diff options
Diffstat (limited to 'java/src')
| -rw-r--r-- | java/src/com/android/intentresolver/contentpreview/payloadtoggle/ui/composable/ShareouselComposable.kt | 100 |
1 files changed, 67 insertions, 33 deletions
diff --git a/java/src/com/android/intentresolver/contentpreview/payloadtoggle/ui/composable/ShareouselComposable.kt b/java/src/com/android/intentresolver/contentpreview/payloadtoggle/ui/composable/ShareouselComposable.kt index 9ac36a87..e40d98bd 100644 --- a/java/src/com/android/intentresolver/contentpreview/payloadtoggle/ui/composable/ShareouselComposable.kt +++ b/java/src/com/android/intentresolver/contentpreview/payloadtoggle/ui/composable/ShareouselComposable.kt @@ -45,6 +45,7 @@ import androidx.compose.material3.LocalContentColor import androidx.compose.material3.MaterialTheme import androidx.compose.material3.Text import androidx.compose.runtime.Composable +import androidx.compose.runtime.LaunchedEffect import androidx.compose.runtime.derivedStateOf import androidx.compose.runtime.getValue import androidx.compose.runtime.mutableStateOf @@ -71,6 +72,7 @@ import com.android.intentresolver.contentpreview.payloadtoggle.shared.model.Prev import com.android.intentresolver.contentpreview.payloadtoggle.ui.viewmodel.ShareouselPreviewViewModel import com.android.intentresolver.contentpreview.payloadtoggle.ui.viewmodel.ShareouselViewModel import kotlin.math.abs +import kotlin.math.min import kotlinx.coroutines.launch @Composable @@ -104,44 +106,48 @@ private fun PreviewCarousel( previews: PreviewsModel, viewModel: ShareouselViewModel, ) { - val centerIdx = previews.startIdx - val carouselState = - rememberLazyListState( - initialFirstVisibleItemIndex = centerIdx, - prefetchStrategy = remember { ShareouselLazyListPrefetchStrategy() } - ) var maxAspectRatio by remember { mutableStateOf(0f) } var viewportHeight by remember { mutableStateOf(0) } - - val horizontalPadding = 16.dp + var viewportCenter by remember { mutableStateOf(0) } + var horizontalPadding by remember { mutableStateOf(0.dp) } Box( modifier = Modifier.fillMaxWidth() .height(dimensionResource(R.dimen.chooser_preview_image_height_tall)) .layout { measurable, constraints -> val placeable = measurable.measure(constraints) - val aspectRatio = + val (minItemWidth, maxAR) = if (placeable.height <= 0) { - 0f + 0f to 0f } else { - val maxItemWidth = - maxOf(0, placeable.width - 2 * horizontalPadding.roundToPx()) - (maxItemWidth.toFloat() / placeable.height).coerceIn( - 0f, - MAX_ASPECT_RATIO - ) + val minItemWidth = (MIN_ASPECT_RATIO * placeable.height) + val maxItemWidth = maxOf(0, placeable.width - 32.dp.roundToPx()) + val maxAR = + (maxItemWidth.toFloat() / placeable.height).coerceIn( + 0f, + MAX_ASPECT_RATIO + ) + minItemWidth to maxAR } - maxAspectRatio = aspectRatio + viewportCenter = placeable.width / 2 + maxAspectRatio = maxAR viewportHeight = placeable.height + horizontalPadding = ((placeable.width - minItemWidth) / 2).toDp() layout(placeable.width, placeable.height) { placeable.place(0, 0) } }, ) { - if (maxAspectRatio <= 0) { + if (maxAspectRatio <= 0 && previews.previewModels.isNotEmpty()) { // Do not compose the list until we know the viewport size return@Box } - // TODO: start item needs to be centered, check out ScalingLazyColumn impl or see if - // HorizontalPager works for our use-case + + var firstSelectedIndex by remember { mutableStateOf(null as Int?) } + + val carouselState = + rememberLazyListState( + prefetchStrategy = remember { ShareouselLazyListPrefetchStrategy() }, + ) + LazyRow( state = carouselState, horizontalArrangement = Arrangement.spacedBy(4.dp), @@ -149,26 +155,38 @@ private fun PreviewCarousel( modifier = Modifier.fillMaxSize().systemGestureExclusion(), ) { itemsIndexed(previews.previewModels, key = { _, model -> model.uri }) { index, model -> + val visibleItem by remember { + derivedStateOf { + carouselState.layoutInfo.visibleItemsInfo.firstOrNull { it.index == index } + } + } + // Index if this is the element in the center of the viewing area, otherwise null val previewIndex by remember { derivedStateOf { - carouselState.layoutInfo.visibleItemsInfo - .firstOrNull { it.index == index } - ?.let { - val viewportCenter = carouselState.layoutInfo.viewportEndOffset / 2 - val halfPreviewWidth = it.size / 2 - val previewCenter = it.offset + halfPreviewWidth - val previewDistanceToViewportCenter = - abs(previewCenter - viewportCenter) - if (previewDistanceToViewportCenter <= halfPreviewWidth) { - index - } else { - null - } + visibleItem?.let { + val halfPreviewWidth = it.size / 2 + val previewCenter = it.offset + halfPreviewWidth + val previewDistanceToViewportCenter = + abs(previewCenter - viewportCenter) + if (previewDistanceToViewportCenter <= halfPreviewWidth) { + index + } else { + null } + } } } + val previewModel = + viewModel.preview(model, viewportHeight, previewIndex, rememberCoroutineScope()) + val selected by + previewModel.isSelected.collectAsStateWithLifecycle(initialValue = false) + + if (selected) { + firstSelectedIndex = min(index, firstSelectedIndex ?: Int.MAX_VALUE) + } + ShareouselCard( viewModel.preview( model, @@ -180,6 +198,22 @@ private fun PreviewCarousel( ) } } + + firstSelectedIndex?.let { index -> + LaunchedEffect(Unit) { + val visibleItem = + carouselState.layoutInfo.visibleItemsInfo.firstOrNull { it.index == index } + val center = + with(carouselState.layoutInfo) { + ((viewportEndOffset - viewportStartOffset) / 2) + viewportStartOffset + } + + carouselState.scrollToItem( + index = index, + scrollOffset = visibleItem?.size?.div(2)?.minus(center) ?: 0, + ) + } + } } } |