Android/frameworks_base
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Migrate to AndroidX HorizontalPager

Browse Source 
Bug: 260660819
Test: Manually with Gallery
Test: Manually with Settings
Change-Id: I6b35c1cd4a233b4547291c99f5e55133e6a6df61
This commit is contained in:
Chaohui Wang
2022-12-14 00:27:02 +08:00
parent fd4d3eaa40
commit 585705ad23
4 changed files with 6 additions and 650 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
packages/SettingsLib/Spa/spa/build.gradle
View File

@@ -108,7 +108,6 @@ task coverageReport(type: JacocoReport, dependsOn: "connectedDebugAndroidTest")
// Excludes files forked from Accompanist.
"com/android/settingslib/spa/framework/compose/DrawablePainter*",
"com/android/settingslib/spa/framework/compose/Pager*",
// Excludes inline functions, which is not covered in Jacoco reports.
"com/android/settingslib/spa/framework/util/Collections*",

329
packages/SettingsLib/Spa/spa/src/com/android/settingslib/spa/framework/compose/Pager.kt
View File

@@ -1,329 +0,0 @@
/*
* Copyright (C) 2022 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 com.android.settingslib.spa.framework.compose
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.PaddingValues
import androidx.compose.foundation.layout.wrapContentSize
import androidx.compose.foundation.lazy.LazyColumn
import androidx.compose.foundation.lazy.LazyRow
import androidx.compose.runtime.Composable
import androidx.compose.runtime.LaunchedEffect
import androidx.compose.runtime.Stable
import androidx.compose.runtime.remember
import androidx.compose.runtime.snapshotFlow
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.input.nestedscroll.NestedScrollConnection
import androidx.compose.ui.input.nestedscroll.NestedScrollSource
import androidx.compose.ui.input.nestedscroll.nestedScroll
import androidx.compose.ui.platform.LocalDensity
import androidx.compose.ui.unit.Dp
import androidx.compose.ui.unit.Velocity
import androidx.compose.ui.unit.dp
import kotlinx.coroutines.flow.distinctUntilChanged
import kotlinx.coroutines.flow.drop
import kotlinx.coroutines.flow.filter
/**
* *************************************************************************************************
* This file was forked from
* https://github.com/google/accompanist/blob/main/pager/src/main/java/com/google/accompanist/pager/Pager.kt
* and will be removed once it lands in AndroidX.
*/
/**
* A horizontally scrolling layout that allows users to flip between items to the left and right.
*
* @sample com.google.accompanist.sample.pager.HorizontalPagerSample
*
* @param count the number of pages.
* @param modifier the modifier to apply to this layout.
* @param state the state object to be used to control or observe the pager's state.
* @param reverseLayout reverse the direction of scrolling and layout, when `true` items will be
* composed from the end to the start and [PagerState.currentPage] == 0 will mean
* the first item is located at the end.
* @param itemSpacing horizontal spacing to add between items.
* @param key the scroll position will be maintained based on the key, which means if you
* add/remove items before the current visible item the item with the given key will be kept as the
* first visible one.
* @param content a block which describes the content. Inside this block you can reference
* [PagerScope.currentPage] and other properties in [PagerScope].
*/
@Composable
fun HorizontalPager(
count: Int,
modifier: Modifier = Modifier,
state: PagerState = rememberPagerState(),
reverseLayout: Boolean = false,
itemSpacing: Dp = 0.dp,
contentPadding: PaddingValues = PaddingValues(0.dp),
verticalAlignment: Alignment.Vertical = Alignment.CenterVertically,
key: ((page: Int) -> Any)? = null,
content: @Composable PagerScope.(page: Int) -> Unit,
) {
Pager(
count = count,
state = state,
modifier = modifier,
isVertical = false,
reverseLayout = reverseLayout,
itemSpacing = itemSpacing,
verticalAlignment = verticalAlignment,
key = key,
contentPadding = contentPadding,
content = content
)
}
/**
* A vertically scrolling layout that allows users to flip between items to the top and bottom.
*
* @sample com.google.accompanist.sample.pager.VerticalPagerSample
*
* @param count the number of pages.
* @param modifier the modifier to apply to this layout.
* @param state the state object to be used to control or observe the pager's state.
* @param reverseLayout reverse the direction of scrolling and layout, when `true` items will be
* composed from the bottom to the top and [PagerState.currentPage] == 0 will mean
* the first item is located at the bottom.
* @param itemSpacing vertical spacing to add between items.
