Merge "Force prefetch if item is needed in the next frame for lazy layouts" into androidx-main
diff --git a/compose/foundation/foundation/api/current.txt b/compose/foundation/foundation/api/current.txt
index e026507..f8dc027 100644
--- a/compose/foundation/foundation/api/current.txt
+++ b/compose/foundation/foundation/api/current.txt
@@ -1132,6 +1132,7 @@
public static sealed interface LazyLayoutPrefetchState.PrefetchHandle {
method public void cancel();
+ method public void markAsUrgent();
}
public final class Lazy_androidKt {
@@ -1156,8 +1157,7 @@
}
@SuppressCompatibility @androidx.compose.foundation.ExperimentalFoundationApi public interface PrefetchRequestScope {
- method public long getAvailableTimeNanos();
- property public abstract long availableTimeNanos;
+ method public long availableTimeNanos();
}
@SuppressCompatibility @androidx.compose.foundation.ExperimentalFoundationApi public interface PrefetchScheduler {
diff --git a/compose/foundation/foundation/api/restricted_current.txt b/compose/foundation/foundation/api/restricted_current.txt
index cc020da..8ffe7e9 100644
--- a/compose/foundation/foundation/api/restricted_current.txt
+++ b/compose/foundation/foundation/api/restricted_current.txt
@@ -1134,6 +1134,7 @@
public static sealed interface LazyLayoutPrefetchState.PrefetchHandle {
method public void cancel();
+ method public void markAsUrgent();
}
public final class Lazy_androidKt {
@@ -1158,8 +1159,7 @@
}
@SuppressCompatibility @androidx.compose.foundation.ExperimentalFoundationApi public interface PrefetchRequestScope {
- method public long getAvailableTimeNanos();
- property public abstract long availableTimeNanos;
+ method public long availableTimeNanos();
}
@SuppressCompatibility @androidx.compose.foundation.ExperimentalFoundationApi public interface PrefetchScheduler {
diff --git a/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/grid/LazyGridPrefetcherTest.kt b/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/grid/LazyGridPrefetcherTest.kt
index 087d8db..c4d5b3a 100644
--- a/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/grid/LazyGridPrefetcherTest.kt
+++ b/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/grid/LazyGridPrefetcherTest.kt
@@ -14,14 +14,20 @@
* limitations under the License.
*/
+@file:Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE")
+
package androidx.compose.foundation.lazy.grid
import androidx.compose.foundation.AutoTestFrameClock
+import androidx.compose.foundation.ExperimentalFoundationApi
import androidx.compose.foundation.gestures.Orientation
import androidx.compose.foundation.gestures.scrollBy
import androidx.compose.foundation.layout.PaddingValues
import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.lazy.layout.TestPrefetchScheduler
+import androidx.compose.runtime.Composable
import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.remember
import androidx.compose.ui.Modifier
import androidx.compose.ui.layout.Remeasurement
import androidx.compose.ui.layout.RemeasurementModifier
@@ -58,6 +64,16 @@
val itemsSizeDp = with(rule.density) { itemsSizePx.toDp() }
lateinit var state: LazyGridState
+ private val scheduler = TestPrefetchScheduler()
+
+ @OptIn(ExperimentalFoundationApi::class)
+ @Composable
+ fun rememberState(
+ initialFirstVisibleItemIndex: Int = 0,
+ initialFirstVisibleItemScrollOffset: Int = 0
+ ): LazyGridState = remember {
+ LazyGridState(initialFirstVisibleItemIndex, initialFirstVisibleItemScrollOffset, scheduler)
+ }
@Test
fun notPrefetchingForwardInitially() {
@@ -85,8 +101,8 @@
}
}
- waitForPrefetch(4)
- waitForPrefetch(5)
+ waitForPrefetch()
+ waitForPrefetch()
rule.onNodeWithTag("4")
.assertExists()
@@ -106,8 +122,8 @@
}
}
- waitForPrefetch(2)
- waitForPrefetch(3)
+ waitForPrefetch()
+ waitForPrefetch()
rule.onNodeWithTag("2")
.assertExists()
@@ -127,8 +143,8 @@
}
}
- waitForPrefetch(6)
- waitForPrefetch(7)
+ waitForPrefetch()
+ waitForPrefetch()
rule.onNodeWithTag("6")
.assertExists()
@@ -144,8 +160,8 @@
}
}
- waitForPrefetch(0)
- waitForPrefetch(1)
+ waitForPrefetch()
+ waitForPrefetch()
rule.onNodeWithTag("0")
.assertExists()
@@ -165,7 +181,7 @@
}
}
- waitForPrefetch(4)
+ waitForPrefetch()
rule.runOnIdle {
runBlocking {
@@ -174,7 +190,7 @@
}
}
- waitForPrefetch(6)
+ waitForPrefetch()
rule.onNodeWithTag("4")
.assertIsDisplayed()
@@ -194,7 +210,7 @@
}
}
- waitForPrefetch(4)
+ waitForPrefetch()
rule.runOnIdle {
runBlocking {
@@ -203,7 +219,7 @@
}
}
- waitForPrefetch(2)
+ waitForPrefetch()
rule.onNodeWithTag("4")
.assertIsDisplayed()
@@ -225,8 +241,7 @@
}
}
- waitForPrefetch(6)
- waitForPrefetch(7)
+ waitForPrefetch()
rule.onNodeWithTag("6")
.assertExists()
@@ -244,8 +259,7 @@
}
}
- waitForPrefetch(0)
- waitForPrefetch(1)
+ waitForPrefetch()
rule.onNodeWithTag("0")
.assertExists()
@@ -283,7 +297,7 @@
}
}
- waitForPrefetch(6)
+ waitForPrefetch()
rule.onNodeWithTag("8")
.assertExists()
@@ -296,7 +310,7 @@
}
}
- waitForPrefetch(0)
+ waitForPrefetch()
rule.onNodeWithTag("0")
.assertExists()
@@ -316,7 +330,7 @@
) { constraints ->
val placeable = if (emit) {
subcompose(Unit) {
- state = rememberLazyGridState()
+ state = rememberState()
LazyGrid(
2,
Modifier.mainAxisSize(itemsSizeDp * 1.5f),
@@ -355,7 +369,7 @@
fun snappingToOtherPositionWhilePrefetchIsScheduled() {
val composedItems = mutableListOf<Int>()
rule.setContent {
- state = rememberLazyGridState()
+ state = rememberState()
LazyGrid(
1,
Modifier.mainAxisSize(itemsSizeDp * 1.5f),
@@ -410,7 +424,7 @@
}
}
- waitForPrefetch(13)
+ waitForPrefetch()
rule.runOnIdle {
runBlocking(AutoTestFrameClock()) {
@@ -424,14 +438,13 @@
}
}
- private fun waitForPrefetch(index: Int) {
- rule.waitUntil {
- activeNodes.contains(index) && activeMeasuredNodes.contains(index)
+ private fun waitForPrefetch() {
+ rule.runOnIdle {
+ scheduler.executeActiveRequests()
}
}
private val activeNodes = mutableSetOf<Int>()
- private val activeMeasuredNodes = mutableSetOf<Int>()
private fun composeGrid(
firstItem: Int = 0,
@@ -440,7 +453,7 @@
contentPadding: PaddingValues = PaddingValues(0.dp)
) {
rule.setContent {
- state = rememberLazyGridState(
+ state = rememberState(
initialFirstVisibleItemIndex = firstItem,
initialFirstVisibleItemScrollOffset = itemOffset
)
@@ -456,7 +469,6 @@
activeNodes.add(it)
onDispose {
activeNodes.remove(it)
- activeMeasuredNodes.remove(it)
}
}
Spacer(
@@ -465,7 +477,6 @@
.testTag("$it")
.layout { measurable, constraints ->
val placeable = measurable.measure(constraints)
- activeMeasuredNodes.add(it)
layout(placeable.width, placeable.height) {
placeable.place(0, 0)
}
diff --git a/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/layout/LazyLayoutTest.kt b/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/layout/LazyLayoutTest.kt
index bb6d01a..5596f14 100644
--- a/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/layout/LazyLayoutTest.kt
+++ b/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/layout/LazyLayoutTest.kt
@@ -257,7 +257,8 @@
.then(modifier))
}
var needToCompose by mutableStateOf(false)
- val prefetchState = LazyLayoutPrefetchState()
+ val scheduler = TestPrefetchScheduler()
+ val prefetchState = LazyLayoutPrefetchState(scheduler)
rule.setContent {
LazyLayout(itemProvider, prefetchState = prefetchState) {
val item = if (needToCompose) {
@@ -273,9 +274,10 @@
assertThat(measureCount).isEqualTo(0)
prefetchState.schedulePrefetch(0, constraints)
- }
- rule.waitUntil { measureCount == 1 }
+ scheduler.executeActiveRequests()
+ assertThat(measureCount).isEqualTo(1)
+ }
rule.onNodeWithTag("0").assertIsNotDisplayed()
@@ -303,20 +305,18 @@
}
}
}
- val prefetchState = LazyLayoutPrefetchState()
+ val scheduler = TestPrefetchScheduler()
+ val prefetchState = LazyLayoutPrefetchState(scheduler)
rule.setContent {
LazyLayout(itemProvider, prefetchState = prefetchState) {
layout(100, 100) {}
}
}
- val handle = rule.runOnIdle {
- prefetchState.schedulePrefetch(0, Constraints.fixed(50, 50))
- }
-
- rule.waitUntil { composed }
-
rule.runOnIdle {
+ val handle = prefetchState.schedulePrefetch(0, Constraints.fixed(50, 50))
+ scheduler.executeActiveRequests()
+ assertThat(composed).isTrue()
handle.cancel()
}
diff --git a/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/layout/TestPrefetchScheduler.kt b/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/layout/TestPrefetchScheduler.kt
new file mode 100644
index 0000000..ad3b8a6
--- /dev/null
+++ b/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/layout/TestPrefetchScheduler.kt
@@ -0,0 +1,39 @@
+/*
+ * Copyright 2024 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.layout
+
+import androidx.compose.foundation.ExperimentalFoundationApi
+
+@OptIn(ExperimentalFoundationApi::class)
+internal class TestPrefetchScheduler : PrefetchScheduler {
+
+ private var activeRequests = mutableListOf<PrefetchRequest>()
+ override fun schedulePrefetch(prefetchRequest: PrefetchRequest) {
+ activeRequests.add(prefetchRequest)
+ }
+
+ fun executeActiveRequests() {
+ activeRequests.forEach {
+ with(it) { scope.execute() }
+ }
+ activeRequests.clear()
+ }
+
+ private val scope = object : PrefetchRequestScope {
+ override fun availableTimeNanos(): Long = Long.MAX_VALUE
+ }
+}
diff --git a/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/list/LazyListFocusMoveCompositionCountTest.kt b/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/list/LazyListFocusMoveCompositionCountTest.kt
index b8a37d5..21f1531 100644
--- a/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/list/LazyListFocusMoveCompositionCountTest.kt
+++ b/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/list/LazyListFocusMoveCompositionCountTest.kt
@@ -14,11 +14,14 @@
* limitations under the License.
