Upgrade to Pro — share decks privately, control downloads, hide ads and more …

Discovering Jetpack Compose

Gerard
February 28, 2020

Discovering Jetpack Compose

Jetpack Compose will be the new declarative UI to build Android apps. Based on this new paradigm, let's see how we can use it with some simple samples!

Gerard

February 28, 2020
Tweet

More Decks by Gerard

Other Decks in Technology

Transcript

  1. @GerardPaligot
    DISCOVERING
    JETPACK COMPOSE

    View Slide

  2. WHAT’S JETPACK COMPOSE?
    100% Kotlin
    Compiler Open Source
    Declarative UI toolkit
    Android Team

    View Slide

  3. THINK DIFFERENT.

    View Slide

  4. View Slide

  5. View Slide

  6. MovieMetadata
    Rating
    TopAppBar
    Poster
    PosterNoted
    MovieItem

    View Slide

  7. View Slide

  8. View Slide

  9. View Slide

  10. View Slide

  11. App
    MovieHome
    Home
    Section
    Home
    Section
    Home
    Section
    Data
    Events

    View Slide

  12. App
    MovieHome
    Home
    Section
    Home
    Section
    Home
    Section
    Data
    Events

    View Slide

  13. PLACING ELEMENTS

    View Slide

  14. @Composable
    fun MovieMetadata(
    title: String,
    genres: List,
    releaseDate: String,
    runtime: Int
    ) {
    }

    View Slide

  15. @Composable
    fun MovieMetadata(
    title: String,
    genres: List,
    releaseDate: String,
    runtime: Int
    ) {
    Text(
    text = title
    )
    }

    View Slide

  16. @Composable
    fun MovieMetadata(
    title: String,
    genres: List,
    releaseDate: String,
    runtime: Int
    ) {
    Text(
    text = title,
    style = MaterialTheme.typography.h6
    )
    }

    View Slide

  17. @Composable
    fun MovieMetadata(
    title: String,
    genres: List,
    releaseDate: String,
    runtime: Int
    ) {
    Text(
    text = title,
    style = MaterialTheme.typography.h6,
    maxLines = 2,
    overflow = TextOverflow.Ellipsis
    )
    }

    View Slide

  18. @Composable
    fun MovieMetadata(
    title: String,
    genres: List,
    releaseDate: String,
    runtime: Int
    ) {
    Column {
    Text(
    text = title,
    style = MaterialTheme.typography.h6,
    maxLines = 2,
    overflow = TextOverflow.Ellipsis
    )
    }
    }

    View Slide

  19. @Composable
    fun MovieMetadata(
    title: String,
    genres: List,
    releaseDate: String,
    runtime: Int
    ) {
    Column {
    Text(...)
    }
    }

    View Slide

  20. @Composable
    fun MovieMetadata(
    title: String,
    genres: List,
    releaseDate: String,
    runtime: Int
    ) {
    Column {
    Text(...)
    genres.forEach {
    Tag(text = it)
    }
    }
    }

    View Slide

  21. @Composable
    fun MovieMetadata(
    title: String,
    genres: List,
    releaseDate: String,
    runtime: Int
    ) {
    Column {
    Text(...)
    Row {
    genres.forEach {
    Tag(text = it)
    }
    }
    }
    }

    View Slide

  22. @Composable
    fun MovieMetadata(
    title: String,
    genres: List,
    releaseDate: String,
    runtime: Int
    ) {
    Column {
    Text(...)
    Row(modifier = Modifier.padding(top = 5.dp)) {
    genres.forEach {
    Tag(text = it)
    }
    }
    }
    }

    View Slide

  23. @Composable
    fun MovieMetadata(
    title: String,
    genres: List,
    releaseDate: String,
    runtime: Int
    ) {
    Column {
    Text(...)
    Row(modifier = Modifier.padding(top = 5.dp)) {
    ...
    }
    }
    }

    View Slide

  24. @Composable
    fun MovieMetadata(
    title: String,
    genres: List,
    releaseDate: String,
    runtime: Int
    ) {
    Column {
    Text(...)
    Row(modifier = Modifier.padding(top = 5.dp)) {
    ...
    }
    val year = releaseDate.getCalendar().get(Calendar.YEAR)
    val time = "${runtime / 60}h ${runtime % 60}min"
    Text(
    text ="$year - $time",
    modifier = Modifier.padding(top = 5.dp)
    )
    }
    }

    View Slide

  25. @Composable
    fun MovieMetadata(
    title: String,
    genres: List,
    releaseDate: String,
    runtime: Int
    ) {
    Column {
    Text(...)
    Row(modifier = Modifier.padding(top = 5.dp)) {
    ...
    }
    val year = releaseDate.getCalendar().get(Calendar.YEAR)
    val time = "${runtime / 60}h ${runtime % 60}min"
    Text(
    text = if (runtime != 0) "$year - $time" else "$year",
    modifier = Modifier.padding(top = 5.dp)
    )
    }
    }

