2009647 - Add measuring reflow in printing scenario for fragmentainer-aware abspos positioning

Status: RESOLVED FIXED

(Core :: Layout: Positioned, task)

Description

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

Bug 1994346 added measuring reflow logic in nsColumnSetFrame to compute the unfragmented positions of absolutely positioned descendants in multicol contexts. This is needed for fragmentainer-aware positioning to determine whether an abspos first-in-flow needs to be pushed to the next fragmentainer continuation.

We need similar logic for printing scenario, which may be added in PageSequenceFrame::Reflow().

Comment 1

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

Attachment: Bug 2009647 Part 1 - Rename mIsInColumnMeasuringReflow to mIsInFragmentainerMeasuringReflow. r?#layout

This renames the measuring reflow flag to use "fragmentainer" terminology,
making it applicable to both multicol and printing contexts. This doesn't change
behavior.

Comment 2

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

Attachment: Bug 2009647 Part 2 - Add measuring reflow in printing scenarios for fragmentainer-aware abspos positioning. r?#layout

This extends the measuring reflow mechanism from multicol (Bug 1994346) to
printing scenarios. When absolutely positioned elements exists, we now perform
an initial measuring reflow with an unconstrained page height to compute
unfragmented positions, sizes, etc.

Each frame type (nsPageSequenceFrame, nsPageFrame, PrintedSheetFrame,
nsPageContentFrame) has their own logic to calculate the available size for its
child, and they do not derived the size its own reflow input's available size.
To avoid substantial refactoring, this patch checks
mIsInFragmentainerMeasuringReflow and overrides the available block-size to
unconstrained when running a measuring reflow.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/04b46f1dcc7d
https://hg.mozilla.org/integration/autoland/rev/5c6ab63f61dd
Part 1 - Rename mIsInColumnMeasuringReflow to mIsInFragmentainerMeasuringReflow. r=layout-reviewers,dshin
https://github.com/mozilla-firefox/firefox/commit/19124a708fc4
https://hg.mozilla.org/integration/autoland/rev/94b404c5c152
Part 2 - Add measuring reflow in printing scenarios for fragmentainer-aware abspos positioning. r=layout-reviewers,dshin

Comment 5

[Cristian Tuns]

https://hg.mozilla.org/mozilla-central/rev/5c6ab63f61dd
https://hg.mozilla.org/mozilla-central/rev/94b404c5c152