1811823 - CSS Custom Highlight API: Invalidation and prioritization

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, task)

Description

[Jan Jaeschke [:jjaschke]]

Prioritization of custom highlights is not implemented yet, as well as Range upating/invalidation.

Comment 1

[Jan Jaeschke [:jjaschke]]

Attachment: WIP: Bug 1811823, part 1: Order highlight selections by insertion order. r=masayuki

Comment 2

[Jan Jaeschke [:jjaschke]]

Attachment: WIP: Bug 1811823, part 2: Fixed some prioritization issues for Custom Highlight API. r=emilio!

Main part of this patch is a refactoring of nsTextFrame::ResolveSelections(),
which was necessary in order to determine the correct highlight selection to be painted.
Instead of returning the prevailing selection for a segment, it now returns
an array of Selections per segment, ordered by the priority.
In the future, this array can be used to combine different selection types properly:

• overlapping highlights where the higher prioritized highlight does not define text color,
  and therefore the next-lower-priority text color should be used
• When a highlighted segment is also selected by normal selection, the selections could be blended together. Right now only normal selection is painted.

Depends on D174480

Comment 3

[Phabricator Automation]

Comment on attachment 9326634 [details]
WIP: Bug 1811823, part 1: Order highlight selections by insertion order. r=masayuki

Revision D174480 was moved to bug 1836013. Setting attachment 9326634 [details] to obsolete.

Comment 4

[Jan Jaeschke [:jjaschke]]

Attachment: Bug 1811823, part 1: Added `HighlightSelectionData` struct. r=emilio

The idea of this struct is to allow live data of a highlight selection to be passed into layout.
Layout needs highlight properties such as priority or type to resolve combinations of highlights correctly.

Comment 5

[Jan Jaeschke [:jjaschke]]

Attachment: Bug 1811823, part 2: Add correct prioritization for custom highlights. r=emilio!,jfkthame,#dom-core

Due to the prioritization rules for custom highlights, it is not feasible to rely on cascading.
Instead, highlights need to be stacked by their priority (and order of insertion).
Text and background color of the highest-prioritized highlight which defines that property should be used.

Since highlights are implemented as special Selections, the algorithm that determines the prevailing selection for a text frame needed to be adapted to instead return a list of selections.

Depends on D181142

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/a8cecdf5e3ff
part 1: Added `HighlightSelectionData` struct. r=emilio
https://hg.mozilla.org/integration/autoland/rev/7a9232452ebf
part 2: Add correct prioritization for custom highlights. r=emilio

Comment 7

[Cristina Horotan [:chorotan]]

https://hg.mozilla.org/mozilla-central/rev/a8cecdf5e3ff
https://hg.mozilla.org/mozilla-central/rev/7a9232452ebf