    View Slide

  26. @Composable
    fun MovieMetadata(
    title: String,
    genres: List,
    releaseDate: String,
    runtime: Int
    ) {
    Column {
    Text(...)
    Row(modifier = Modifier.padding(top = 5.dp)) {
    ...
    }
    CompositionLocalProvider(
    LocalContentAlpha provides ContentAlpha.medium
    ) {
    val year = releaseDate.getCalendar().get(Calendar.YEAR)
    val time = "${runtime / 60}h ${runtime % 60}min"
    Text(
    text = if (runtime != 0) "$year - $time" else "$year",
    modifier = Modifier.padding(top = 5.dp)
    )
    }
    }
    }

    View Slide

  27. @Composable
    fun MovieMetadata(
    title: String,
    genres: List,
    releaseDate: String,
    runtime: Int
    ) {
    Column {
    Text(...)
    Row(modifier = Modifier.padding(top = 5.dp)) {
    ...
    }
    CompositionLocalProvider(
    LocalContentAlpha provides ContentAlpha.medium
    ) {
    ...
    }
    }
    }

    View Slide

  28. @Composable
    fun MovieMetadata(
    title: String,
    genres: List,
    releaseDate: String,
    runtime: Int,
    modifier: Modifier = Modifier
    ) {
    Column(modifier = modifier) {
    Text(...)
    Row(modifier = Modifier.padding(top = 5.dp)) {
    ...
    }
    CompositionLocalProvider(
    LocalContentAlpha provides ContentAlpha.medium
    ) {
    ...
    }
    }
    }

    View Slide

  29. LET’S CODE A LIST

    View Slide

  30. @Composable
    fun PosterNoted(
    posterUrl: String,
    voteAverage: Int,
    ratingSize: Dp,
    ratingAlignment: Alignment,
    onClick: () -> Unit = {}
    )

    View Slide

  31. @Composable
    fun MovieItem(
    movie: Movie,
    modifier: Modifier = Modifier,
    onClick: (movie: Movie) -> Unit
    ) {
    }

    View Slide

  32. @Composable
    fun MovieItem(
    movie: Movie,
    modifier: Modifier = Modifier,
    onClick: (movie: Movie) -> Unit
    ) {
    PosterNoted(
    posterUrl = movie.pictureUrl,
    voteAverage = movie.percentage,
    ratingSize = 50.dp,
    ratingAlignment = Alignment.TopEnd
    )
    }

    View Slide

  33. @Composable
    fun MovieItem(
    movie: Movie,
    modifier: Modifier = Modifier,
    onClick: (movie: Movie) -> Unit
    ) {
    Box(
    modifier = Modifier
    .width(130.dp)
    .aspectRatio(0.7f)
    ) {
    PosterNoted(
    posterUrl = movie.pictureUrl,
    voteAverage = movie.percentage,
    ratingSize = 50.dp,
    ratingAlignment = Alignment.TopEnd
    )
    }
    }

    View Slide

  34. @Composable
    fun MovieItem(
    movie: Movie,
    modifier: Modifier = Modifier,
    onClick: (movie: Movie) -> Unit
    ) {
    Box(
    modifier = Modifier
    .width(130.dp)
    .aspectRatio(0.7f)
    ) {

    }
    }

    View Slide

  35. @Composable
    fun MovieItem(
    movie: Movie,
    modifier: Modifier = Modifier,
    onClick: (movie: Movie) -> Unit
    ) {
    Box(modifier = modifier) {
    Box(
    modifier = Modifier
    .width(130.dp)
    .aspectRatio(0.7f)
    ) {
    ...
    }
    }
    }

    View Slide

  36. @Composable
    fun MovieItem(
    movie: Movie,
    modifier: Modifier = Modifier,
    onClick: (movie: Movie) -> Unit
    ) {
    val posterWidth = 130
    val height = (posterWidth / 0.7f).roundToInt()
    Box(modifier = modifier) {
    Surface(
    modifier = Modifier
    .fillMaxWidth()
    .preferredHeight((height - 30).dp)
    ) {
    }
    Box(
    modifier = Modifier
    .width(posterWidth.dp)
    .aspectRatio(0.7f)
    ) {
    ...
    }
    }
    }

    View Slide

  37. @Composable
    fun MovieItem(
    movie: Movie,
    modifier: Modifier = Modifier,
    onClick: (movie: Movie) -> Unit
    ) {
    val posterWidth = 130
    val height = (posterWidth / 0.7f).roundToInt()
    Box(modifier = modifier) {
    Surface(
    modifier = Modifier
    .padding(top = 60.dp)
    .fillMaxWidth()
    .preferredHeight((height - 30).dp)
    ) {
    }
    Box(
    modifier = Modifier
    .width(posterWidth.dp)
    .aspectRatio(0.7f)
    ) {
    ...
    }
    }
    }

