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

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

Expand for full commit details

Adds OverscrollEffect#withoutDrawing and OverscrollEffect#withoutEventHandling 
 
These APIs allow overscroll to have events dispatched to it by one component, and rendered in a separate component. 
 
Fixes: b/266550551 
Fixes: b/204650733 
Fixes: b/255554340 
Fixes: b/229537244 
Test: OverscrollTest 
Relnote: "Adds OverscrollEffect#withoutDrawing and OverscrollEffect#withoutEventHandling APIs - these APIs create a wrapped instance of the provided overscroll effect that doesn't draw / handle events respectively, which allows for rendering  overscroll in a separate component from the component that is dispatching events. For example, disabling drawing the overscroll inside a lazy list, and then drawing the overscroll separately on top / elsewhere." 
Change-Id: Idbb3d91546b49c1987a041f959bce4b2b09a9f61

Files:

M compose/foundation/foundation/api/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/OverscrollDemo.kt
M compose/foundation/foundation/samples/src/main/java/androidx/compose/foundation/samples/OverscrollSample.kt
M compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/OverscrollTest.kt
M compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/Overscroll.kt

Hash: f64e25b7a473c757d080521e7dd97b3f6670f60d
Date: Fri Nov 01 18:43:56 2024

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

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

androidx.compose.foundation:foundation:1.8.0-alpha06
androidx.compose.foundation:foundation-android:1.8.0-alpha06
androidx.compose.foundation:foundation-jvmstubs:1.8.0-alpha06
androidx.compose.foundation:foundation-linuxx64stubs:1.8.0-alpha06

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

As I mentioned above, I exposed InteractionState on the scrollable containers (and their states), so you are now able to understand whether fling or drag is happening and distinguish between them. This thought doesn't solve your issue, as you need to wait for a proper nested scrolling support, unfortunately.

Closing this as the main feature request of exposing ongoing scroll/fling is completed, please, follow the rest of the work here: b/162408885

Issue 169509805