1811410 - Dragging the splitter is very inefficient

Status: RESOLVED FIXED

(Thunderbird :: General, defect)

Description

[Geoff Lankow (:darktrojan)]

The splitter updates on every mousemove event, and every update causes a reflow. This is a horrible waste of CPU time. I'm going to stop it from updating more than once per frame, as any more frequently does nothing of value, it's not even drawn to the screen.

It's still going to need to reflow at every update because that's how it works out whether it's reached the edge of the allowed area. For simple situations we could pre-calculate this and avoid reflows, but most situations are not simple.

Comment 1

[Geoff Lankow (:darktrojan)]

Attachment: Bug 1811410 - Improve the performance of dragging the splitter. r=aleca

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/comm-central/rev/457840c56921
Improve the performance of dragging the splitter. r=aleca

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/comm-central/rev/dd49b861e1b5
follow-up - Fix missed review comment. rs=me