* @param key the scroll position will be maintained based on the key, which means if you
* add/remove items before the current visible item the item with the given key will be kept as the
* first visible one.
* @param content a block which describes the content. Inside this block you can reference
* [PagerScope.currentPage] and other properties in [PagerScope].
*/
@Composable
fun VerticalPager(
count: Int,
modifier: Modifier = Modifier,
state: PagerState = rememberPagerState(),
reverseLayout: Boolean = false,
itemSpacing: Dp = 0.dp,
contentPadding: PaddingValues = PaddingValues(0.dp),
horizontalAlignment: Alignment.Horizontal = Alignment.CenterHorizontally,
key: ((page: Int) -> Any)? = null,
content: @Composable PagerScope.(page: Int) -> Unit,
) {
Pager(
count = count,
state = state,
modifier = modifier,
isVertical = true,
reverseLayout = reverseLayout,
itemSpacing = itemSpacing,
horizontalAlignment = horizontalAlignment,
key = key,
contentPadding = contentPadding,
content = content
)
}
@Composable
internal fun Pager(
count: Int,
modifier: Modifier,
state: PagerState,
reverseLayout: Boolean,
itemSpacing: Dp,
isVertical: Boolean,
key: ((page: Int) -> Any)?,
contentPadding: PaddingValues,
verticalAlignment: Alignment.Vertical = Alignment.CenterVertically,
horizontalAlignment: Alignment.Horizontal = Alignment.CenterHorizontally,
content: @Composable PagerScope.(page: Int) -> Unit,
) {
require(count >= 0) { "pageCount must be >= 0" }
LaunchedEffect(count) {
state.currentPage = minOf(count - 1, state.currentPage).coerceAtLeast(0)
}
// Once a fling (scroll) has finished, notify the state
LaunchedEffect(state) {
// When a 'scroll' has finished, notify the state
snapshotFlow { state.isScrollInProgress }
.filter { !it }
// initially isScrollInProgress is false as well and we want to start receiving
// the events only after the real scroll happens.
.drop(1)
.collect { state.onScrollFinished() }
}
LaunchedEffect(state) {
snapshotFlow { state.mostVisiblePageLayoutInfo?.index }
.distinctUntilChanged()
.collect { state.updateCurrentPageBasedOnLazyListState() }
}
val density = LocalDensity.current
LaunchedEffect(density, state, itemSpacing) {
with(density) { state.itemSpacing = itemSpacing.roundToPx() }
}
val pagerScope = remember(state) { PagerScopeImpl(state) }
// We only consume nested flings in the main-axis, allowing cross-axis flings to propagate
// as normal
val consumeFlingNestedScrollConnection = remember(isVertical) {
ConsumeFlingNestedScrollConnection(
consumeHorizontal = !isVertical,
consumeVertical = isVertical,
pagerState = state,
)
}
if (isVertical) {
LazyColumn(
state = state.lazyListState,
verticalArrangement = Arrangement.spacedBy(itemSpacing, verticalAlignment),
horizontalAlignment = horizontalAlignment,
reverseLayout = reverseLayout,
contentPadding = contentPadding,
userScrollEnabled = false,
modifier = modifier,
) {
items(
count = count,
key = key,
) { page ->
Box(
Modifier
// We don't any nested flings to continue in the pager, so we add a
// connection which consumes them.
// See: https://github.com/google/accompanist/issues/347
.nestedScroll(connection = consumeFlingNestedScrollConnection)
// Constraint the content height to be <= than the height of the pager.
.fillParentMaxHeight()
.wrapContentSize()
) {
pagerScope.content(page)
}
}
}
} else {
LazyRow(
state = state.lazyListState,
verticalAlignment = verticalAlignment,
horizontalArrangement = Arrangement.spacedBy(itemSpacing, horizontalAlignment),
reverseLayout = reverseLayout,
contentPadding = contentPadding,
userScrollEnabled = false,
modifier = modifier,
) {
items(
count = count,
key = key,
) { page ->
Box(
Modifier
// We don't any nested flings to continue in the pager, so we add a
// connection which consumes them.
// See: https://github.com/google/accompanist/issues/347
.nestedScroll(connection = consumeFlingNestedScrollConnection)
// Constraint the content width to be <= than the width of the pager.
