| /* |
| * Copyright 2023 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package androidx.tv.material3 |
| |
| import androidx.compose.animation.AnimatedVisibility |
| import androidx.compose.animation.ContentTransform |
| import androidx.compose.animation.ExperimentalAnimationApi |
| import androidx.compose.animation.slideInHorizontally |
| import androidx.compose.animation.slideOutHorizontally |
| import androidx.compose.animation.with |
| import androidx.compose.foundation.focusable |
| import androidx.compose.foundation.layout.Box |
| import androidx.compose.runtime.Composable |
| import androidx.compose.runtime.DisposableEffect |
| import androidx.compose.runtime.LaunchedEffect |
| import androidx.compose.runtime.getValue |
| import androidx.compose.runtime.mutableStateOf |
| import androidx.compose.runtime.remember |
| import androidx.compose.runtime.setValue |
| import androidx.compose.ui.ExperimentalComposeUiApi |
| import androidx.compose.ui.Modifier |
| import androidx.compose.ui.focus.FocusDirection |
| import androidx.compose.ui.focus.FocusState |
| import androidx.compose.ui.focus.onFocusChanged |
| import androidx.compose.ui.input.key.onKeyEvent |
| import androidx.compose.ui.platform.LocalFocusManager |
| import androidx.compose.ui.platform.LocalLayoutDirection |
| import androidx.compose.ui.unit.LayoutDirection |
| import androidx.tv.material3.KeyEventPropagation.ContinuePropagation |
| |
| /** |
| * This composable is intended for use in Carousel. |
| * A composable that has |
| * - a [background] layer that is rendered as soon as the composable is visible. |
| * - a [content] layer that is rendered on top of the [background] |
| * |
| * @param background composable defining the background of the item |
| * @param itemIndex current active item index of the carousel |
| * @param modifier modifier applied to the CarouselItem |
| * @param contentTransform content transform to be applied to the content of the item when |
| * scrolling |
| * @param content composable defining the content displayed on top of the background |
| */ |
| @Suppress("IllegalExperimentalApiUsage") |
| @OptIn(ExperimentalAnimationApi::class, ExperimentalComposeUiApi::class) |
| @ExperimentalTvMaterial3Api |
| @Composable |
| internal fun CarouselItem( |
| itemIndex: Int, |
| modifier: Modifier = Modifier, |
| background: @Composable () -> Unit = {}, |
| contentTransform: ContentTransform = |
| CarouselItemDefaults.contentTransformStartToEnd, |
| content: @Composable () -> Unit, |
| ) { |
| var containerBoxFocusState: FocusState? by remember { mutableStateOf(null) } |
| val focusManager = LocalFocusManager.current |
| var exitFocus by remember { mutableStateOf(false) } |
| |
| var isVisible by remember { mutableStateOf(false) } |
| |
| DisposableEffect(itemIndex) { |
| isVisible = true |
| onDispose { isVisible = false } |
| } |
| |
| // This box holds the focus until the overlay animation completes |
| Box( |
| modifier = modifier |
| .onKeyEvent { |
| exitFocus = it.isBackPress() && it.isTypeKeyDown() |
| ContinuePropagation |
| } |
| .onFocusChanged { |
| containerBoxFocusState = it |
| if (it.isFocused && exitFocus) { |
| focusManager.moveFocus(FocusDirection.Exit) |
| exitFocus = false |
| } |
| } |
| .focusable() |
| ) { |
| background() |
| |
| AnimatedVisibility( |
| visible = isVisible, |
| enter = contentTransform.targetContentEnter, |
| exit = contentTransform.initialContentExit, |
| ) { |
| LaunchedEffect(transition.isRunning, containerBoxFocusState?.isFocused) { |
| if (!transition.isRunning && containerBoxFocusState?.isFocused == true) { |
| focusManager.moveFocus(FocusDirection.Enter) |
| } |
| } |
| content.invoke() |
| } |
| } |
| } |
| |
| @ExperimentalTvMaterial3Api |
| object CarouselItemDefaults { |
| /** |
| * Transform the content from right to left |
| */ |
| // Keeping this as public so that users can access it directly without the isLTR helper |
| val contentTransformRightToLeft: ContentTransform |
| @Composable get() = |
| slideInHorizontally { it * 4 } |
| .with(slideOutHorizontally { it * 4 }) |
| |
| /** |
| * Transform the content from left to right |
| */ |
| // Keeping this as public so that users can access it directly without the isLTR helper |
| val contentTransformLeftToRight: ContentTransform |
| @Composable get() = |
| slideInHorizontally() |
| .with(slideOutHorizontally()) |
| |
| /** |
| * Content transform applied when moving forward taking isLTR into account |
| */ |
| val contentTransformStartToEnd |
| @Composable get() = |
| if (isLtr()) |
| contentTransformRightToLeft |
| else |
| contentTransformLeftToRight |
| |
| /** |
| * Content transform applied when moving backward taking isLTR into account |
| */ |
| val contentTransformEndToStart |
| @Composable get() = |
| if (isLtr()) |
| contentTransformLeftToRight |
| else |
| contentTransformRightToLeft |
| } |
| |
| @Composable |
| private fun isLtr() = LocalLayoutDirection.current == LayoutDirection.Ltr |