libmx3

Cross platform has been well studied on desktop, but this is an exploration in doing that on mobile and an open request for comments and improvements.

The name

"mobile times 3", Android, iOS, and Windows Phone. (todo, windows phone support)

Learning

• Mobile C++ Slack instance!
• UIKonf 2014
• CppCon 2014 - A Deep Dive Into Two Cross-Platform Mobile Apps Written in C++
• CppCon 2014 - Practical Cross-Platform Mobile C++ Development
• CppCon 2014 - Microsoft w/ C++ to Deliver Office Across Different Platforms, Part II
• Google Inbox
• JVM at Google
• Know of a good resource? put up a PR to add it!

Tools of the Trade

• djinni (pronounced genie) a tool which generates interface bindings from Java -> C++ and ObjC -> C++
• gyp a meta-build system used to generate native project files across platforms
• cmake (not used in this project) an alternative to gyp
• gradle build automation
• json11 a minimalist C++11 library for json serialization
• optional a reference implementation of std::experimental::optional
• juce cross platform C++ toolkit (not used here)
• j2objc (not used in this project)
• xamarin (not used in the project)
• Visual Studio's cross platform mobile support and a related video
• Know of a tool? put up a PR to add it!

Contributing

There are many ways to contribute to mx3:

1. new proposals for architecture and techniques
2. bugfixes
3. documentation of any kind
4. new target platforms
5. educating us about your use case for cross platform mobile

There are a few things laid out in TODO, if you want to contribute but don't know how. If you are building a large feature, please file an issue first to ensure that it aligns with the goals of mx3 - if it does, please submit a Pull Request during development to solicit feedback and enable incremental code review throughout the process.

Requirements

• python (required for gyp)
• xcode & xcodebuild
• android ndk and ndk-build on your PATH to build for android
• windows phone developer tools (eventually...)
• Configure the paths to your Android SDK and Android NDK by creating a file using the template at example_android/local.properties.example.

Installation

1. Run git submodule update --init to download all dependencies
2. Optionally gem install xcpretty to make the output of xcodebuild nice
3. Run make play. You should see "Hello, #{your login name}" printed to the console, if so, you seem to already have all the requirements met for building on iOS.
4. Run make android to build the example android application.

Objective-C

Run make play ios or make play mac

Android

Be sure to create a example_android/local.properties file pointing to the android-ndk and android-sdk.

Building

Running any of the make commands will automatically download gyp and create .xcodeproj files for each platform.

Build files are generated in build_ios/mx3.xcodeproj, build_mac/mx3.xcodeproj, and GypAndroid.mk but be careful, running make commands again will overwrite any changes you make to these files. If you need to change something, you should be able to do so from common.gypi or mx3.gyp and recompile your buildfiles.

Make targets:

• clean - clean all generated files
• make test - run the c++ tests
• ios, mac - builds a static library for each platform
• android - build the example app APK
• make play - to write some quick "playground" style code in objc (see objc/play.m)

Directory structure

├── Application.mk # the android make file
├── Makefile # helper for interacting with gyp, and using command line builds (no xcode!!)
├── android/ # Java bindings to mx3::Api
├── common.gypi # a gyp include which defines project wide settings
├── deps/ # third party dependencies
├── example_android/ # the Android example project
├── example_ios/ # an external xcodeproj which uses libmx3 ("the client" in a client/server model)
├── include/ # header include paths, no code here
├── mx3.gyp # gyp meta-build file for per-target settings
├── objc/ # objc bindings to mx3::Api. Very simple api translation (NSString * -> std::string, lowerCamel -> under_lower, etc.)
├── src/ # the c++ library, there should be no objc/java code here ("the server" in a client/server model)
└── test/ # c++ tests