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  • This is a private group project for school, for academic purpose.
  • Any reuse of the code is not authorized.
  • We do not responsible for anything may caused by using our code.
  • Unless specified, all the codes in this repo is written by ourselves.


Included third party open source codes

  1. FMDB: An Objective-C wrapper around SQLite by ccgus
  2. ocean: A free iOS interface customize template from

System Implementation Overview

Underlying Technical Complexity

  • The queries with SQLite database are all done through FMDB.
  • GeoGraph System as a whole, is the subsystem responsible for executing database query and data packing. It provide a facade interface for upper layer subsystems (i.e., GeoGraph Utilities) to access all the Geographic data.
  • User Profile is the subsystem responsible to store user's favorites and user's search history (not implemented yet). It utilize the Core Data storage provide by iOS SDK to store all the contents generated by the user. One important reason for us to choose Core Data for this task is, everything saved in it are automatically backed up in iCloud.
  • We use Xcode as the IDE (No other choice). No code generation tools. All the elements in our design are mapped by hand. Thanks Xcode's auto completion.

Implementation Process

  • Accomplished:
    • Browse all the POIs in a building / on a floor
    • Favorite's management
    • Navigation in the same building
  • Future Enhancements:
    • Implement the calculation of path between buildings
    • Use the IPS technology to track user's location accurately indoor and do turn by turn navigation.

Compliance with Software Architecture

Subsystem Design

  • GeoGraph System (GGSystem)

    • Besides the facade, singleton and proxy pattern is used.
    • Upper layer components obtain the GeoGraph System singleton instance by calling [GGSystem sharedGeoGraphSystem].
    • Three dictionaries (for buildings, floorPlans and points) are used in the system implementation for data caching.
    • GeoGraph Components
      • The connections between components (i.e., a floorPlan belongs to a building) are weak links represent by id's (i.e., each building has a bId).
      • Component user can directly access the connected components as readonly. Underlying, the component will ask the GGSystem singleton to provide the connected component objects, rather than save them directly.
      • Therefore, all the components are cached and managed by GGSystem. Results in lower coupling between components.
  • GeoGraph Utilities (GGPool)

    • These are the containers for GeoGraph data. Include couple of utility functions to fetch/filter the data.
    • All the View Controllers, who deal with a pile of data from GGSystem, use these containers to obtain useful information.
  • User Profile (CNUserProfile)

    • It is implemented with singleton pattern as well, since Core Data's managedObjectContext is singleton at the first place.
    • It manages the user's favorites (and history in the future). Providing methods for upper layer components to add, remove or modify the user's favorites.
  • Path Calculation (CNPathCalculator)

    • CNPathCalculator is a template class. To calculate, must be instantiated as CNSameFloorPathCalculator or CNSameBuildingPathCalculator. Different calculator use different details in each step.
    • All the calculator start the calculation upon executeCalculation call.
    • Ideally, the calculation should be done asynchronously, and post an kCNPathCalculationDidFinishNotification notification with the calculation result. But for now, since the calculation is not too slow to be done synchronously, this mechanism has not been implemented.
  • View Controllers

    • These are all the UI controllers, one for each view. The views are defined in Storyboard.
    • Currently, the floor plan map rendering is in the controller logic. But they should definitely be placed into a separate subsystem and done asynchronously.

Architectural Drift and Erosion


  • GGBuilding
    • This data structure is added to generalize the data hierarchy. So that one Building can contain more information rather than just a name.
  • History is not implemented yet.
  • The path calculation and map rendering was designed to be done asynchronously. Not implemented due to time limitation.


  • GGPool and its children class is used instead of POI Utility. POI Utility subsystem was designed with too narrowed functionality.

Compliance with Detailed Software Design

Control Flow Implementation

  • The navigation and communication between controllers are done in two different way:
    1. If there is a segue define in Storyboard, the new view is a direct pushed to the UINavigationController's stack and present to the user. Data are passed to the new view by overriding the - (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender method.
    2. If there is not a segue, then the new view is trying to promote itself to the front upon receiving a notification (i.e., kCNNavConfigNotification is received for navigation source or destination changes). Data are passed together with the notification.
  • The data for all the ViewController come from GeoGraph Utilities, User Profile or Path Calculation. The lower layer GeoGraph System may be include to accessing the data structures, but no direct call to GGSystem.

Boundary Control Implementation

  • Initialization
    • CNUICustomize's class methods (static methods) will be called in - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions to customize the UI components .
    • All the singletons are initiated lazily.
    • View Controllers are created by the iOS System/SDK implicitly.


Lead your way between classrooms. In building route finder.






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