svn checkout http://google-api-objectivec-client.googlecode.com/svn/trunk/ google-api-objectivec-client-read-only
        

#import <UIKit/UIKit.h>
#import <MobileCoreServices/MobileCoreServices.h>

#import "GTMOAuth2ViewControllerTouch.h"
#import "GTLDrive.h"

@interface ViewController : UIViewController 

@property (nonatomic, retain) GTLServiceDrive *driveService;

@end

#import "ViewController.h"

static NSString *const kKeychainItemName = @"YOUR PROJECT NAME";
static NSString *const kClientID = @"YOUR_CLIENT_ID";
static NSString *const kClientSecret = @"YOUR_CLIENT_SECRET";

@implementation ViewController

@synthesize driveService;

- (void)viewDidLoad
{
    [super viewDidLoad];

    // Initialize the drive service & load existing credentials from the keychain if available
    self.driveService = [[GTLServiceDrive alloc] init];
    self.driveService.authorizer = [GTMOAuth2ViewControllerTouch authForGoogleFromKeychainForName:kKeychainItemName
                                                                                         clientID:kClientID
                                                                                     clientSecret:kClientSecret];
}

- (void)viewDidAppear:(BOOL)animated
{
    // Always display the camera UI.
    [self showCamera];
}

- (void)showCamera
{
    UIImagePickerController *cameraUI = [[UIImagePickerController alloc] init];
    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
    {
        cameraUI.sourceType = UIImagePickerControllerSourceTypeCamera;
    }
    else
    {
        // In case we're running the iPhone simulator, fall back on the photo library instead.
        cameraUI.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
        if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPad)
        {
            [self showAlert:@"Error" message:@"Sorry, iPad Simulator not supported!"];
            return;
        }
    };
    cameraUI.mediaTypes = [[NSArray alloc] initWithObjects: (NSString *) kUTTypeImage, nil];
    cameraUI.allowsEditing = YES;
    cameraUI.delegate = self;
    [self presentModalViewController:cameraUI animated:YES];

    if (![self isAuthorized])
    {
        // Not yet authorized, request authorization and push the login UI onto the navigation stack.
        [cameraUI pushViewController:[self createAuthController] animated:YES];
    }
}

// Handle selection of an image
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    UIImage *image = [info valueForKey:UIImagePickerControllerOriginalImage];
    [self dismissModalViewControllerAnimated:YES];
    [self uploadPhoto:image];
}

// Handle cancel from image picker/camera.
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{
    [self dismissModalViewControllerAnimated:YES];
}

// Helper to check if user is authorized
- (BOOL)isAuthorized
{
    return [((GTMOAuth2Authentication *)self.driveService.authorizer) canAuthorize];
}

// Creates the auth controller for authorizing access to Google Drive.
- (GTMOAuth2ViewControllerTouch *)createAuthController
{
    GTMOAuth2ViewControllerTouch *authController;
    authController = [[GTMOAuth2ViewControllerTouch alloc] initWithScope:kGTLAuthScopeDriveFile
                                                                clientID:kClientID
                                                            clientSecret:kClientSecret
                                                        keychainItemName:kKeychainItemName
                                                                delegate:self
                                                        finishedSelector:@selector(viewController:finishedWithAuth:error:)];
    return authController;
}

// Handle completion of the authorization process, and updates the Drive service
// with the new credentials.
- (void)viewController:(GTMOAuth2ViewControllerTouch *)viewController
      finishedWithAuth:(GTMOAuth2Authentication *)authResult
                 error:(NSError *)error
{
    if (error != nil)
    {
        [self showAlert:@"Authentication Error" message:error.localizedDescription];
        self.driveService.authorizer = nil;
    }
    else
    {
        self.driveService.authorizer = authResult;
    }
}

// Uploads a photo to Google Drive
- (void)uploadPhoto:(UIImage*)image
{
    NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
    [dateFormat setDateFormat:@"'Quickstart Uploaded File ('EEEE MMMM d, YYYY h:mm a, zzz')"];

    GTLDriveFile *file = [GTLDriveFile object];
    file.title = [dateFormat stringFromDate:[NSDate date]];
    file.descriptionProperty = @"Uploaded from the Google Drive iOS Quickstart";
    file.mimeType = @"image/png";

    NSData *data = UIImagePNGRepresentation((UIImage *)image);
    GTLUploadParameters *uploadParameters = [GTLUploadParameters uploadParametersWithData:data MIMEType:file.mimeType];
    GTLQueryDrive *query = [GTLQueryDrive queryForFilesInsertWithObject:file
                                                       uploadParameters:uploadParameters];

    UIAlertView *waitIndicator = [self showWaitIndicator:@"Uploading to Google Drive"];

    [self.driveService executeQuery:query
        completionHandler:^(GTLServiceTicket *ticket,
                            GTLDriveFile *insertedFile, NSError *error) {
            [waitIndicator dismissWithClickedButtonIndex:0 animated:YES];
            if (error == nil)
            {
                NSLog(@"File ID: %@", insertedFile.identifier);
                [self showAlert:@"Google Drive" message:@"File saved!"];
            }
            else
            {
                NSLog(@"An error occurred: %@", error);
                [self showAlert:@"Google Drive" message:@"Sorry, an error occurred!"];
            }
        }];
}

// Helper for showing a wait indicator in a popup
- (UIAlertView*)showWaitIndicator:(NSString *)title
{
    UIAlertView *progressAlert;
    progressAlert = [[UIAlertView alloc] initWithTitle:title
                                               message:@"Please wait..."
                                              delegate:nil
                                     cancelButtonTitle:nil
                                     otherButtonTitles:nil];
    [progressAlert show];

    UIActivityIndicatorView *activityView;
    activityView = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhite];
    activityView.center = CGPointMake(progressAlert.bounds.size.width / 2,
                                      progressAlert.bounds.size.height - 45);

    [progressAlert addSubview:activityView];
    [activityView startAnimating];
    return progressAlert;
}

// Helper for showing an alert
- (void)showAlert:(NSString *)title message:(NSString *)message
{
    UIAlertView *alert;
    alert = [[UIAlertView alloc] initWithTitle: title
                                               message: message
                                              delegate: nil
                                     cancelButtonTitle: @"OK"
                                     otherButtonTitles: nil];
    [alert show];
}
@end