iPhone SDK 3.2 Beta 4 now available

I just took a look at my inbox only to find a message from Apple Developer Connection: iPhone SDK 3.2 beta 4 For iPad Development Now Available...

Apple iPhone developers download it here.

It looks as if we're entering the last mile of beta releases with a final on the horizon and an iPad ship date set for April 3rd.  Are you ready?  Have you started porting any of your apps for the iPad?

iPad release date set for April 3

I just checked Apple's website and noticed a little change on their home page:

It would seem that Apple has set an official date for the release of the magical and revolutionary new device: the Apple iPad.

Will you be in line?  Will you wait a month for 3G?  Or will you be waiting for next year's iPad, the one with the purposed camera and iChat?  Let us know.  Comment below.

iPhone SDK: Shake, Rattle & Roll - Accelerometer and Vibrate

I’d like to share with you a bit of functionality that we use in most of our applications and that I am asked about frequently: how to implement the accelerometer and the vibrate functions of the iPhone SDK.

There are three parts to the accelerometer equation:
UIAccelerometer Class: lets you register to receive acceleration related data from the hardware, this class is not directly created but rather accessed using a shared UIAccelerometer object.

UIAcceleration Class: this contains x, y, and z axis acceleration data (measured in G-force) as well as a relative timestamp.

UIAccelerometerDelegate Protocol: receives the acceleration related data from the system.

...and only one part to the vibrate equation... which we'll cover below.

For more information on the classes and protocols visit the iPhone Dev Center.

Skake: Using the Accelerometer
Implementing the use of the accelerometer is quite simple and only requires a few steps to start sensing the motion of your iPhone/iPod touch.  In this example we’re going to use a fictitious class MainViewController.

First thing we do is add the UIAccelerometerDelegate protocol to MainViewController.h allowing the class to respond to acceleration related data sent from the device.  Also, note that UIAccelerometer is part of the UIKit Framework.

#import <UIKit/UIKit.h>

@interface MainViewController : UIViewController <UIAccelerometerDelegate> {

}

@end

The UIAccelerometerDelegate protocol only has only has one instance method which delivers acceleration data to the delegate (which we’ll add to the implementation file):

- (void)accelerometer:(UIAccelerometer *)accelerometer
        didAccelerate:(UIAcceleration *)acceleration;

As the accelerometer is a shared object and is constantly updated I like to add on/off methods to my class so that I can control when the updates are handled.  For example you might want the acceleration to only happen when the view controller is visible.

Also, as the information sent from the UIAcceleration delegate is a stream of data updated at a defined interval I want to be able to create a threshold (minimum) before acting upon the data.  I add this in the method itself, but you could create a #define for each of the three axis.  Also, I’d like to point out that this is not complete code as you will still need to implement your view, init, etc, and this covers adding functionality.

Let’s add the methods and definition to our implementation file (MainViewController.m):

#import "MainViewController.h"

@interface MainViewController ()

- (void)startAccelerometer;
- (void)stopAccelerometer;

@end


@implementation MainViewController

- (void)accelerometer:(UIAccelerometer *)accelerometer
        didAccelerate:(UIAcceleration *)acceleration
{
  double const kThreshold = 2.0;
  if (   fabsf(acceleration.x) > kThreshold
      || fabsf(acceleration.y) > kThreshold
      || fabsf(acceleration.z) > kThreshold) {
    NSLog(@"Hey, stop shaking me!");
  }
}

- (void)startAccelerometer {
  UIAccelerometer *accelerometer = [UIAccelerometer sharedAccelerometer];
  accelerometer.delegate = self;
  accelerometer.updateInterval = 0.25;
}

- (void)stopAccelerometer {
  UIAccelerometer *accelerometer = [UIAccelerometer sharedAccelerometer];
  accelerometer.delegate = nil;
}

- (void)viewDidAppear:(BOOL)animated {
  [self startAccelerometer];
}

- (void)viewWillDisappear:(BOOL)animated {
  [self stopAccelerometer];
}

@end

That’s it.  Simple.  When viewDidAppear is called it calls startAccelerometer and we can start listening for acceleration related data.  If the data is above 2g then we log a message.  When viewWillDisappear is called it calls stopAccelerometer and we nil out our delegate and we stop listening for the accelerometer data.

