Expose OverscrollEffect [266550551]

Fixed

Bug

Status Update

No update yet.

Description

cj...@gmail.com

created issue #1

Jan 24, 2023 08:41PM

Jetpack Compose version: 1.4.0-alpha04

We have a screen with a "header" item containing an image at the top of a LazyColumn.

On overscroll we want to slightly scale the image but the entire overscroll API is hidden / not extensible.

Wold it be possible to expose OverScrollEffect either as a composition local or provide an ability to override the overscroll per scrollable (for both the lazy layouts & normal Modifier.scrollable cases)

Comments

ma...@google.com <ma...@google.com> #2Jan 25, 2023 01:03PM

Reassigned to lp...@google.com.

Project: platform/frameworks/support
Branch: androidx-main

commit cb1afd67dacbf14cd22206c6f5b543dbf18cec1f
Author: Tony Mak <tonymak@google.com>
Date: Thu Jan 06 14:52:58 2022

Deprecate all the APIs in textclassifier

Bug: 210509084

Test: Check api/current.txt and ensure all classes are deprecated

Relnote: "Deprecate all the APIs in the textclassifier module"

Change-Id: Idc18063196531c0e926162fefeadf2dc5f559da1

M textclassifier/textclassifier/src/main/java/androidx/textclassifier/TextSelection.java
M textclassifier/textclassifier/src/main/java/androidx/textclassifier/TextLinks.java
M textclassifier/textclassifier/src/main/java/androidx/textclassifier/TextClassificationSessionId.java
M textclassifier/textclassifier/api/public_plus_experimental_current.txt
M textclassifier/textclassifier/src/main/java/androidx/textclassifier/TextClassification.java
M textclassifier/textclassifier/src/main/java/androidx/textclassifier/TextClassificationManager.java
M textclassifier/textclassifier/api/current.txt
M textclassifier/textclassifier/src/main/java/androidx/textclassifier/TextClassificationContext.java
M textclassifier/textclassifier/src/main/java/androidx/textclassifier/TextLinksParams.java
M textclassifier/textclassifier/api/restricted_current.txt
M textclassifier/textclassifier/src/main/java/androidx/textclassifier/ConversationAction.java
M textclassifier/textclassifier/src/main/java/androidx/textclassifier/TextClassifier.java
M textclassifier/textclassifier/src/main/java/androidx/textclassifier/ConversationActions.java
M textclassifier/textclassifier/src/main/java/androidx/textclassifier/ExtrasUtils.java

https://android-review.googlesource.com/1938773

cj...@gmail.com <cj...@gmail.com> #3Jan 25, 2023 01:06PM

Is there any update when the alpha04 will be available? We need it to target api 31 because of the PendingIntent mutability flags missing in alpha03.

lp...@google.com <lp...@google.com> #4Jan 25, 2023 03:17PM

I'll schedule it for the next release. Note that alpha04 is a complete turn-down of the library where all APIs are marked as Deprecated, so you'll also want to start removing your usages of the library.

cj...@gmail.com <cj...@gmail.com> #5Jan 25, 2023 10:00PM

Project: platform/frameworks/support
Branch: androidx-main

commit 19ed7e69823a09f3c63f8c8cdf339af8ca1645ab
Author: Alan Viverette <alanv@google.com>
Date: Mon Mar 14 15:18:16 2022

Bump textclassifier for final release and turn-down

Bug: 210509084
Change-Id: Ib8b2386903bb49baa3211f7de7fe1587fdda1483
Test: ./gradlew checkApi

M libraryversions.toml

https://android-review.googlesource.com/2024823

lp...@google.com <lp...@google.com> #6Jan 26, 2023 03:42PM

Bugjuggler: wait until 2022-03-23

cj...@gmail.com <cj...@gmail.com> #7Jan 30, 2023 08:33AM

Hi. I've received your bug and will wait until 2022-03-23 00:00 -0400 EDT and then assign the bug to alanv@google.com.

cj...@gmail.com <cj...@gmail.com> #8Jan 30, 2023 08:45AM

Is there a replacement or should we just abandon TextClassifier for android older than API Level 26 ?

