[E-book viever] scrolling feels wrong

[Panel]

Hello

Generally scroll is working but It simply dosent feel right and it can be improved to improve over all reading experience. To be more clear I have distinguished few cases alla of witch relate to "flow mode", so:

1. Keyboard scroll - pressing Up/Down key should scroll to full line
a. Now scroll position is fixed value, but this value should be calculated based on the text line height (up arrow first line height, down arrow last line on page height). Also notice that text should be scrolled in such way so after scroll new (prev/next displayed) line is fully visible (not halt of it) . This is more anoyng when font size is increased because with large fonts pressing up/down arrow will scroll only small part of the text line.

This is implemented much better in foxit reader, so to to reproduce and understand the feeling simply open document in both programs (calibre / foxit reader), increase font size / zoom it and compare how those two programs behave when using up/down arrows for scrolling

2. Keyboard scroll - pressing Up/Down key should scroll faster
It's seems to slow - I believe 'scroll intterval' when holding arrow key shoul be decreased (again scroll by holding up/down key and compare to foxit reader experience).

3. Scroll using mouse whell
This should be definitly decreased to the point that it's possible to actually scroll one line of text (some mouses like Logitech have sensitive wheel so with such large scrolling rate it's difficult to scroll).

4. Vertical scroll
When font is increased boundries for max horizontal scrol lare calculated incorrectly. On scrollbar it looks fine, bhut then selecting text and more courcor max to right the page will be scrolled to the right (see attached screenshot)

[kovidgoyal]

The viewer uses a browser engine. Browser dont do line scrolling. Therefore the viewer does not do line scrolling. There is nothing that can be done about that. One could have the scroll scroll by the line height of the body font, but then that wont work for lines of different font heights.

[victoryhollow]

Actually came to this forum looking for a fix for the ebook viewer scrolling... I typically use my mouse to scroll while I'm reading, but it's so jumpy that it's easy to very lose my place (unlike scrolling, say, on a webpage)... disappointed to hear that there's no easy fix for this.

[kovidgoyal]

I can definitely add an option to control the amount by which the mouse wheel scrolls. I cannot however implement line scrolling since the underlying engine does not support it.

[kovidgoyal]

https://github.com/kovidgoyal/calibr...d49a61c49dd936