Rattle: Vibrate
To make the device vibrate we need to use the AudioToolbox Framework.  You may be asking why audio, and that is a good question but don’t have a solid answer.  I only know how to make it work and that’s the key.

Import the AudioToolbox into the MainViewController.m file and add a declaration and method:

#import "MainViewController.h"
#import <AudioToolbox/AudioToolbox.h>

@interface MainViewController ()

- (void)vibrate;

@end

@implementation MainViewController

- (void)vibrate {
  AudioServicesPlaySystemSound(kSystemSoundID_Vibrate);
}

@end

That’s it.  And it’s simpler than dealing with the shaking of the accelerometer.  Just one line of code (more or less) and you have vibrating in your app.

Roll: Combining Accelerometer and Vibrate
What I like to do is add the vibrate method to the accelerometer:didAccelerate: method so that when user shakes their device it fires off the vibration to give haptic feedback of the action.

All you need to do is modify the accelerometer:didAccelerate: method:

- (void)accelerometer:(UIAccelerometer *)accelerometer
        didAccelerate:(UIAcceleration *)acceleration
{
  double const kThreshold = 2.0;
  if (   fabsf(acceleration.x) > kThreshold
      || fabsf(acceleration.y) > kThreshold
      || fabsf(acceleration.z) > kThreshold) {
  [self vibrate];
  }
}

Now when you shake the device, it vibrates.  Simple to implement and good user feedback.

We first implement this in our kids' application Fridgemags and I have to say that kids like shaking the device and feeling it vibrate.  We also move colored alphabet letters around  the screen and make a whooshing sound of sorts to engage the kids and keeps them busy for a good amount of time.

iPhone SDK 3.2 Beta 3 now available

After a day of being posted and pulled from the Apple (iPhone) Developer Center the iPhone 3.2 beta 3 is again available for download.

I just started the download process and it seems to be coming along nicely.  In a little over an hour I should have completed the download and well into the installation process.  Cheers!

Apple iPhone developers download it here.

original link

iPhone Friday - February 19, 2010

Hello and welcome to another iPhone Friday...  We are in the process of revamping some of our older post so that we'll have some fresh new content for the iPad when it debuts.  But for now, here is a collection of iPhone and iPod touch wallpapers that are a variant of a collection I call, See Mike Play With Spot.  Enjoy!

iTunes Connect Developer Guide - Updated

On February 16, 2010 at 11:00AM Apple update their iTunes Connect Developer Guide (version 5.3).  After reviewing the guide I have to say Apple is making the iTunes Connect experience a little more understandable.

The guide covers and explains some of the trickier aspects of iTunes Connect such as creating a Demo Account, In-App Purchases, the New Territories feature, additional information on export compliance and overall app submission best practices.

One thing I noticed is that Apple has done away with the Device Requirements metadata (UIRequiredDeviceCapabilities) as an option - it is now a requirement.  The UIRequiredDeviceCapabilities let's iTunes and the App Store know which app related features the app requires in order to run such as video-camera, wifi, accelerometer and opengles-1 to name a few.

To download the latest version of the iTunes Connect Developer Guide login to iTunes Connect  and click the download link (at the bottom of the home page).

For more information UIRequiredDeviceCapabilities read the iPhone Application Programming Guide (specifically the section on Device Support) available in your iPhone SDK Developer Documentation or online in the Apple Developer Connection documents (Library) area.

iPhone Friday - February 12, 2010

Hello and happy iPhone Friday.  Todays collection of iPhone/iPod touch wallpapers are a set of stills from a couple of motion graphic projects.  Enjoy.