Wednesday, June 17, 2009

New iPhone software - now with podcast speedup

WARNING: This blog entry was imported from my old blog on (which used different blogging software), so formatting and links may not be correct.

The new iPhone 3.0 software was released a little under an hour ago. The upgrade was trivial. I clicked the Check For Update a few minutes after the release, and it downloaded the new OS in around 3 minutes! I recently switched ISPs so I have really good bandwidth now - but I had expected a lot of traffic on Apple's servers to slow things down.

The update looks really good. I tested a few of the things I have been looking forward to -- I personally don't care about the feature highlights listed on most sites, such as MMS, Copy and Paste, etc.

The first feature I've been waiting for is the ability in the browser to open a link in another window. With tabbed browsing I'm used to just ctrl-clicking on links such that pages load in the background, and when I'm done with the current page I go read the other tabs which by then are fully loaded. On the iPhone on the other hand I haven't been able to do this, since there hasn't been a way to open a link without throwing away the page you're on. But in 3.0, it's there - just click and hold a link and you get the option to open the link in a new page. It's not as good as tabbed browsing - it instantly jumps to the new, not yet loaded page, but it's trivial to jump back and keep reading while the new page is loading.

The second feature I've been waiting for is improved iPod controls. The primary usage for my iPhone is as an iPod - while running, doing chores or driving - and I listen to a lot of podcasts. With 3.0, the scrubbing feature is improved - it's now a lot easier to jump to arbitrary points in the podcast. I like to listen to This Week in Technology for example, but I'm getting really, REALLY sick of the 5+ minutes of Audible commercials in each and every episode. This is the DVR generation -- if a commercial is longer than 30 seconds I'm going to start resenting you. In 2.0 it was difficult to either fast forward (too slow, then too fast) or jump to arbitrary points in the podcast. With 3.0 it works really well - I just place my thumb on the scrollbar and lean it to the right then left to tweak the final endpoint.

Another iPod improvement is the ability to play podcasts at a faster rate. For the Java Posse some volunteers (thank you!) set up a server which would download our podcasts, apply audio processing to speed up the podcast, and then release these as faster versions of our episodes - called the Tempo Posse. This is no longer necessary with 3.0 - there's a button you can click to cycle between half speed, full speed and double speed playback:

I don't think this will run the Tempo Posse out of "business", because I looked at our download stats the other day and nearly half of all episodes are downloaded outside of iTunes! Are there really that many Zune users? ;-)

Tuesday, June 16, 2009

Code Advice #16: Don't Encode Symbol Type in Variable Names!

WARNING: This blog entry was imported from my old blog on (which used different blogging software), so formatting and links may not be correct.

(See intro for a background and caveats on these coding advice blog entries.)

I came across a JavaWorld coding-advice article the other day. While the thread which led me there referenced the second point of the article, I couldn't get past the first one where the author argues that

...a reader needs to know which items are local variables, which are fields, and which are method arguments. [...] It's likely best to use a simple naming convention to distinguish between these three cases.

I couldn't disagree more!

His key argument seems to be that when you are reading code, it's important to know whether something is a field since when you read a method, you might suddenly see a reference to something you haven't seen before. To make his point he shows this graphic:

His improved version is here:

I have a couple of problems with this.

First of all, why encode this information in the symbol name when IDEs will show this information automatically? NetBeans will show fields in greens, and statics in italics - and it will always be right, whereas the code might lie. Just like comments can get out of sync with reality, you could inline a field without remembering to change its name (especially if another developer did it without realizing the meaning of the variable prefix). Or if you get in the habit of seeing an "f" prefix as meaning field, what about local variables that legitimately should start with an f, such as "focus" ? Sure, the second variable should be capitalized, but what about typographically similar symbols like lowercase l and uppercase I?

Here's how the same function looks in NetBeans:

In addition to showing us the fields in clear green, the IDE also pointed out that this method is overriding another method (I hovered over the overrides glyph in the editor margin). The yellow line is warning us that this override doesn't have an @Override explicit annotation on it.
Information about overrides is just as important as whether an identifier is a field.

Highlighting fields in green isn't specific to Java... We do this for many other languages - see some screenshots of
Ruby, PHP, Groovy, etc.

Here's a snippet of JavaScript - notice how we have a reference to a global variable in there shown in green:

The key point here is that you shouldn't write your code to target reading code in black and white on paper. You shouldn't print out your code at all! Reading code with an IDE lets you easily check any condition you encounter (and just like in a browser there is a little go-back icon in the editor toolbar which maintains a visit stack so you can easily pursue multiple ctrl-clicks to track something down and then easily go back).

