linebender/druid

`request_anim_frame()` prevents redrawing in multi-window

Open

#2339 opened on Jan 17, 2023

View on GitHub
 (9 comments) (0 reactions) (0 assignees)Rust (9,091 stars) (567 forks)batch import
bughelp wanted

Description

I have a custom widget that has an animation. After opening two windows with it inside, I found only the focused one was redrawn. The other ones won't redraw even if there's a data change. After deleting request_anim_frame(), it would redraw if there's a data change, but as a result, it's impossible for me to update my animation. Why would this happen? Is multi-window simply just doesn't supports animation or are there any options for me to enable it?

image

Contributor guide

Tech stack
rust
Domain
frontend
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.
1-2 days
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
Basic knowledge of RustFamiliarity with druid's Widget trait
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
30
Research direction
Investigate the druid source code, particularly the windowing and animation scheduling logic in src/win handler.rs and src/widget/widget.rs. Examine how request anim frame() interacts with multiple windows. The user reports that removing the call fixes redrawing for data changes but breaks animation. Look for any window specific state that might cause animation requests to be ignored for unfocused windows. Check if there is a known limitation or bug in the multi window support. Review comments in the issue for any clues from maintainers.