Jetpack Compose

Oct 11 2022 Kotlin 1.7.10, Android 13, Android Studio Chipmunk

Part 1: Jetpack Compose Basics

8. Build Common UI Components - Part 3

Episode complete

Play next episode

Next
Save for later
About this episode
See versions

See forum comments
Cinema mode Mark complete Download course materials
Previous episode: 7. Build Common UI Components - Part 2 Next episode: 9. Apply Error & Data Handling to the UI

The student materials have been reviewed and are updated as of September 2022.

In ui/reviews/ui/BookReviewsList file, within BookReviewItem() composable function, replace CoilImage() composable by AsyncImage() composable with updated parameters. CoilImage composable is old and not compatible with current Jetpack Compose version.

Heads up... You've reached locked video content where the transcript will be shown as obfuscated text.

You can unlock the rest of this video course, and our entire catalogue of books and videos, with a kodeco.com Professional subscription.

Unlock Now

Demo

Last thing that you have to build in this three-part chunk of episodes, is the BookReviews and AddBookReview features.

@Composable
fun BookPicker(
  books: List<BookAndGenre>,
  selectedBookId: String,
  onItemPicked: (BookAndGenre) -> Unit
) {
  val isPickerOpen = remember { mutableStateOf(false) }
  val selectedBookName =
    books.firstOrNull { it.book.id == selectedBookId }?.book?.name ?: "None"

  Row(verticalAlignment = Alignment.CenterVertically) {
    TextButton(
      onClick = { isPickerOpen.value = true },
      content = { Text(text = stringResource(id = R.string.genre_select)) })

    DropdownMenu(
      expanded = isPickerOpen.value,
      onDismissRequest = { isPickerOpen.value = false }) {

      for (book in books) {
        DropdownMenuItem(onClick = {
          onItemPicked(book)
          isPickerOpen.value = false
        }) {
          Text(text = book.book.name)
        }
      }
    }

    Text(text = selectedBookName)
  }
}

private val _books = mutableStateOf(emptyList<BookAndGenre>())

  override fun onCreate(savedInstanceState: Bundle?) {
	...
    loadBooks()
  }

  private fun loadBooks() {
    lifecycleScope.launch {
      _books.value = repository.getBooks()
    }
  }



  @Composable
  fun AddBookReviewForm() {
	...
    val currentRatingFilter = remember { mutableStateOf(0) }
    val currentlySelectedBook = remember { mutableStateOf(EMPTY_BOOK_AND_GENRE) }
      
    ...
      
    BookPicker(books = _books.value,
      selectedBookId = currentlySelectedBook.value.book.id,
      onItemPicked = { bookAndGenre ->
      _bookReviewState.value = _bookReviewState.value?.copy(bookAndGenre = bookAndGenre)
      currentlySelectedBook.value = bookAndGenre
    })
      
    ...
  }

RatingBar(
  modifier = Modifier.align(CenterHorizontally),
  range = 1..5,
  currentRating = currentRatingFilter.value,
  isLargeRating = true,
  onRatingChanged = { newRating -> currentRatingFilter.value = newRating })

val bookReviewsState = mutableStateOf(emptyList<BookReview>())

override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
  super.onViewCreated(view, savedInstanceState)

  lifecycleScope.launch {
    bookReviewsState.value = repository.getReviews()
  }
}

@Composable
fun BookReviewsContentWrapper() {
  val bookReviews = bookReviewsState.value

  BookReviewsList(bookReviews, onItemClick = ::onItemSelected)
}

@Composable
fun BookReviewsList(
  bookReviews: List<BookReview>,
  onItemClick: (BookReview) -> Unit
) {
  LazyColumn {
    items(bookReviews) { bookReview ->
      BookReviewItem(bookReview = bookReview, onItemClick)
    }
  }
}

Card(
    elevation = 8.dp,
    border = BorderStroke(1.dp, MaterialTheme.colors.primary),
    shape = RoundedCornerShape(16.dp),
    modifier = Modifier
      .wrapContentHeight()
      .padding(16.dp)
  ) {

Card(
    elevation = 8.dp,
    border = BorderStroke(1.dp, MaterialTheme.colors.primary),
    shape = RoundedCornerShape(16.dp),
    modifier = Modifier
      .wrapContentHeight()
      .padding(16.dp)
      .clickable(
        onClick = { onItemClick(bookReview) },
        indication = null
      )
  ) {
    Row(modifier = Modifier.fillMaxSize()) {
      Spacer(modifier = Modifier.width(16.dp))

      Column(
        modifier = Modifier
          .weight(0.6f)
          .fillMaxHeight()
      ) {}

      Spacer(modifier = Modifier.width(16.dp))

      Card(
        modifier = Modifier.weight(0.4f),
        shape = RoundedCornerShape(
          topEnd = 16.dp,
          topStart = 16.dp,
          bottomStart = 0.dp,
          bottomEnd = 16.dp
        ),
        elevation = 16.dp
      ) {
          AsyncImage(
            model = bookReview.review.imageUrl,
            contentScale = ContentScale.FillWidth,
            contentDescription = null
          )
      }

Spacer(modifier = Modifier.height(16.dp))

Text(
  text = bookReview.book.name,
  color = MaterialTheme.colors.primary,
  fontSize = 18.sp,
  fontWeight = FontWeight.Bold
)

Spacer(modifier = Modifier.height(8.dp))

Row {
  Text(
    text = stringResource(id = R.string.rating_text)
  )
...
}

  RatingBar(
    modifier = Modifier.align(CenterVertically),
    range = 1..5,
    currentRating = bookReview.review.rating,
    isSelectable = false,
    isLargeRating = false
  )
}

Text(
  text = stringResource(
  id = R.string.number_of_reading_entries,
  bookReview.review.entries.size
))

Spacer(modifier = Modifier.height(8.dp))

Text(
  text = bookReview.review.notes,
  fontSize = 12.sp,
  modifier = Modifier.fillMaxSize(),
  overflow = TextOverflow.Ellipsis,
  fontStyle = FontStyle.Italic,
  maxLines = 4
)

Spacer(modifier = Modifier.height(16.dp))