Android Weekly Issue #473

Debugging Story: The Case of Rogue Reflection

一个和反射相关的问题的追踪过程.

Kotlin Multiplatform Mobile Codelab

KMP的codelab.

Creating a retro-style game with Jetpack Compose

复古风的游戏.

Scalable Jetpack Compose Navigation

如何扩展Jetpack Compose的Navigation.

定义一个navigation的factory:

// An interface is created to allow a feature module to add their Composable to the NavGraph.
// Defined within a library module
interface ComposeNavigationFactory {
  fun create(builder: NavGraphBuilder, navController: NavHostController)
}

然后每个feature实现它:

// An implementation of the interface, as well as a Dagger 2 module installed via hilt.
// Defined within a feature module
internal class Feature1ComposeNavigationFactory @Inject constructor() : ComposeNavigationFactory {
  override fun create(builder: NavGraphBuilder, navController: NavHostController) {
    builder.composable(
      route = "feature1",
      content = {
        Feature1(
          navController = navController
        )
      }
    )
  }
}

// Defined within the 'feature 1' module
@Module
@InstallIn(SingletonComponent::class)
internal interface ComposeNavigationFactoryModule {
  @Singleton
  @Binds
  @IntoSet
  fun bindComposeNavigationFactory(factory: Feature1ComposeNavigationFactory): ComposeNavigationFactory
}

最后注入:

// An example of a set of factories being used to construct a NavHost.
// Potentially defined within the app module
@AndroidEntryPoint
class ExampleActivity: AppCompatActivity {
  @Inject
  lateinit var composeNavigationFactories: @JvmSuppressWildcards Set<ComposeNavigationFactory>

  @Composable
  fun JetpackNavigationHiltApp() {
    val navController = rememberNavController()

    NavHost(navController, startDestination = "feature1") {
      composeNavigationFactories.forEach { factory ->
        factory.create(this, navController)
      }
    }
  }
}

作者把这个搞了个库:
https://github.com/LachlanMcKee/Hilt-Compose-Navigation-Factory

还有其他方案比如: https://github.com/zsoltk/compose-router

Providing AssistedInject supported ViewModel for Composable using Hilt

AssistedInject: 处理有一些参数需要运行时提供.

在composable里需要借助EntryPoint这样搞一波:

@Composable
fun noteDetailViewModel(noteId: String): NoteDetailViewModel {
    val factory = EntryPointAccessors.fromActivity(
        LocalContext.current as Activity,
        MainActivity.ViewModelFactoryProvider::class.java
    ).noteDetailViewModelFactory()

    return viewModel(factory = NoteDetailViewModel.provideFactory(factory, noteId))
}

用的时候:

NavHost(navController, startDestination = Screen.Notes.route, route = NOTY_NAV_HOST_ROUTE) {
    composable(
        Screen.NotesDetail.route,
        arguments = listOf(navArgument(Screen.NotesDetail.ARG_NOTE_ID) { type = NavType.StringType })
    ) {
        val noteId = it.arguments?.getString(Screen.NotesDetail.ARG_NOTE_ID)!!
        NoteDetailsScreen(navController, noteDetailViewModel(noteId))
    }
}

底部是一个全kotlin技术栈的应用:
https://github.com/PatilShreyas/NotyKT

Two-way communication without internet: Nearby Connections (Part 2 of 3)

利用Nearby API, 没网的时候也可以通信.

Using Composition in Kotlin

在kotlin中使用组合.

Advanced Usage of WorkManager in multi-process apps

WorkManager多进程的例子:
https://github.com/android/architecture-components-samples/tree/main/WorkManagerMultiprocessSample

Scope Storage Myths

Android 11之后, 如果app不访问别的app拥有的文件, 则不需要请求READ_EXTERNAL_STORAGE权限.

还可以这样:

<uses-permission
    android:name="android.permission.READ_EXTERNAL_STORAGE"
    android:maxSdkVersion="29" />

Refactoring Kotlin type-signatures for fun and profit

https://www.http4k.org/

Compose: Strikethru Animation

一个icon的动画.

Browsing Jetpack Compose samples

看Jetpack Compose Sample的方法.

有一个Android Code Search的网站:
https://cs.android.com/

有一个code search plugin:
https://plugins.jetbrains.com/plugin/12578-codesearch

源码:
https://github.com/guojianhua/code-search

Code

• 笔记应用: https://github.com/PatilShreyas/NotyKT
• 一个要取代ViewModel的小工具: https://github.com/marcellogalhardo/retained
• 选取图片和照相的库: https://github.com/SimformSolutionsPvtLtd/SSImagePicker