How are bindings to existing native frameworks generated?

RoboPods

If you're looking for a binding to a popular 3rd party library, it maybe already be done by the RoboPod project. For a list of current supported libraries take a look at: https://github.com/MobiVM/robovm-robopods/issues/1

bro-gen

bro-gen is a Ruby script that generates RoboVM bindings semi-automatically. You need to write a YAML mapping file for the library to generate the binding. For details head over to our fork of bro-gen which works with the current RoboVM version https://github.com/MobiVM/robovm-bro-gen

For some examples of YAML mapping files take a look at the config files for the iOS Cocoatouch or UIKit bindings in this repository https://github.com/MobiVM/robovm/tree/master/compiler/cocoatouch/src/main/bro-gen Those mappings are automatically generated with our bro-gen fork.

Tutorials

Generate Admob Bindings with bro gen Tutorial

Another bro gen Tutorial

Create bindings manually

For small to medium sized libraries it maybe feasible to write the bindings manually. For a simple example binding take a look at the bindings to the SVGgh library https://github.com/florianf/robopod-ghs-svg.

The original RoboVM documentation has a nice introduction to the binding mechanism used by RoboVm https://github.com/MobiVM/robovm/wiki/The-Bro-Java-to-Native-Bridge

Tips & Tricks

• CGRect and CGSize method parameters should always be annotated with the @ByVal annotation.
• Bro doesn't support float, always use a double annotated with @MachineSizedFloat

Simple example

@Method(selector = "asImageWithSize:andScale:")
public native UIImage asImageWithSize(@ByVal CGSize maximumSize, @MachineSizedFloat double scale);