Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/xlab/android-go

The android-go project provides a platform for writing native Android apps in Go programming language.
https://github.com/xlab/android-go

Last synced: 10 days ago
JSON representation

The android-go project provides a platform for writing native Android apps in Go programming language.

Awesome Lists containing this project

README 

        
android-go [![Go Report Card](https://goreportcard.com/badge/github.com/xlab/android-go)](https://goreportcard.com/report/github.com/xlab/android-go) ![Lines of Code](https://img.shields.io/badge/lines-7K-blue.svg)

==========



The **android-go** project aims to provide a platform (namely an SDK) for

writing native Android apps in Go programming language. All things here were

designed to be less coupled as possible, thus maintaining a great level of

flexibility while keeping things simple and easy to use. The approach and tools

are different from [gomobile](https://github.com/golang/mobile), please

distinguish them apart.



The project was one of [the best Go Newsletter items of 2016](http://golangweekly.com/issues/140). In this final issue of the year, they look back at the most popular Go news and links of 2016. 🌟



❗️Important! Please see [cmd/android-project](/cmd/android-project) utility that replaces the original `android` from SDK that has been stripped in latest SDK releases. All example Makefiles were updated, I advise you to do the same rather than stick to old SDK versions.



## Project structure



### android [![GoDoc](https://godoc.org/github.com/xlab/android-go/android?status.svg)](https://godoc.org/github.com/xlab/android-go/android)



Package **android** provides Go bindings for the Android NDK API. They've been

automatically generated by [c-for-go](https://git.io/c-for-go) using the

official NDK headers from `android-23` platform. Keep in mind that different NDK

platforms may implement different sets of API available, thus some of features

used by this binding may not be available in older versions of platform. But I

tested with the `android-21` toolchain and got no issues. Some files, like

[android/sensors.go] for example, have been written by hand to expose some

features that CGO does not handle well.



This package allows to write code that works directly with NDK API, bypassing

all the CGO bookkeeping and boilerplate bloat in your code. But safety is

strictly advised. There is also a JNI calling mechanism that allows easy interactions with

Java VM and exposes the full potential of Android SDK! See [android/jni_util.go] for example

of toggling Android keyboard and other JNI-based utils.



**Example usages:** [app/queue.go], [example], [example-egl], [nk-android].



[app/queue.go]: https://github.com/xlab/android-go/blob/master/app/queue.go

[android/jni_util.go]: https://github.com/xlab/android-go/blob/master/android/jni_util.go

[android/sensors.go]: https://github.com/xlab/android-go/blob/master/android/sensors.go



### cmd/android-project



Tool **android-project** is a simple replacement for infamous `android` util from Android SDK, prior to Android SDK Tools [Revision 25.3.0 (March 2017) release](https://developer.android.com/studio/releases/sdk-tools.html) when they dropped that util abruptly and got back a stripped version later. Needs to be installed first:



```

go get github.com/xlab/android-go/cmd/android-project

```



### app [![GoDoc](https://godoc.org/github.com/xlab/android-go/app?status.svg)](https://godoc.org/github.com/xlab/android-go/app)



Package **app** implements a NativeActivity glue layer required to properly

handle the startup process and the native activity events. Import this package

into your Go application to make it Android-compatible. Some pieces required

for a proper `main.main` trampoline have been borrowed from gomobile, the

absolute minimum to get this stuff invokable as a native activity. Most of the

code in this package provides wrappers around NativeActivity event callbacks.



**Example usages:** [example], [example-egl], [nk-android].



[example]: https://github.com/xlab/android-go/tree/master/example

[example-egl]: https://github.com/xlab/android-go/tree/master/example-egl



### egl [![GoDoc](https://godoc.org/github.com/xlab/android-go/egl?status.svg)](https://godoc.org/github.com/xlab/android-go/egl)



Package **egl** provides Go bindings for EGL API. They've been automatically

generated by [c-for-go](https://c-for-go.com) using the official NDK headers

from `android-23` platform. All functions have their reference to the offical

Khronos documentation. Some files, like [egl/errors.go] for example, have been

written by hand to expose some features that would make it more idiomatic in the

Go world.



Examples of usage in conjuction with the **android** package: [example-egl], [nk-android].



[egl/errors.go]: https://github.com/xlab/android-go/blob/master/egl/errors.go



### gles [![GoDoc](https://godoc.org/github.com/xlab/android-go/gles?status.svg)](https://godoc.org/github.com/xlab/android-go/gles)



Package **gles** provides Go bindings for the OpenGL ES v1 API. They've been

automatically generated by [c-for-go](https://c-for-go.com) using the

official NDK headers from `android-23` platform. All functions have their

reference to the offical documentation.



Example of usage in conjuction with the **android** package: [example-egl].



