Originally the drawing for the giveaway was to be held March 12th, however, given that the event is still 6+ weeks out, it seems to make sense to extend the deadline for submitting entries.

How the Contest Works

If you are interested to register for the drawing, all you need to do is click the Refer-A-Friend button below and fill in the popup form to refer one or more friends to this blog post. Make sure your email address is correct in the form, as that will be your ticket in the drawing. It’s that simple! I respect your privacy, your email will be used only for registration in the event.

The Details

The deadline to register for the drawing is March 24th, 2010. The winner will be announced on March 25th, 2010. The drawing is for one free admission pass only, you will have to pay any additional travel or related expenses.

Good luck!

Building on the previous post, the example created here starts the camera on the iPhone, and once a photo is snapped, launches the email application, attaching the resulting image to the email.

Start the iPhone Camera

The user interface of this application is quite simple, there is one button on the UI that will start the camera. Once the button is tapped, the method shown below will be called. Here we create an image picker controller, set the source type to the camera, point the delegate to self and specify not to allow image editing. From there, simply show a modal view controller to enable the camera.

- (void)buttonPressed:(UIButton *)button
{
  // Create image picker controller
  UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];
 
  // Set source to the camera
  imagePicker.sourceType =  UIImagePickerControllerSourceTypeCamera;
 
  // Delegate is self
  imagePicker.delegate = self;
 
  // Allow editing of image ?
  imagePicker.allowsImageEditing = NO;
 
  // Show image picker
  [self presentModalViewController:imagePicker animated:YES];	
}

Convert Camera Image to NSData Object

Once the camera has taken a photo, the method below will be called, passing in a dictionary of related information, such as the original image, edited image (if any), URL to a movie (when applicable), etc. We grab the image from the dictionary and create a UIImage object. From there, dismiss the camera, then pass the camera image to the method emailImage where we will construct an email and append the image.

-- (void) imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
  // Access the uncropped image from info dictionary
  UIImage *image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
 
  // Dismiss the camera
  [self dismissModalViewControllerAnimated:YES];
 
  // Pass the image from camera to method that will email the same
  // A delay is needed so camera view can be dismissed
  [self performSelector:@selector(emailImage:) withObject:image afterDelay:1.0];
 
  // Release picker
  [picker release];
}

Email Camera Image

The last step is to compose an email and attach the image from the camera. We begin be creating a MFMailComposeViewController object, setting the delegate to self. We then step through the configuration preferences for the email, setting the subject, the list of recipients (to, carbon copy, and blind carbon copy) and creating the body of the message.

Our next step is to convert theUIImage from the camera into an NSData object, which we can attach to our email. As you’ll notice in the code below, I’ve created the NSData as a PNG representation, you could also use JPG format if you prefer (which allows you to specify a value for image compression).

Once the image is attached to the email, we show a modal view controller which will launch the email application – one note, I am making the assumption that iPhone OS 3.x is the active platform.

- (void)emailImage:(UIImage *)image
{
  MFMailComposeViewController *picker = [[MFMailComposeViewController alloc] init];
  picker.mailComposeDelegate = self;
 
  // Set the subject of email
  [picker setSubject:@"Picture from my iPhone!"];
 
  // Add email addresses
  // Notice three sections: "to" "cc" and "bcc"	
  [picker setToRecipients:[NSArray arrayWithObjects:@"emailaddress1@domainName.com", @"emailaddress2@domainName.com", nil]];
  [picker setCcRecipients:[NSArray arrayWithObject:@"emailaddress3@domainName.com"]];	
  [picker setBccRecipients:[NSArray arrayWithObject:@"emailaddress4@domainName.com"]];
 
  // Fill out the email body text
  NSString *emailBody = @"I just took this picture, check it out.";
 
  // This is not an HTML formatted email
  [picker setMessageBody:emailBody isHTML:NO];
 
  // Create NSData object as PNG image data from camera image
  NSData *data = UIImagePNGRepresentation(image);
 
  // Attach image data to the email
  // 'CameraImage.png' is the file name that will be attached to the email
  [picker addAttachmentData:data mimeType:@"image/png" fileName:@"CameraImage"];
 
  // Show email view	
  [self presentModalViewController:picker animated:YES];
 
  // Release picker
  [picker release];
}
 
- (void)mailComposeController:(MFMailComposeViewController*)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError*)error 
{
  // Called once the email is sent
  // Remove the email view controller	
  [self dismissModalViewControllerAnimated:YES];
}

Caveat

To keep things simple, this application runs on a single thread. It works fine, however, there is a few second delay when moving from the camera application to the email application. Ideally you would add a little logic to better manage the user interface.

