iOS Development Introduction

1 Agenda

• iOS Overview
  • System Architecture, Runtime Environment
• Development Tools
• MacOS Basics
• Git & Gitlab

2 iOS Overview - Facts

• Formerly known as iPhone OS, introduced on 29th July 2007 with the Apple iPhone
• Derived from Mac OS X, based on Darwin a free, Unix like OS
• Kernel type: Hybrid
• Supported platforms: ARM
• Size: approx. 3 GB
• Current version: 18.0
• Current iOS devices: iPhone, iPod Touch, iPad (derivate iPadOS), Apple TV (derivate tvOS), Apple Watch (derivate watchOS)

3 iOS Architecture

4 Application Runtime Environment

• Applications run in a UNIX based environment and have full support for threads, sockets, etc. but differences to Mac OS X exist, e.g.:
• Virtual Memory
  • Virtual Memory is constrained to physical available memory (no paging to disk)
  • Read-only pages are released when more memory is needed
  • No Garbage Collector
• Multitasking (iOS > 4.0)
  • Apps in background are suspended
  • Apps can ask system for background execution

5 Application Runtime Environment

• Security features
  • Application sandbox
    • iOS Apps are restricted to a unique location in the file system
  • File protection (iOS > 4.0)
    • Allows to encrypt files and make them inaccessible when the device is locked
  • Keychain
    • similar to Mac OS X keychain, allows to store passwords
    • Stored outside the application sandbox

6 Development Tools - XCode

7 Development Tools - Simulator

8 Development Tools - Instruments

• Instruments: tracing and profiling tool

Source: Apple

9 Development Tools - Interface Builder

• Interface Builder: tool for creating GUIs

10 Development Tools - Storyboards

• Storyboards: Interface Builder feature since Xcode 4.2, before using XIBs
• Allows to specify screens and the triggers and transitions between them

11 Development Tools - SwiftUI

• SwiftUI Framework & Preview
• https://developer.apple.com/documentation/swiftui
• SwiftUI Tutorials

12 MacOS Basics

• MacOS is based on Darwin (like iOS)
• Kernel type: Hybrid (like iOS)
• Supported platforms: Intel, ARM

12.1 Important Tools

Finder

• Show hidden files: Command + Shift + .
• Show Library folder: Shift + Command + L

Spotlight

• Search: Command + Space

Keyboard Settings

• Focus on next window: Command + <

Keyboard tips

• Backslash (\): Shift+Option+7
• Pipe (|): Option+7
• Brackets ([]): Option +5 for [, Option + 6 for ]
• Curly braces ({}): Option + 8 for {, Option + 9 for }
• Change keyboard (e.g. for smileys): fn
• @ sign: Option+L
• Copy: Command+c
• Paste: Command+v
• Undo: Command+z
• Redo: Command+r
• Select All: Command+a
• Save: Command+s

XCode Tips

• Re-Indent selection: Control+I
• Use Folders for organizing files
• Use Option + Click to open files in new tabs

Xcode terminology

• Template: Project type
• Workspace: Project
• Target: Build configuration
  • All files for a specific build configuration (e.g. Debug, Release)
  • Destinations for building the app (e.g. iPhone, MacOS, Apple TV,Apple Vision)
• Scheme: Build configuration + target

13 Git & Gitlab

• Git: Version control system
• Gitlab: Web-based Git repository manager

13.1 Important Git Commands

• Clone repository: git clone <repository_url>
• Push changes: git push
• Pull changes: git pull
• Commit changes: git commit -m "Commit message"
• Add changes: git add <file>
• Add changes for all files from root of repository: git add :/
• Check status: git status
• Check log: git log
• Check remote url: git remote get-url origin
• checkout branch: git checkout <branch_name>
• create branch: git checkout -b <branch_name>
• merge branch: git merge <branch_name>
• delete branch: git branch -d <branch_name>

14 Recap Questions

• iOS is based on which operation system?
• What is the difference between an emulator and a simulator?
• What is the instrument tool used for?
• What is the purpose of the storyboard?
• What is SwiftUI?