.fillParentMaxWidth()
.wrapContentSize()
) {
pagerScope.content(page)
}
}
}
}
}
private class ConsumeFlingNestedScrollConnection(
private val consumeHorizontal: Boolean,
private val consumeVertical: Boolean,
private val pagerState: PagerState,
) : NestedScrollConnection {
override fun onPostScroll(
consumed: Offset,
available: Offset,
source: NestedScrollSource
): Offset = when (source) {
// We can consume all resting fling scrolls so that they don't propagate up to the
// Pager
NestedScrollSource.Fling -> available.consume(consumeHorizontal, consumeVertical)
else -> Offset.Zero
}
override suspend fun onPostFling(consumed: Velocity, available: Velocity): Velocity {
return if (pagerState.currentPageOffset != 0f) {
// The Pager is already scrolling. This means that a nested scroll child was
// scrolled to end, and the Pager can use this fling
Velocity.Zero
} else {
// A nested scroll child is still scrolling. We can consume all post fling
// velocity on the main-axis so that it doesn't propagate up to the Pager
available.consume(consumeHorizontal, consumeVertical)
}
}
}
private fun Offset.consume(
consumeHorizontal: Boolean,
consumeVertical: Boolean,
): Offset = Offset(
x = if (consumeHorizontal) this.x else 0f,
y = if (consumeVertical) this.y else 0f,
)
private fun Velocity.consume(
consumeHorizontal: Boolean,
consumeVertical: Boolean,
): Velocity = Velocity(
x = if (consumeHorizontal) this.x else 0f,
y = if (consumeVertical) this.y else 0f,
)
/**
* Scope for [HorizontalPager] content.
*/
@Stable
interface PagerScope {
/**
* Returns the current selected page
*/
val currentPage: Int
/**
* The current offset from the start of [currentPage], as a ratio of the page width.
*/
val currentPageOffset: Float
}
private class PagerScopeImpl(
private val state: PagerState,
) : PagerScope {
override val currentPage: Int get() = state.currentPage
override val currentPageOffset: Float get() = state.currentPageOffset
}
/**
* Calculate the offset for the given [page] from the current scroll position. This is useful
* when using the scroll position to apply effects or animations to items.
*
* The returned offset can positive or negative, depending on whether which direction the [page] is
* compared to the current scroll position.
*
* @sample com.google.accompanist.sample.pager.HorizontalPagerWithOffsetTransition
*/
fun PagerScope.calculateCurrentOffsetForPage(page: Int): Float {
return (currentPage - page) + currentPageOffset
}

316
packages/SettingsLib/Spa/spa/src/com/android/settingslib/spa/framework/compose/PagerState.kt
View File

@@ -1,316 +0,0 @@
/*
* Copyright (C) 2022 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 com.android.settingslib.spa.framework.compose
import androidx.annotation.FloatRange
import androidx.annotation.IntRange
import androidx.compose.foundation.MutatePriority
import androidx.compose.foundation.gestures.ScrollScope
import androidx.compose.foundation.gestures.ScrollableState
import androidx.compose.foundation.interaction.InteractionSource
import androidx.compose.foundation.lazy.LazyListItemInfo
import androidx.compose.foundation.lazy.LazyListState
import androidx.compose.runtime.Composable
import androidx.compose.runtime.Stable
import androidx.compose.runtime.derivedStateOf
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.Saver
import androidx.compose.runtime.saveable.listSaver
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import kotlin.math.abs
import kotlin.math.absoluteValue
import kotlin.math.roundToInt
/**
* *************************************************************************************************
* This file was forked from
* https://github.com/google/accompanist/blob/main/pager/src/main/java/com/google/accompanist/pager/PagerState.kt
* and will be removed once it lands in AndroidX.
*/
/**
* Creates a [PagerState] that is remembered across compositions.
*
* Changes to the provided values for [initialPage] will **not** result in the state being
* recreated or changed in any way if it has already
* been created.
*
* @param initialPage the initial value for [PagerState.currentPage]
*/
@Composable
fun rememberPagerState(
@IntRange(from = 0) initialPage: Int = 0,
): PagerState = rememberSaveable(saver = PagerState.Saver) {
PagerState(
currentPage = initialPage,
)
}
/**
* A state object that can be hoisted to control and observe scrolling for [HorizontalPager].
*
* In most cases, this will be created via [rememberPagerState].