*/
+@file:Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE")
+
package androidx.compose.foundation.lazy.list
import androidx.compose.foundation.focusable
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.lazy.LazyListState
import androidx.compose.foundation.lazy.LazyRow
import androidx.compose.runtime.SideEffect
import androidx.compose.ui.Modifier
@@ -45,6 +48,10 @@
private val composedItems = mutableSetOf<Int>()
+ private val state = LazyListState().also {
+ it.prefetchingEnabled = false
+ }
+
@Test
fun moveFocus() {
// Arrange.
@@ -52,7 +59,7 @@
lateinit var focusManager: FocusManager
rule.setContent {
focusManager = LocalFocusManager.current
- LazyRow(Modifier.size(rowSize)) {
+ LazyRow(Modifier.size(rowSize), state) {
items(100) { index ->
Box(
Modifier
@@ -71,7 +78,7 @@
rule.runOnIdle { focusManager.moveFocus(FocusDirection.Right) }
// Assert
- rule.runOnIdle { assertThat(composedItems).containsExactly(5, 6) }
+ rule.runOnIdle { assertThat(composedItems).containsExactly(5) }
}
@Test
@@ -81,7 +88,7 @@
lateinit var focusManager: FocusManager
rule.setContent {
focusManager = LocalFocusManager.current
- LazyRow(Modifier.size(rowSize)) {
+ LazyRow(Modifier.size(rowSize), state) {
items(100) { index ->
Box(Modifier.size(itemSize).focusable()) {
Box(Modifier.size(itemSize).focusable().testTag("$index"))
@@ -97,7 +104,7 @@
rule.runOnIdle { focusManager.moveFocus(FocusDirection.Right) }
// Assert
- rule.runOnIdle { assertThat(composedItems).containsExactly(5, 6) }
+ rule.runOnIdle { assertThat(composedItems).containsExactly(5) }
}
@Test
@@ -107,7 +114,7 @@
lateinit var focusManager: FocusManager
rule.setContent {
focusManager = LocalFocusManager.current
- LazyRow(Modifier.size(rowSize)) {
+ LazyRow(Modifier.size(rowSize), state) {
items(100) { index ->
Box(Modifier.size(itemSize).focusable()) {
Box(Modifier.size(itemSize).focusable()) {
@@ -125,6 +132,6 @@
rule.runOnIdle { focusManager.moveFocus(FocusDirection.Right) }
// Assert
- rule.runOnIdle { assertThat(composedItems).containsExactly(5, 6) }
+ rule.runOnIdle { assertThat(composedItems).containsExactly(5) }
}
}
diff --git a/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/list/LazyListNestedPrefetchingTest.kt b/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/list/LazyListNestedPrefetchingTest.kt
index ebd489b..229f84a 100644
--- a/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/list/LazyListNestedPrefetchingTest.kt
+++ b/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/list/LazyListNestedPrefetchingTest.kt
@@ -26,6 +26,8 @@
import androidx.compose.foundation.lazy.LazyListPrefetchStrategy
import androidx.compose.foundation.lazy.LazyListState
import androidx.compose.foundation.lazy.layout.NestedPrefetchScope
+import androidx.compose.foundation.lazy.layout.PrefetchScheduler
+import androidx.compose.foundation.lazy.layout.TestPrefetchScheduler
import androidx.compose.runtime.Composable
import androidx.compose.runtime.DisposableEffect
import androidx.compose.runtime.remember
@@ -70,11 +72,19 @@
private val itemsSizePx = 30
private val itemsSizeDp = with(rule.density) { itemsSizePx.toDp() }
private val activeNodes = mutableSetOf<String>()
- private val activeMeasuredNodes = mutableSetOf<String>()
+ private val scheduler = TestPrefetchScheduler()
+
+ @OptIn(ExperimentalFoundationApi::class)
+ private val strategy = object : LazyListPrefetchStrategy by LazyListPrefetchStrategy() {
+ override val prefetchScheduler: PrefetchScheduler = scheduler
+ }
+
+ @OptIn(ExperimentalFoundationApi::class)
+ private fun createState(): LazyListState = LazyListState(prefetchStrategy = strategy)
@Test
fun nestedPrefetchingForwardAfterSmallScroll() {
- val state = LazyListState()
+ val state = createState()
composeList(state)
val prefetchIndex = 2
@@ -85,7 +95,7 @@
}
}
- waitForPrefetch(tagFor(prefetchIndex))
+ waitForPrefetch()
}
// We want to make sure nested children were precomposed before the parent was premeasured
@@ -111,7 +121,7 @@
@Test
fun cancelingPrefetchCancelsItsNestedPrefetches() {
- val state = LazyListState()
+ val state = createState()
composeList(state)
rule.runOnIdle {
@@ -122,7 +132,7 @@
}
}
- waitForPrefetch(tagFor(3))
+ waitForPrefetch()
rule.runOnIdle {
assertThat(activeNodes).contains(tagFor(3))
@@ -141,7 +151,7 @@
}
}
- waitForPrefetch(tagFor(7))
+ waitForPrefetch()
rule.runOnIdle {
runBlocking(AutoTestFrameClock()) {
@@ -160,7 +170,7 @@
@OptIn(ExperimentalFoundationApi::class)
@Test
fun overridingNestedPrefetchCountIsRespected() {
- val state = LazyListState()
+ val state = createState()
composeList(
state,
createNestedLazyListState = {
@@ -177,7 +187,7 @@
}
}
- waitForPrefetch(tagFor(prefetchIndex))
+ waitForPrefetch()
}
// Since the nested prefetch count on the strategy is 1, we only expect index 0 to be
@@ -197,7 +207,7 @@
fun nestedPrefetchIsMeasuredWithProvidedConstraints() {
val nestedConstraints =
Constraints(minWidth = 20, minHeight = 20, maxWidth = 20, maxHeight = 20)
- val state = LazyListState()
+ val state = createState()
composeList(
state,
createNestedLazyListState = {
@@ -214,7 +224,7 @@
}
}
- waitForPrefetch(tagFor(prefetchIndex))
+ waitForPrefetch()
}
assertThat(actions).containsExactly(
@@ -232,7 +242,7 @@
@Test
fun nestedPrefetchStartsFromFirstVisibleItemIndex() {
- val state = LazyListState()
+ val state = createState()
composeList(
state,
createNestedLazyListState = {
@@ -247,7 +257,7 @@
}
}
- waitForPrefetch(tagFor(prefetchIndex))
+ waitForPrefetch()
}
assertThat(actions).containsExactly(
@@ -273,9 +283,9 @@
}
}
- private fun waitForPrefetch(tag: String) {
- rule.waitUntil {
- activeNodes.contains(tag) && activeMeasuredNodes.contains(tag)
+ private fun waitForPrefetch() {
+ rule.runOnIdle {
+ scheduler.executeActiveRequests()
}
}
@@ -332,17 +342,14 @@
actions?.add(Action.Compose(index, nestedIndex))
onDispose {
activeNodes.remove(tag)
- activeMeasuredNodes.remove(tag)
}
}
}
private fun Modifier.trackWhenMeasured(index: Int, nestedIndex: Int? = null): Modifier {
- val tag = tagFor(index, nestedIndex)
return this then Modifier.layout { measurable, constraints ->
actions?.add(Action.Measure(index, nestedIndex))
val placeable = measurable.measure(constraints)
- activeMeasuredNodes.add(tag)
layout(placeable.width, placeable.height) {
placeable.place(0, 0)
}
diff --git a/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/list/LazyListPrefetchStrategyTest.kt b/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/list/LazyListPrefetchStrategyTest.kt
index 31dd332..0d773c2 100644
--- a/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/list/LazyListPrefetchStrategyTest.kt
+++ b/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/list/LazyListPrefetchStrategyTest.kt
@@ -29,9 +29,10 @@
import androidx.compose.foundation.lazy.LazyListState
import androidx.compose.foundation.lazy.layout.LazyLayoutPrefetchState
