fun Messages()

in Jetchat/app/src/main/java/com/example/compose/jetchat/conversation/Conversation.kt [208:287]

• 66 lines of code
• 5 McCabe index (conditional complexity)

fun Messages(
    messages: List<Message>,
    navigateToProfile: (String) -> Unit,
    scrollState: LazyListState,
    modifier: Modifier = Modifier
) {
    val scope = rememberCoroutineScope()
    Box(modifier = modifier) {

        val authorMe = stringResource(id = R.string.author_me)
        LazyColumn(
            reverseLayout = true,
            state = scrollState,
            // Add content padding so that the content can be scrolled (y-axis)
            // below the status bar + app bar
            // TODO: Get height from somewhere
            contentPadding = rememberInsetsPaddingValues(
                insets = LocalWindowInsets.current.statusBars,
                additionalTop = 90.dp
            ),
            modifier = Modifier
                .testTag(ConversationTestTag)
                .fillMaxSize()
        ) {
            for (index in messages.indices) {
                val prevAuthor = messages.getOrNull(index - 1)?.author
                val nextAuthor = messages.getOrNull(index + 1)?.author
                val content = messages[index]
                val isFirstMessageByAuthor = prevAuthor != content.author
                val isLastMessageByAuthor = nextAuthor != content.author

                // Hardcode day dividers for simplicity
                if (index == messages.size - 1) {
                    item {
                        DayHeader("20 Aug")
                    }
                } else if (index == 2) {
                    item {
                        DayHeader("Today")
                    }
                }

                item {
                    Message(
                        onAuthorClick = { name -> navigateToProfile(name) },
                        msg = content,
                        isUserMe = content.author == authorMe,
                        isFirstMessageByAuthor = isFirstMessageByAuthor,
                        isLastMessageByAuthor = isLastMessageByAuthor
                    )
                }
            }
        }
        // Jump to bottom button shows up when user scrolls past a threshold.
        // Convert to pixels:
        val jumpThreshold = with(LocalDensity.current) {
            JumpToBottomThreshold.toPx()
        }

        // Show the button if the first visible item is not the first one or if the offset is
        // greater than the threshold.
        val jumpToBottomButtonEnabled by remember {
            derivedStateOf {
                scrollState.firstVisibleItemIndex != 0 ||
                    scrollState.firstVisibleItemScrollOffset > jumpThreshold
            }
        }

        JumpToBottom(
            // Only show if the scroller is not at the bottom
            enabled = jumpToBottomButtonEnabled,
            onClicked = {
                scope.launch {
                    scrollState.animateScrollToItem(0)
                }
            },
            modifier = Modifier.align(Alignment.BottomCenter)
        )
    }
}