[Bug Report][3.9.0] VTreeview slow load and freezes browser when using many groups

[daniel-komlosi]

Environment

Vuetify Version: 3.9.0
Last working version: 2.7.2
Vue Version: 3.5.17
Browsers: Firefox 140.0
OS: Windows 10

Steps to reproduce

Hi,

When loading groups and children into VTreeview it slows down the whole page and freezes the browser until it is rendered. Please review this, opening the branches/groups also slow.

Thank you.

Expected Behavior

In v2 the rendering of the groups was significantly faster.

Actual Behavior

Slow rendering.

Reproduction Link

https://play.vuetifyjs.com/#...

[KaelWD]

Known issue: #19919

Looks like it got worse again in 3.9.0-beta.1 though.

[J-Sek]

Is it just me or does the element click have ~1.5s lag in comparison to direct click on the expand icon?

[daniel-komlosi]

Is it just me or does the element click have ~1.5s lag in comparison to direct click on the expand icon?

the same for me

[KaelWD]

Happens on leaf nodes too, selection re-renders the entire tree. #21325 should help with this.

[daniel-komlosi]

Known issue: #19919

Looks like it got worse again in 3.9.0-beta.1 though.

it was the same with 3.8.12, I upgraded today to check if this was resolved

[LeonardoGalante0]

i also have the same problem, all page is slow because of the large amount of data of the treeview @KaelWD

[J-Sek]

It is only around ~1300 nodes so definitely reasonable, but I am curious if instead of fixing the bottleneck we should rather focus on making it work with VVirtualScroll.

Anyway, activatable seems to make a big impact when clicking outside of expand button.

Edit: item-key should be replaced with item-value (in the original playground)