    View Slide

  38. @Composable
    fun MovieItem(
    movie: Movie,
    modifier: Modifier = Modifier,
    onClick: (movie: Movie) -> Unit
    ) {
    val posterWidth = 130
    val height = (posterWidth / 0.7f).roundToInt()
    Box(modifier = modifier) {
    Surface(
    modifier = Modifier
    .padding(top = 60.dp)
    .fillMaxWidth()
    .preferredHeight((height - 30).dp)
    .clickable(onClick = { onClick(movie) })
    ) {
    }
    Box(
    modifier = Modifier
    .width(posterWidth.dp)
    .aspectRatio(0.7f)
    ) {
    ...
    }
    }
    }

    View Slide

  39. @Composable
    fun MovieItem(
    movie: Movie,
    modifier: Modifier = Modifier,
    onClick: (movie: Movie) -> Unit
    ) {
    val posterWidth = 130
    val height = (posterWidth / 0.7f).roundToInt()
    Box(modifier = modifier) {
    Surface(
    modifier = Modifier
    .padding(top = 60.dp)
    .fillMaxWidth()
    .preferredHeight((height - 30).dp)
    .clickable(onClick = { onClick(movie) }),
    shape = RoundedCornerShape(8.dp)
    ) {
    }
    Box(
    modifier = Modifier
    .width(posterWidth.dp)
    .aspectRatio(0.7f)
    ) {
    ...
    }
    }
    }

    View Slide

  40. @Composable
    fun MovieItem(
    movie: Movie,
    modifier: Modifier = Modifier,
    onClick: (movie: Movie) -> Unit
    ) {
    val posterWidth = 130
    val height = (posterWidth / 0.7f).roundToInt()
    Box(modifier = modifier) {
    Surface(
    modifier = Modifier
    .padding(top = 60.dp)
    .fillMaxWidth()
    .preferredHeight((height - 30).dp)
    .clickable(onClick = { onClick(movie) }),
    shape = RoundedCornerShape(8.dp),
    elevation = 5.dp
    ) {
    }
    Box(
    modifier = Modifier
    .width(posterWidth.dp)
    .aspectRatio(0.7f)
    ) {
    ...
    }
    }
    }

    View Slide

  41. val posterWidth = 130
    val height = (posterWidth / 0.7f).roundToInt()
    Box(modifier = modifier) {
    Surface(
    modifier = Modifier
    .padding(top = 60.dp)
    .fillMaxWidth()
    .preferredHeight((height - 30).dp)
    .clickable(onClick = { onClick(movie) }),
    shape = RoundedCornerShape(8.dp),
    elevation = 5.dp
    ) {
    }
    Box(
    modifier = Modifier
    .width(posterWidth.dp)
    .aspectRatio(0.7f)
    ) {
    ...
    }
    }
    }

    View Slide

  42. val posterWidth = 130
    val height = (posterWidth / 0.7f).roundToInt()
    Box(modifier = modifier) {
    Surface(
    modifier = Modifier
    .padding(top = 60.dp)
    .fillMaxWidth()
    .preferredHeight((height - 30).dp)
    .clickable(onClick = { onClick(movie) }),
    shape = RoundedCornerShape(8.dp),
    elevation = 5.dp
    ) {
    }
    Box(
    modifier = Modifier
    .padding(start = 30.dp)
    .width(posterWidth.dp)
    .aspectRatio(0.7f)
    ) {
    ...
    }
    }
    }

    View Slide

  43. val posterWidth = 130
    val height = (posterWidth / 0.7f).roundToInt()
    Box(modifier = modifier) {
    Surface(
    modifier = Modifier
    .padding(top = 60.dp)
    .fillMaxWidth()
    .preferredHeight((height - 30).dp)
    .clickable(onClick = { onClick(movie) }),
    shape = RoundedCornerShape(8.dp),
    elevation = 5.dp
    ) {
    MovieMetadata(
    title = movie.title, genres = movie.genres,
    releaseDate = movie.releaseDate, runtime = movie.runtime,
    modifier = Modifier.padding(start = (posterWidth + 15).dp)
    .align(alignment = Alignment.CenterStart)
    )
    }
    Box(
    modifier = Modifier
    .padding(start = 30.dp)
    .width(posterWidth.dp)
    .aspectRatio(0.7f)
    ) {
    ...
    }
    }

    View Slide

  44. @Composable
    fun MovieList(
    title: String,
    movies: List,
    onClick: (movie: Movie) -> Unit
    ) {
    }

    View Slide

  45. @Composable
    fun MovieList(
    title: String,
    movies: List,
    onClick: (movie: Movie) -> Unit
    ) {
    val state = rememberScrollState()
    Column(modifier = Modifier.verticalScroll(state = state)) {
    movies.forEach {
    MovieItem(
    movie = it,
    modifier = Modifier
    .padding(start = 10.dp, top = 10.dp, end = 10.dp),
    onClick = onClick
    )
    }
    }
    }

    View Slide

  46. @Composable
    fun MovieList(
    title: String,
    movies: List,
    onClick: (movie: Movie) -> Unit
    ) {
    LazyColumn {
    items(movies) { movie ->
    MovieItem(
    movie = movie,
    modifier = Modifier
    .padding(start = 10.dp, top = 10.dp, end = 10.dp),
    onClick = onClick
    )
    }
    }
    }

