Unwanted synchronous layout for the full document in Writer after inserting a new implicit page

[vmiklos]

Is your feature request related to a problem?

Open the attached document of 300 pages: orig.odt

Go to the end of the first page, where there is an explicit page break between page 1 and page 2.

Press enter.

Wait a bit till Writer is responsible again.

Now you can type at the start of the new page 2.

Describe the solution you'd like

I would like a fast rendering for the visible area, then an idle layout for the rest of the document when I don't type. Similar to how this works already for the #9735 case (paste).

Describe alternatives you've considered

It would be nice if laying out 300 pages would be so fast that you don't even notice it, but that's not a reasonable goal.

Additional context

The current state is that you can see this output in the Chrome dev console:

15:08:33.803 global.js:566 1738073313803 OUTGOING: key type=up char=0 key=1280
...
15:08:34.249 global.js:566 1738073314249 INCOMING: delta: nviewid=1000 part=0 width=256 height=256 tileposx=11520 tileposy=11520 tilewidth=3840 tileheight=3840 oldwid=1 wid=1081 ver=43306 imgsize=1

This looks like 446 ms from "key up" to the first delta arriving to the browser. Ideal would be be something that is less than 40ms, so not really noticeable.