1898408 - Updating `<br>` to a padding one cannot cause text change notification to IME

Status: RESOLVED FIXED

(Core :: DOM: Editor, defect)

Description

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

When <br> element is set to a padding one, ContentEventHandler treats it as hidden. However, updating the type from or to padding one is not observable from IMEContentObserver. Therefore, when a connect <br> element becomes a padding <br>, it's not notified IME but it should cause a removing text notification.

This might cause bug 1824143.

Comment 1

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

Attachment: Bug 1898408 - Make our editor disconnect `<br>` element temporarily when its type is changed from or to padding one r=m_kato!

Currently, the <br> element type -- whether normal <br> element or padding
<br> element for empty editor or last line -- is managed by the flags of
nsINode. Therefore, changing the flag does not cause mutation, so
IMEContentObserver cannot observe the type changes. However,
ContentEventHandler treats the padding <br> elements as invisible.
Therefore, when a <br> element becomes a padding one, IMEContentObserver
needs to notify IME of atext removed notification, and also when a <br>
element becomes a normal one (i.e., visible), IMEContentObserver needs to
notify IME of a text added notification.

Therefore, this patch makes EditorBase disconnect the <br> element
temporarily to make IMEContentObserver observable the type change.

Depends on D211698

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/ef63f8e565ed
Make our editor disconnect `<br>` element temporarily when its type is changed from or to padding one r=m_kato

Comment 3

[pstanciu]

https://hg.mozilla.org/mozilla-central/rev/ef63f8e565ed