    View Slide

  47. @Composable
    fun MovieList(
    title: String,
    movies: List,
    onClick: (movie: Movie) -> Unit
    ) {
    MovieScaffold(title = title) {
    LazyColumn {
    items(movies) { movie ->
    MovieItem(
    movie = it,
    modifier = Modifier
    .padding(start = 10.dp, top = 10.dp, end = 10.dp),
    onClick = onClick
    )
    }
    }
    }
    }

    View Slide

  48. @Composable
    fun Scaffold(
    modifier: Modifier = Modifier,
    scaffoldState: ScaffoldState = rememberScaffoldState(),
    topBar: @Composable () -> Unit = emptyContent(),
    bottomBar: @Composable () -> Unit = emptyContent(),
    snackbarHost: @Composable (SnackbarHostState) -> Unit = { SnackbarHost(it) },
    floatingActionButton: @Composable () -> Unit = emptyContent(),
    floatingActionButtonPosition: FabPosition = FabPosition.End,
    isFloatingActionButtonDocked: Boolean = false,
    drawerContent: @Composable (ColumnScope.() -> Unit)? = null,
    drawerGesturesEnabled: Boolean = true,
    drawerShape: Shape = MaterialTheme.shapes.large,
    drawerElevation: Dp = DrawerConstants.DefaultElevation,
    drawerBackgroundColor: Color = MaterialTheme.colors.surface,
    drawerContentColor: Color = contentColorFor(drawerBackgroundColor),
    drawerScrimColor: Color = DrawerConstants.defaultScrimColor,
    backgroundColor: Color = MaterialTheme.colors.background,
    contentColor: Color = contentColorFor(backgroundColor),
    bodyContent: @Composable (PaddingValues) -> Unit
    )

    View Slide

  49. LET’S CODE A LIST
    WITH ACTUAL FRAMEWORK UI

    View Slide


  50. xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/list"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" />

    View Slide


  51. xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent" android:layout_height="80dp">
    android:layout_width="match_parent" android:layout_height="match_parent">
    android:layout_width="50dp" android:layout_height="50dp" android:layout_marginStart="20dp"
    app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent" tools:srcCompat="@tools:sample/avatars" />
    android:layout_width="wrap_content" android:layout_height="wrap_content"
    android:orientation="vertical" app:layout_constraintGuide_begin="100dp" />

    View Slide

  52. android:layout_width="0dp" android:layout_height="wrap_content"
    android:layout_marginEnd="20dp" android:orientation="vertical"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toStartOf="@+id/price"
    app:layout_constraintStart_toStartOf="@+id/guideline3"
    app:layout_constraintTop_toTopOf="parent">
    android:layout_width="wrap_content" android:layout_height="wrap_content"
    android:textAppearance="@style/TextAppearance.Decathlon.Subtitle2"
    android:textColor="@color/colorOnSurface" />
    android:layout_width="wrap_content" android:layout_height="wrap_content"
    android:textAppearance="@style/TextAppearance.Decathlon.Subtitle2"
    android:textColor="@color/grey" />

    View Slide

  53. android:id="@+id/price"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginEnd="20dp"
    android:textAppearance="@style/TextAppearance.Decathlon.Subtitle2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    tools:text="50$" />


    View Slide

  54. data class Activity(
    @DrawableRes val picture: Int,
    val displayName: String,
    val type: String,
    val price: Int
    )
    class ActivityListAdapter(val items: MutableList) :
    RecyclerView.Adapter() {
    val onClick: LiveData
    get() = this._onClick
    private val _onClick: MutableLiveData by lazy {
    return@lazy MutableLiveData()
    }

    View Slide

  55. override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ActivityViewHolder =
    ActivityViewHolder(LayoutInflater.from(parent.context).inflate(R.layout.item_activity, parent, false))
    override fun getItemCount(): Int = items.size
    override fun onBindViewHolder(holder: ActivityViewHolder, position: Int) {
    val activity = items[position]
    holder.bind(activity, View.OnClickListener {
    _onClick.value = activity
    })
    }
    fun update(items: List) {
    this.items.clear()
    this.items.addAll(items)
    notifyDataSetChanged()
    }

    View Slide

  56. class ActivityViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
    fun bind(activity: Activity, onClickListener: View.OnClickListener) {
    itemView.setOnClickListener(onClickListener)
    itemView.picture.setImageDrawable(ContextCompat.getDrawable(itemView.context,
    activity.picture))
    itemView.name.text = activity.displayName
    itemView.type.text = activity.type
    val color = if (activity.price > 0)
    ContextCompat.getColor(itemView.context, R.color.green)
    else
    ContextCompat.getColor(itemView.context, R.color.red)
    itemView.price.setTextColor(color)
    }
    }
    }

