Compose Calculator

This is a simple calculator app written in Kotlin Multiplatform using Compose Multiplatform mobile application.

Fork from compose-multiplatform-template

Note Compose Multiplatform for iOS is in Alpha. It may change incompatibly and require manual migration in the future. We would appreciate your feedback on it in the public Slack channel #compose-ios. If you have any issues, please report them on GitHub.

Set up the environment

Warning You need a Mac with macOS to write and run iOS-specific code on simulated or real devices. This is an Apple requirement.

To run this project, you need:

• A machine running a recent version of macOS
• Xcode
• Android Studio

The Kotlin Multiplatform Mobile plugin

• The CocoaPods dependency manager

Check your environment

Before you start, use the KDoctor tool to ensure that your development environment is configured correctly:

1. Install KDoctor with Homebrew:

   brew install kdoctor
   

2. Run KDoctor in your terminal:

   kdoctor
   

   If everything is set up correctly, you'll see valid output:

   Environment diagnose (to see all details, use -v option):
   [✓] Operation System
   [✓] Java
   [✓] Android Studio
   [✓] Xcode
   [✓] Cocoapods
   
   Conclusion:
     ✓ Your system is ready for Kotlin Multiplatform Mobile development!
   

Otherwise, KDoctor will highlight which parts of your setup still need to be configured and will suggest a way to fix them.

Examine the project structure

Open the project in Android Studio and switch the view from Android to Project to see all the files and targets belonging to the project:

The Compose Multiplatform project includes 3 modules:

shared

This is a Kotlin module that contains the logic common for both Android and iOS applications, that is, the code you share between platforms.

This shared module is also where you’ll write your Compose Multiplatform code. In shared/src/commonMain/kotlin/ComposeCalculatorApp.kt, you can find the shared root @Composable function.

On androidMain you will see a MainAndroid.kt file that contains a @Composable function called MainView that is used to render the UI on Android from ComposeCalculatorApp.

On iosMain you will see a MainIos.kt file that contains a function called MainViewController that is used to render the UI on iOS from ComposeCalculatorApp.

It uses Gradle as the build system. You can add dependencies and change settings in shared/build.gradle.kts. The shared module builds into an Android library and an iOS framework.

androidApp

This is a Kotlin module that builds into an Android application. It uses Gradle as the build system. The androidApp module depends on and uses the shared module as a regular Android library.

The com.jesusdmedinac.compose.calculator.MainActivity use a setContent function to render the MainView composable function from MainAndroid.kt.

iosApp

This is an Xcode project that builds into an iOS application. It depends on and uses the shared module as a CocoaPods dependency.

The ContentView.swift file uses a UIHostingController to render the MainViewController from MainIos.kt.

Run the application

On Android

To run the application on an Android emulator:

1. Ensure you have an Android virtual device available. Otherwise, create one.

2. In the list of run configurations, select androidApp.

3. Choose your virtual device and click Run:

   

Alternatively, use Gradle

To install an Android application on a real Android device or an emulator, run ./gradlew installDebug in the terminal.

On iOS

Running on a simulator

To run your application on an iOS simulator in Android Studio, modify the iosApp run configuration:

1. In the list of run configurations, select Edit Configurations:

   

2. Navigate to iOS Application | iosApp.

3. In the Execution target list, select your target device. Click OK:

   

4. The iosApp run configuration is now available. Click Run next to your virtual device:

Running on a real device

You can run your Compose Multiplatform application on a real iOS device for free. To do so, you'll need the following:

• The TEAM_ID associated with your Apple ID
• The iOS device registered in Xcode

Note Before you continue, we suggest creating a simple "Hello, world!" project in Xcode to ensure you can successfully run apps on your device. You can follow the instructions below or watch this Stanford CS193P lecture recording.

How to create and run a simple project in Xcode

1. On the Xcode welcome screen, select Create a new project in Xcode.
2. On the iOS tab, choose the App template. Click Next.
3. Specify the product name and keep other settings default. Click Next.
4. Select where to store the project on your computer and click Create. You'll see an app that displays "Hello, world!" on the device screen.
5. At the top of your Xcode screen, click on the device name near the Run button.
6. Plug your device into the computer. You'll see this device in the list of run options.
7. Choose your device and click Run.

Finding your Team ID

In the terminal, run kdoctor --team-ids to find your Team ID. KDoctor will list all Team IDs currently configured on your system, for example:

3ABC246XYZ (Max Sample)
ZABCW6SXYZ (SampleTech Inc.)

Alternative way to find your Team ID

If KDoctor doesn't work for you, try this alternative method:

1. In Android Studio, run the iosApp configuration with the selected real device. The build should fail.
2. Go to Xcode and select Open a project or file.
3. Navigate to the iosApp/iosApp.xcworkspace file of your project.
4. In the left-hand menu, select iosApp.
5. Navigate to Signing & Capabilities.
6. In the Team list, select your team.

If you haven't set up your team yet, use the Add account option and follow the steps.

To run the application, set the TEAM_ID:

1. In the template, navigate to the iosApp/Configuration/Config.xcconfig file.
2. Set your TEAM_ID.
3. Re-open the project in Android Studio. It should show the registered iOS device in the iosApp run configuration.