsessive compulsion with whole numbers), but realistically, I think 70kg/~11 stone is the weight I’ll maintain. I’m now training for strength to change my body composition to something that will more easily allow me to maintain this weight.

A lot of people helped me to get this far. Ryan was especially encouraging and helped me train when I started to up the exercise. Without Jonathan’s competition, I may have settled for a weight that was still really above the weight I should be and last but not least, I have to thank my wonderful partner Laura for accommodating my new diet and helping me find lots of tasty things to eat. Not to mention my wonderful friends, family and colleagues, all of whom have been terrifically encouraging and supportive. Thanks, everyone

For the last week I’ve been using a Geeksphone Keon as my only phone. There’s been no cheating here, I don’t have a backup Android phone and I’ve not taken to carrying around a tablet everywhere I go (though its use has increased at home slightly…) On the whole, the experience has been positive. Considering how entrenched I was in Android applications and Google services, it’s been surprisingly easy to make the switch. I would recommend anyone getting the Geeksphones to build their own OS images though, the shipped images are pretty poor.

Among the many things I missed (Spotify is number 1 in that list btw), I could have done with a countdown timer. Contrary to what the interfaces of most Android timer apps would have you believe, it’s not rocket-science to write a usable timer, so I figured this would be a decent entry-point into writing mobile web applications. For the most part, this would just be your average web-page, but I did want it to feel ‘native’, so I started looking at the new building blocks site that documents the FirefoxOS shared resources. I had elaborate plans for tabs and headers and such, but turns out, all I really needed was the button style. The site doesn’t make hugely clear that you’ll actually need to check out the shared resources yourself, which can be found on GitHub.

Writing the app was easy, except perhaps for getting things to align vertically (for which I used the nested div/”display: table-cell; vertical-alignment: middle;” trick), but it was a bit harder when I wanted to use some of the new APIs. In particular, I wanted the timer to continue to work when the app is closed, and I wanted it to alert you only when you aren’t looking at it. This required use of the Alarm API, the Notifications API and the Page Visibility API.

The page visibility API was pretty self-explanatory, and I had no issues using it. I use this to know when the app is put into the background (which, handily, always happens before closing it. I think). When the page gets hidden, I use the Alarm API to set an alarm for when the current timer is due to elapse to wake up the application. I found this particularly hard to use as the documentation is very poor (though it turns out the code you need is quite short). Finally, I use the Notifications API to spawn a notification if the app isn’t visible when the timer elapses. Notifications were reasonably easy to use, but I’ve yet to figure out how to map clicking on a notification to raising my application – I don’t really know what I’m doing wrong here, any help is appreciated! Update: Thanks to Thanos Lefteris in the comments below, this now works – activating the notification will bring you back to the app.

The last hurdle was deploying to an actual device, as opposed to the simulator. Apparently the simulator has a deploy-to-device feature, but this wasn’t appearing for me and it would mean having to fire up my Linux VM (I have my reasons) anyway, as there are currently no Windows drivers for the Geeksphone devices available. I obviously don’t want to submit this to the Firefox marketplace yet, as I’ve barely tested it. I have my own VPS, so ideally I could just upload the app to a directory, add a meta tag in the header and try it out on the device, but unfortunately it isn’t as easy as that.

Getting it to work well as a web-page is a good first step, and to do that you’ll want to add a meta viewport tag. Getting the app to install itself from that page was easy to do, but difficult to find out about. I think the process for this is harder than it needs to be and quite poorly documented, but basically, you want this in your app:

if (navigator.mozApps) {   var request = navigator.mozApps.getSelf();   request.onsuccess = function() {     if (!this.result) {       request = navigator.mozApps.install(location.protocol + "//" + location.host + location.pathname + "manifest.webapp");       request.onerror = function() {         console.log("Install failed: " + this.error.name);       };     }   }; }

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if (navigator.mozApps) {   var request = navigator.mozApps.getSelf();   request.onsuccess = function() {     if (!this.result) {       request = navigator.mozApps.install(location.protocol + "//" + location.host + location.pathname + "manifest.webapp");       request.onerror = function() {         console.log("Install failed: " + this.error.name);       };     }   }; }

And you want all paths in your manifest and appcache manifest to be absolute (you can assume the host, but you can’t have paths relative to the directory the files are in). This last part makes deployment very awkward, assuming you don’t want to have all of your app assets in the root directory of your server and you don’t want to setup vhosts for every app. You also need to make sure your server has the webapp mimetype setup. Mozilla has a great online app validation tool that can help you debug problems in this process.

Visiting the page will offer to install the app for you on a device that supports app installation (i.e. a Firefox OS device). Not bad for a night’s work! Feel free to laugh at my n00b source and tell me how terrible it is in the comments

I’m starting to type this up as EdgeConf draws to a close. I spoke on the performance panel, with Shane O’Sullivan, Rowan Beentje and Pavel Feldman, moderated by Matt Delaney, and tried to bring a platform perspective to the affair. I found the panel very interesting, and it reminded me how little I know about the high-level of web development. Similarly, I think it also highlighted how little consideration there usually is for the platform when developing for the web. On the whole, I think that’s a good thing (platform details shouldn’t be important, and they have a habit of changing), but a little platform knowledge can help in structuring things in a way that will be fast today, and as long as it isn’t too much of a departure from your design, it doesn’t hurt to think about it. At one point in the panel, I listed a few things that are particularly slow from a platform perspective today. While none of these were intractable problems, they may not be fixed in the near future and feedback indicated that they aren’t all common knowledge. So what follows are a few things to avoid, and a few things to do that will help make your pages scroll smoothly on both desktop and mobile. I’m going to try not to write lies, but I hope if I get anything slightly or totally wrong, that people will correct me in the comments and I can update the post accordingly

Avoid reflow

When I mentioned this at the conference, I prefaced it with a quick explanation of how rendering a web page works. It’s probably worth reiterating this. After network and such have happened and the DOM tree has been created, this tree gets translated into what we call the frame tree. This tree is similar to the DOM tree, but it’s structured in a way that better represents how the page will be drawn. This tree is then iterated over and the