*
* @param currentPage the initial value for [PagerState.currentPage]
*/
@Stable
class PagerState(
@IntRange(from = 0) currentPage: Int = 0,
) : ScrollableState {
// Should this be public?
internal val lazyListState = LazyListState(firstVisibleItemIndex = currentPage)
private var _currentPage by mutableStateOf(currentPage)
// finds the page which has larger visible area within the viewport not including paddings
internal val mostVisiblePageLayoutInfo: LazyListItemInfo?
get() {
val layoutInfo = lazyListState.layoutInfo
return layoutInfo.visibleItemsInfo.maxByOrNull {
val start = maxOf(it.offset, 0)
val end = minOf(
it.offset + it.size,
layoutInfo.viewportEndOffset - layoutInfo.afterContentPadding
)
end - start
}
}
internal var itemSpacing by mutableStateOf(0)
private val currentPageLayoutInfo: LazyListItemInfo?
get() = lazyListState.layoutInfo.visibleItemsInfo.lastOrNull {
it.index == currentPage
}
/**
* [InteractionSource] that will be used to dispatch drag events when this
* list is being dragged. If you want to know whether the fling (or animated scroll) is in
* progress, use [isScrollInProgress].
*/
val interactionSource: InteractionSource
get() = lazyListState.interactionSource
/**
* The number of pages to display.
*/
@get:IntRange(from = 0)
val pageCount: Int by derivedStateOf {
lazyListState.layoutInfo.totalItemsCount
}
/**
* The index of the currently selected page. This may not be the page which is
* currently displayed on screen.
*
* To update the scroll position, use [scrollToPage] or [animateScrollToPage].
*/
@get:IntRange(from = 0)
var currentPage: Int
get() = _currentPage
internal set(value) {
if (value != _currentPage) {
_currentPage = value
}
}
/**
* The current offset from the start of [currentPage], as a ratio of the page width.
*
* To update the scroll position, use [scrollToPage] or [animateScrollToPage].
*/
val currentPageOffset: Float by derivedStateOf {
currentPageLayoutInfo?.let {
(-it.offset / (it.size + itemSpacing).toFloat()).coerceIn(-0.5f, 0.5f)
} ?: 0f
}
/**
* The target page for any on-going animations.
*/
private var animationTargetPage: Int? by mutableStateOf(null)
/**
* Animate (smooth scroll) to the given page to the middle of the viewport.
*
* Cancels the currently running scroll, if any, and suspends until the cancellation is
* complete.
*
* @param page the page to animate to. Must be >= 0.
* @param pageOffset the percentage of the page size to offset, from the start of [page].
* Must be in the range -1f..1f.
*/
suspend fun animateScrollToPage(
@IntRange(from = 0) page: Int,
@FloatRange(from = -1.0, to = 1.0) pageOffset: Float = 0f,
) {
requireCurrentPage(page, "page")
requireCurrentPageOffset(pageOffset, "pageOffset")
try {
animationTargetPage = page
// pre-jump to nearby item for long jumps as an optimization
// the same trick is done in ViewPager2
val oldPage = lazyListState.firstVisibleItemIndex
if (abs(page - oldPage) > 3) {
lazyListState.scrollToItem(if (page > oldPage) page - 3 else page + 3)
}
if (pageOffset.absoluteValue <= 0.005f) {
// If the offset is (close to) zero, just call animateScrollToItem and we're done
lazyListState.animateScrollToItem(index = page)
} else {
// Else we need to figure out what the offset is in pixels...
lazyListState.scroll { } // this will await for the first layout.
val layoutInfo = lazyListState.layoutInfo
var target = layoutInfo.visibleItemsInfo
.firstOrNull { it.index == page }
if (target != null) {
// If we have access to the target page layout, we can calculate the pixel
// offset from the size
lazyListState.animateScrollToItem(
index = page,
scrollOffset = ((target.size + itemSpacing) * pageOffset).roundToInt()
)
} else if (layoutInfo.visibleItemsInfo.isNotEmpty()) {
// If we don't, we use the current page size as a guide
val currentSize = layoutInfo.visibleItemsInfo.first().size + itemSpacing
lazyListState.animateScrollToItem(
index = page,
scrollOffset = (currentSize * pageOffset).roundToInt()
)
// The target should be visible now
target = layoutInfo.visibleItemsInfo.firstOrNull { it.index == page }
if (target != null && target.size + itemSpacing != currentSize) {
// If the size we used for calculating the offset differs from the actual
// target page size, we need to scroll again. This doesn't look great,
// but there's not much else we can do.
lazyListState.animateScrollToItem(
index = page,
scrollOffset = ((target.size + itemSpacing) * pageOffset).roundToInt()
)
}
}
}
} finally {
// We need to manually call this, as the `animateScrollToItem` call above will happen
// in 1 frame, which is usually too fast for the LaunchedEffect in Pager to detect
// the change. This is especially true when running unit tests.
onScrollFinished()
}
}
/**
* Instantly brings the item at [page] to the middle of the viewport.