Message last modified on Jan 30, 2023 09:08AM

lp...@google.com <lp...@google.com> #9Jan 30, 2023 05:24PM

Abandon. The owning team had no plans to release a replacement library.

cj...@gmail.com <cj...@gmail.com> #10Feb 4, 2023 09:55AM

Yeah sure, the gist of the implementation is basically:

@Composable
private fun rememberScalePhotoOverscrollEffect(): ScalePhotoOverscrollEffect {
  val density = LocalDensity.current
  return remember(density) { ScalePhotoOverscrollEffect(with(density) { 148.dp.toPx() }) }
}

// Todo: Its not possible to actually scale the header photo yet, see b/266550551
private class ScalePhotoOverscrollEffect(private val maxPullDistance: Float) : OverscrollEffect {
  var pullDistance by mutableStateOf(0f)
  val scale by derivedStateOf { 1f + (0.1f * pullDistance / maxPullDistance) }
  val modifier = Modifier.graphicsLayer { scale(scale) }

  override val isInProgress get() = pullDistance > 0f

  // This modifier is unconditionally applied to the scrolling component.
  // Make it a no-op & apply [modifier] to the image instead
  override val effectModifier = Modifier

  override fun applyToScroll(delta: Offset, source: NestedScrollSource, performScroll: (Offset) -> Offset): Offset {
    if (source != NestedScrollSource.Drag) return performScroll(delta)
    // Todo: Handle reverse main axis drag here

    val available = delta - performScroll(delta)
    pullDistance = (pullDistance + available.y).coerceIn(0f, maxPullDistance)

    return delta // consume it all, the system doesn't need it lol
  }

  override suspend fun applyToFling(velocity: Velocity, performFling: suspend (Velocity) -> Velocity) {
    coroutineScope {
      launch { // Fling is our cue to start decay animation, animate back to zero
        if (pullDistance != 0f) {
          animate(
            initialValue = pullDistance,
            targetValue = 0f,
            animationSpec = spring(),
            block = { value, _ -> pullDistance = value },
          )
        }
      }
      launch { // While also performing the default fling
        performFling(velocity)
      }
    }
  }
}

cj...@gmail.com <cj...@gmail.com> #11Nov 30, 2023 02:21PM

Is it still the plan to overhaul the overscroll implementation?

lp...@google.com <lp...@google.com> #12Nov 30, 2023 04:28PM

The plan is still to separate the effect and the controller, and make some other small changes, but the overall API shape should remain the same, in terms of handling deltas and flings. But the separation of the effect and controller will make it easier to handle this use case, as you can configure scrollable to not render the overscroll effect

cj...@gmail.com <cj...@gmail.com> #13Dec 2, 2023 11:42AM

Amazing. Sounds good. I'll remain on the lookout.

ap...@google.com <ap...@google.com> #14Oct 10, 2024 02:12PM

Project: platform/frameworks/support
Branch: androidx-main
Author: Louis Pullen-Freilich <lpf@google.com>
Link: https://android-review.googlesource.com/3300456

Adds overloads for scroll and lazy APIs that allow specifying overscroll

Expand for full commit details

Adds overloads for scroll and lazy APIs that allow specifying overscroll

Bug: b/266550551
Fixes: b/234274772
Fixes: b/224572538
Fixes: b/353805117
Test: new tests
Relnote: "Adds overloads to horizontalScroll, verticalScroll, LazyColumn, LazyRow, LazyHorizontalGrid, LazyVerticalGrid, LazyHorizontalStaggeredGrid, LazyVerticalStaggeredGrid, HorizontalPager, and VerticalPager with support for specifying a custom OverscrollEffect. The provided OverscrollEffect will receive events, and be rendered within the bounds of these components. Note that drawing the same OverscrollEffect twice is unsupported - so you cannot draw the same OverscrollEffect provided to one of these components separately with Modifier.overscroll. The use case of drawing the overscroll outside of the bounds of these components will be addressed separately in the future."
Change-Id: I2dc42851c824a63e495312246eb5389c33121af8

Files:

M compose/foundation/foundation/api/current.txt
M compose/foundation/foundation/api/restricted_current.txt
M compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/BaseLazyLayoutTestWithOrientation.kt
M compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/grid/BaseLazyGridTestWithOrientation.kt
M compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/grid/LazyGridTest.kt
M compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/list/BaseLazyListTestWithOrientation.kt
M compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/list/LazyListHeadersTest.kt
M compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/list/LazyListTest.kt
M compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/list/LazyListsIndexedTest.kt
M compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/staggeredgrid/BaseLazyStaggeredGridWithOrientation.kt
M compose/foundation/foundation/integration-tests/lazy-tests/src/androidTest/kotlin/androidx/compose/foundation/lazy/staggeredgrid/LazyStaggeredGridTest.kt
M compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/ScrollTest.kt
M compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/lazy/list/BaseLazyListTestWithOrientation.kt
M compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/pager/BasePagerTest.kt
M compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/pager/PagerNestedScrollContentTest.kt
M compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/pager/PagerTest.kt
M compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/Scroll.kt
M compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/LazyDsl.kt
M compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/LazyList.kt
M compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/grid/LazyGrid.kt
M compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/grid/LazyGridDsl.kt
M compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/staggeredgrid/LazyStaggeredGrid.kt
M compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/staggeredgrid/LazyStaggeredGridDsl.kt
M compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/pager/LazyLayoutPager.kt
M compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/pager/Pager.kt

Hash: 18a2c333f118b50a0febd5206c2f2f31d81bb9bc
Date: Wed Oct 09 18:09:54 2024

lp...@google.com <lp...@google.com> #15Oct 10, 2024 11:41PM

Update: we are currently working on stabilising overscroll, and we just landed a change to expose OverscrollEffect in vertical/horizontalScroll and lazy APIs. However after some discussions we decided not to go ahead with the API separation mentioned previously, this causes a few ergonomic problems and adds a lot of complexity in general in order to improve a minority of cases.

Instead though we can probably just provide a wrapper extension API like OverscrollEffect#withoutDrawing() (naming TBD, note that also this could be written in user code currently) that creates a new OverscrollEffect instance that just calls through to the initial one, but without applying the modifier. This way usage would look something like:

val myOverscrollEffect = remember { MyOverscrollEffect() }

// LazyColumn will dispatch events to overscroll, but will not render anything as this will return an empty modifier
LazyColumn(overscrollEffect = myOverscrollEffect.withoutDrawing()) {
    // some content
    ...
    // Render the custom overscroll effect on the box, which is being driven by LazyColumn
    Box(Modifier.overscroll(myOverscrollEffect))...
}

pa...@gmail.com <pa...@gmail.com> #16Oct 11, 2024 02:23PM

not sure im getting this, how would this work in a normal lazy column with items? For example i wanna apply the same overscroll effect as in IOS, would the items in the lazy column have bounce effect? or only the box would bounce? Thanks for the feature btw

lp...@google.com <lp...@google.com> #17Oct 11, 2024 02:35PM

not sure im getting this, how would this work in a normal lazy column with items? For example i wanna apply the same overscroll effect as in IOS, would the items in the lazy column have bounce effect? or only the box would bounce? Thanks for the feature btw

If you just want the lazy column to apply a different overscroll effect, you can just provide the overscrollEffect parameter to the lazy column. What I mentioned above is for custom cases where you want the overscroll to apply outside the bounds of the lazy column, or to a specific item inside - but not to the entire list and all of its items.

pa...@gmail.com <pa...@gmail.com> #18Oct 11, 2024 02:46PM

Got it! Very niche usecase but its worth having at least the possibility

ap...@google.com <ap...@google.com> #19Nov 1, 2024 05:00PM

Marked as fixed.

Project: platform/frameworks/support
Branch: androidx-main
Author: Louis Pullen-Freilich <lpf@google.com>
Link: https://android-review.googlesource.com/3328184

Adds OverscrollEffect#withoutDrawing and OverscrollEffect#withoutEventHandling