261040 - Borders should not be included in GetActualScrollbarSizes

Status: RESOLVED FIXED

(Core :: Web Painting, defect)

Description

[Aaron Leventhal]

When implementing support for tabbability of css scrollable areas with
scrollbars, I had trouble reliably knowing when there was a scrollbar.

Robert O'callahan says this is partially due to margins being included in
GetActualScrollbarSizes (hopefully I've got that right).

Comment 1

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Attachment: fix

fix

Comment 2

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Attachment: correct patch

Sorry, the previous patch was the wrong patch. This is the right patch.

Comment 3

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Comment on attachment 160114 [details] [diff] [review]
correct patch

This moves GetActualScrollbarSizes to nsGfxScrollFrameInner and makes it use
the scrollframe's content rect so that the scrollframe's border, if any, is not
incorrectly included in the scrollbar sizes. (Yes, nsBox::GetClientRect
actually returns the content rect --- and nsBox::GetContentRect returns the
border rect!!!)

I also deCOMtaminated GetScrolledSize because I simply couldn't resist.

Comment 4

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Comment on attachment 160114 [details] [diff] [review]
correct patch

Shouldn't the summary of this bug say "padding and border", not "margins"?

Comment 5

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Yeah, In fact really it should just say "borders" since padding is applied to
the scrolled child, not the outer scrollframe. Thanks!

Comment 6

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Fix checked in.