There are some other conventions left over from the days of code written on tiny terminals and printed out on paper for review - such as the "maximum 72 characters per line" limit. There's no reason for that when using modern tools. If the code is more readable unwrapped at 100 characters, leave it that way rather than introduce arbitrary breaks in the middle. (Having said that, don't take this as an endorsement to write deeply nested methods, that's a sign of poorly thought out design.)

My second objection to the article is that it is not clear to me that knowing whether something is a field or not is the critical piece of information you need. I think the following questions are probably more important:

  • What is the meaning of the variable, and what is the intended use?
  • Can it be null? Can it be negative?
  • What is its type?
  • Where else is it referenced?

And so on. Just prepending an "f" on a field reduces readability in order to avoid a simple lookup, when I believe you in general
need to know more context anyway.
And again, a tool can help you here. In NetBeans, hold down the Ctrl key (Command on the Mac) and hover over a symbol and you get help like

(As a side note: I heard that at a Scala talk in JavaOne, Bill Venners was showing NetBeans through most of his talk, but he switched
to Eclipse to show one feature: Pointing at symbols show the actual inferred types of scala identifiers. Scala is as you know a statically
typed language, but uses a lot of type inference so the types aren't obvious from looking at the source. That's a very useful feature,
and I thought I'd point out that NetBeans has this feature too -- using the exact same mechanism as the above; just hold the Cmd/Ctrl key
and hover over a symbol, and you will see its type.)

Finally, the article makes a point that you probably want to distinguish parameters as well. I agree with that, but again not by changing
the name of the parameters, but through color identification. In Ruby, JavaScript, Python etc. we do that automatically in NetBeans - parameters are orange by default. For Java, it's not enabled by default (at one point it was, but somebody determined that the source code just looked too colorful, so the default color scheme was dialed back. I was working on Ruby at the time so my colors flew under the radar... and
all GSF-based languages such as JavaScript, Python, Scala etc. now inherit that color scheme...)

You can turn this on for Java as well. Just open the preferences, and for Fonts and Colors choose the Java language, then customize the Parameter Use and Parameter Declaration values:

Some languages like Ruby use sigils, where fields start with @, globals with $, symbols with : and so on. I don't have a problem with that
since I don't think these are as obtrusive as -letters- in variable names.

If you are reading code on paper, or with an editor that doesn't support semantic highlighting, you are voluntarily handicapping yourself.

Format All

WARNING: This blog entry was imported from my old blog on (which used different blogging software), so formatting and links may not be correct.

One feature I'm missing from NetBeans is the ability to format a whole project, or a package or directory. Opening each file only to press Ctrl-Shift-F to format it is just too cumbersome.

Fortunately, this is trivial to fix. I wrote a simple plugin to do this, and uploaded it to the Plugin Portal:

Once you've installed the plugin, you can right click on projects, or select a project, package (nonrecursive folder) or directory, and choose Source | Format Files.

TODO: picture

TODO: team comment

TODO: Generic, not java specific.

Monday, June 8, 2009

The Authoring Tool

WARNING: This blog entry was imported from my old blog on (which used different blogging software), so formatting and links may not be correct.

We lifted the veil on the new designer tool for JavaFX last week at the JavaOne 2009 conference. Here's a screenshot:

The tool made a number of appearances:

  • First in the Tuesday keynote where my boss Nandini showed the basics of the tool.
    starts at 23:08.

  • Then in the mobile keynote where Eric Klein showed the multiscreen support and mobile deployment.
    starts at the beginning.

  • And finally in the Friday keynote where I got to do a longer 10 minute segment on the tool.
    starts at 10:25.

The above video links just point to small chapters of each keynote; for full video replay go to
the keynote replay page.

I've scanned the blogosphere and twitter for comments on the tool and demos and the feedback is very positive.
a particularly detailed blog post with pictures and video snippets detailing the Friday demo.
Now we just need to finish the feature set, fix the bugs and polish everything! It's been a sprint for the whole team to get to this point. But we're not building a demo! We're building a product! So we're not getting much of a rest, it's right back to work to finish this thing!

(Photo by Balz Schreier)

P.S. In case you missed it, Larry Ellison from Oracle went on stage and made several comments regarding JavaFX in case the acquisition should happen - here's one article, there are many others.

P.S.2. We had our fourth annual Java Posse BOF live recording session last week. It was a blast. Dick stayed up editing and releasing
the podcast
the same night. If you're wondering what happened in the middle of the episode, where there's not much audio and a lot of laughing, that's me nearly drowning. I took a big swig of beer just as Joe made a joke; the beer went down the wrong tube, and then I was laughing so hard I couldn't breathe. My eyes were runny and I had beer all over my face and chest. Pretty embarrassing but reportedly also entertaining for others! Here's a photo from our get-together at a bar afterwards:

(Photo by
Toni Epple)