h6ah4i/android-advancedrecyclerview

Group collapse animation

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#244 opened on May 11, 2016

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help wantedquestion

Description

I've been using a custom implementation of this library for a while (so just downloading the latest version would overwrite my customizations).

See the animated GIF below. When collapsing, the "Lab" group disappears and then shows up under "Exams" instead of smoothly moving up beneath it. This used to be a much smoother transition and I'm wondering if someone can help me figure out what's changed in recent Android updates and which classes from this library I need to update to correct this. I've already gone through and tried updating the animator classes, but to no avail. I'd appreciate any tips. Thanks.

Animation of behavior - GIF

Contributor guide

Tech stack
java
Domain
mobile
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
needs investigation
Prerequisites
Android RecyclerView animationsItemAnimator API
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
30
Research direction
Investigate the ItemAnimator and related animator classes in the library (e.g., `ExpandableItemAnimator` or `AdvancedItemAnimator`). Compare the current implementation with earlier versions to identify what changed in the animation behavior. The issue mentions a regression from a custom implementation; look at recent commits around the library's animation files. Reproduce the collapse animation and trace the animation sequence to find where the smooth transition is broken.