import androidx.compose.foundation.lazy.layout.NestedPrefetchScope
+import androidx.compose.foundation.lazy.layout.PrefetchScheduler
+import androidx.compose.foundation.lazy.layout.TestPrefetchScheduler
import androidx.compose.foundation.lazy.list.LazyListPrefetchStrategyTest.RecordingLazyListPrefetchStrategy.Callback
import androidx.compose.foundation.lazy.rememberLazyListState
-import androidx.compose.runtime.DisposableEffect
import androidx.compose.runtime.MutableState
import androidx.compose.runtime.mutableStateOf
import androidx.compose.ui.Modifier
@@ -74,10 +75,11 @@
private val itemsSizeDp = with(rule.density) { itemsSizePx.toDp() }
lateinit var state: LazyListState
+ private val scheduler = TestPrefetchScheduler()
@Test
fun callbacksTriggered_whenScrollForwardsWithoutVisibleItemsChanged() {
- val strategy = RecordingLazyListPrefetchStrategy()
+ val strategy = RecordingLazyListPrefetchStrategy(scheduler)
composeList(prefetchStrategy = strategy)
@@ -104,7 +106,7 @@
@Test
fun callbacksTriggered_whenScrollBackwardsWithoutVisibleItemsChanged() {
- val strategy = RecordingLazyListPrefetchStrategy()
+ val strategy = RecordingLazyListPrefetchStrategy(scheduler)
composeList(firstItem = 10, itemOffset = 10, prefetchStrategy = strategy)
@@ -131,7 +133,7 @@
@Test
fun callbacksTriggered_whenScrollWithVisibleItemsChanged() {
- val strategy = RecordingLazyListPrefetchStrategy()
+ val strategy = RecordingLazyListPrefetchStrategy(scheduler)
composeList(prefetchStrategy = strategy)
@@ -161,7 +163,7 @@
@Test
fun callbacksTriggered_whenItemsChangedWithoutScroll() {
- val strategy = RecordingLazyListPrefetchStrategy()
+ val strategy = RecordingLazyListPrefetchStrategy(scheduler)
val numItems = mutableStateOf(100)
composeList(prefetchStrategy = strategy, numItems = numItems)
@@ -196,20 +198,17 @@
}
}
- waitForPrefetch(2)
+ waitForPrefetch()
rule.onNodeWithTag("2")
.assertExists()
}
- private fun waitForPrefetch(index: Int) {
- rule.waitUntil {
- activeNodes.contains(index) && activeMeasuredNodes.contains(index)
+ private fun waitForPrefetch() {
+ rule.runOnIdle {
+ scheduler.executeActiveRequests()
}
}
- private val activeNodes = mutableSetOf<Int>()
- private val activeMeasuredNodes = mutableSetOf<Int>()
-
@OptIn(ExperimentalFoundationApi::class)
private fun composeList(
firstItem: Int = 0,
@@ -228,13 +227,6 @@
state,
) {
items(numItems.value) {
- DisposableEffect(it) {
- activeNodes.add(it)
- onDispose {
- activeNodes.remove(it)
- activeMeasuredNodes.remove(it)
- }
- }
Spacer(
Modifier
.mainAxisSize(itemsSizeDp)
@@ -242,7 +234,6 @@
.testTag("$it")
.layout { measurable, constraints ->
val placeable = measurable.measure(constraints)
- activeMeasuredNodes.add(it)
layout(placeable.width, placeable.height) {
placeable.place(0, 0)
}
@@ -256,7 +247,10 @@
/**
* LazyListPrefetchStrategy that just records callbacks without scheduling prefetches.
*/
- private class RecordingLazyListPrefetchStrategy : LazyListPrefetchStrategy {
+ private class RecordingLazyListPrefetchStrategy(
+ override val prefetchScheduler: PrefetchScheduler?
+ ) : LazyListPrefetchStrategy {
+
sealed interface Callback {
data class OnScroll(val delta: Float, val visibleIndices: List<Int>) : Callback
data class OnVisibleItemsUpdated(val visibleIndices: List<Int>) : Callback
diff --git a/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/list/LazyListPrefetcherTest.kt b/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/list/LazyListPrefetcherTest.kt
index 70a88d8..ef1aed5 100644
--- a/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/list/LazyListPrefetcherTest.kt
+++ b/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/list/LazyListPrefetcherTest.kt
@@ -22,7 +22,10 @@
import androidx.compose.foundation.gestures.scrollBy
import androidx.compose.foundation.layout.PaddingValues
import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.lazy.LazyListPrefetchStrategy
import androidx.compose.foundation.lazy.LazyListState
+import androidx.compose.foundation.lazy.layout.PrefetchScheduler
+import androidx.compose.foundation.lazy.layout.TestPrefetchScheduler
import androidx.compose.foundation.lazy.rememberLazyListState
import androidx.compose.runtime.DisposableEffect
import androidx.compose.ui.Modifier
@@ -71,6 +74,13 @@
lateinit var state: LazyListState
+ private val scheduler = TestPrefetchScheduler()
+
+ @OptIn(ExperimentalFoundationApi::class)
+ private val strategy = object : LazyListPrefetchStrategy by LazyListPrefetchStrategy() {
+ override val prefetchScheduler: PrefetchScheduler = scheduler
+ }
+
@Test
fun notPrefetchingForwardInitially() {
composeList()
@@ -97,7 +107,7 @@
}
}
- waitForPrefetch(preFetchIndex)
+ waitForPrefetch()
rule.onNodeWithTag("$preFetchIndex")
.assertExists()
@@ -115,7 +125,7 @@
}
}
- waitForPrefetch(1)
+ waitForPrefetch()
rule.onNodeWithTag("1")
.assertExists()
@@ -134,7 +144,7 @@
}
}
var prefetchIndex = initialIndex + 2
- waitForPrefetch(prefetchIndex)
+ waitForPrefetch()
rule.onNodeWithTag("$prefetchIndex")
.assertExists()
@@ -149,7 +159,7 @@
}
prefetchIndex -= 3
- waitForPrefetch(prefetchIndex)
+ waitForPrefetch()
rule.onNodeWithTag("$prefetchIndex")
.assertExists()
@@ -167,7 +177,7 @@
}
}
- waitForPrefetch(2)
+ waitForPrefetch()
rule.runOnIdle {
runBlocking {
@@ -178,7 +188,7 @@
val prefetchIndex = 3
- waitForPrefetch(prefetchIndex)
+ waitForPrefetch()
rule.onNodeWithTag("${prefetchIndex - 1}")
.assertIsDisplayed()
@@ -198,7 +208,7 @@
}
}
- waitForPrefetch(2)
+ waitForPrefetch()
rule.runOnIdle {
runBlocking {
@@ -207,7 +217,7 @@
}
}
- waitForPrefetch(1)
+ waitForPrefetch()
rule.onNodeWithTag("2")
.assertIsDisplayed()
@@ -230,7 +240,7 @@
var prefetchIndex = initialIndex + 2
- waitForPrefetch(prefetchIndex)
+ waitForPrefetch()
rule.onNodeWithTag("$prefetchIndex")
.assertExists()
@@ -245,7 +255,7 @@
}
prefetchIndex -= 3
- waitForPrefetch(prefetchIndex)
+ waitForPrefetch()
rule.onNodeWithTag("$prefetchIndex")
.assertExists()
@@ -281,7 +291,7 @@
}
var prefetchIndex = initialIndex + 1
- waitForPrefetch(prefetchIndex)
+ waitForPrefetch()
rule.onNodeWithTag("${prefetchIndex + 1}")
.assertExists()
@@ -295,7 +305,7 @@
}
prefetchIndex -= 3
- waitForPrefetch(prefetchIndex)
+ waitForPrefetch()
rule.onNodeWithTag("$prefetchIndex")
.assertExists()
@@ -458,7 +468,7 @@
}
}
- waitForPrefetch(7)
+ waitForPrefetch()
rule.runOnIdle {
runBlocking(AutoTestFrameClock()) {
@@ -472,14 +482,13 @@
}
}
- private fun waitForPrefetch(index: Int) {
- rule.waitUntil {
- activeNodes.contains(index) && activeMeasuredNodes.contains(index)
+ private fun waitForPrefetch() {
+ rule.runOnIdle {
+ scheduler.executeActiveRequests()
}
}
private val activeNodes = mutableSetOf<Int>()
- private val activeMeasuredNodes = mutableSetOf<Int>()
private fun composeList(
firstItem: Int = 0,
@@ -488,9 +497,11 @@
contentPadding: PaddingValues = PaddingValues(0.dp)
) {
rule.setContent {
