Swift iOS Demos

Endorse

The following apps demo Swift, as well as the expanded capabilities of Xcode 11

SwiftUI

Build Sheets

BullsEye

• Uses SwiftUI w/UIKit

MacBullsEye

• SwiftUI on macOS and iPadOS

Packages

• Swift Packages of the game thus far

RGBullsEye

• SwiftUI demo app
• Original app's capabilities then expanded upon
• Uses UIKit w/SwiftUI

TVBullsEye

• SwiftUI on AppleTV

Notes

• Declarative app development
  • declare how views should look and what data they depend on
  • declare how view's state affects its appearance & how SwiftUI should react to change in data dependencies
• Essentially a reactive UI
• Help speed up app development
  • Views
    • Declarative UI doesn't need stringly-typed identifiers to stay in sync with code
    • use views 4 layout and navigation and encapsulate presentation logic for a specific piece of data
    • API consistent across platforms
    • Controls describe their role not appearance - same control looks appropriate for every platform
  • Data
    • Declarative data dependencies update views upon data change - the framework recomputes the views and all their children, then renders what has changed
    • View's state depends on its data => declare how view uses data, how view reacts to data changes, or how data affects the view
    • Declare possible states for view and how view appears in each state
  • Navigation
    • Conditional subviews can replace navigation
  • Integration
    • Easy to integrate SwiftUI into UIKit app and vice versa
  • SwiftUI manages dependencies to keep views consistent with their state => don't have to worry about doing things in the right order or forgetting to update a UI object
  • Canvas means no need for storyboard
  • Subviews keep selves updated means no need for view controller
  • Live preview means not as much a need for simulator

AdaptiveWeather

AdaptiveWeather’s two views are truly universal, scaling to any device and transitioning from a vertical stack, to horizontal row depending on orientation. No code alteration necessary, results were achieved purely through Storyboard.

• Adaptive Layout

• Adaptive Font

• Device-Dependent Images (Including Retina HD images for iPhone 6 Plus)

CoreDataTest

• Username & Password storage and retrieval

Audio Session / EZAudio / CocoaPods Code is Up - Tutorial in Progress

• Measuring incoming audio levels using AVAudioSession while simultaneously drawing a waveform using EZAudio

  • A tutorial explaining the previous will be available at techEd

Data Structures & Algorithms

Data Structures:

Stack

• LIFO
• Essential operations
  • push
  • pop

Linked List

• Linear & unidirectional
• O(1) time complexity for head-first insertion (Arrays have O(n) time complexity for head-first insertions)
• Conforming to collection protocols, Sequence and Collection, affords host of methods for fairly small set of requirements
• Copy-on-write (value semantics)

Queues

• FIFO
• Enqueue inserts at end of queue
• Dequeue removes from front of queue
• Elements not stored in contiguous memory blocks like Array. This scattered storage has potential for cache misses.
• Ring-buffer-queue good for queues of fixed size
• Leveraging two stacks improves dequeue(_:) time complexity to amortized O(1)
• Double-stack beats out Linked List in spacial locality