Selecting too many nodes blocks the UI thread

danipen commented 1 year ago

In the demo app, if you select a large number of nodes (around 15k), it makes the app slow and unresponsive. This happens because the selection process takes a long time and it's happening on the main UI thread.

Steps to reproduce:

Create a directory on disk with 15k files.
Open the demo app, and go to the "Files" tab.
Expand the directory with 15k.
Scroll to the top.
Select the root node.
Scroll to the bottom.
Press Shift and click the last node, to cause the TreeDataGridto select all the nodes.
The application becomes unresponsive.

You can see the problem in this video:

https://github.com/AvaloniaUI/Avalonia.Controls.TreeDataGrid/assets/501613/6795679f-27c8-42e5-b816-89b9dc69ec1b

grokys commented 12 months ago

Just tried, and indeed it was slow, so I hit pause and noticed that it's logging a load of messages to the debug window. If I comment out these lines from the sample app, it's instantaneous on my machine:

https://github.com/AvaloniaUI/Avalonia.Controls.TreeDataGrid/blob/master/samples/TreeDataGridDemo/ViewModels/FilesPageViewModel.cs#L215-L218

Could you commenting out those lines on your machine?

danipen commented 12 months ago

Yes, the slowdown was caused by the log. We can close this issue.

AvaloniaUI / Avalonia.Controls.TreeDataGrid

Selecting too many nodes blocks the UI thread #222