Typing a multi-line message makes chat scroll up (then you have to scroll to see new messages)

[WofWca]

• Operating System (Linux/Mac/Windows/iOS/Android): Windows

• Delta Chat Version: 1.44.0

• Expected behavior: The last message stays visible

• Actual behavior: The chat scrolls up a little and the last message is obstructed. If new messages arrive, they are also obstructed.

• Steps to reproduce the problem:

• Screenshots:

  https://github.com/deltachat/deltachat-desktop/assets/39462442/ae733a96-0b52-4d01-b472-c34b374e0b6e

• Logs: none

On the video I've caught a rare case where this doesn't happen for a few lines, but then it starts happening again. I always found it about the most annoying thing about Delta Chat Desktop.

• [ ] This thing also happens when you quote a message.

Workaround: keep pressing "Page Down" while you're writing your message.

Related:

• https://github.com/deltachat/deltachat-desktop/issues/3753#issuecomment-2045828431 - may be a part of the fix

• 654

[missytake]

Oh thanks this is annoying me so much, I tried to report it once, but then when I failed to reproduce it on purpose

[WofWca]

Ok, a few discoveries. I wrote this test simple bench:

HTML

```html

1. sample message
2. sample message
3. sample message
4. sample message
5. sample message
6. sample message
7. sample message
8. sample message
9. sample message
10. sample message
11. sample message
12. sample message
13. sample message
14. sample message
15. sample message
16. sample message
17. sample message
18. sample message
19. sample message
20. sample message
21. sample message
22. sample message
23. sample message
24. sample message
25. sample message
26. sample message
27. sample message
28. sample message
29. sample message
30. sample message
31. sample message
32. sample message
33. sample message
34. sample message
35. sample message
36. sample message
37. sample message
38. sample message
39. sample message
40. sample message
41. sample message
42. sample message
43. sample message
44. sample message
45. sample message
46. sample message
47. sample message
48. sample message
49. sample message
50. sample message
51. sample message
52. sample message
53. sample message
54. sample message
55. sample message
56. sample message
57. sample message
58. sample message
59. sample message
60. sample message
61. sample message
62. sample message
63. sample message
64. sample message
65. sample message
66. sample message
67. sample message
68. sample message
69. sample message
70. sample message
71. sample message
72. sample message
73. sample message
74. sample message
75. sample message
76. sample message
77. sample message
78. sample message
79. sample message
80. sample message

```

And the issue is also present there, so I suppose it's not something specific to Delta Chat.

What I found is sometimes the message list stays scrolled down under specific circumstances:

1. Reload the page
2. Expand the <textarea> up. The last message will hide behind it (the issue).
3. Scroll message list to the bottom.
4. Shrink the textarea down.
5. Expand the textarea up. The chat will keep being scrolled down up to the point where you resize the textarea to the biggest size it had in step 2.

https://github.com/user-attachments/assets/030491be-55d5-42ae-9e1c-75d7ed7f8e2b

This looks Chromium-internal. This behavior is not reproducible on Firefox. This is also why the issue looks not 100% reproducible.

I suppose a hacky solution would be to, on initial render

1. expand the composer up
2. scroll the chat to the bottom
3. shrink the composer back to its normal size

I also looked at Signal code (which doesn't have this issue) and played around with it using dev tools (./Signal.exe --enable-dev-tools), and I found that if this element is removed from DOM, then the buggy behavior comes in.

This is where they use the element. They set newIsNearBottom = true if the element is visible and go from there, supposedly scrolling chat to bottom (but I didn't check further). So they're taking a more thorough approach and not the hacky one that I mentioned above.