Source Code

Here is the link to the source code: Email Camera Image Application.

In over 20 years of software development, I’ve delivered 1000+ hours of developer training. No question, classroom training can be helpful to learn a new programming language and related tools. On the other hand, with few exceptions, course content and delivery is not tailored to your specific development experience and needs, which can result in a loss of focus and time spent on areas that are not relevant to your projects.

Regardless of the platform and tools, in my experience, one of the most effective ways to get up to speed quickly is to work alongside an experienced developer. With that in mind, I am offering customized mentoring for developers interested to learn iPhone application development.

You decide what’s important to you, based on your projects and current skill set. Unlike classroom training, the content is entirely your call.

Potential topics:

• Effective wireframes (tools and approaches)
• Creating wireframe/specification for your project
• Getting up to speed with Xcode
• Objective-C crash course
• Code walk-through of working applications
• Developer program registration, profiles and certificates
• Creating and distributing adhoc/beta builds
• Deployment process and tips
• Working with the simulator
• Playing audio and video content
• Calling web-services, using JSON
• Working with property lists (plists)
• Recommended open source projects (with code examples)
• Any other topics you need…

Benefits of mentoring:

• Focus on your specific needs and interests
• Working with an experienced iPhone developer
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• Extensive experience teaching developers
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   Visit 3SixtySoftware.com for more information about my apps
• 20+ years designing and developing software
• Published author including a best-selling mobile developer book

Pricing:

My objective is to provide a very effective learning process at a reasonable price, offering one-on-one guidance that isn’t available in traditional classroom training. Rates for mentoring are based on the number of developers involved – I recommend mentoring be limited to 1-3 individuals which will keep the pace moving quickly. Any travel related expenses would be additional.

For more information:

To learn more, including pricing and scheduling availability, please contact me by email: John at 3SixtySoftware dot com or fill out this Contact Form.

Get UIImage Data as PNG or JPEG

UIKit includes two C functions, UIImageJPEGRepresentation and UIImagePNGRepresentation which will return an NSData object that represents an image in JPEG or PNG format, respectively. With this information in hand, you can then use the writeToFile method of the NSData object to write the image data to a specified path.

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// Create paths to output images
NSString  *pngPath = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/Test.png"];
NSString  *jpgPath = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/Test.jpg"];
 
// Write a UIImage to JPEG with minimum compression (best quality)
// The value 'image' must be a UIImage object
// The value '1.0' represents image compression quality as value from 0.0 to 1.0
[UIImageJPEGRepresentation(image, 1.0) writeToFile:jpgPath atomically:YES];
 
// Write image to PNG
[UIImagePNGRepresentation(image) writeToFile:pngPath atomically:YES];
 
// Let's check to see if files were successfully written...
 
// Create file manager
NSError *error;
NSFileManager *fileMgr = [NSFileManager defaultManager];
 
// Point to Document directory
NSString *documentsDirectory = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];
 
// Write out the contents of home directory to console
NSLog(@"Documents directory: %@", [fileMgr contentsOfDirectoryAtPath:documentsDirectory error:&error]);

Important note, on lines 6 and 9, the value image must be a UIImage object.

Source Code

I’ve changed the example from the original post that wrote a UIImage from the camera to the Photo Album, to write instead to the test files shown above. You can download the source code for the application here: Write UIImage Object as a PNG or JPEG File.

Simulator Not Supported

One last note, this application will only run on an actual device as the simulator does not have camera support.

The idea is to break apart the incoming string into substrings, using the invalid character set as the characters to split the string. The result returned is an array of objects that have been divided by the invalid characters. If the array has more than one entry, at least one invalid characters was found.

One note, typically the incoming string is just a single character (as typed by the user). However, for cases where the user has pasted a string, the string will vary in length.

If you are a fan of regular expressions you could change up the code using a library such as RegexKitLite.

