Bad performance/lagging in tabs "recent notes" and "browse"

[fybx]

First of all, here are the related issues: #1110, #1237, #993 and #293.

Here's a recent screen recording, showing the lag I'm talking about. It should be clear that many frames get skipped when swiping the note gallery:

out2.mp4

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I've prompted Claude 3.5 Sonnet about the issue, the related pieces of the source code, and it was able to claim a few "necessary" improvements, however I'm in no position to analyse Dart/Flutter code or judge anyone's skills, so giving just a heads up.

Thanks in advance.

[QubaB]

It also occurs on my tablet, but I don't consider it a problem. The gradual display of thumbnails is a result of the thumbnails only loading when they are needed.

[fybx]

I don't consider it a problem

but it actually is a problem, and a fairly easy to solve one. It gets worse when you have many, many notes; even with a fairly organized folder setup you'll still get artifacts which is not cool.

thumbnails only loading when they are needed

Bear with me here, I'm only assuming: the thumbnails are getting lazily "generated" from the actual "data", right? If that's the case, a simple solution would be to generate a preview image when a note is saved to disk, and store the preview image in the note. The preview image can be small, too; that'll keep the file size small.

[QubaB]

Thumbnails are created when note is saved. Thumbnails are png images and are saved as filename.sba.p. So they are not generated on demand. Problem is with loading them to memory and rendering it.

Each thumbnail has size 50kB-1MB (depending on note), it takes time to read it and display.

[fybx]

Hmm, then there must be some other bottleneck since it really shouldn't be an issue to load and render literal PNG files on mid to high end devices. I'll reserve time to look into this issue.