1960253 - Make `PresShell::EventHandler` computable the event target `PresShell` without processing the pending pointer captures

Status: RESOLVED FIXED

(Core :: DOM: Events, task)

Description

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)]

We need to consider whether dispatch or not pointerrawupdate events before processing pending pointer captures to keep the traditional behavior on the documents/windows which do not use pointerrawupdate events. However, currently, the computation depends on flushing the pending pointer captures. So, we need to rewrite the computation which won't depend on the pointer capture state.

Comment 1

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)]

Attachment: Bug 1960253 - Split the computation of target frame/content of events using coordinates from `EventHandler::HandleEventUsingCoordinates` r=smaug!,#dom-core

We'll need to compute the target PresShell before processing the pending
pointer capture to check whether the corresponding window needs
pointerrawupdate events (bug 1550462).

However, currently code needs to flush the pending pointer capture and that
will change the behavior in some edge cases if the window does not need
pointerrawupdate events.

Therefore, we need a code to compute the target PresShell without processing
the pending pointer capture (and also without running any script) to consider
whether PresShell dispatches a pointerrawupdate at start of handling it.

Unfortunately, the code needs to return some information for the further
handling. Therefore, this makes a new nested struct and its constructor
computes everything with/without running script.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/ddd6c187d02d
Split the computation of target frame/content of events using coordinates from `EventHandler::HandleEventUsingCoordinates` r=smaug

Comment 3

[agoloman]

https://hg.mozilla.org/mozilla-central/rev/ddd6c187d02d