+ @OptIn(ExperimentalFoundationApi::class)
state = rememberLazyListState(
initialFirstVisibleItemIndex = firstItem,
- initialFirstVisibleItemScrollOffset = itemOffset
+ initialFirstVisibleItemScrollOffset = itemOffset,
+ prefetchStrategy = strategy
)
LazyColumnOrRow(
Modifier.mainAxisSize(itemsSizeDp * 1.5f),
@@ -504,7 +515,6 @@
activeNodes.add(it)
onDispose {
activeNodes.remove(it)
- activeMeasuredNodes.remove(it)
}
}
Spacer(
@@ -514,7 +524,6 @@
.testTag("$it")
.layout { measurable, constraints ->
val placeable = measurable.measure(constraints)
- activeMeasuredNodes.add(it)
layout(placeable.width, placeable.height) {
placeable.place(0, 0)
}
diff --git a/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/staggeredgrid/LazyStaggeredGridPrefetcherTest.kt b/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/staggeredgrid/LazyStaggeredGridPrefetcherTest.kt
index 224a1cc..72084b7 100644
--- a/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/staggeredgrid/LazyStaggeredGridPrefetcherTest.kt
+++ b/compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/staggeredgrid/LazyStaggeredGridPrefetcherTest.kt
@@ -14,6 +14,8 @@
* limitations under the License.
*/
+@file:Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE")
+
package androidx.compose.foundation.lazy.staggeredgrid
import androidx.compose.foundation.AutoTestFrameClock
@@ -22,7 +24,10 @@
import androidx.compose.foundation.gestures.Orientation
import androidx.compose.foundation.gestures.scrollBy
import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.lazy.layout.TestPrefetchScheduler
+import androidx.compose.runtime.Composable
import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.remember
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.layout.Remeasurement
@@ -63,6 +68,20 @@
val itemsSizeDp = with(rule.density) { itemsSizePx.toDp() }
internal lateinit var state: LazyStaggeredGridState
+ private val scheduler = TestPrefetchScheduler()
+
+ @OptIn(ExperimentalFoundationApi::class)
+ @Composable
+ fun rememberState(
+ initialFirstVisibleItemIndex: Int = 0,
+ initialFirstVisibleItemOffset: Int = 0
+ ): LazyStaggeredGridState = remember {
+ LazyStaggeredGridState(
+ intArrayOf(initialFirstVisibleItemIndex),
+ intArrayOf(initialFirstVisibleItemOffset),
+ scheduler
+ )
+ }
@Test
fun notPrefetchingForwardInitially() {
@@ -90,7 +109,7 @@
}
}
- waitForPrefetch(5)
+ waitForPrefetch()
rule.onNodeWithTag("4")
.assertExists()
@@ -110,7 +129,7 @@
}
}
- waitForPrefetch(2)
+ waitForPrefetch()
rule.onNodeWithTag("2")
.assertExists()
@@ -130,7 +149,7 @@
}
}
- waitForPrefetch(9)
+ waitForPrefetch()
rule.onNodeWithTag("8")
.assertExists()
@@ -145,7 +164,7 @@
}
}
- waitForPrefetch(2)
+ waitForPrefetch()
rule.onNodeWithTag("2")
.assertExists()
@@ -165,7 +184,7 @@
}
}
- waitForPrefetch(4)
+ waitForPrefetch()
rule.runOnIdle {
runBlocking {
@@ -174,7 +193,7 @@
}
}
- waitForPrefetch(6)
+ waitForPrefetch()
rule.onNodeWithTag("4")
.assertIsDisplayed()
@@ -194,7 +213,7 @@
}
}
- waitForPrefetch(4)
+ waitForPrefetch()
rule.runOnIdle {
runBlocking {
@@ -203,7 +222,7 @@
}
}
- waitForPrefetch(2)
+ waitForPrefetch()
rule.onNodeWithTag("4")
.assertIsDisplayed()
@@ -226,7 +245,7 @@
}
}
- waitForPrefetch(13)
+ waitForPrefetch()
rule.onNodeWithTag("12")
.assertExists()
@@ -378,7 +397,7 @@
fun snappingToOtherPositionWhilePrefetchIsScheduled() {
val composedItems = mutableListOf<Int>()
rule.setContent {
- state = rememberLazyStaggeredGridState()
+ state = rememberState()
LazyStaggeredGrid(
1,
Modifier.mainAxisSize(itemsSizeDp * 1.5f),
@@ -433,7 +452,7 @@
}
}
- waitForPrefetch(13)
+ waitForPrefetch()
rule.runOnIdle {
runBlocking(AutoTestFrameClock()) {
@@ -450,7 +469,7 @@
@Test
fun scrollingWithStaggeredItemsPrefetchesCorrectly() {
rule.setContent {
- state = rememberLazyStaggeredGridState()
+ state = rememberState()
LazyStaggeredGrid(
2,
Modifier.mainAxisSize(itemsSizeDp * 5f),
@@ -461,7 +480,6 @@
activeNodes.add(it)
onDispose {
activeNodes.remove(it)
- activeMeasuredNodes.remove(it)
}
}
Spacer(
@@ -471,7 +489,6 @@
.testTag("$it")
.layout { measurable, constraints ->
val placeable = measurable.measure(constraints)
- activeMeasuredNodes.add(it)
layout(placeable.width, placeable.height) {
placeable.place(0, 0)
}
@@ -495,8 +512,8 @@
}
}
- waitForPrefetch(7)
- waitForPrefetch(8)
+ waitForPrefetch()
+ waitForPrefetch()
// ┌─┬─┐
// │2├─┤
@@ -520,14 +537,14 @@
// │6├─┤
// └─┴─┘
- waitForPrefetch(9)
+ waitForPrefetch()
}
@Test
fun fullSpanIsPrefetchedCorrectly() {
val nodeConstraints = mutableMapOf<Int, Constraints>()
rule.setContent {
- state = rememberLazyStaggeredGridState()
+ state = rememberState()
LazyStaggeredGrid(
2,
Modifier.mainAxisSize(itemsSizeDp * 5f).crossAxisSize(itemsSizeDp * 2f),
@@ -546,7 +563,6 @@
activeNodes.add(it)
onDispose {
activeNodes.remove(it)
- activeMeasuredNodes.remove(it)
}
}
Spacer(
@@ -555,7 +571,6 @@
.testTag("$it")
.layout { measurable, constraints ->
val placeable = measurable.measure(constraints)
- activeMeasuredNodes.add(it)
nodeConstraints.put(it, constraints)
layout(placeable.width, placeable.height) {
placeable.place(0, 0)
@@ -577,7 +592,7 @@
state.scrollBy(itemsSizeDp * 5f)
assertThat(activeNodes).contains(9)
- waitForPrefetch(10)
+ waitForPrefetch()
val expectedConstraints = if (vertical) {
Constraints.fixedWidth(itemsSizePx * 2)
} else {
@@ -589,7 +604,7 @@
@Test
fun fullSpanIsPrefetchedCorrectly_scrollingBack() {
rule.setContent {
- state = rememberLazyStaggeredGridState()
+ state = rememberState()
LazyStaggeredGrid(
2,
Modifier.mainAxisSize(itemsSizeDp * 5f),
@@ -608,7 +623,6 @@
activeNodes.add(it)
onDispose {
activeNodes.remove(it)
- activeMeasuredNodes.remove(it)
}
}
Spacer(
@@ -618,7 +632,6 @@
.testTag("$it")
.layout { measurable, constraints ->
val placeable = measurable.measure(constraints)
- activeMeasuredNodes.add(it)
layout(placeable.width, placeable.height) {
placeable.place(0, 0)
}
@@ -647,27 +660,26 @@
state.scrollBy(-1.dp)
- waitForPrefetch(10)
+ waitForPrefetch()
}
- private fun waitForPrefetch(index: Int) {
- rule.waitUntil {
- activeNodes.contains(index) && activeMeasuredNodes.contains(index)
+ private fun waitForPrefetch() {
+ rule.runOnIdle {
+ scheduler.executeActiveRequests()
}
}
private val activeNodes = mutableSetOf<Int>()
- private val activeMeasuredNodes = mutableSetOf<Int>()
private fun composeStaggeredGrid(
firstItem: Int = 0,
itemOffset: Int = 0,
) {
- state = LazyStaggeredGridState(
- initialFirstVisibleItemIndex = firstItem,
- initialFirstVisibleItemOffset = itemOffset
- )
rule.setContent {
+ state = rememberState(
+ initialFirstVisibleItemIndex = firstItem,
+ initialFirstVisibleItemOffset = itemOffset
+ )
LazyStaggeredGrid(
2,
Modifier.mainAxisSize(itemsSizeDp * 1.5f),
@@ -678,7 +690,6 @@
activeNodes.add(it)
onDispose {
activeNodes.remove(it)
- activeMeasuredNodes.remove(it)
}
}
Spacer(
@@ -688,7 +699,6 @@
.testTag("$it")
.layout { measurable, constraints ->
