Android Weekly Notes #465

Android Weekly Issue #465

Learning Live Templates for Jetpack Compose

如何创建live templates.

一个有用的快捷键: alt + cmd + j.
会弹出来让你选择包围控件.

Jetpack Compose的一些有用的live templates.

Bottom Navigation and Navigation Drawer Using Scaffold from Jetpack Compose

这个例子既有BottomNavigation又有侧面的Drawer.

ViewModel记住了当前Screen:

class MainViewModel : ViewModel() {

    private val _currentScreen = MutableLiveData(Screens.DrawerScreens.Home)
    val currentScreen: LiveData = _currentScreen

    fun setCurrentScreen(screen: Screens) {
        _currentScreen.value = screen
    }
}

BottomBar的部分:

@Composable
fun BottomBar(modifier: Modifier = Modifier, screens: List, navController: NavController) {
    BottomNavigation(modifier = modifier) {
        val navBackStackEntry by navController.currentBackStackEntryAsState()
        val currentRoute = navBackStackEntry?.arguments?.getString(KEY_ROUTE)
        screens.forEach { screen ->
            BottomNavigationItem(
                icon = { Icon(imageVector = screen.icon, contentDescription = "") },
                label = { Text(screen.title) },
                selected = currentRoute == screen.route,
                onClick = {
                    navController.navigate(screen.route) {
                        popUpTo = navController.graph.startDestination
                        launchSingleTop = true
                    }
                }
            )
        }
    }
}

Back的处理:

setContent {
    NavigationDrawerTheme {
        CompositionLocalProvider(LocalBackPressedDispatcher provides this.onBackPressedDispatcher) {
            AppScaffold()
        }
    }
}

How I built an "Asteroids" game using Jetpack Compose for Desktop

用Jetpack Compose Desktop搭建游戏.

全部代码:
https://github.com/SebastianAigner/asteroids-compose-for-desktop

Jetpack Compose — Reveal effect

一个明暗Theme切换的效果实现.
最终代码有一个gist: https://gist.github.com/bmonjoie/8506040b2ea534eac931378348622725

Migrating From Python to Kotlin for Our Backend Services

把后端从Python迁移到kotlin了.

几个protobuffers相关的库:

• https://github.com/marcoferrer/kroto-plus
• https://github.com/daviddenton/protokruft
• https://github.com/grpc/grpc-kotlin

Android Lifecycle

Android的生命周期.

Supporting different screen sizes on Android with Jetpack Compose

关于不同屏幕的支持.

PS: 其实我觉得把尺寸放在xml里就好.

Things to know about Flow’s shareIn and stateIn operators

比较这两个操作符:

• shareIn
• stateIn

例子是一个location的callback flow.

• shareIn -> SharedFlow
• stateIn -> StateFlow

文档StateFlow and SharedFlow

举了几个实际的例子来说明用法, 好文章, 推荐阅读.

Code

• KMMT 模板工程.
• asteroids-compose-for-desktop Compose桌面游戏.
• DailyDoc Compose做的note应用.
• https://github.com/mitchtabian/Food2Fork-KMM
• https://github.com/Hamza417/Inure
• https://github.com/android/compose-samples