    View Slide

  57. LIGHT DARK

    View Slide

  58. val orange800 = Color(255, 150, 29)
    val orange900 = Color(255, 118, 26)
    val blue400 = Color(26, 163, 255)
    private val LightColorPalette = lightColors(
    primary = orange900,
    primaryVariant = orange800,
    secondary = blue400,
    background = Color.White,
    surface = Color.White,
    onPrimary = Color.White,
    onSecondary = Color.Black,
    onBackground = Color.Black,
    onSurface = Color.Black,
    )

    View Slide

  59. val orange400 = Color(255, 205, 56)
    val blue800 = Color(0, 98, 203)
    val blue900 = Color(0, 68, 171)
    val grayDark = Color(45, 47, 49)
    private val DarkColorPalette = darkColors(
    primary = blue900,
    primaryVariant = blue800,
    secondary = orange400,
    background = grayDark,
    surface = grayDark,
    onPrimary = Color.White,
    onSecondary = Color.Black,
    onBackground = Color.White,
    onSurface = Color.White
    )

    View Slide

  60. val typography = Typography(
    h5 = TextStyle(
    fontFamily = FontFamily.Default,
    fontWeight = FontWeight.W700,
    fontSize = 24.sp
    ),
    subtitle1 = TextStyle(
    fontFamily = FontFamily.Default,
    fontWeight = FontWeight.W700,
    fontSize = 16.sp
    ),
    body1 = TextStyle(
    fontFamily = FontFamily.Default,
    fontWeight = FontWeight.Normal,
    fontSize = 16.sp
    ),
    caption = TextStyle(
    fontFamily = FontFamily.Default,
    fontWeight = FontWeight.W400,
    fontSize = 10.sp
    )
    )

    View Slide

  61. val shapes = Shapes(
    small = RoundedCornerShape(2.dp),
    medium = RoundedCornerShape(4.dp),
    large = RoundedCornerShape(8.dp)
    )

    View Slide

  62. @Composable
    fun MaterialTheme(
    colors: Colors = MaterialTheme.colors,
    typography: Typography = MaterialTheme.typography,
    shapes: Shapes = MaterialTheme.shapes,
    content: @Composable () -> Unit
    )

    View Slide

  63. @Composable
    fun ExploringMoviesTheme(
    isDarkMode: Boolean = isSystemInDarkTheme(),
    content: @Composable() () -> Unit
    ) {
    }

    View Slide

  64. @Composable
    fun ExploringMoviesTheme(
    isDarkMode: Boolean = isSystemInDarkTheme(),
    content: @Composable() () -> Unit
    ) {
    MaterialTheme(
    content = content
    )
    }

    View Slide

  65. @Composable
    fun ExploringMoviesTheme(
    isDarkMode: Boolean = isSystemInDarkTheme(),
    content: @Composable() () -> Unit
    ) {
    MaterialTheme(
    colors =
    if (isDarkMode) DarkColorPalette else LightColorPalette,
    content = content
    )
    }

    View Slide

  66. @Composable
    fun ExploringMoviesTheme(
    isDarkMode: Boolean = isSystemInDarkTheme(),
    content: @Composable() () -> Unit
    ) {
    MaterialTheme(
    colors =
    if (isDarkMode) DarkColorPalette else LightColorPalette,
    typography = typography,
    content = content
    )
    }

    View Slide

  67. @Composable
    fun ExploringMoviesTheme(
    isDarkMode: Boolean = isSystemInDarkTheme(),
    content: @Composable() () -> Unit
    ) {
    MaterialTheme(
    colors =
    if (isDarkMode) DarkColorPalette else LightColorPalette,
    typography = typography,
    shapes = shapes,
    content = content
    )
    }

    View Slide

  68. @Composable
    fun MovieList(
    title: String,
    movies: List,
    onClick: (movie: Movie) -> Unit
    ) {
    MovieScaffold(
    title = title
    ){
    LazyColumnFor(items = movies) {
    MovieItem(
    movie = it,
    modifier = Modifier
    .padding(start = 10.dp, top = 10.dp, end = 10.dp),
    onClick = onClick
    )
    }
    }
    }

    View Slide

  69. @Composable
    fun MovieList(
    title: String,
    movies: List,
    isDarkModeActive: Boolean,
    switchDarkMode: () -> Unit = {},
    onClick: (movie: Movie) -> Unit
    ) {
    MovieScaffold(
    title = title,
    isDarkModeActive = isDarkModeActive,
    switchDarkMode = switchDarkMode
    ){
    LazyColumnFor(items = movies) {
    MovieItem(
    movie = it,
    modifier = Modifier
    .padding(start = 10.dp, top = 10.dp, end = 10.dp),
    onClick = onClick
    )
    }
    }
    }

    View Slide

  70. setContent {
    val isSystemDark = isSystemInDarkTheme()
    }

    View Slide

  71. setContent {
    val isSystemDark = isSystemInDarkTheme()
    val isDarkModeState = remember { mutableStateOf(isSystemDark) }
    }

    View Slide

  72. setContent {
    val isSystemDark = isSystemInDarkTheme()
    val isDarkModeState = remember { mutableStateOf(isSystemDark) }
    ExploringMoviesTheme(isDarkMode = isDarkModeState.value) {
    }
    }

