Expose onScrollStarted/onScrollStopped listeners in verticalScroll modifier [169509805]

Fixed

Bug

Status Update

No update yet.

Description

ya...@gmail.com

created issue #1

Sep 28, 2020 02:45PM

Component used: ScrollableColumn/verticalScroll modifier

Version used: alpha-03

Devices/Android versions reproduced on: Irrelevant

The scrollable modifier has onScrollStarted/onScrollStopped parameters, but the verticalScroll/horizontalScroll modifiers are not exposing those. Some type visibility like state.scrollableController make it impossible to use scrollable manually.

Would also be nice to have those on ScrollableColumn/ScrollableRow I guess.

Use case: I'd like to receive the event where the user stopped scrolling, and use the velocity to trigger a snap behavior.

I have the following page:

Stack {
    val collapsingToolbarExpandedSize = ...
    ScrollableColumn(){
       Spacer(modifier = Modifier.height(collapsingToolbarSize))
    }
    CollapsingToolbar {
          ....
    }
}

I want to be able to trigger a smooth scroll to a certain value (0 or collapsingToolbarSize) to snap the toolbar state.

Maybe there is a different way of doing this. I tried using the rawDragGestureFilter, but the onStop was always receiving a value of 0 for the offset. Maybe this is a bug?

Thanks.

Comments

so...@google.com <so...@google.com> Sep 28, 2020 03:46PM

Assigned to ma...@google.com.

ma...@google.com <ma...@google.com> #2Sep 28, 2020 05:14PM

This is a browser bug related to user selectable zoom level.

ya...@gmail.com <ya...@gmail.com> #3Sep 28, 2020 09:06PM

This appears to be the same issue I'm experiencing.

ap...@google.com <ap...@google.com> #4Oct 13, 2020 04:16PM

Marked as fixed.

Project: platform/frameworks/support
Branch: androidx-master-dev

commit 03b8c488e9eb8764bd36e30590f5171823f9560a
Author: Matvei Malkov <malkov@google.com>
Date: Thu Oct 08 18:19:09 2020

Add InteractionState to scrollable and corresponding containers, add animation observation to LazyList

This CL adds InteractionState to the ScrollableColumn/Row and Lazy lists to allow people to observe interactions that are happening on this element. While doing so, to make functionality on par, I added isAnimationRunning and stopAnimation is LazyState, so people won't miss this menthods while migrating from ScrollableColumn.

Change-Id: I815666e1b4544dcd5da9f253ec1b539fdd777529
Relnote: Added interactionState to Modifier.scrollable, ScrollableColumn and LazyColumnFor
Fixes: 169509805
Test: added

M compose/foundation/foundation/api/current.txt
M compose/foundation/foundation/api/public_plus_experimental_current.txt
M compose/foundation/foundation/api/restricted_current.txt
M compose/foundation/foundation/integration-tests/foundation-demos/src/main/java/androidx/compose/foundation/demos/ListDemos.kt
M compose/foundation/foundation/samples/src/main/java/androidx/compose/foundation/samples/ScrollerSamples.kt
M compose/foundation/foundation/src/androidAndroidTest/kotlin/androidx/compose/foundation/ScrollableTest.kt
M compose/foundation/foundation/src/androidAndroidTest/kotlin/androidx/compose/foundation/lazy/LazyColumnForTest.kt
M compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/Scroll.kt
M compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/gestures/Scrollable.kt
M compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/LazyListState.kt

https://android-review.googlesource.com/1454897

ma...@google.com <ma...@google.com> #5Oct 19, 2020 01:27PM

I am experiencing the same issue. white lines are appearing in IE browser.
does any one know how to get rid of this?

Issue 169509805