ViewModelFactory and Dagger

ViewModelFactory

package net.yslibrary.omnitweety.base

import android.arch.lifecycle.ViewModel
import android.arch.lifecycle.ViewModelProvider
import javax.inject.Inject
import javax.inject.Provider
import javax.inject.Singleton

/**
 * Created by yshrsmz on 2017/07/22.
 */
@Singleton
class ViewModelFactory @Inject constructor(
    private val creators: Map<Class<out ViewModel>, @JvmSuppressWildcards Provider<ViewModel>>
) : ViewModelProvider.Factory {

  override fun <T : ViewModel> create(modelClass: Class<T>): T {
    val creator = creators[modelClass]
        ?: creators.entries.firstOrNull { (key) -> modelClass.isAssignableFrom(key) }?.value
        ?: throw IllegalArgumentException("Unknown ViewModel Class: $modelClass")

    @Suppress("UNCHECKED_CAST")
    return try {
      creator.get() as T
    } catch (e: Exception) {
      throw RuntimeException(e)
    }
  }
}

ViewModelModule.kt

package net.yslibrary.omnitweety.base

import android.arch.lifecycle.ViewModel
import android.arch.lifecycle.ViewModelProvider
import dagger.Binds
import dagger.MapKey
import dagger.Module
import dagger.multibindings.IntoMap
import net.yslibrary.omnitweety.compose.TweetComposeViewModel
import net.yslibrary.omnitweety.entry.EntryViewModel
import net.yslibrary.omnitweety.history.HistoryViewModel
import net.yslibrary.omnitweety.license.LicenseViewModel
import net.yslibrary.omnitweety.setting.SettingsViewModel
import net.yslibrary.omnitweety.settingadvanced.AdvancedSettingsViewModel
import kotlin.reflect.KClass

/**
 * Created by yshrsmz on 2017/07/22.
 */
@Module
abstract class ViewModelModule {

  @Binds
  @IntoMap
  @ViewModelKey(EntryViewModel::class)
  abstract fun bindEntryViewModel(viewModel: EntryViewModel): ViewModel

  @Binds
  @IntoMap
  @ViewModelKey(HistoryViewModel::class)
  abstract fun bindHistoryViewModel(viewModel: HistoryViewModel): ViewModel

  @Binds
  @IntoMap
  @ViewModelKey(LicenseViewModel::class)
  abstract fun bindLicenseViewModel(viewModel: LicenseViewModel): ViewModel

  @Binds
  @IntoMap
  @ViewModelKey(SettingsViewModel::class)
  abstract fun bindSettingsViewModel(viewModel: SettingsViewModel): ViewModel

  @Binds
  @IntoMap
  @ViewModelKey(AdvancedSettingsViewModel::class)
  abstract fun bindAdvancedSettingsViewModel(viewModel: AdvancedSettingsViewModel): ViewModel

  @Binds
  @IntoMap
  @ViewModelKey(TweetComposeViewModel::class)
  abstract fun bindTweetComposeViewModel(viewModel: TweetComposeViewModel): ViewModel

  @Binds
  abstract fun bindViewModelFactory(factory: ViewModelFactory): ViewModelProvider.Factory
}


@MustBeDocumented
@Target(AnnotationTarget.FUNCTION)
@Retention(AnnotationRetention.RUNTIME)
@MapKey
annotation class ViewModelKey(val value: KClass<out ViewModel>)