    View Slide

  73. setContent {
    val isSystemDark = isSystemInDarkTheme()
    val isDarkModeState = remember { mutableStateOf(isSystemDark) }
    ExploringMoviesTheme(isDarkMode = isDarkModeState.value) {
    App(
    isDarkModeActive = isDarkModeState.value
    )
    }
    }

    View Slide

  74. setContent {
    val isSystemDark = isSystemInDarkTheme()
    val isDarkModeState = remember { mutableStateOf(isSystemDark) }
    ExploringMoviesTheme(isDarkMode = isDarkModeState.value) {
    App(
    isDarkModeActive = isDarkModeState.value,
    switchDarkMode = {
    isDarkModeState.value = !isDarkModeState.value
    }
    )
    }
    }

    View Slide

  75. OBSERVING DATA WITH
    VIEWMODEL

    View Slide

  76. class MovieViewModel : ViewModel() {
    fun getPopulars() = flow {
    ...
    }
    fun getDailyTrending() = flow {
    ...
    }
    fun getUpComing() = flow {
    ...
    }
    fun getMovieDetail(movieId: Int) = flow {
    ...
    }
    }

    View Slide

  77. ▸ LiveData.observeAsState()
    ▸ Flow.collectAsState()
    ▸ Observable.subscribeAsState()

    View Slide

  78. @Composable
    fun MyExample() {
    // Returns the same instance as long as the activity is alive,
    // just as if you grabbed the instance from an Activity or
    // Fragment
    val viewModel: MovieViewModel = viewModel()
    }
    @Composable
    fun MyExample2() {
    // Same instance as in MyExample
    val viewModel: MovieViewModel = viewModel()
    }

    View Slide

  79. @Composable
    fun MovieListViewModel(
    movieSection: MovieSection,
    isDarkModeActive: Boolean,
    switchDarkMode: () -> Unit = {},
    onClick: (movie: Movie) -> Unit
    ) {
    MovieList(
    title = title,
    movies = movies.value,
    isDarkModeActive = isDarkModeActive,
    switchDarkMode = switchDarkMode,
    onClick = onClick
    )
    }

    View Slide

  80. @Composable
    fun MovieListViewModel(
    movieSection: MovieSection,
    isDarkModeActive: Boolean,
    switchDarkMode: () -> Unit = {},
    onClick: (movie: Movie) -> Unit
    ) {
    val viewModel: MovieViewModel = viewModel()
    MovieList(
    title = title,
    movies = movies.value,
    isDarkModeActive = isDarkModeActive,
    switchDarkMode = switchDarkMode,
    onClick = onClick
    )
    }

    View Slide

  81. @Composable
    fun MovieListViewModel(
    movieSection: MovieSection,
    isDarkModeActive: Boolean,
    switchDarkMode: () -> Unit = {},
    onClick: (movie: Movie) -> Unit
    ) {
    val viewModel: MovieViewModel = viewModel()
    val movies = when (movieSection) {
    MovieSection.UPCOMING -> viewModel.getUpComing()
    .collectAsState(initial = emptyList())
    MovieSection.POPULAR -> viewModel.getPopulars()
    .collectAsState(initial = emptyList())
    MovieSection.TRENDING -> viewModel.getDailyTrending()
    .collectAsState(initial = emptyList())
    }
    MovieList(
    movies = movies.value,
    isDarkModeActive = isDarkModeActive,
    switchDarkMode = switchDarkMode,
    onClick = onClick
    )
    }

    View Slide

  82. @GerardPaligot
    DISCOVERING
    JETPACK COMPOSE

    View Slide

  83. @GerardPaligot
    DISCOVERING
    COMPOSE MULTIPLATFORM

    View Slide

  84. UI/UX UI/UX UI/UX
    BUSINESS LOGIC AND CORE

    View Slide

  85. UI/UX UI/UX UI/UX
    BUSINESS LOGIC AND CORE
    ACTUAL ACTUAL ACTUAL

    View Slide

  86. BUSINESS LOGIC AND CORE
    ACTUAL ACTUAL ACTUAL
    COMPOSE MULTIPLATFORM

    View Slide

  87. View Slide

  88. BUSINESS LOGIC AND CORE
    ACTUAL ACTUAL ACTUAL
    COMPOSE MULTIPLATFORM

    View Slide

  89. UX UX UX
    BUSINESS LOGIC AND CORE
    ACTUAL ACTUAL ACTUAL
    COMPOSE MULTIPLATFORM

    View Slide

  90. COMPILER
    RUNTIME
    UI
    FOUNDATION-LAYOUT
    ANIMATION
    FOUNDATION
    MATERIAL 3
    Transf m @C posable functi s Pro amming model, state
    management and runtime f
    the c pose c pil plugin
    Fundamental c p ents
    Basics lay ts like B , R
    and C umn
    C p ents animati s
    Basics c p ents and int acti s
    Implementati of Mat ial Design
    specificati s
    Implementati of Mat ial Y

