Go Mobile

The golang/mobile repository provides packages and build tools designed to enable Go code to run on mobile platforms (Android and iOS). It supports two primary workflows:

1. All-Go apps: Building applications written entirely in Go.
2. Libraries for SDK apps: Building Go libraries that can be called from existing native Android or iOS applications using gobind.

Warning: The Go Mobile project is experimental. Use it at your own risk; neither Google nor the Go team provides end-user support.

The gomobile command requires access to the Android SDK and NDK. It attempts to find them automatically, but if it fails, you must manually set the ANDROID_HOME and ANDROID_NDK_HOME environment variables to point to their respective directories.

export ANDROID_HOME=/path/to/sdk-directory
export ANDROID_NDK_HOME=/path/to/ndk-directory

The project depends on robpike.io/ivy and golang.org/x/mobile. To update these dependencies to their latest versions, use go get followed by go mod tidy to clean up the module file.

go get -d golang.org/x/mobile@latest
go get -d robpike.io/ivy/mobile
go mod tidy

Before building the Ivy iOS app, you must generate the Mobile.xcframework from the Go implementation of Ivy. This requires installing gomobile and gobind, initializing a workspace, and running the gomobile bind command with specific targets.

# 1. Install tools
go install golang.org/x/mobile/cmd/gomobile@latest
go install golang.org/x/mobile/cmd/gobind@latest

# 2. Create workspace and fetch dependencies
mkdir work; cd work
go mod init work
go get -d golang.org/x/mobile/bind@latest
go get -d robpike.io/ivy/mobile

# 3. Bind the Go packages to iOS targets
gomobile bind -target=ios,iossimulator,maccatalyst,macos robpike.io/ivy/mobile robpike.io/ivy/demo

To use the Go mobile build system, you must install the gomobile command. This requires Go 1.5 or later. Detailed installation instructions and setup steps can be found at the official Go Mobile wiki:

https://golang.org/wiki/Mobile

The following requirements must be met to build the Ivy Android project:

• Go 1.17 or newer
• Android SDK
• Android NDK
• golang.org/x/mobile/cmd/gomobile

After placing the generated Mobile.xcframework directory into the Ivy iOS source directory, open ivy.xcodeproj in Xcode. You must configure a Development Team to enable code signing:

Navigate to: Project Settings -> Targets -> Signing & Capabilities -> Signing -> Team.

To build the Ivy Big Number Calculator Android project, you must first ensure you have the necessary Go and Android development tools installed. The build process involves using gomobile bind to create an .aar file from the robpike.io/ivy/mobile package, which can then be used in Android Studio.

# Install required tools
go install golang.org/x/mobile/cmd/gomobile@latest
go install golang.org/x/mobile/cmd/gobind@latest

# Build the Android Archive (.aar)
gomobile bind -o app/ivy.aar robpike.io/ivy/mobile

The gomobile tool requires an Android NDK to build for Android. It searches for the NDK in the following order of priority:

1. The ANDROID_NDK_HOME environment variable (highest priority).
2. The side-by-side NDK directory located under your Android SDK path ($ANDROID_HOME/ndk).
3. The legacy ndk-bundle directory under your Android SDK path.

If you need to explicitly point to a specific NDK version, set the ANDROID_NDK_HOME environment variable.

To create an XCFramework for iOS from a Go package, use the gomobile bind command with the -target=ios flag. This generates the necessary framework files required for integration into an Xcode project.

Run the following command in your terminal, replacing the package path with your target package:

gomobile bind -target=ios golang.org/x/mobile/example/bind/hello

The gendex tool generates a .dex file used by Go apps created with gomobile. This DEX file acts as a thin extension of NativeActivity, providing access to certain Android platform features that are not easily accessible via standard NDK headers.

Prerequisites

• Android SDK: The tool respects the ANDROID_HOME environment variable to locate the Android SDK.
• Java Compiler: javac must be available in your system PATH.
• Android Build Tools: The tool requires the dx tool from your Android SDK build-tools directory.

Before using gomobile to build mobile applications, you must initialize the toolchain. If the toolchain is not installed or the path is not found in your $GOPATH/pkg/gomobile, you will encounter an error. Run the following command to set up the environment:

gomobile init