1251980 - [was present 9+ years] Items in Bookmarks panel scroll by very small number of bookmarks when I rotate mouse wheel (inconsistency with other panels)

Status: VERIFIED DUPLICATE of bug 1251987

(Core :: DOM: Events, defect)

Description

[arni2033]

>>>   My Info:   Win7_64, Nightly 47, 32bit, ID 20160225030209
STR:
0. Move bookmarks toolbarbutton to toolbar
1. Open attached page "bookmarks 1", select all text in textarea and copy it to clipboard
2. Open bookmarks sidebar and click "Bookmarks menu" there to focus it
3. Press Ctrl+V to create 1000 bookmarks. Wait until they are completely added
4. Click Bookmarks button on toolbar
5. Hover mouse over any bookmark inside that panel
6. Rotate mouse wheel down once
7. Rotate mouse wheel up once

AR:  Bookmarks list is scrolled to the end
ER:  Bookmarks panel should respect mouse option "scroll by N lines" / "scroll by 1 page",
     just like all other panels. Just like bookmarks sidebar.

Comment 1

[arni2033]

Attachment: bookmarks 1 - Items in Bokmarks panel scroll to the very end or beginning.htm

Comment 2

[arni2033]

This was regressed even more after bug 1263975. And I won't report a new bug for the same thing.

Comment 3

[Markus Stange [:mstange]]

In what way has it changed after bug 1263975?

Comment 4

[arni2033]

The same way the summary has chenged... Scrolling is now completely useless.

Comment 5

[arni2033]

Sometimes when I rotate mouse wheel, tabs list scrolls by ~20 pixels. Sometimes it scrolls by 1 tab. That's what I call "by very small number of tabs". Btw, bug 1251987 is way more obvious.

Comment 6

[Markus Stange [:mstange]]

Ok, so here's what I see happening:
 - With the setting "scroll by N lines", it now scrolls by N menu items on each scroll. Whenever you change scroll directions, it might scroll N-1 rows the first time you scroll in that direction.
 - With the setting "scroll one screen at a time", it scrolls by one menu item. This is definitely a bug.

Can you confirm that the "scroll by N lines" setting is working correctly?

Comment 7

[arni2033]

(In reply to Markus Stange [:mstange] from comment #6)
> Can you confirm that the "scroll by N lines" setting is working correctly?
I'm not in the mood to test this, as nobody in Mozilla cared to test browser and make a simple fix
for 10+ years (bug 1257815). The browser was and still is very broken, and everybody pretends it's OK

Comment 8

[Markus Stange [:mstange]]

As you wish. Have a nice day.

Comment 10

[Markus Stange [:mstange]]

Bug 1251987 fixed per-page scrolling for all XUL <scrollbox> elements, so I think this is fixed now.

Comment 11

[arni2033]

(In reply to Markus Stange [:mstange] from comment #10)
> Bug 1251987 fixed per-page scrolling for all XUL <scrollbox> elements, so I think this is fixed now
Hmm, right. First time I checked this, I got wrong result. Now I see TWO cases handled in the patch.

To clarify the whole story: for 9+ years <arrowscrollbox> used broken DOMMouseScroll event, so
comment 0 was present. DOMMouseScroll is itself completely broken (explained in bug 1257815).
Quite recently - in bug 1263975 - <arrowscrollbox> switched to 'wheel' event (which is not broken), but behavior was still buggy, on front-end. It was completely fixed in bug 1251987.