Add ScrollerPosition.scrollToElement() or equivalent [161584524]

Fixed

Bug

Status Update

No update yet.

Description

na...@gmail.com

created issue #1

Jul 19, 2020 10:55AM

When an app programmatically scrolls to a certain point, it is usually because a specific element in the list should be highlighted to the user.
It would be very useful if the ScrollerPosition class had one or multiple methods for scrolling to a specific element index instead of a position in pixels. The current API forces developers to do the calculate the height of each element themselves and figure out at which pixel location the desired element is from that.

Comments

ma...@google.com <ma...@google.com> #2Jul 20, 2020 12:03PM

Reassigned to an...@google.com.

Hi,

I also see my text cut off when I set maxLines = 2. Is it the same issue?

  Box(
    modifier =
      Modifier.size(
        width = 108dp,
        height = 34dp,
      ),
    contentAlignment = Alignment.Center,
  ) {
    BasicText(
      text = "text text text",
      maxLines = 2,
      autoSize = AutoSize.StepBased(minFontSize = 1.sp, maxFontSize = 13.sp, stepSize = 0.2.sp),
    )
  }

na...@gmail.com <na...@gmail.com> #3Jul 21, 2020 03:29PM

Project: platform/frameworks/support
Branch: androidx-main
Author: Jossi Wolf <jossiwolf@google.com>
Link: https://android-review.googlesource.com/3450389

Fix TextAutoSize bug with maxLines = 1

Expand for full commit details

Fix TextAutoSize bug with maxLines = 1 
 
We were overcaching the paragraphIntrinsics in MultiParagraphLayoutCache when mutating the style. For `AutoSizeStepBased` instances with biased windows (more values smaller/bigger than the optimal), this could result in performing layout with outdated intrinsics, and thus an outdated style and font size, without surfacing this in the TextLayoutResult. 
 
Test: New MultiParagraphLayoutCacheTests and manual testing 
Relnote: Fixed a bug in BasicText with TextAutoSize and maxLines set to 1. 
Fixes: 376834366 
 
Change-Id: Ic0450c763c5d764492995b44ee1fe570246a9689

Files:

M compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/text/modifiers/MultiParagraphLayoutCacheTest.kt
M compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/text/modifiers/MultiParagraphLayoutCache.kt

Hash: e1b712d78cc60384ed67a56c006148291ba146a6
Date: Tue Jan 07 18:52:26 2025

an...@google.com <an...@google.com> #4Jul 24, 2020 04:56PM

Reassigned to ry...@google.com.

#2, yeah, that's the same issue.

an...@google.com <an...@google.com> #5Nov 26, 2020 08:46PM

Thanks @jo...@google.com for fixing this! Do you know when the fix would be available for g3 apps?

je...@google.com <je...@google.com> #6Mar 24, 2021 10:56AM

Moving the internal discussion offline. The bug is fixed and the fix available in snapshot builds. We will comment on this issue when the bug fix is included in a release.

ap...@google.com <ap...@google.com> #7Apr 20, 2021 08:56PM

The following release(s) address this bug.It is possible this bug has only been partially addressed:

androidx.compose.foundation:foundation:1.8.0-beta01
androidx.compose.foundation:foundation-android:1.8.0-beta01
androidx.compose.foundation:foundation-jvmstubs:1.8.0-beta01
androidx.compose.foundation:foundation-linuxx64stubs:1.8.0-beta01

ap...@google.com <ap...@google.com> #8Sep 24, 2021 07:35AM

Marked as fixed.

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

commit 59dca3bb1906b988bcc55a2bc44f93063e87a48f
Author: Jelle Fresen <jellefresen@google.com>
Date: Thu Apr 08 16:20:32 2021

Add scroll to matcher action for LazyLists in tests

Adds an action to SemanticsNodeInteraction to scroll to content in a
LazyList identified by a SemanticsMatcher. Adds a filter as well to find
nodes that support this scroll action.

Fix: 161584524
Fix: 182259407
Fix: 182260995
Test: Added ScrollToNodeTest
Relnote: "Added `performScrollToNode(matcher: SemanticsMatcher)` that
scrolls a scrollable container to the content that is matched by the
given matcher."

Change-Id: Ic1cb855e351c7bb683962d618d68782628b70f62

M compose/ui/ui-test/src/commonMain/kotlin/androidx/compose/ui/test/Actions.kt
M compose/ui/ui-test/api/current.txt
M compose/ui/ui-test/api/public_plus_experimental_current.txt
M compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/LazyListState.kt
A compose/ui/ui-test/src/androidAndroidTest/kotlin/androidx/compose/ui/test/actions/ScrollToNodeTest.kt
M compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/LazySemantics.kt
M compose/ui/ui-test/src/commonMain/kotlin/androidx/compose/ui/test/Filters.kt
M compose/ui/ui-test/api/restricted_current.txt

https://android-review.googlesource.com/1815782