To use this code, add the method below in the class which is the delegate for the TextField.

 
// You can add/tailor the acceptable values here...
#define CHARACTERS          @" ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
#define CHARACTERS_NUMBERS  [CHARACTERS stringByAppendingString:@"1234567890"]
 
/*---------------------------------------------------
* Called whenever user enters/deletes character
*--------------------------------------------------*/
- (BOOL)textField:(UITextField *)textField 
    shouldChangeCharactersInRange:(NSRange)range 
    replacementString:(NSString *)string
{
  // These are the characters that are ~not~ acceptable
  NSCharacterSet *unacceptedInput =
    [[NSCharacterSet characterSetWithCharactersInString:CHARACTERS] invertedSet];
 
  // Create array of strings from incoming string using the unacceptable
  // characters as the trigger of where to split the string.
  // If array has more than one entry, there was at least one unacceptable character
  if ([[string componentsSeparatedByCharactersInSet:unacceptedInput] count] > 1)
    return NO;
  else 
    return YES;
}

You can adjust the character sets as you need to match the input requirements of your application. One more idea would be to manage the character sets inside the method, using a flag to indicate which set to compare against.

It’s surprising easy to create a bare bones camera application on the iPhone. UIImagePickerController provides a means to access the camera, take a photo and preview the results. There is also an option to allow resizing and scaling of a photo once captured. Using UIImageWriteToSavedPhotosAlbum in the UIKit, you can easily save an image to the Photo Album.

The image on the left in the figure below shows the camera active in the application. The image on the right is the preview option once a photo has been taken.

Start the Camera

To work with the camera we begin by creating a UIImagePickerController object and setting the sourceType to UIImagePickerControllerSourceTypeCamera. For this example, I set allowsImageEditing to NO to disable editing of photos image. I use presentModalViewController to initiate the display of the camera.

// Create image picker controller
UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];
 
// Set source to the camera
imagePicker.sourceType =  UIImagePickerControllerSourceTypeCamera;
 
// Delegate is self
imagePicker.delegate = self;
 
// Allow editing of image ?
imagePicker.allowsImageEditing = NO;
 
// Show image picker
[self presentModalViewController:imagePicker animated:YES];

Save Image to Photo Album

Once a photo has been taken, the method didFinishPickingMediaWithInfo will be called, providing the opportunity to write the image to the Photo Album:

- (void) imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
  // Access the uncropped image from info dictionary
  UIImage *image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
 
  // Save image
  UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);
 
  [picker release];
}

Notice the call selector reference above, this selector will be called once the image has been written to the system. For this example I display an alert showing the result of attempting to save the image:

- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo
{
  UIAlertView *alert;
 
  // Unable to save the image  
  if (error)
    alert = [[UIAlertView alloc] initWithTitle:@"Error" 
                            message:@"Unable to save image to Photo Album." 
                            delegate:self cancelButtonTitle:@"Ok" 
                            otherButtonTitles:nil];
  else // All is well
    alert = [[UIAlertView alloc] initWithTitle:@"Success" 
                            message:@"Image saved to Photo Album." 
                            delegate:self cancelButtonTitle:@"Ok" 
                            otherButtonTitles:nil];
  [alert show];
  [alert release];
}

Optional Updates

This is a good, if not simple, place to start. Here are two additional updates to this application you can tinker with:

#1 – Check for a camera on device. Refer to this post Does iPhone Support Camera to learn more.

#2 – Set the image editing option to YES. This will require a few additional changes including a request to the information dictionary to return the cropping rectangle that was applied to the original image (see UIImagePickerControllerCropRect).

Source Code

You can download the source code for the camera application here.

Simulator Not Supported

One last note, this application will only run on an actual device as the simulator does not have camera support.

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Voices That Matter is a two-day event and will offer many sessions covering the latest and most intriguing technology in application development for the iPhone and the iPad. A partial list of topics includes:

* Killer User Interfaces for iPhone OS Devices
* Core Animation
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* Xcode

Free Pass Giveaway

As we did for the conference in October of 2009, Voices That Matter and iPhone Developer Tips are giving away one free pass to the event in Seattle, quite an opportunity as the full admission price is $695 for the two-day event.

