ViewModelFactory.kt

package clean.architecture.example.utils

import android.arch.lifecycle.ViewModel
import android.arch.lifecycle.ViewModelProvider
import clean.architecture.example.postlist.PostListViewModel


class ViewModelFactory : ViewModelProvider.Factory {


    override fun <T : ViewModel> create(modelClass: Class<T>): T {
        if (modelClass == PostListViewModel::class.java) {
            return PostListViewModel(
                    Injection.provideUseCaseHandler()
                    , Injection.provideGetPosts(), Injection.provideSavePost()) as T
        }
        throw IllegalArgumentException("unknown model class $modelClass")
    }

    companion object {
        private var INSTANCE: ViewModelFactory? = null

        fun getInstance(): ViewModelFactory {
            if (INSTANCE == null) {
                INSTANCE = ViewModelFactory()
            }
            return INSTANCE!!
        }
    }
}