    View Slide

  91. COMPILER
    RUNTIME
    UI
    FOUNDATION-LAYOUT
    ANIMATION
    FOUNDATION
    MATERIAL 3
    Transf m @C posable functi s Pro amming model, state
    management and runtime f
    the c pose c pil plugin

    View Slide

  92. COMPILER
    RUNTIME
    UI
    FOUNDATION-LAYOUT
    ANIMATION
    FOUNDATION
    MATERIAL 3
    Transf m @C posable functi s Pro amming model, state
    management and runtime f
    the c pose c pil plugin
    WEB-CORE-RUNTIME
    WEB-CORE
    WIDGETS
    Runtime dedicated to web apps
    to gen ate DOM tags
    Basics native web c p ents
    Modifi s and lay ts

    View Slide

  93. UX UX UX
    BUSINESS LOGIC AND CORE
    ACTUAL ACTUAL ACTUAL
    COMPOSE MULTIPLATFORM

    View Slide

  94. UX UX UX
    BUSINESS LOGIC AND CORE
    ACTUAL ACTUAL ACTUAL
    COMPOSE MULTIPLATFORM COMPOSE WEB

    View Slide

  95. WHY COMPOSE WEB?
    ▸ Compose Canvas rendering not compatible (yet) with web technologies
    ▸ Compose Web emit DOM UI for NPM librairies compatibility and SEO

    View Slide

  96. :android-app :desktop-app
    :data

    View Slide

  97. :android-app :desktop-app
    :data

    View Slide

  98. :android-app :desktop-app
    :data :components
    :theming

    View Slide

  99. :android-app :desktop-app
    :data :components
    :theming

    View Slide

  100. plugins {
    id("com.android.library")
    }
    android {
    ...
    }

    View Slide

  101. plugins {
    id("com.android.library")
    kotlin("multiplatform")
    id("org.jetbrains.compose")
    }
    android {
    ...
    }

    View Slide

  102. plugins {
    id("com.android.library")
    kotlin("multiplatform")
    id("org.jetbrains.compose")
    }
    android {
    ...
    }
    kotlin {
    android()
    jvm("desktop")
    }

    View Slide

  103. import org.jetbrains.compose.compose
    plugins {
    id("com.android.library")
    kotlin("multiplatform")
    id("org.jetbrains.compose")
    }
    android {
    ...
    }
    kotlin {
    android()
    jvm("desktop")
    sourceSets {
    named("commonMain") {
    dependencies {
    implementation(compose.runtime)
    implementation(compose.foundation)
    implementation(compose.material)
    }
    }
    }
    }

    View Slide

  104. SOURCE SET
    desktopMain
    SOURCE SET
    androidMain
    SOURCE SET
    commonMain

    View Slide

  105. @Composable
    expect fun Font(
    fontName: String,
    weight: FontWeight,
    style: FontStyle
    ): Font
    SOURCE SET
    commonMain

    View Slide

  106. @Composable
    actual fun Font(
    fontName: String,
    weight: FontWeight,
    style: FontStyle
    ): Font {
    val context = LocalContext.current
    val id = context.resources
    .getIdentifier(fontName, "font", context.packageName)
    return Font(id, weight, style)
    }
    SOURCE SET
    androidMain

    View Slide

  107. @Composable
    actual fun Font(
    fontName: String,
    weight: FontWeight,
    style: FontStyle
    ): Font {
    return androidx.compose.ui.text.platform.Font(
    "font/${fontName}.ttf",
    weight,
    style
    )
    }
    SOURCE SET
    desktopMain

    View Slide

  108. object Fonts {
    val roboto: FontFamily
    @Composable
    get() = FontFamily(
    Font(
    "roboto_bold",
    FontWeight.Bold,
    FontStyle.Normal
    ),
    Font(
    "roboto_italic",
    FontWeight.Normal,
    FontStyle.Italic
    ),
    Font(
    "roboto_regular",
    FontWeight.Normal,
    FontStyle.Normal
    )
    )
    }
    SOURCE SET
    commonMain

    View Slide

  109. object Fonts {
    val roboto: FontFamily
    @Composable
    get() = ...
    }
    SOURCE SET
    commonMain

    View Slide

  110. object Fonts {
    val roboto: FontFamily
    @Composable
    get() = ...
    }
    object Typographies {
    val roboto: Typography
    @Composable
    get() = Typography(defaultFontFamily = Fonts.roboto)
    }
    SOURCE SET
    commonMain

    View Slide

  111. object Fonts {
    val roboto: FontFamily
    @Composable
    get() = ...
    }
    object Typographies {
    val roboto: Typography
    @Composable
    get() = Typography(defaultFontFamily = Fonts.roboto)
    }
    @Composable
    fun ExploringMoviesTheme(
    isDarkMode: Boolean = isSystemInDarkTheme(),
    content: @Composable () -> Unit
    ) {
    MaterialTheme(
    colors =
    if (isDarkMode) DarkColorPalette else LightColorPalette,
    typography = Typographies.roboto,
    shapes = shapes,
    content = content
    )
    }
    SOURCE SET
    commonMain

