1 Agenda

• Tools Overview
• Integrated Development Environments for Android
• Native Build Process
• Version Control Systems
• Testing and Distribution Tools
• Collaboration Tools
• Continuous Integration

2 Basic Tools for App Development

• An Integrated Development Environment (IDE) including (*optional):
  • Source-code editor*
  • Debugger*
  • Cross-Compiler
  • Linker*
• Software Development Kit (SDK) for the target platform including:
  • Emulator & Simulator
  • Platform specific debug service
  • Platform libraries and source code or header files
  • Other build and platform relevant tools
• Version Control System*, e.g. Git, SVN
• Testing and Distribution Tools*, e.g. Firebase App Distribution, Google Play Console testing tracks, Bitrise
• Collaboration and Project Management Software*, e.g. GitLab, GitHub, Jira, Trello, Slack
• Continuous Integration Tools*, e.g. GitLab CI, GitHub Actions, Jenkins

Most of the tools provide nowadays combined services.

3 Android IDE

For Android app development it is strongly recommended to use Android Studio.

Android Studio (based on IntelliJ IDEA): https://developer.android.com/studio

Use the current stable release. The starter projects of the assignments are set up for Android Studio 2026.1 with the Android Gradle Plugin 9.1.

4 Android Studio contains

• Editor with Kotlin and Compose support, Compose Preview, Layout Inspector, Profiler
• SDK Manager: downloads platform versions (API levels), build tools and system images
• Device Manager: creates and runs Android Virtual Devices (the emulator)
• ADB (Android Debug Bridge): installs and debugs apps on devices and emulators
• D8: the dexer, compiles .class files to Dalvik Executable (.dex) bytecode for the Android Runtime
• R8: the shrinker, removes unused code and resources and obfuscates release builds (successor of ProGuard)
• Gradle + Android Gradle Plugin (AGP): the build system. Build scripts are written in Kotlin (build.gradle.kts), library versions live in the version catalog gradle/libs.versions.toml

// app/build.gradle.kts: alias from the version catalog instead of a hard-coded coordinate
dependencies {
    implementation(libs.androidx.navigation.compose)
}

5 Native Build Process

6 Cross-Compilation

• Different CPUs have different instruction sets
• In order to run an application on a certain processor it has to be compiled to the machine code corresponding to the processors Application Binary Interface (ABI)

  

7 Simulator & Emulator

• Developing and deploying on the target device is time consuming
• Debugging might be more difficult
• Sometimes the target device is not available
• Thus, development environments usually provide a simulator or emulator, e.g.:
• XCode (iOS):
  • iPhone Simulator
• Android SDK:
  • Android Emulator

8 Simulator vs. Emulator

9 Version Control System (VCS)

• Allow to track changes to files (e.g. sourcecode)
• Most popular VCS
  • Git
  • Subversion (SVN)
• Free hosting options:
  • GitHub
  • Bitbucket
• In HdM: GitLab (self-hosted)

10 Why Version Control

• Supports collaboration, i.e. development of source code in a team
• Stores different versions of a software efficiently without using too much storage space
• Keeps track and allows to restore older versions
• Efficient backup tool for you work

11 Git Clients

• Command line interface (git), works everywhere and is used in the Git Intro
• Git clients for Mac & Windows
  • Atlassian SourceTree (free)
  • GitHub Desktop (free, works with any Git remote)
  • Fork
• IDE integrations:
  • Android Studio
  • Visual Studio Code

12 Crash Reporting and Beta Delivery Tools

• Google Play Console
  • Testing tracks: internal testing, closed testing (alpha/beta) and open testing before the production release
  • Pre-Launch Reports: automatic tests on real devices
  • Android vitals: crash rate, ANRs, battery
• Firebase App Distribution
  • Distributes debug/release builds to testers without the Play Store
• Firebase Crashlytics
  • Supports Android, iOS and Unity
  • Curated crash reports
  • Analytics integration
• Sentry
  • Crash and performance monitoring, can be hosted on own server
• Legacy: Visual Studio App Center (retired March 2025), HockeyApp, Fabric (both merged into the tools above)

13 Collaboration Tools (examples)

• Citrix Podio
  • Chat, App, Wiki, ...
• Redmine
  • OpenSource
  • Wiki, activities, gantt, tickets,...
• Atlassian Jira Software
  • Issue tracking, scrum support, code integration
  • Often used in larger companies
• GitLab / GitHub
  • Issues, boards, wiki, merge/pull requests and CI in one tool

14 Continuous Integration (CI)

• Development procedure where changes are integrated frequently into a repository
• Principles
  • Maintain a code repository
  • Automate the build
  • Test the build automatically
  • Daily commit of every developer & build including test of every commit
    • Keep the build fast (otherwise it would take too long for CI)
    • Testing is done in a realistic but not productive environment (clone)
• Automate deployment for user tests
  • Make it easy for developers & testers to access the latest builds and see the build results
  • Also called Continuous Delivery (CD)

15 Continuous Integration (CI)

• Some advantages of CI
  • Bugs can be found and fixed immediately
  • Due to frequent builds, integration problems can be fixed at an early stage (reducing debug time)
  • Can increase code quality
• Disadvantages of CI
  • Initial setup is time consuming
  • Good test-tools are required
• Tools for CI
  • GitLab CI: built into GitLab (also the HdM GitLab), configured by a .gitlab-ci.yml in the repository
  • GitHub Actions: built into GitHub, workflows in .github/workflows/*.yml
  • Jenkins: OpenSource CI server written in Java (forked from Hudson), self-hosted

16 CI Example: GitLab CI

These slides are built and deployed by GitLab CI. The complete .gitlab-ci.yml of the lecture repository:

variables:
  GIT_SUBMODULE_STRATEGY: recursive

pages:
  stage: deploy
  image: node:alpine
  script:
    - sh master/build.sh
    - mv dist public
  artifacts:
    paths:
      - public
  only:
  - master

• Every push to master starts a job in a Docker container (node:alpine), runs the build script and publishes the result as GitLab Pages
• An Android job works the same way: an image with the Android SDK, ./gradlew test and ./gradlew assembleDebug as script, the APK as artifact

17 Summary

• A mobile toolchain consists of IDE, SDK (emulator, debug bridge, platform libraries), VCS, testing/distribution tools and CI
• Android Studio bundles the SDK tools; Gradle with the Android Gradle Plugin builds the app, D8 produces the .dex bytecode, R8 shrinks release builds
• Apps are cross-compiled for the ABI of the target CPU; the emulator runs a full Android system image on your machine
• Git is the VCS of this course, hosted on the HdM GitLab
• CI builds and tests every commit automatically, GitLab CI and GitHub Actions are integrated into the hosting platform

18 Recap Questions

• What are the benefit and drawbacks of a simulator vs. an emulator?
• What is an ABI? Which tool makes use of this?
• What is an instruction set?
• What do D8 and R8 do in the Android build?
• Explain the concept of continuous integration? What are the benefits?
• Which file configures a GitLab CI pipeline and what does a job consist of?