18196 - [Tree]scrolling w/arrow keys unpredictable in tree

Status: VERIFIED FIXED

(Core :: XUL, defect, P3)

Description

[Claudius Gayle]

Overview Description:
	Sorry for the muddy summary but there is no good way to capture the problem.
Selecting an item in a tree view and then using the arrow keys to sroll around has strange
-and tricky to repro results.

Steps to Reproduce:

1) Open the bookmarks window. Expand the tree such that it is longer than the window.
2) Select an item that is not the topmost or bottommost viewable item.
3) Use the arrow down arrow key to try and scroll the other items into the viewable area.

Actual Results:
	What happens most of the time is the selection scrolls to the top of the viewable
area instead of scrolling the tree - but only the first time through the list. If you keep
scrolling down the view will then scroll. After the selection mistakenly scrolls scrolling up
and down (up even the you are at the top of the tree) will do wierd things. Sometimes
it will wrap sometimes the topmost item is unselectable.


Expected Results:
	navigating down the tree should scroll the view after the last visible item is reached.
I'm not sure what should happen when you hit up arrow at the topmost item. Currently Nova
does nothing.

Build Date & Platform Bug Found:
	This bug is XP and repro's on all platforms with the 1999110709 builds.

Comment 1

[Claudius Gayle]

Attachment: MacsBug stack trace

Comment 2

[Claudius Gayle]

I forgot to mention this crashed my mac, I've attached the entire MacsBug report

Comment 3

[selmer (gone)]

Marking [Tree], changed summary to (hopefully) better reflect main problem in
the description.

Comment 4

[selmer (gone)]

Alec wants all the scrolling bugs since he's fixing them as a group right now.

Comment 5

[Alec Flett]

ok, I fixed this for trees with no header row. there were some row index
corruption problems....there's something else I'm missing with trees that have
column headers (i.e. most trees)

Comment 6

[Alec Flett]

Ahah! I've got the fix. Turns out EnsureRowIsVisible and IsValidRow both
expected zero-based values not row indicies.... in the case of trees with a
header (i.e. most trees) you got off by one, which just confused things.

Awaiting a code review from hyatt.

Comment 7

[Alec Flett]

whoo hoo... finally fixed.
It behaves normally now - no more invisible items selected, scrolling works as
expected, and so forth.

Comment 8

[Claudius Gayle]

this one is VERIFIED fixed, but there'll be more to come shortly...

Comment 9

[Claudius Gayle]

verified with 1999111608 builds that is.