*
* Cancels the currently running scroll, if any, and suspends until the cancellation is
* complete.
*
* @param page the page to snap to. Must be >= 0.
* @param pageOffset the percentage of the page size to offset, from the start of [page].
* Must be in the range -1f..1f.
*/
suspend fun scrollToPage(
@IntRange(from = 0) page: Int,
@FloatRange(from = -1.0, to = 1.0) pageOffset: Float = 0f,
) {
requireCurrentPage(page, "page")
requireCurrentPageOffset(pageOffset, "pageOffset")
try {
animationTargetPage = page
// First scroll to the given page. It will now be laid out at offset 0
lazyListState.scrollToItem(index = page)
updateCurrentPageBasedOnLazyListState()
// If we have a start spacing, we need to offset (scroll) by that too
if (pageOffset.absoluteValue > 0.0001f) {
currentPageLayoutInfo?.let {
scroll {
scrollBy((it.size + itemSpacing) * pageOffset)
}
}
}
} finally {
// We need to manually call this, as the `scroll` call above will happen in 1 frame,
// which is usually too fast for the LaunchedEffect in Pager to detect the change.
// This is especially true when running unit tests.
onScrollFinished()
}
}
internal fun updateCurrentPageBasedOnLazyListState() {
// Then update the current page to our layout page
mostVisiblePageLayoutInfo?.let {
currentPage = it.index
}
}
internal fun onScrollFinished() {
// Clear the animation target page
animationTargetPage = null
}
override suspend fun scroll(
scrollPriority: MutatePriority,
block: suspend ScrollScope.() -> Unit
) = lazyListState.scroll(scrollPriority, block)
override fun dispatchRawDelta(delta: Float): Float {
return lazyListState.dispatchRawDelta(delta)
}
override val isScrollInProgress: Boolean
get() = lazyListState.isScrollInProgress
override fun toString(): String = "PagerState(" +
"pageCount=$pageCount, " +
"currentPage=$currentPage, " +
"currentPageOffset=$currentPageOffset" +
")"
private fun requireCurrentPage(value: Int, name: String) {
require(value >= 0) { "$name[$value] must be >= 0" }
}
private fun requireCurrentPageOffset(value: Float, name: String) {
require(value in -1f..1f) { "$name must be >= -1 and <= 1" }
}
companion object {
/**
* The default [Saver] implementation for [PagerState].
*/
val Saver: Saver<PagerState, *> = listSaver(
save = {
listOf<Any>(
it.currentPage,
)
},
restore = {
PagerState(
currentPage = it[0] as Int,
)
}
)
}
}

10
packages/SettingsLib/Spa/spa/src/com/android/settingslib/spa/widget/scaffold/SettingsPager.kt
View File

@@ -16,19 +16,21 @@
package com.android.settingslib.spa.widget.scaffold
import androidx.compose.foundation.ExperimentalFoundationApi
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.pager.HorizontalPager
import androidx.compose.foundation.pager.rememberPagerState
import androidx.compose.material3.TabRow
import androidx.compose.runtime.Composable
import androidx.compose.runtime.rememberCoroutineScope
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import com.android.settingslib.spa.framework.compose.HorizontalPager
import com.android.settingslib.spa.framework.compose.rememberPagerState
import com.android.settingslib.spa.framework.theme.SettingsDimension
import kotlin.math.absoluteValue
import kotlinx.coroutines.launch
@OptIn(ExperimentalFoundationApi::class)
@Composable
fun SettingsPager(titles: List<String>, content: @Composable (page: Int) -> Unit) {
check(titles.isNotEmpty())
@@ -52,7 +54,7 @@ fun SettingsPager(titles: List<String>, content: @Composable (page: Int) -> Unit
SettingsTab(
title = title,
selected = pagerState.currentPage == page,
currentPageOffset = pagerState.currentPageOffset.absoluteValue,
currentPageOffset = pagerState.currentPageOffsetFraction.absoluteValue,
onClick = {
coroutineScope.launch {
pagerState.animateScrollToPage(page)
@@ -62,7 +64,7 @@ fun SettingsPager(titles: List<String>, content: @Composable (page: Int) -> Unit
}
}
HorizontalPager(count = titles.size, state = pagerState) { page ->
HorizontalPager(pageCount = titles.size, state = pagerState) { page ->
content(page)
}
}