Trembita

This tiny library base on annotation processing and kotlin-poet can help you to write Kotlin-style interfaces and make your code more readable. So lets check which problem it solves:

I'm sure you have such interfaces in your code:

interface Callback {
    fun success(response: String, code: Int)
    fun error(errorCode: Int)
}

Then if you need to use it, probably you have something like this:

someClass.setCallback(object : Callback {
     override fun success(response: String, code: Int) {
     }
     override fun error(errorCode: Int) {
     }
})

With @Trembita you could write more attractive interfaces. Here is an example: First that you need, just add @Trembita annotation to your interface

@Trembita
interface Callback {
    fun success(response: String, code: Int)
    fun error(errorCode: Int)
}

Then rebuild a project, and add method for interface initialization to class where you are going to use interface instance:

class SomeClass {

    lateinit var callBack: Callback

    fun setListener(init: TrembitaCallback.() -> Unit) {
       callBack = TrembitaCallback().apply(init)
    }

    fun responseReceived() {
        callBack.success("response", 200)
     }
 }

So now your interface implementation will look like this:

someClass.setListener {
     success { response, code -> processResponse(response, code) }
     error { _ -> }
}

Now you can use lambdas and the whole Kotlin power. One more important thing is that all methods are optional

Implementation Add this code to your build.gradle in project level:

allprojects {
     repositories {
        ...
        maven { url 'https://jitpack.io' }
     }
}

Then add this two dependencies to your module:

compile 'com.github.root1991.Trembita:trembita-processor:0.1.0-alpha'
compile 'com.github.root1991.Trembita:trembita-annotations:0.1.0-alpha'

Problems that would be fixed in following releases

• You should rebuild the project after adding @Trembita annotation
• Library supports only methods that return Unit
• Library does not support properties in interfaces

PS: If you have any suggestions or bugs, please create issues or Pull Requests.

Enjoy!