Dashboard UI flickers between two states when large number of files is dragged on top of it

[denisahearn]

Initial checklist

• [X] I understand this is a bug report and questions should be posted in the Community Forum
• [X] I searched issues and couldn’t find anything (or linked relevant results below)

Link to runnable example

https://www.screencast.com/t/l88uDWBikf

Steps to reproduce

When I drag a large number of files (1500+) over the top of the Dashboard, it flickers between the "Drop files here or browse files" screen and the "Drop your files here" screen, and you have to time your drop just right in order for the dropped files to be added to the Dashboard. This flickering doesn't happen when you drag fewer files over the Dashboard.

Behavior can be seen in this short video: https://www.screencast.com/t/l88uDWBikf

Here is a small web app with an Uppy instance that was used to demonstrate the issue in that video. This .zip file contains instructions for how to build and run this app. uppy-sandbox.zip

Expected behavior

The Dashboard UI should not flicker back and forth when a large number of flies are dragged on top of it. The "Drop your files here" screen should be displayed and remain displayed.

Actual behavior

The Dashboard flickers between the "Drop files here or browse files" screen and the "Drop your files here" screen when a large number of files is dragged on top of it.

[denisahearn]

@arturi Do you know if this is something that will be investigated?

[denisahearn]

Just following up on this. Any chance someone could take a look at this bug?

[arturi]

@denisahearn would you like to contribute a PR? We'll help with guidance and code review.

[gppsteinberg]

First of all, I love Uppy, it is a fantastic uploader.

Second of all, I am also having this issue. Is there any chance someone out there is able/willing to fix it?

[arturi]

@lakesare do you think you could take a look? Sounds like your area of Uppy expertise :)

[lakesare]

@arturi, yes, worked around that area!

@denisahearn, @gppsteinberg, this issue is absent in Firefox, however I could reproduce it in Chrome - I will take a look.

[GSteinberg]

@lakesare SO much appreciated!! Let me know how it goes!

[denisahearn]

@lakesare Thank you for being willing to look into this, much appreciated!