1587645 - Remove ScrollFrameHelper::GetFrameForDir()

Status: RESOLVED FIXED

(Core :: Layout: Block and Inline, task, P3)

Description

[Ting-Yu Lin [:TYLin] (PDT, UTC-7)]

Another suggestion by Emilio per https://mozilla.logbot.info/layout/20190920#c16630059. After bug 1102175 landed, we can remove ScrollFrameHelper::GetFrameForDir().

Also, it might worth auditing all the frame classes that still get "writing-mode", "direction", and "text-orientation" from computed style instead of mWritingMode stored in nsIFrame.

Comment 1

[Ting-Yu Lin [:TYLin] (PDT, UTC-7)]

Attachment: Bug 1587645 Part 1 - Remove ScrollFrameHelper::GetFrameForDir().

After bug 1102175, the root scroll frame always obtains its used
WritingMode from either body element or root element. The if (mIsRoot)
in GetFrameForDir() block becomes redundant, so does GetFrameForDir()
itself.

Comment 2

[Ting-Yu Lin [:TYLin] (PDT, UTC-7)]

Attachment: Bug 1587645 Part 2 - Add WritingMode::IsPhysicalLTR().

I discovered this while improving ScrollFrameHelper::IsPhysicalLTR().
Our code base needs a notion of physical direction. Let's add it to
WritingMode.

Depends on D49817

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/712c3e31d097
Part 1 - Remove ScrollFrameHelper::GetFrameForDir(). r=emilio
https://hg.mozilla.org/integration/autoland/rev/b6f7644d72da
Part 2 - Add WritingMode::IsPhysicalLTR(). r=jfkthame

Comment 4

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/712c3e31d097
https://hg.mozilla.org/mozilla-central/rev/b6f7644d72da