Scroll Sync Do Not Function

[defencedog]

Describe the bug
Scroll Sync icon doesn't function when side by side prevview windows is open

To Reproduce
Steps to reproduce the behavior:
Whether you enable or disable scroll sync icon there is no effect

Expected behavior
When I scroll both source code & preview should scroll in sync

Device

• OS: Win11 x64
• App Version v2.6.11

[PathGao]

Scroll sync was rewritten in #196 (pixel-based sync positions instead of line/ratio), which first shipped in v2.6.12 — released 2026-07-13, after this report was filed against v2.6.11. Could you retest on v2.6.12? If sync works there, this issue can be closed.

[Guardiancelte]

looks like it is working. but sync is not perfect, I cannot share the exact file that I was using so I ask GPT to to give me a test file.

When reaching the end of the file it is quite a few lines off. I had this issue in both stress test (I asked a easier one from GPT as I thought it might be the problem with too many format and tables and charts in the hard one, but actually was in both)

Stress Test Easy.md
Stress Test Hard.md

Another issue which shows a lot more on the hard one, but a little on the easy one as well, is when typing text on left side, both the right and left panel are jumping up and down for every character typed (not even doing return to the line, just typing normal chararcters). Which is highly disturbing.

Otherwise I am actually impressed by the displaying capabilities.

[PathGao]

I traced the typing-related jump to Editor.svelte: editor-to-preview sync subscribed to onDidChangeCursorPosition, so every ordinary edit repositioned the paired pane. #304 removes that trigger and adds a regression test; real editor scroll events remain synchronized.

The reported end-of-document drift is a separate mapping/measurement problem and stays tracked here for a reproducible fixture and platform retest.

[PathGao]

I traced the remaining end-of-document offset to Monaco’s scrollBeyondLastLine padding being included in the pixel-ratio sync range. #316 calculates the editor sync range from content height instead, while preserving the editor’s padding preference and the front-matter split. It follows #304; please retest the attached fixtures after the stack merges.

[Guardiancelte]

Ok. Thanks! Will have a look when it is integrated into release. Very cool project!