Wednesday, November 18, 2009

My Unibody MacBook had Been Grinding to a Halt

I'm used to my Macs being reliable; of going months between forced restarts. And yet, two weeks ago, I found myself restarting my unibody MacBook a couple times an hour. Apps would just lock up with the spinning disk cursor, and I'd go to another app and it would soon lock up to. I associated this with something fairly disk intensive, like doing a Spotlight search, and I found that if I avoided Spotlight things would be OK most days. I tried rebuilding the Spotlight database, reinstalling 10.6.0, upgrading to 10.6.2, etc., with no help.

Finally, under the working theory something was wrong with my 500 GB Western Digital Scorpio Blue drive, I ordered and installed a new 640 GB Western Digital Scorpio Blue drive. And this worked. I don't know if it was the hardware or the completely clean install or the act of reinserting the drive, but it worked and my Mac is back to its normal reliable self. And I've got more disk space than I know what to do with. I learned my lesson a few years back about waiting for a hard drive to fail; I no longer give them a second chance at catastrophe.

This might be the last mechanical hard drive I ever buy for a laptop. SSD capacities are overtaking mechanical, and I would certainly pay $300 for a 512 GB SSD of reasonable read and write throughput. Maybe this time next year.

Monday, November 16, 2009

When the Books are Free - Amazon Vine

A few months ago, I noticed an invitation to join Amazon Vine program on my Amazon front page. I clicked on it, realized it wasn't a scam and signed up. And now I get 4 free things a month; from a limited catalog of newly released products. Mostly books are available, but I've also received software and iPod accessories. All I have to do is review three fourths of what I get and I stay in good standing.


It is awesome getting free stuff. The Phillips iPod dock/CD Player/Radio in the kitchen is sweet. But that is the exception, only the quickest get gadgets, and most of the time I have a choice between books and nothing. And getting a free book is hardly a bargain: It takes hundreds of dollars of my time to read, and I don't have the universe of books to pick from, I have whatever is in the newsletter, so I have to be picky and choose only titles which are of use—a book on business law for my wife's business—or of interest—a book on how to draw dinosaurs and aliens.


One nice thing is the motivation to read; to keep up my 75% review rate. It isn't often I read 3 books in 2 months. I just wish they offered more books about software engineering and fewer about adolescent vampires (or whatever constitutes juvenile fiction).


Amazon gets value from me. Under the theory I'll get offered items similar to things I buy or review, I bought a laptop hard drive from Amazon rather than Newegg; and I've been making sure to review anything that moves to push up my ranking. Just passed into the top 3000 woo hoo..


As to whether I'm unbiased about products I'm given to hold on to (I can't resell them), I think I'm OK. I certainly have a happy feeling about being given something nice, but on the other hand, a mediocre book is such a pain to trudge through, and a junky alarm clock just takes up space. So far, I've given out a variety of star ratings, pretty much in line with things I've purchased with my own dimes; maybe a bit lower as at least when I buy something on my own I have some expectation it will be of high quality.


Anyway, when you see the "Vine Voice" badge on a review on Amazon, you'll know it's somebody like me; just an ordinary consumer who likes to write reviews and lucked into getting free stuff.

Tuesday, November 10, 2009

When Apple Doesn't Follow It's Patterns: UIScrollView

A comment in UIScrollView.h
// override points. default is to call touch methods on the content subview. if -touchesShouldCancelInContentView: returns NO in order to start dragging after we have started tracking the content view, we don't drag and continue to feed events to the content subview. if -touchesShouldBegin:withEvent:inContentView: returns NO, we don't send events even if we don't drag

So basically, if you want to modify the behavior of how a UIScrollView drags, you need to create a subclass. Fine, that's basic polymorphism, but it isn't the way most UI behaviors are changed in Cocoa on the iPhone. Typically, behaviors are changed by the use of delegate objects, and there already is a UIScrollViewDelegate interface defined. It's not clear to me why touchesShouldBegin:withEvent:inContentView and touchesShouldCancelInContentView were not just added to the delegate.


Why is this important? Well first of all, one of the joys of Cocoa programming on the iPhone is that the object model tends to be more consistent then desktop Cocoa. Everything fits together, and you know where to look for the hook which allows you to customize your app's behavior.


Secondly, I think Apple was right to choose the delegate model over object subclassing. It's less fragile, in that you are less likely to rely on the original object's behavior being constant. And some Cocoa objects are basically impossible to subclass; for instance UIButton cannot be subclassed because it isn't a "real" object. And from a coding point of view, the delegate solves both the problem of changing behavior and intercommunicating between objects.


So, when you see a comment like the above, it sticks out like a sore thumb in what is normally a disciplined and consistent API.

Monday, November 02, 2009

New Version of Signal GH

Apple has sent me a notice that version 1.1.3 of Signal GH—my iPhone app to get the signal quality of OTA TV broadcasts with an HDHomerun—is available for download. There's nothing flashy about this release, just a variety of bug fixes, including some pretty vexing ones.
 
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