LTU Mobile iOS SDK

This guide will help you get started on using the LTU Cloud API with your iPhone app via the LTU Mobile iOS SDK. The provided sample code uses ARC.

Requirements

The LTU Mobile iOS SDK library is built for use with iOS 5 and up. The sample projects require XCode 4.5 and up. It uses AFNetworking (which is provided by the LTU SDK).

The LTU SDK also uses the following frameworks:

• AVFoundation
• CoreImage
• CoreMedia
• CoreVideo

Setup

Before you get started on coding and using the LTU Mobile iOS SDK, you must set up your Xcode project. We suggest that you add the LTU SDK as a submodule of your project.

This setup is done in a few simple steps:

• Drag the LTUSDK.xcodeproj inside your Xcode project.

• Link all the required iOS Frameworks specified above:

  • AVFoundation
  • CoreImage
  • CoreMedia
  • CoreVideo
  • libLTUSDK-lib.a

• Add "$(SRCROOT)" with the recursive option to the Build Settings variable "User Header Search Paths". This is used for finding LTUSDK headers during compilation and archiving (the LTUSDK directory must be contained inside your source directory).

Usage

Import the LTUManager header for accessing all the classes and helper methods:

#import "LTUManager.h"

#####Initialize Shared LTUManager

This can be done in the app delegate. The shared manager will let you send queries, create visuals and get a list of your projects.

[LTUManager initializeSharedLTUManagerWithUsername:@"myUsername"
                                       andPassword:@"myPassword"];

#####Using the LTUCameraView

The LTU Mobile iOS SDK provides you with robust camera functionality. The LTUCameraView is a subclass of UIView with extra functionality, such as previewing the camera, and ability to capture images instantly from the camera. The LTUCameraView can be added via StoryBoard by using the LTUCameraView instead of UIView, and assigning an outlet to the ViewController. It can also be added programmatically as such in the viewDidLoad:

// The Camera preview has an aspect ratio of 1.3, the screen aspect ratio
// has an aspect ratio of the height / width.  This changes between iPhone 4, 5 and iPad)
// To fit the preview nicely, we normalize this by making the preview frame wider
CGFloat screenAspectRatio = self.view.frame.size.height / self.view.frame.size.width;
CGFloat normalizeRatio = screenAspectRatio / 1.3;
CGRect cameraFrame = CGRectMake(0,
                                0,
                                self.view.frame.size.width * normalizeRatio,
                                self.view.frame.size.height);
self.camView = [[LTUCameraView alloc] initWithFrame:cameraFrame];
[self.view insertSubview:self.camView atIndex:0];

You can pause the camera preview as follows:

[self.camView pausePreview];

By default the preview is already started, but if paused manually, it can be started again:

[self.camView startPreview];

To capture the image from the LTUCameraView:

UIImage *image = [self.camView captureImage];

#####Get Project Listing

All your projects can be retrieved via the LTU API as follows:

[[LTUManager sharedManager] getProjectsWithSuccess:^(NSArray *projectList) {
        // Store projects somewhere
    }

    failure:^(NSError *error) {
        // Handle error
    }

    finished:^ {
        // Shared code on project request completion.
    }];

#####Searching Images

The following is an example on how to search an image within a project:

UIImage *image = [self.camView captureImage];
NSArray *projectIDs = @[@8];
[[LTUManager sharedManager] searchInProjects:projectIDs
                                   withImage:image
                                  withSource:(NSString *)source // User-defined field (user id for instance)
                              withSourceDesc:(NSString *)sourceDesc
                                 withTimeout:(int)timeout
    success:^(LTUQuery *queryResult) {
        // Parse Results
    }

    failure:^(NSError *error) {
        // Handle error
    }

    finished:^ {
        // Shared code on Search Image request completion.
    }
    uploadProgressBlock:^(NSUInteger bytesRead, long long totalBytesRead, long long totalBytesExpectedToRead) {
        // Always executed after the success/failure blocks
    }];

#####Creating Visuals

To Create a Visual you must collect an array of LTUMetaData objects, and pass it to the LTUManager's createVisual method:

UIImage *image = [self.camView captureImage];
LTUMetaData *myData = [[LTUMetaData alloc] initWithValue:@"message"
                                                  forKey:@"Some Message"
                                             andOrdering:0];

NSArray *myMetadata = @[myData];
[[LTUManager sharedManager] createVisualInProject:6
                                        withTitle:@"FooTitle"
                                        withImage:image
                                      andMetadata:myMetadata
    success:^(LTUVisual *createdVisual) {
        // Handle events when visual is created
    }

    failure:^(NSError *error) {
        // Handle error
    }

    finished:^ {
        // Shared code on Creating Visual request completion.
    }
    uploadProgressBlock:^(NSUInteger bytesRead, long long totalBytesRead, long long totalBytesExpectedToRead) {
      // Always executed after the success/failure blocks
    }];

#####Canceling Requests

There are 2 helper methods to help cancel requests.

You can cancel all current searchImage requests:

[[LTUManager sharedManager] cancelAllSearchRequests];

You can also cancel all requests which includes getting a project list, creating visuals, and searching images:

[[LTUManager sharedManager] cancelAllRequests];

Class Overview

More detailed documentation about each class can be found under the docs/ folder provided with the SDK.