| /* |
| * Copyright 2021 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.compose.foundation.lazy.list |
| |
| import androidx.compose.foundation.ExperimentalFoundationApi |
| import androidx.compose.foundation.lazy.LazyItemScope |
| import androidx.compose.foundation.lazy.LazyListScope |
| import androidx.compose.foundation.lazy.layout.IntervalList |
| import androidx.compose.foundation.lazy.layout.MutableIntervalList |
| import androidx.compose.runtime.Composable |
| |
| internal class LazyListScopeImpl : LazyListScope { |
| |
| private val _intervals = MutableIntervalList<LazyListIntervalContent>() |
| val intervals: IntervalList<LazyListIntervalContent> = _intervals |
| |
| private var _headerIndexes: MutableList<Int>? = null |
| val headerIndexes: List<Int> get() = _headerIndexes ?: emptyList() |
| |
| override fun items( |
| count: Int, |
| key: ((index: Int) -> Any)?, |
| itemContent: @Composable LazyItemScope.(index: Int) -> Unit |
| ) { |
| _intervals.add( |
| count, |
| LazyListIntervalContent( |
| key = key, |
| content = { index -> @Composable { itemContent(index) } } |
| ) |
| ) |
| } |
| |
| override fun item(key: Any?, content: @Composable LazyItemScope.() -> Unit) { |
| _intervals.add( |
| 1, |
| LazyListIntervalContent( |
| key = if (key != null) { _: Int -> key } else null, |
| content = { @Composable { content() } } |
| ) |
| ) |
| } |
| |
| @ExperimentalFoundationApi |
| override fun stickyHeader(key: Any?, content: @Composable LazyItemScope.() -> Unit) { |
| val headersIndexes = _headerIndexes ?: mutableListOf<Int>().also { |
| _headerIndexes = it |
| } |
| headersIndexes.add(_intervals.totalSize) |
| |
| item(key, content) |
| } |
| } |
| |
| internal class LazyListIntervalContent( |
| val key: ((index: Int) -> Any)?, |
| val content: LazyItemScope.(index: Int) -> @Composable () -> Unit |
| ) |