val placeable = measurable.measure(constraints)
- activeMeasuredNodes.add(it)
layout(placeable.width, placeable.height) {
placeable.place(0, 0)
}
diff --git a/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/pager/BasePagerTest.kt b/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/pager/BasePagerTest.kt
index bf5658f..dd8c1ce 100644
--- a/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/pager/BasePagerTest.kt
+++ b/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/pager/BasePagerTest.kt
@@ -30,9 +30,11 @@
import androidx.compose.foundation.layout.fillMaxHeight
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.lazy.layout.PrefetchScheduler
import androidx.compose.foundation.text.BasicText
import androidx.compose.runtime.Composable
import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.runtime.remember
import androidx.compose.runtime.rememberCoroutineScope
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
@@ -131,13 +133,21 @@
key: ((index: Int) -> Any)? = null,
snapPosition: SnapPosition = config.snapPosition.first,
flingBehavior: TargetedFlingBehavior? = null,
+ prefetchScheduler: PrefetchScheduler? = null,
pageContent: @Composable PagerScope.(page: Int) -> Unit = { Page(index = it) }
) {
rule.setContent {
- val state = rememberPagerState(initialPage, initialPageOffsetFraction, pageCount).also {
- pagerState = it
+ val state = if (prefetchScheduler == null) {
+ rememberPagerState(initialPage, initialPageOffsetFraction, pageCount)
+ } else {
+ remember {
+ object : PagerState(initialPage, initialPageOffsetFraction, prefetchScheduler) {
+ override val pageCount: Int get() = pageCount()
+ }
+ }
}
+ pagerState = state
composeView = LocalView.current
focusManager = LocalFocusManager.current
CompositionLocalProvider(
diff --git a/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/pager/PagerAccessibilityTest.kt b/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/pager/PagerAccessibilityTest.kt
index d72d1e3..19d6748 100644
--- a/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/pager/PagerAccessibilityTest.kt
+++ b/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/pager/PagerAccessibilityTest.kt
@@ -17,6 +17,7 @@
package androidx.compose.foundation.pager
import android.view.accessibility.AccessibilityNodeProvider
+import androidx.compose.foundation.ExperimentalFoundationApi
import androidx.compose.foundation.focusable
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.fillMaxSize
@@ -41,6 +42,7 @@
import org.junit.runner.RunWith
import org.junit.runners.Parameterized
+@OptIn(ExperimentalFoundationApi::class)
@RunWith(Parameterized::class)
class PagerAccessibilityTest(config: ParamConfig) : BasePagerTest(config = config) {
diff --git a/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/pager/PagerPrefetcherTest.kt b/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/pager/PagerPrefetcherTest.kt
index 1f9cc0b..f9414d3 100644
--- a/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/pager/PagerPrefetcherTest.kt
+++ b/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/pager/PagerPrefetcherTest.kt
@@ -56,6 +56,7 @@
var pageSizePx = 300
val pageSizeDp = with(rule.density) { pageSizePx.toDp() }
var touchSlope: Float = 0.0f
+ private val scheduler = TestPrefetchScheduler()
@Test
fun notPrefetchingForwardInitially() {
@@ -83,7 +84,7 @@
}
}
- waitForPrefetch(preFetchIndex)
+ waitForPrefetch()
rule.onNodeWithTag("$preFetchIndex")
.assertExists()
@@ -102,7 +103,7 @@
}
}
- waitForPrefetch(preFetchIndex)
+ waitForPrefetch()
rule.onNodeWithTag("$preFetchIndex")
.assertExists()
@@ -126,7 +127,7 @@
up()
}
- waitForPrefetch(preFetchIndex)
+ waitForPrefetch()
rule.onNodeWithTag("$preFetchIndex")
.assertExists()
@@ -151,7 +152,7 @@
up()
}
- waitForPrefetch(preFetchIndex)
+ waitForPrefetch()
rule.onNodeWithTag("$preFetchIndex")
.assertExists()
@@ -170,7 +171,7 @@
}
}
var prefetchIndex = initialIndex + 2
- waitForPrefetch(prefetchIndex)
+ waitForPrefetch()
rule.onNodeWithTag("$prefetchIndex")
.assertExists()
@@ -185,7 +186,7 @@
}
prefetchIndex -= 3
- waitForPrefetch(prefetchIndex)
+ waitForPrefetch()
rule.onNodeWithTag("$prefetchIndex")
.assertExists()
@@ -203,7 +204,7 @@
}
}
- waitForPrefetch(2)
+ waitForPrefetch()
rule.runOnIdle {
runBlocking {
@@ -214,7 +215,7 @@
val prefetchIndex = 3
- waitForPrefetch(prefetchIndex)
+ waitForPrefetch()
rule.onNodeWithTag("${prefetchIndex - 1}")
.assertIsDisplayed()
@@ -236,7 +237,7 @@
}
}
- waitForPrefetch(preFetchIndex)
+ waitForPrefetch()
rule.runOnIdle {
runBlocking {
@@ -245,7 +246,7 @@
}
}
- waitForPrefetch(preFetchIndex - 1)
+ waitForPrefetch()
rule.onNodeWithTag("$preFetchIndex")
.assertIsDisplayed()
@@ -268,7 +269,7 @@
var prefetchIndex = initialIndex + 2
- waitForPrefetch(prefetchIndex)
+ waitForPrefetch()
rule.onNodeWithTag("$prefetchIndex")
.assertExists()
@@ -283,7 +284,7 @@
}
prefetchIndex -= 3
- waitForPrefetch(prefetchIndex)
+ waitForPrefetch()
rule.onNodeWithTag("$prefetchIndex")
.assertExists()
@@ -319,7 +320,7 @@
}
var prefetchIndex = initialIndex + 1
- waitForPrefetch(prefetchIndex)
+ waitForPrefetch()
rule.onNodeWithTag("${prefetchIndex + 1}")
.assertExists()
@@ -333,7 +334,7 @@
}
prefetchIndex -= 3
- waitForPrefetch(prefetchIndex)
+ waitForPrefetch()
rule.onNodeWithTag("$prefetchIndex")
.assertExists()
@@ -457,7 +458,7 @@
}
}
- waitForPrefetch(7)
+ waitForPrefetch()
rule.runOnIdle {
runBlocking(AutoTestFrameClock()) {
@@ -477,14 +478,13 @@
return consumed
}
- private fun waitForPrefetch(index: Int) {
- rule.waitUntil {
- activeNodes.contains(index) && activeMeasuredNodes.contains(index)
+ private fun waitForPrefetch() {
+ rule.runOnIdle {
+ scheduler.executeActiveRequests()
}
}
private val activeNodes = mutableSetOf<Int>()
- private val activeMeasuredNodes = mutableSetOf<Int>()
private fun composePager(
initialPage: Int = 0,
@@ -499,6 +499,7 @@
beyondViewportPageCount = paramConfig.beyondViewportPageCount,
initialPage = initialPage,
initialPageOffsetFraction = initialPageOffsetFraction,
+ prefetchScheduler = scheduler,
pageCount = { 100 },
pageSize = {
object : PageSize {
@@ -516,7 +517,6 @@
activeNodes.add(it)
onDispose {
activeNodes.remove(it)
- activeMeasuredNodes.remove(it)
}
}
@@ -527,7 +527,6 @@
.testTag("$it")
.layout { measurable, constraints ->
val placeable = measurable.measure(constraints)
- activeMeasuredNodes.add(it)
layout(placeable.width, placeable.height) {
placeable.place(0, 0)
}
diff --git a/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/pager/TestPrefetchScheduler.kt b/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/pager/TestPrefetchScheduler.kt
new file mode 100644
index 0000000..04c60b750
--- /dev/null
+++ b/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/pager/TestPrefetchScheduler.kt
@@ -0,0 +1,42 @@
+/*
+ * Copyright 2024 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.pager
