Split the SIDEWAYS bit in WritingMode
Categories
(Core :: Layout: Block and Inline, task, P3)
Tracking
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| Tracking | Status | |
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| firefox71 | --- | fixed |
People
(Reporter: TYLin, Assigned: TYLin)
References
Details
Attachments
(1 file)
This bug is spun from the review in D45912 of bug 1102175. Currently, writing-mode:sideways-* and writing-mode:vertical-*; text-orientation:sideways; both set the same SIDEWAYS bit.
However, we need to distingish how the sideways bit is set on used value of WritingMode on nsIFrame. One use case is: when propagating <body>'s used writing-mode to <html>, <html>'s used writing-mode is different from its computed writing-mode, and we need to set block formatting context bits to <html>'s children if their writing-mode are different from <html>'s, per writing-mode spec..
If a box has a different writing-mode value than its parent box ... If the box is a block container, then it establishes an independent block formatting context.
That is, we need to differentiate vertical-rl from sideways-rl, and vertical-lr from sideways-lr on WritingMode. Some layout code tried hard to decipher the bits on the latter case, but there's no way for the former case.
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Comment 1•5 years ago
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Currently, there's no way to tell whether the SIDEWAYS bits is set from
writing-mode:sideways-* or writing-mode:vertical-*; text-orientation:sideways;. To be able to tell them apart, split SIDEWAYS bits
into VERTICAL_SIDEWAYS and TEXT_SIDEWAYS.
Also, provide convenience methods related to sideways writing-mode, and replace
obscure checks in the codebase.
Note that we don't have the use cases to distinguish vertical-rl from
sideways-rl in layout, but for the completeness, IsSidewaysLR() is still
defined.
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Updated•5 years ago
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Updated•5 years ago
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Comment 3•5 years ago
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| bugherder | ||
Description
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