iPhone: Voice Mill

Yesterday I’ve played a bit with AVAudioRecorder, and this is a very small and funny example.
The main Idea is to create something like a wind mill that works with voice instead of wind.

The code below shows you how to record something. Then with the updateMeters() and peakPowerForChannel() you can extract the audio “noise”.

NSURL *url = [NSURL fileURLWithPath:@"/dev/null"];
NSDictionary *settings = [NSDictionary dictionaryWithObjectsAndKeys:
    [NSNumber numberWithFloat:44100.0], AVSampleRateKey,
    [NSNumber numberWithInt:kAudioFormatAppleLossless], AVFormatIDKey,
    [NSNumber numberWithInt:1], AVNumberOfChannelsKey,
    [NSNumber numberWithInt:AVAudioQualityLow], AVEncoderAudioQualityKey,
    nil];

NSError *error;
recorder = [[AVAudioRecorder alloc] initWithURL:url
            settings:settings error:&error];
if (recorder) {
    [recorder prepareToRecord];
    recorder.meteringEnabled = YES;
    [recorder record];
    ...
}

The SWF Video is available here Voice Mill Video.
The Source Code is available here Cocoa Voice Mill Source Code.

iPhone: Touch, Drag, Hit!

Yesterday, Fredrik has asked me something like “Drag & Drop with Hit Test” on the iPhone. Here’s a simple example.  There’s a simple UIView class that handles the touch events and a protocol that says that if the “DragMe View” has hit or not the “HitMe View”. Below you can see the result and the Source Code Link.

The source code is available here: Touch, Drag, Hit Source Code.

iPhone: Download and Display Gravatar

Back to the real iPhone for a while… Gravatar, or globally recognized avatar, is an interesting free service. It can be integrated with AddressBook app or other apps that can have a picture related to email address. Here an Objective-C Example to retrive the Gravatar. It’s really simple!

The Source Code is Available Here: iPhone Gravatar Example.

The Apple Worldwide Developers Conference (WWDC) takes place June 8-12, 2009 held at Moscone Center West in San Francisco. http://developer.apple.com/WWDC/.

Objective-C: SQLite Wrapper

I’ve written a simple SQLite Wrapper with two Examples one for Mac and one for the iPhone. The Wrapper class has the same source code for both platforms.

Here you can find the Mac Example Source Code and the iPhone Example Source Code.

This is a simple usage example:

Sqlite *sqlite = [[Sqlite alloc] init];

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
                             NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *writableDBPath = [documentsDirectory
                        stringByAppendingPathComponent:@"SQLiteTest.db"];
if (![sqlite open:writableDBPath])
  return;

[sqlite executeNonQuery:@"CREATE TABLE test (key TEXT NOT NULL, value TEXT);"];
[sqlite executeNonQuery:@"DELETE FROM test;"];
[sqlite executeNonQuery:@"INSERT INTO test VALUES (?, ?);",
                        [Sqlite createUuid], @"PROVA"];
[sqlite executeNonQuery:@"INSERT INTO test VALUES (?, ?);",
                         [Sqlite createUuid], @"PROVA 2"];
[sqlite executeNonQuery:@"INSERT INTO test VALUES (?, ?);",
                         [Sqlite createUuid], @"PROVA 3"];

NSArray *results = [sqlite executeQuery:@"SELECT * FROM test;"];
for (NSDictionary *dictionary in results) {
  NSLog(@"Row");
  for (NSString *key in [dictionary keyEnumerator])
      NSLog(@" - %@ %@", key, [dictionary objectForKey:key]);
}

[results release];
[sqlite release];

“Hello World” iPhone

Four easy steps to make iPhone Hello World.