+
+import androidx.compose.foundation.ExperimentalFoundationApi
+import androidx.compose.foundation.lazy.layout.PrefetchRequest
+import androidx.compose.foundation.lazy.layout.PrefetchRequestScope
+import androidx.compose.foundation.lazy.layout.PrefetchScheduler
+
+@OptIn(ExperimentalFoundationApi::class)
+internal class TestPrefetchScheduler : PrefetchScheduler {
+
+ private var activeRequests = mutableListOf<PrefetchRequest>()
+ override fun schedulePrefetch(prefetchRequest: PrefetchRequest) {
+ activeRequests.add(prefetchRequest)
+ }
+
+ fun executeActiveRequests() {
+ activeRequests.forEach {
+ with(it) { scope.execute() }
+ }
+ activeRequests.clear()
+ }
+
+ private val scope = object : PrefetchRequestScope {
+ override fun availableTimeNanos(): Long = Long.MAX_VALUE
+ }
+}
diff --git a/compose/foundation/foundation/src/androidMain/kotlin/androidx/compose/foundation/lazy/layout/PrefetchScheduler.android.kt b/compose/foundation/foundation/src/androidMain/kotlin/androidx/compose/foundation/lazy/layout/PrefetchScheduler.android.kt
index 54abefd..fd93543 100644
--- a/compose/foundation/foundation/src/androidMain/kotlin/androidx/compose/foundation/lazy/layout/PrefetchScheduler.android.kt
+++ b/compose/foundation/foundation/src/androidMain/kotlin/androidx/compose/foundation/lazy/layout/PrefetchScheduler.android.kt
@@ -126,16 +126,19 @@
}
val latestFrameVsyncNs = TimeUnit.MILLISECONDS.toNanos(view.drawingTime)
val nextFrameNs = latestFrameVsyncNs + frameIntervalNs
- val oneOverTimeTaskAllowed = System.nanoTime() > nextFrameNs
- val scope = PrefetchRequestScopeImpl(nextFrameNs, oneOverTimeTaskAllowed)
+ val scope = PrefetchRequestScopeImpl(nextFrameNs)
var scheduleForNextFrame = false
while (prefetchRequests.isNotEmpty() && !scheduleForNextFrame) {
- val request = prefetchRequests[0]
- val hasMoreWorkToDo = with(request) { scope.execute() }
- if (hasMoreWorkToDo) {
- scheduleForNextFrame = true
+ if (scope.availableTimeNanos() > 0) {
+ val request = prefetchRequests[0]
+ val hasMoreWorkToDo = with(request) { scope.execute() }
+ if (hasMoreWorkToDo) {
+ scheduleForNextFrame = true
+ } else {
+ prefetchRequests.removeAt(0)
+ }
} else {
- prefetchRequests.removeAt(0)
+ scheduleForNextFrame = true
}
}
@@ -182,24 +185,10 @@
class PrefetchRequestScopeImpl(
private val nextFrameTimeNs: Long,
- isOneOverTimeTaskAllowed: Boolean
) : PrefetchRequestScope {
- private var canDoOverTimeTask = isOneOverTimeTaskAllowed
-
- override val availableTimeNanos: Long
- get() {
- // This logic is meant to be temporary until we replace the isOneOverTimeTaskAllowed
- // logic with something more general. For now, we assume that a PrefetchRequest
- // impl will check availableTimeNanos once per task and we give it a large amount
- // of time the first time it checks if we allow an overtime task.
- return if (canDoOverTimeTask) {
- canDoOverTimeTask = false
- Long.MAX_VALUE
- } else {
- max(0, nextFrameTimeNs - System.nanoTime())
- }
- }
+ override fun availableTimeNanos() =
+ max(0, nextFrameTimeNs - System.nanoTime())
}
companion object {
diff --git a/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/LazyListPrefetchStrategy.kt b/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/LazyListPrefetchStrategy.kt
index dc29f8c..83840e9 100644
--- a/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/LazyListPrefetchStrategy.kt
+++ b/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/LazyListPrefetchStrategy.kt
@@ -147,21 +147,38 @@
} else {
layoutInfo.visibleItemsInfo.first().index - 1
}
- if (indexToPrefetch != [email protected] &&
- indexToPrefetch in 0 until layoutInfo.totalItemsCount
- ) {
- if (wasScrollingForward != scrollingForward) {
- // the scrolling direction has been changed which means the last prefetched
- // is not going to be reached anytime soon so it is safer to dispose it.
- // if this item is already visible it is safe to call the method anyway
- // as it will be no-op
- currentPrefetchHandle?.cancel()
+ if (indexToPrefetch in 0 until layoutInfo.totalItemsCount) {
+ if (indexToPrefetch != [email protected]) {
+ if (wasScrollingForward != scrollingForward) {
+ // the scrolling direction has been changed which means the last prefetched
+ // is not going to be reached anytime soon so it is safer to dispose it.
+ // if this item is already visible it is safe to call the method anyway
+ // as it will be no-op
+ currentPrefetchHandle?.cancel()
+ }
+ [email protected] = scrollingForward
+ [email protected] = indexToPrefetch
+ currentPrefetchHandle = schedulePrefetch(
+ indexToPrefetch
+ )
}
- [email protected] = scrollingForward
- [email protected] = indexToPrefetch
- currentPrefetchHandle = schedulePrefetch(
- indexToPrefetch
- )
+ if (scrollingForward) {
+ val lastItem = layoutInfo.visibleItemsInfo.last()
+ val spacing = layoutInfo.mainAxisItemSpacing
+ val distanceToPrefetchItem =
+ lastItem.offset + lastItem.size + spacing - layoutInfo.viewportEndOffset
+ // if in the next frame we will get the same delta will we reach the item?
+ if (distanceToPrefetchItem < -delta) {
+ currentPrefetchHandle?.markAsUrgent()
+ }
+ } else {
+ val firstItem = layoutInfo.visibleItemsInfo.first()
+ val distanceToPrefetchItem = layoutInfo.viewportStartOffset - firstItem.offset
+ // if in the next frame we will get the same delta will we reach the item?
+ if (distanceToPrefetchItem < delta) {
+ currentPrefetchHandle?.markAsUrgent()
+ }
+ }
}
}
}
diff --git a/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/grid/LazyGridState.kt b/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/grid/LazyGridState.kt
index ab042b2..d12d075 100644
--- a/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/grid/LazyGridState.kt
+++ b/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/grid/LazyGridState.kt
@@ -22,6 +22,7 @@
import androidx.compose.foundation.gestures.Orientation
import androidx.compose.foundation.gestures.ScrollScope
import androidx.compose.foundation.gestures.ScrollableState
+import androidx.compose.foundation.gestures.snapping.offsetOnMainAxis
import androidx.compose.foundation.gestures.stopScroll
import androidx.compose.foundation.interaction.InteractionSource
import androidx.compose.foundation.interaction.MutableInteractionSource
@@ -31,6 +32,7 @@
import androidx.compose.foundation.lazy.layout.LazyLayoutPinnedItemList
import androidx.compose.foundation.lazy.layout.LazyLayoutPrefetchState
import androidx.compose.foundation.lazy.layout.ObservableScopeInvalidator
+import androidx.compose.foundation.lazy.layout.PrefetchScheduler
import androidx.compose.foundation.lazy.layout.animateScrollToItem
import androidx.compose.runtime.Composable
import androidx.compose.runtime.Stable
@@ -81,19 +83,26 @@
* A state object that can be hoisted to control and observe scrolling.
*
* In most cases, this will be created via [rememberLazyGridState].
