Scrollbar is tiny on initial session load; resizing window fixes it

[nalin-singh]

Description

On first loading a session, the vertical scrollbar is rendered extremely small and almost unusable. If I resize the window down and then back to its original size, the scrollbar is recalculated and becomes normal-sized and usable.

Steps to Reproduce

1. Open the app.
2. Load an existing session (or create a new one with enough content to need scrolling).
3. Look at the vertical scrollbar on the right side.
4. Without interacting with the content, resize the window to be smaller.
5. Resize the window back to its previous size.

Actual Result

• On step 3: The scrollbar thumb is very small and hard to grab, even though the content is not extremely long.
• After steps 4–5: The scrollbar thumb becomes larger and matches the expected size for the amount of scrollable content.

Expected Result

• The scrollbar thumb should be correctly sized and usable as soon as the session loads, without needing to resize the window

OpenCode version

1.0.162

Steps to reproduce

1. Open the app.
2. Load an existing session (or create a new one with enough content to need scrolling).
3. Look at the vertical scrollbar on the right side.
4. Without interacting with the content, resize the window to be smaller.
5. Resize the window back to its previous size.

Screenshot and/or share link

https://github.com/user-attachments/assets/dbc0b960-ac94-4086-abc1-7059cb676a88

Operating System

macOS

Terminal

Ghostty

[github-actions[bot]]

This issue might be a duplicate of existing issues. Please check:

• #5592: Scroll bar will cover the content

Feel free to ignore if none of these address your specific case.

[nalin-singh]

This is an example chat where the initial load is still not that bad, I've a few other sessions where it will unusable.

[nalin-singh]

I can work a fix for this

[rekram1-node]

sounds good! could possibly require upstream change in sst/opentui

[nalin-singh]

will give it a try, won't hog for long