ScrollableState.animateScrollBy does not preserve velocity when interrupting a previous call [220119990]

Bug

Status Update

No update yet.

Description

kl...@google.com

created issue #1

Feb 17, 2022 03:07PM

If ScrollableState.animateScrollBy is called and then before it completes it is called again in another coroutine, the first animation will be cancelled before starting the second one. However, unlike calls to Animatable.animateTo, the velocity of the previous animation will not be preserved.

Possible solutions

This isn't a trivial fix because ScrollableState itself does not keep any animation or velocity state – animateScrollBy is an extension function. It also does not provide any signal about whether it's being scrolled by an animation or the user, so if we track the velocity externally then we could end up in a weird state if the user interrupts an animation.

Option 1: Move `animateScrollBy` into `ScrollableState`

This would allow ScrollableState to keep track of animated scroll velocity internally. It should also allow it to be reset to zero when the animation is interrupted by a user scroll. However, ScrollableState is a public interface so to avoid breaking binary compatibility we would need to wait for Kotlin 1.6.20 and then give it a default implementation. The default implementation could simply be the current implementation.

Option 2: Expose scroll velocity from `ScrollableState`

I'm not sure how feasible this is – tracking velocity requires tracking timestamps, which ScrollableState does not currently do and would probably make the API super gross.

Comments

kl...@google.com <kl...@google.com> #2Jun 14, 2022 06:06PM

Accepted by kl...@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

ap...@google.com <ap...@google.com> #3Jul 7, 2022 08:56PM

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.

kl...@google.com <kl...@google.com> #4Aug 5, 2022 01:51AM

Assigned to le...@google.com.

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.

le...@google.com <le...@google.com> May 22, 2023 01:22PM

Status: New

Issue 220119990

Description

Possible solutions

Option 1: Move animateScrollBy into ScrollableState

Option 2: Expose scroll velocity from ScrollableState

Issue summary