- *
- * @param firstVisibleItemIndex the initial value for [LazyGridState.firstVisibleItemIndex]
- * @param firstVisibleItemScrollOffset the initial value for
- * [LazyGridState.firstVisibleItemScrollOffset]
*/
@OptIn(ExperimentalFoundationApi::class)
@Stable
-class LazyGridState constructor(
+class LazyGridState internal constructor(
firstVisibleItemIndex: Int = 0,
- firstVisibleItemScrollOffset: Int = 0
+ firstVisibleItemScrollOffset: Int = 0,
+ prefetchScheduler: PrefetchScheduler?,
) : ScrollableState {
/**
+ * @param firstVisibleItemIndex the initial value for [LazyGridState.firstVisibleItemIndex]
+ * @param firstVisibleItemScrollOffset the initial value for
+ * [LazyGridState.firstVisibleItemScrollOffset]
+ */
+ constructor(
+ firstVisibleItemIndex: Int = 0,
+ firstVisibleItemScrollOffset: Int = 0
+ ) : this(firstVisibleItemIndex, firstVisibleItemScrollOffset, null)
+
+ /**
* The holder class for the current scroll position.
*/
private val scrollPosition =
@@ -413,23 +422,40 @@
}
closestNextItemToPrefetch = info.visibleItemsInfo.first().index - 1
}
- if (lineToPrefetch != this.lineToPrefetch &&
- closestNextItemToPrefetch in 0 until info.totalItemsCount
- ) {
- if (wasScrollingForward != scrollingForward) {
- // the scrolling direction has been changed which means the last prefetched
- // is not going to be reached anytime soon so it is safer to dispose it.
- // if this line is already visible it is safe to call the method anyway
- // as it will be no-op
- currentLinePrefetchHandles.forEach { it.cancel() }
+ if (closestNextItemToPrefetch in 0 until info.totalItemsCount) {
+ if (lineToPrefetch != this.lineToPrefetch) {
+ if (wasScrollingForward != scrollingForward) {
+ // the scrolling direction has been changed which means the last prefetched
+ // is not going to be reached anytime soon so it is safer to dispose it.
+ // if this line is already visible it is safe to call the method anyway
+ // as it will be no-op
+ currentLinePrefetchHandles.forEach { it.cancel() }
+ }
+ this.wasScrollingForward = scrollingForward
+ this.lineToPrefetch = lineToPrefetch
+ currentLinePrefetchHandles.clear()
+ info.prefetchInfoRetriever(lineToPrefetch).fastForEach {
+ currentLinePrefetchHandles.add(
+ prefetchState.schedulePrefetch(it.first, it.second)
+ )
+ }
}
- this.wasScrollingForward = scrollingForward
- this.lineToPrefetch = lineToPrefetch
- currentLinePrefetchHandles.clear()
- info.prefetchInfoRetriever(lineToPrefetch).fastForEach {
- currentLinePrefetchHandles.add(
- prefetchState.schedulePrefetch(it.first, it.second)
- )
+ if (scrollingForward) {
+ val lastItem = info.visibleItemsInfo.last()
+ val distanceToPrefetchItem = lastItem.offsetOnMainAxis(info.orientation) +
+ lastItem.mainAxisSizeWithSpacings - info.viewportEndOffset
+ // if in the next frame we will get the same delta will we reach the item?
+ if (distanceToPrefetchItem < -delta) {
+ currentLinePrefetchHandles.forEach { it.markAsUrgent() }
+ }
+ } else {
+ val firstItem = info.visibleItemsInfo.first()
+ val distanceToPrefetchItem = info.viewportStartOffset -
+ firstItem.offsetOnMainAxis(info.orientation)
+ // if in the next frame we will get the same delta will we reach the item?
+ if (distanceToPrefetchItem < delta) {
+ currentLinePrefetchHandles.forEach { it.markAsUrgent() }
+ }
}
}
}
@@ -454,7 +480,7 @@
}
}
- internal val prefetchState = LazyLayoutPrefetchState()
+ internal val prefetchState = LazyLayoutPrefetchState(prefetchScheduler)
private val numOfItemsToTeleport: Int get() = 100 * slotsPerLine
diff --git a/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/layout/LazyLayoutPrefetchState.kt b/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/layout/LazyLayoutPrefetchState.kt
index 11c2a13..20d6ca5 100644
--- a/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/layout/LazyLayoutPrefetchState.kt
+++ b/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/layout/LazyLayoutPrefetchState.kt
@@ -79,6 +79,15 @@
* was precomposed already it will be disposed.
*/
fun cancel()
+
+ /**
+ * Marks this prefetch request as urgent, which is a way to communicate that the requested
+ * item is expected to be needed during the next frame.
+ *
+ * For urgent requests we can proceed with doing the prefetch even if the available time
+ * in the frame is less than we spend on similar prefetch requests on average.
+ */
+ fun markAsUrgent()
}
private inner class NestedPrefetchScopeImpl : NestedPrefetchScope {
@@ -169,6 +178,7 @@
@ExperimentalFoundationApi
private object DummyHandle : PrefetchHandle {
override fun cancel() {}
+ override fun markAsUrgent() {}
}
/**
@@ -212,6 +222,7 @@
private val isComposed get() = precomposeHandle != null
private var hasResolvedNestedPrefetches = false
private var nestedPrefetchController: NestedPrefetchController? = null
+ private var isUrgent = false
private val isValid
get() = !isCanceled &&
@@ -225,13 +236,24 @@
}
}
+ override fun markAsUrgent() {
+ isUrgent = true
+ }
+
+ private fun PrefetchRequestScope.shouldExecute(average: Long): Boolean {
+ val available = availableTimeNanos()
+ // even for urgent request we only do the work if we have time available, as otherwise
+ // it is better to just return early to allow the next frame to start and do the work.
+ return (isUrgent && available > 0) || average < available
+ }
+
override fun PrefetchRequestScope.execute(): Boolean {
if (!isValid) {
return false
}
if (!isComposed) {
- if (prefetchMetrics.averageCompositionTimeNanos < availableTimeNanos) {
+ if (shouldExecute(prefetchMetrics.averageCompositionTimeNanos)) {
prefetchMetrics.recordCompositionTiming {
trace("compose:lazy:prefetch:compose") {
performComposition()
@@ -242,27 +264,35 @@
}
}
- // Nested prefetch logic is best-effort: if nested LazyLayout children are
- // added/removed/updated after we've resolved nested prefetch states here or resolved
- // nestedPrefetchRequests below, those changes won't be taken into account.
- if (!hasResolvedNestedPrefetches) {
- if (availableTimeNanos > 0) {
- trace("compose:lazy:prefetch:resolve-nested") {
- nestedPrefetchController = resolveNestedPrefetchStates()
- hasResolvedNestedPrefetches = true
+ // if the request is urgent we better proceed with the measuring straight away instead
+ // of spending time trying to split the work more via nested prefetch. nested prefetch
+ // is always an estimation and it could potentially do work we will not need in the end,
+ // but the measuring will only do exactly the needed work (including composing nested
+ // lazy layouts)
+ if (!isUrgent) {
+ // Nested prefetch logic is best-effort: if nested LazyLayout children are
+ // added/removed/updated after we've resolved nested prefetch states here or resolved
+ // nestedPrefetchRequests below, those changes won't be taken into account.
+ if (!hasResolvedNestedPrefetches) {
+ if (availableTimeNanos() > 0) {
+ trace("compose:lazy:prefetch:resolve-nested") {
+ nestedPrefetchController = resolveNestedPrefetchStates()
+ hasResolvedNestedPrefetches = true
+ }
+ } else {
+ return true
}
- } else {
+ }
+
+ val hasMoreWork =
+ nestedPrefetchController?.run { executeNestedPrefetches() } ?: false
+ if (hasMoreWork) {
return true
}
}
- val hasMoreWork = nestedPrefetchController?.run { executeNestedPrefetches() } ?: false
- if (hasMoreWork) {
- return true
- }
-
if (!isMeasured && constraints != null) {
- if (prefetchMetrics.averageMeasureTimeNanos < availableTimeNanos) {
+ if (shouldExecute(prefetchMetrics.averageMeasureTimeNanos)) {
prefetchMetrics.recordMeasureTiming {
trace("compose:lazy:prefetch:measure") {
performMeasure(constraints)
@@ -349,7 +379,7 @@
trace("compose:lazy:prefetch:nested") {
while (stateIndex < states.size) {
if (requestsByState[stateIndex] == null) {
- if (availableTimeNanos <= 0) {
+ if (availableTimeNanos() <= 0) {
// When we have time again, we'll resolve nested requests for this
// state
return true
diff --git a/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/layout/PrefetchScheduler.kt b/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/layout/PrefetchScheduler.kt
index d3497f8..131eb4f 100644
--- a/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/layout/PrefetchScheduler.kt
+++ b/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/layout/PrefetchScheduler.kt
@@ -75,5 +75,5 @@
* How much time is available to do prefetch work. Implementations of [PrefetchRequest] should
* do their best to fit their work into this time without going over.
