At first glance setting a height dynamically for table view cells seems a little daunting and the first most obvious answers that come to mind are not necessarily correct. In this post I will show you how to set your table view cell heights dynamically based upon the text content without subclassing UITableViewCell. You can subclass it, however, doing so does not make the code much cleaner as setting the height is done in your delegate for the table view itself rather than the cell anyhow. Read on to see what you need to know to make dynamic cell height sizing a breeze. (more…)

I’ve seen a good bit of sample code that shows how to implement using a UINavigationController in a view controller that is managed by a UITabBarController, but I haven’t seen much on how to do it with Interface Builder. Turns out that it’s pretty simple and I’m going to show you how. (more…)

Update: This is documented behavior.

Every now and again while doing development you stumble upon something that makes you go, hmmmm. Those are normally the moments at which you have to ask yourself, “is this a bug or a feature”. If it’s a bug, then you should file a radar with Apple, however, what if it’s a feature? You blog about it, of course!

I have done a bit less iPhone development than Marcus, so he was a little stumped while looking through some of my code where I created a view controller using a simple alloc/init. Most interestingly is that fact that the app works. It loads the correct nib and displays the view just fine without any trouble. Notice I said alloc/init and not alloc/initWithNibName. How can this possibly work? How did my controller “know” which view to use? (more…)

Every once in a while I find a way to combine multiple technologies that, while they don’t produce anything terribly useful, are very interesting when combined. In this post I will be taking a look at combining Core Animation and QuickTime. As you may or may not be aware, you can draw in a graphics context while your Core Animation animation is running and add each image created to a QTMovie object from QTKit. This enables you to create a QuickTime movie of your Core Animation animation. Here’s how. (more…)

NSLog() is a great tool that helps debugging efforts. Unfortunately it is expensive, especially on the iPhone, and depending on how it’s used or what you’re logging, it could leak sensitive or proprietary information. If you look around the web, you’ll find a few different ways to drop NSLog in your release builds. Here is what I’ve put together based on those. (more…)

iTunes has a very neat way of searching your library, where it takes each word in your search and tries to find that word in multiple fields. For example, you can search for “yesterday beatles” and it will match “yesterday” in the Name field and “beatles” in the Artist field. The basic predicate binding for NSSearchField provided by Interface Builder is not complex enough to archive this kind of search. I need to build the predicate dynamically since I can’t assume what field the user is trying to search and that each additional word should filter the list further – just like iTunes. Here is how to go about adding iTunes-style searching. (more…)

As you develop applications for the iPhone, you will likely use the project templates provided in Xcode. One such template, called “Tab Bar Application” helps you get a tab bar application set up quickly, but by default the application it generates only supports portrait mode for display. So how can you make the application also support landscape or even only support landscape? In this post we will address that question. (more…)

Starting and stopping animations in Core Animation is as simple as adding and removing your animation from the layer upon which is being run. In this post I am going to talk about how to interrupt animation progress and how to determine whether an animation completed its full run or was interrupted. This is accomplished with the animation delegate -animationDidStop:finished. (more…)

It is often helpful to create a custom control for you application that will display a value as a level like a gas gauge shows how full your tank is. In this post I will demonstrate how to create a three layer tree that will show the current rotation of a circular layer as the value from a slider (NSSlider) is updated in real time. The layers include the root layer, the rotation layer, and a text layer that will display the current rotation in degrees. (more…)

Similar to one of my first blog posts on building a basic application for Mac OS X using xcode 3.0, I am going to explain for beginning iPhone/iPod Touch developers how to build the most basic Cocoa Touch application using Interface Builder and an application delegate in xcode 3.1. This tutorial post is really to provide a quick how-to. I won’t go into any depth explaining why things are done the way they are done, but this should help you get up and running with your first application pretty quickly so that you too can clog the App Store with useless superfluous apps (kidding… just kidding).

If you are a visual learner, it may be helpful to you to instead watch a video presentation of this tutorial. I’ve posted it on the site, but you’ll have to click the link to see my Cocoa Touch Video Tutorial. (more…)

Last night at NSCoder night, Fraser Hess was asking question about being able to draw in a Quartz Composer View (QCView) about which none of the rest of us had any knowledge or experience. As I’ve been doing a lot with Core Animation lately, I asked him if it was possible to just make the view layer backed and start adding layers to it. Fraser hasn’t worked with Core Animation much yet, so he was unsure. The other three of us set to looking at docs and making demo apps. The race was on… Oh. It’s not a race? Sorry about that. I thought we were practicing for Iron Coder… (more…)

A couple of weeks ago we discussed how to build frameworks and how to bundle them with a Cocoa application. This week we are going to build on that knowledge and add Plug-ins to a Cocoa application.

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I’ve been experimenting a great deal lately with OpenGL and QuickTime trying to see how the two technologies work together. It’s been a bit challenging, but fortunately Apple provides two really great resources–number one, sample code. I’ve been able to learn a lot just from the samples they provide in the development tools examples as well as online. And second, the cocoa-dev and quicktime-api lists are great. Lot’s of brilliant people there who are willing to share their knowledge. It’s very helpful, prohibition to discuss the iPhone SDK notwithstanding.

Getting two technologies to work together can be a challenge especially when the bridges between the two are not necessarily clearly laid out in documentation. As I pointed out Apple provides some excellent sample code to help you along, but there is no hand-holding approach to any of it. I actually appreciate that having come from the Windows world as it seems that there all you get sometimes is hand-holding where Microsoft doesn’t trust you, the developer to figure things out and really own what you’re doing. But I digress (wouldn’t be a CIMGF post if I didn’t dig on MS a bit). (more…)

There are numerous situations where creating your own framework is advantageous. Perhaps you have a block of code that you use repeatedly in many different projects. Perhaps you are building a plug-in system for your application and want the infrastructure to be available both to the application and to any plugins that are coded.

A Cocoa framework is another project type in Xcode. The end result is a bundle, similar to an application bundle. Inside of this bundle is the compiled code you wrote and any headers that you want exposed. The headers are important. Without them, just like any other piece of Objective-C code, it is very hard to code against.

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Sync Services have come a long way in Leopard. Before Leopard it was an extremely complex operation that was almost completely manual. Needless to say, this sucked and it was probably one of the reasons it was shunned by most developers.

If you are using Core Data in a Leopard application then Sync Services is so trivial that you should be syncing if it makes sense. In this article we are going to cover syncing in a non-Core Data situation as that is quite a bit more complex.

If you have read the Sync Services documentation then you know it is complex. Let me dispel an illusion right away. It is hard. It is not poor documentation, syncing is very hard and very few people get it right. Take a look at Omnifocus to see an example of a company thinking it is easy and losing data. Therefore if you are expecting this subject to be trivial you will be disappointed.

In this example we will be syncing with the bookmarks schema and displaying them in a simple outline view. The outline view itself will be editable and those edits can be synced back. Not terribly useful but provides a very simple example. (more…)