### gles2 [![GoDoc](https://godoc.org/github.com/xlab/android-go/gles2?status.svg)](https://godoc.org/github.com/xlab/android-go/gles2)



Package **gles2** provides Go bindings for the OpenGL ES v2 API. They've been

automatically generated by [c-for-go](https://c-for-go.com) using the

official NDK headers from `android-23` platform. All functions have their

reference to the offical documentation.



Example of usage in conjuction with the **android** package: [nk-android].



### gles3 [![GoDoc](https://godoc.org/github.com/xlab/android-go/gles3?status.svg)](https://godoc.org/github.com/xlab/android-go/gles3)



Package **gles3** provides Go bindings for the OpenGL ES v3 API. They've been

automatically generated by [c-for-go](https://c-for-go.com) using the

official NDK headers from `android-23` platform. All functions have their

reference to the offical documentation.



Example of usage in conjuction with the **android** package: [nk-android].



### gles31 [![GoDoc](https://godoc.org/github.com/xlab/android-go/gles31?status.svg)](https://godoc.org/github.com/xlab/android-go/gles31)



Package **gles31** provides Go bindings for the OpenGL ES v3.1 API. They've been

automatically generated by [c-for-go](https://c-for-go.com) using the

official NDK headers from `android-23` platform. All functions have their

reference to the offical documentation. The OpenGL ES computing API is supported.



## Examples



Refer the example links to get more info about them.



There are three examples. The first [example] is a template app showing how

to create and build an Android application using the absolute minimum of code and

boilerplate. It also shows the primitives of an activity and how to handle

activity events, there is no visual part, so be ready to read the lines from the

ADB logcat. If this one works correctly on your device, my congratulations. If

not, please open an issue.



The [example-egl] leverages all three packages together: **android**, **egl**

and of course **gles** (OpenGL ES 1.0) to create an visual app that animates its color based

on the accelerometer values. It also reads input events such as key events and

multitouch motion events (with pressure, if supported by the device), you can

check these events in the ADB logcat. Please see the video of the expected

behaviour:



[![Golang + EGL/GLES App on Android](https://img.youtube.com/vi/H2cafzATUEw/0.jpg)](https://www.youtube.com/watch?v=H2cafzATUEw)



And recently I took [nuklear] package and implemented a few backends in Go,

including two for Android that initialize OpenGL ES 2 or ES 3 context using

**android**, **egl**, **gles2** and **gles3** packages. They also responsible

for handling touch and other input events. So now it is possible to create GUI

apps for Android, see [nk-android] for an example Nuklear GUI app.



[nuklear]: http://github.com/golang-ui/nuklear

[nk-android]: https://github.com/golang-ui/nuklear/tree/master/cmd/nk-android



[![Nuklear GUI App written in Golang runs on Android](https://img.youtube.com/vi/3-MiceegZlM/0.jpg)](https://www.youtube.com/watch?v=3-MiceegZlM)



Android keyboard toggling [video](https://goo.gl/photos/TFkYFKC48Re6RnbUA).



## On existing tools or why not just use Gomobile



**TL;DR** it's a "three wheel bicycle" in terms of hacking flexibility. Conversely, this

project tries to fill the niche by providing a platform that is minimal as

possible and respects the bleeding-edge features such as OpenGL ES 3.1, ES 3.2

and of course Vulkan API.



GoMobile has different aims and motivation with a lot of implications. First of

all, it has been grown as a bootstrap-script. That's it: a tool with a lot of

hardcoded logic that helped to popularize Go on mobile platforms. Still provides a

simple way to start building Android and iOS apps in no time, without diving

deeply into any of the platform-specific complications. It provides a lot of wrappers and

helpers that abstract all the platform-related boilerplate and logic away,

making your apps look the same on any platform: Android, iOS, PC (Linux/OS

X/Windows).



Also, considering that binding feature of GoMobile, it's a good option to use

when you already have lots of Java/Obj-C code and want to integrate some of Go

libs into the project. The tool is mostly for experienced mobile developers who

just want to try Go sometimes. They provide a framework that hides platform

details, but they also may be to restrictive and limited due to this and can't

be used for crazy experimenting stuff.



An example: for Android developent, gomobile defaults to `r10` SDK with `android-15`

stripped-down NDK, there is a lot of code written to automate this process and

there is no way to override this environment, even by rewriting a lot of

gomobile bootstrapping code. It's a great mess. I wasted too much time trying to

switch to the `r12-beta1` SDK and the `android-23` NDK platform. Instead of providing

a good document how to build the Go-based apps and incorporate them into any of

the existing development process, GoMobile project introduces tons of

hardcoded scripts.



## Contributing



Feel free to share bugs, I expect a lot of weird cases. Please also share this

project in social networks so more people would know how to write Go apps for

Android that are not limited.



## License



All the code except when stated otherwise is licensed under the [MIT license](/LICENSE.txt).