*/
- val availableTimeNanos: Long
+ fun availableTimeNanos(): Long
}
diff --git a/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/staggeredgrid/LazyStaggeredGridState.kt b/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/staggeredgrid/LazyStaggeredGridState.kt
index 09cb286..3a15ecb 100644
--- a/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/staggeredgrid/LazyStaggeredGridState.kt
+++ b/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/staggeredgrid/LazyStaggeredGridState.kt
@@ -34,6 +34,7 @@
import androidx.compose.foundation.lazy.layout.LazyLayoutPrefetchState
import androidx.compose.foundation.lazy.layout.LazyLayoutPrefetchState.PrefetchHandle
import androidx.compose.foundation.lazy.layout.ObservableScopeInvalidator
+import androidx.compose.foundation.lazy.layout.PrefetchScheduler
import androidx.compose.foundation.lazy.layout.animateScrollToItem
import androidx.compose.foundation.lazy.staggeredgrid.LazyStaggeredGridLaneInfo.Companion.FullSpan
import androidx.compose.foundation.lazy.staggeredgrid.LazyStaggeredGridLaneInfo.Companion.Unset
@@ -82,9 +83,10 @@
* In most cases, it should be created via [rememberLazyStaggeredGridState].
*/
@OptIn(ExperimentalFoundationApi::class)
-class LazyStaggeredGridState private constructor(
+class LazyStaggeredGridState internal constructor(
initialFirstVisibleItems: IntArray,
initialFirstVisibleOffsets: IntArray,
+ prefetchScheduler: PrefetchScheduler?
) : ScrollableState {
/**
* @param initialFirstVisibleItemIndex initial value for [firstVisibleItemIndex]
@@ -95,7 +97,8 @@
initialFirstVisibleItemOffset: Int = 0
) : this(
intArrayOf(initialFirstVisibleItemIndex),
- intArrayOf(initialFirstVisibleItemOffset)
+ intArrayOf(initialFirstVisibleItemOffset),
+ null
)
/**
@@ -178,7 +181,7 @@
internal var prefetchingEnabled: Boolean = true
/** prefetch state used for precomputing items in the direction of scroll */
- internal val prefetchState: LazyLayoutPrefetchState = LazyLayoutPrefetchState()
+ internal val prefetchState: LazyLayoutPrefetchState = LazyLayoutPrefetchState(prefetchScheduler)
/** state controlling the scroll */
private val scrollableState = ScrollableState { -onScroll(-it) }
@@ -584,7 +587,7 @@
)
},
restore = {
- LazyStaggeredGridState(it[0], it[1])
+ LazyStaggeredGridState(it[0], it[1], null)
}
)
}
diff --git a/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/pager/PagerState.kt b/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/pager/PagerState.kt
index edf220c..a4310c5 100644
--- a/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/pager/PagerState.kt
+++ b/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/pager/PagerState.kt
@@ -36,6 +36,7 @@
import androidx.compose.foundation.lazy.layout.LazyLayoutPinnedItemList
import androidx.compose.foundation.lazy.layout.LazyLayoutPrefetchState
import androidx.compose.foundation.lazy.layout.ObservableScopeInvalidator
+import androidx.compose.foundation.lazy.layout.PrefetchScheduler
import androidx.compose.runtime.Composable
import androidx.compose.runtime.Stable
import androidx.compose.runtime.derivedStateOf
@@ -147,18 +148,26 @@
/**
* The state that can be used to control [VerticalPager] and [HorizontalPager]
- * @param currentPage The initial page to be displayed
- * @param currentPageOffsetFraction The offset of the initial page with respect to the start of
- * the layout.
*/
@OptIn(ExperimentalFoundationApi::class)
@Stable
-abstract class PagerState(
+abstract class PagerState internal constructor(
currentPage: Int = 0,
- @FloatRange(from = -0.5, to = 0.5) currentPageOffsetFraction: Float = 0f
+ @FloatRange(from = -0.5, to = 0.5) currentPageOffsetFraction: Float = 0f,
+ prefetchScheduler: PrefetchScheduler? = null
) : ScrollableState {
/**
+ * @param currentPage The initial page to be displayed
+ * @param currentPageOffsetFraction The offset of the initial page with respect to the start of
+ * the layout.
+ */
+ constructor(
+ currentPage: Int = 0,
+ @FloatRange(from = -0.5, to = 0.5) currentPageOffsetFraction: Float = 0f
+ ) : this(currentPage, currentPageOffsetFraction, null)
+
+ /**
* The total amount of pages present in this pager. The source of this data should be
* observable.
*/
@@ -431,7 +440,7 @@
*/
val currentPageOffsetFraction: Float get() = scrollPosition.currentPageOffsetFraction
- internal val prefetchState = LazyLayoutPrefetchState()
+ internal val prefetchState = LazyLayoutPrefetchState(prefetchScheduler)
internal val beyondBoundsInfo = LazyLayoutBeyondBoundsInfo()
@@ -716,21 +725,38 @@
} else {
info.visiblePagesInfo.first().index - info.beyondViewportPageCount - PagesToPrefetch
}
- if (indexToPrefetch != this.indexToPrefetch &&
- indexToPrefetch in 0 until pageCount
- ) {
- if (wasPrefetchingForward != isPrefetchingForward) {
- // the scrolling direction has been changed which means the last prefetched
- // is not going to be reached anytime soon so it is safer to dispose it.
- // if this item is already visible it is safe to call the method anyway
- // as it will be no-op
- currentPrefetchHandle?.cancel()
+ if (indexToPrefetch in 0 until pageCount) {
+ if (indexToPrefetch != this.indexToPrefetch) {
+ if (wasPrefetchingForward != isPrefetchingForward) {
+ // the scrolling direction has been changed which means the last prefetched
+ // is not going to be reached anytime soon so it is safer to dispose it.
+ // if this item is already visible it is safe to call the method anyway
+ // as it will be no-op
+ currentPrefetchHandle?.cancel()
+ }
+ this.wasPrefetchingForward = isPrefetchingForward
+ this.indexToPrefetch = indexToPrefetch
+ currentPrefetchHandle = prefetchState.schedulePrefetch(
+ indexToPrefetch, premeasureConstraints
+ )
}
- this.wasPrefetchingForward = isPrefetchingForward
- this.indexToPrefetch = indexToPrefetch
- currentPrefetchHandle = prefetchState.schedulePrefetch(
- indexToPrefetch, premeasureConstraints
- )
+ if (isPrefetchingForward) {
+ val lastItem = info.visiblePagesInfo.last()
+ val pageSize = info.pageSize + info.pageSpacing
+ val distanceToReachNextItem =
+ lastItem.offset + pageSize - info.viewportEndOffset
+ // if in the next frame we will get the same delta will we reach the item?
+ if (distanceToReachNextItem < delta) {
+ currentPrefetchHandle?.markAsUrgent()
+ }
+ } else {
+ val firstItem = info.visiblePagesInfo.first()
+ val distanceToReachNextItem = info.viewportStartOffset - firstItem.offset
+ // if in the next frame we will get the same delta will we reach the item?
+ if (distanceToReachNextItem < -delta) {
+ currentPrefetchHandle?.markAsUrgent()
+ }
+ }
}
}
}
diff --git a/compose/integration-tests/macrobenchmark/src/main/java/androidx/compose/integration/macrobenchmark/ComplexNestedListsScrollBenchmark.kt b/compose/integration-tests/macrobenchmark/src/main/java/androidx/compose/integration/macrobenchmark/ComplexNestedListsScrollBenchmark.kt
index 003b307..c070d43 100644
--- a/compose/integration-tests/macrobenchmark/src/main/java/androidx/compose/integration/macrobenchmark/ComplexNestedListsScrollBenchmark.kt
+++ b/compose/integration-tests/macrobenchmark/src/main/java/androidx/compose/integration/macrobenchmark/ComplexNestedListsScrollBenchmark.kt
@@ -19,6 +19,8 @@
import android.content.Intent
import android.graphics.Point
import androidx.benchmark.macro.CompilationMode
+import androidx.benchmark.macro.ExperimentalMetricApi
+import androidx.benchmark.macro.FrameTimingGfxInfoMetric
import androidx.benchmark.macro.FrameTimingMetric
import androidx.benchmark.macro.junit4.MacrobenchmarkRule
import androidx.test.platform.app.InstrumentationRegistry
@@ -41,11 +43,12 @@
device = UiDevice.getInstance(instrumentation)
}
+ @OptIn(ExperimentalMetricApi::class)
@Test
fun start() {
benchmarkRule.measureRepeated(
packageName = PACKAGE_NAME,
- metrics = listOf(FrameTimingMetric()),
+ metrics = listOf(FrameTimingMetric(), FrameTimingGfxInfoMetric()),
compilationMode = CompilationMode.Full(),
iterations = 8,
setupBlock = {
