| /* |
| * 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.grid |
| |
| import androidx.compose.foundation.ExperimentalFoundationApi |
| import androidx.compose.foundation.lazy.LazyGridItemInfo |
| import androidx.compose.foundation.lazy.LazyGridLayoutInfo |
| import androidx.compose.foundation.lazy.layout.LazyLayoutItemInfo |
| import androidx.compose.foundation.lazy.layout.LazyLayoutMeasureResult |
| import androidx.compose.ui.layout.MeasureResult |
| import androidx.compose.ui.util.fastMap |
| |
| /** |
| * The result of the measure pass for lazy list layout. |
| */ |
| @OptIn(ExperimentalFoundationApi::class) |
| internal class LazyGridMeasureResult( |
| // properties defining the scroll position: |
| /** The new first visible line of items.*/ |
| val firstVisibleLine: LazyMeasuredLine?, |
| /** The new value for [LazyGridState.firstVisibleItemScrollOffset].*/ |
| val firstVisibleLineScrollOffset: Int, |
| /** True if there is some space available to continue scrolling in the forward direction.*/ |
| val canScrollForward: Boolean, |
| /** The amount of scroll consumed during the measure pass.*/ |
| val consumedScroll: Float, |
| /** MeasureResult defining the layout.*/ |
| val measureResult: MeasureResult, |
| // properties representing the info needed for LazyListLayoutInfo: |
| /** see [LazyGridLayoutInfo.visibleItemsInfo] */ |
| override val visibleItemsInfo: List<LazyGridItemInfo>, |
| /** see [LazyGridLayoutInfo.viewportStartOffset] */ |
| override val viewportStartOffset: Int, |
| /** see [LazyGridLayoutInfo.viewportEndOffset] */ |
| override val viewportEndOffset: Int, |
| /** see [LazyGridLayoutInfo.totalItemsCount] */ |
| override val totalItemsCount: Int, |
| ) : LazyGridLayoutInfo, MeasureResult by measureResult { |
| val lazyLayoutMeasureResult: LazyLayoutMeasureResult get() = |
| object : LazyLayoutMeasureResult, MeasureResult by measureResult { |
| override val visibleItemsInfo: List<LazyLayoutItemInfo> |
| get() = this@LazyGridMeasureResult.visibleItemsInfo.fastMap { |
| object : LazyLayoutItemInfo { |
| override val index: Int get() = it.index |
| override val key: Any get() = it.key |
| } |
| } |
| } |
| } |