    View Slide

  112. :android-app :desktop-app
    :data :components
    :theming

    View Slide

  113. @Composable
    expect fun RemoteImage(
    url: String,
    contentDescription: String?,
    modifier: Modifier = Modifier,
    contentScale: ContentScale = ContentScale.Fit
    )
    SOURCE SET
    commonMain

    View Slide

  114. import org.jetbrains.compose.compose
    plugins {
    ...
    }
    android {
    ...
    }
    kotlin {
    android()
    jvm("desktop")
    sourceSets {
    named("commonMain") {
    ...
    }
    named("androidMain") {
    dependencies {
    implementation(Dependencies.Accompanist.coil)
    }
    }
    }
    }

    View Slide

  115. @Composable
    actual fun CrossRemoteImage(
    url: String,
    contentDescription: String?,
    modifier: Modifier,
    contentScale: ContentScale
    ) {
    Image(
    painter = rememberAsyncImagePainter(model = url),
    modifier = modifier,
    contentDescription = contentDescription,
    contentScale = ContentScale.Crop,
    )
    }
    SOURCE SET
    androidMain

    View Slide

  116. import org.jetbrains.compose.compose
    plugins {
    ...
    }
    android {
    ...
    }
    kotlin {
    android()
    jvm("desktop")
    sourceSets {
    named("commonMain") {
    ...
    }
    named("androidMain") {
    ...
    }
    named("desktopMain") {
    dependencies {
    implementation(Dependencies.okhttp)
    }
    }
    }
    }

    View Slide

  117. @Composable
    actual fun CrossRemoteImage(
    url: String,
    contentDescription: String?,
    modifier: Modifier,
    contentScale: ContentScale
    ) {
    val image = remember { mutableStateOf(null) }
    if (image.value != null) {
    Image(
    bitmap = image.value!!,
    contentDescription = contentDescription,
    modifier = modifier,
    contentScale = contentScale
    )
    }
    }
    SOURCE SET
    desktopMain

    View Slide

  118. @Composable
    actual fun CrossRemoteImage(
    url: String,
    contentDescription: String?,
    modifier: Modifier,
    contentScale: ContentScale
    ) {
    val image = remember { mutableStateOf(null) }
    LaunchedEffect(url) {
    }
    if (image.value != null) {
    Image(
    bitmap = image.value!!,
    contentDescription = contentDescription,
    modifier = modifier,
    contentScale = contentScale
    )
    }
    }
    SOURCE SET
    desktopMain

    View Slide

  119. @Composable
    actual fun CrossRemoteImage(
    url: String,
    contentDescription: String?,
    modifier: Modifier,
    contentScale: ContentScale
    ) {
    val image = remember { mutableStateOf(null) }
    LaunchedEffect(url) {
    ImageLoader.load(url)?.let {
    }
    }
    if (image.value != null) {
    Image(
    bitmap = image.value!!,
    contentDescription = contentDescription,
    modifier = modifier,
    contentScale = contentScale
    )
    }
    }
    SOURCE SET
    desktopMain

    View Slide

  120. @Composable
    actual fun CrossRemoteImage(
    url: String,
    contentDescription: String?,
    modifier: Modifier,
    contentScale: ContentScale
    ) {
    val image = remember { mutableStateOf(null) }
    LaunchedEffect(url) {
    ImageLoader.load(url)?.let {
    image.value = org.jetbrains.skia.Image.makeFromEncoded(it)
    .toComposeImageBitmap()
    }
    }
    if (image.value != null) {
    Image(
    bitmap = image.value!!,
    contentDescription = contentDescription,
    modifier = modifier,
    contentScale = contentScale
    )
    }
    }
    SOURCE SET
    desktopMain

    View Slide

  121. WHY SHOULD CARE
    ABOUT COMPOSE?

    View Slide

  122. WHY SHOULD CARE ABOUT COMPOSE?
    ▸ Android UI framework never
    changed since 2008
    ▸ Need to wait very long time before
    bug fixes deployed in production
    ▸ Need to worry about keeping the
    View hierarchy as flat as possible
    ▸ Unbundled from OS
    ▸ Exit View and Fragment
    ▸ Clarify state ownership
    and event handling
    ▸ Writing less code

    View Slide

  123. slack.kotlinlang.org
    #compose
    Open Source Project
    github.com/androidx/androidx

    View Slide

  124. REFERENCES
    ▸ Discovering Movies, GitHub Repository of Gerard Paligot
    https://github.com/GerardPaligot/discovering-movies
    ▸ Official documentation about Jetpack Compose, Developer Android Website
    https://developer.android.com/jetpack/compose/documentation
    ▸ Pathways Compose
    https://developer.android.com/courses/pathways/compose
    ▸ Compose Academy
    https://compose.academy/
    ▸ Samples Compose app by community
    https://jetpackcompose.app/

    View Slide

  125. THANK YOU!
    @GerardPaligot

    View Slide