How the Contest Works

If you are interested to register for the drawing, all you need to do is click the Refer-A-Friend button below and fill in the popup form to refer one or more friends to this blog post. Make sure your email address is correct in the form, as that will be your ticket in the drawing. It’s that simple! I respect your privacy, your email will be used only for registration in the event.

The Details

The deadline to register for the drawing is March 11th, 2010. The winner will be announced on March 12th, 2010. The drawing is for one free admission pass only, you will have to pay any additional travel or related expenses.

Good luck!

The line of code below is a slight modification that shows how to get the name that will appear on the iPhone below the icon:

[[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleDisplayName"];

The CFBundleDisplayName value corresponds to the Bundle Display Name in the application plist file, see the figure below:

You can see the application icon for this example in this figure:

Read and Write Collections to File

NSArray *array = [NSArray arrayWithObjects: 
    @"Hefeweizen", @"IPA", @"Pilsner", @"Stout", nil];
 
NSDictionary *dictionary = [NSDictionary dictionaryWithObjectsAndKeys:
  array, @"array", @"Stout", @"dark", @"Hefeweizen", @"wheat", @"IPA", 
  @"hoppy", nil];
 
// Get path to documents directory
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, 
  NSUserDomainMask, YES);
if ([paths count] > 0)
{
  // Path to save array data
  NSString  *arrayPath = [[paths objectAtIndex:0] 
      stringByAppendingPathComponent:@"array.out"];
 
  // Path to save dictionary
  NSString  *dictPath = [[paths objectAtIndex:0] 
      stringByAppendingPathComponent:@"dict.out"];
 
  // Write array
  [array writeToFile:arrayPath atomically:YES];
 
  // Write dictionary
  [dictionary writeToFile:dictPath atomically:YES];
 
  // Read both back in new collections
  NSArray *arrayFromFile = [NSArray arrayWithContentsOfFile:arrayPath];
  NSDictionary *dictFromFile = [NSDictionary dictionaryWithContentsOfFile:dictPath];
 
  for (NSString *element in arrayFromFile) 
    NSLog(@"Beer: %@", element);
 
  for (NSString *key in dictFromFile) 
    NSLog(@"%@ Style: %@", key, [dictionary valueForKey:key]); 
}

Verify the Output

The output in the console window for the above looks as follows:

In the figure below you can see how a simple alert can be shown (sans buttons) while you are busy doing some other system activity (reading/writing files, etc).

UIAlertView without Buttons

UIAlertView *alert;
 
...
 
alert = [[[UIAlertView alloc] initWithTitle:@"Configuring Preferences\nPlease Wait..." 
  message:nil delegate:self cancelButtonTitle:nil otherButtonTitles: nil] autorelease];
 
[alert show];

Trouble with this approach is that things look a little lopsided, as there is a significant amount of dead space on the bottom where the button(s) are to be shown. We can fix this by adding a few newline characters at the start of our message:

UIAlertView *alert;
 
...
 
// Add two newlines characters at the start of the message
alert = [[[UIAlertView alloc] initWithTitle:@"\n\nConfiguring Preferences\nPlease Wait..." 
  message:nil delegate:self cancelButtonTitle:nil otherButtonTitles: nil] autorelease];
 
[alert show];

The text is nearly centered, yet we’ve created a different problem, there is now white space on the top and bottom. There is one more approach…

UIAlertView with UIActivity Indicator

In the whitespace on the bottom, let’s add an activity indicator. Also, remove the newlines in the message text so the text starts near the top:

UIAlertView *alert;
 
...
 
alert = [[[UIAlertView alloc] initWithTitle:@"Configuring Preferences\nPlease Wait..." message:nil delegate:self cancelButtonTitle:nil otherButtonTitles: nil] autorelease];
[alert show];
 
UIActivityIndicatorView *indicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
 
// Adjust the indicator so it is up a few pixels from the bottom of the alert
indicator.center = CGPointMake(alert.bounds.size.width / 2, alert.bounds.size.height - 50);
[indicator startAnimating];
[alert addSubview:indicator];
[indicator release];

Dismissing the Buttonless UIAlertView

Since there are no buttons associated with the alert, we have to dismiss the alert ourselves, versus the traditional approach where the system dismisses the alert when a button is pressed.

Here is the call to dismiss the alert:

[alert dismissWithClickedButtonIndex:0 animated:YES];