Flet node editor is extremely laggy.

[qyddss]

Question

When I was creating a node editor using Flet, I used Canvas to draw the connecting lines. Each time a connection is made, a Path needs to be added to the Canvas. Once the number of connections exceeds 30, the UI becomes extremely laggy when dragging nodes. How can this be resolved? A normal node editor should support 100–300 nodes without lag. Currently, even with asynchronous operations, I can only achieve smooth performance with up to 30 nodes—50 nodes cause noticeable delay, and once the number reaches 60, it becomes too laggy to use. Without asynchronous operations, it starts lagging at around 20 nodes.

Code sample

No response

Error message

No response

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• I have searched for answers to my question both in the issues and in previous discussions.

[FeodorFitsner]

Can you give a repro/example?

[qyddss]

How should I send the code to you?

[FeodorFitsner]

If you could a do a simple repro and paste here that would be more helpful rather than sensing entire app.

[qyddss]

I have already made it into a standalone node editor as an independent project file. It doesn't contain any other code. I have created a repository and invited you. I'm not very fluent in English—this has all been translated by AI.

[qyddss]

The code has been minimized as much as possible. A complete node editor must include nodes, connection lines, and a canvas, along with implementing drag-and-drop functionality. Removing any part of the current code would prevent the issue from being reproduced. The main file is main.py, and the other few files are imported modules with very little code. In the main file, the last four functions inside the class are the main functions controlling the drag-and-drop updates.