BJ Homer

UIWebView is a workhorse of a view. You can use it to display web pages, of course, but you can also use it to display locally-generated rich content. I was recently using UIWebView and the contentEditable attribute to implement a text field that allows inline images, etc. The fact that I’m using a web view,…

I recently had need for a token field for iOS while implementing a “To:” field like the one in Mail.app. I ran into a problem, though. The token field consists of a label, some number of tokens, and a borderless UITextField at the end where the user can enter text for the next token. It looks…

A short post for iOS people. UIWebView doesn’t (as of iOS 5.0) honor background-attachment: fixed; in CSS, so if you need a fixed background image on a UIWebView, you’re probably searching Google trying to find the answer. Hopefully, this will help. UIWebView *someWebView; someWebView.opaque = NO; someWebView.backgroundColor = [UIColor clearColor]; UIImageView *imageView; imageView.image = [UIImage…

In the comments on a recent Stack Overflow question, someone asked me if there was a significant performance difference between @synchronized and dispatch_once in implementing a singleton. So I wrote a simple test harness to access a singleton using the @synchronized method shown here: @synchronized(self) { if (!synchronizedVar) { synchronizedVar = [[Test alloc] init]; }}return…

Cocoa’s NSInputStream is great, but sometimes it doesn’t have all the functionality you need. For example, you might want to dynamically encrypt the file as you were streaming it off the disk, or you might want to put up a progress bar indicating how far the input stream had progressed through a large file. NSInputStream…

My co-worker Dan posted a blog yesterday entitled “How to Create an Alias Programmatically“. His example is 21 lines long, and is compatible with Leopard and earlier. It only works if the original item is a folder (though creating an alias to a file is not much different). The code messes with resource forks, and…

As of this previous Sunday, 100 Hour Board for iPhone was updated to version 1.2. This update includes support for iPhone OS 3.0, improves the rendering of quotes in Board posts, and teaches the app to remember where you were when you last closed it. There are also a couple minor user interface tweaks; notably,…

Peter Hosey recently tweeted: From the “how NOT to implement a Cocoa singleton” dept: http://developer.apple.com/documentation/Cocoa/Conceptual/CocoaFundamentals/CocoaObjects/CocoaObjects.html#//apple_ref/doc/uid/TP40002974-CH4-SW32 followed by: If something over-releases an object, the bug is not in that object, and overriding methods in it to break retain/release is not fixing it. The code sample in question is in the Apple documentation, and prescribes overriding the…