957192 - Unnecessary -[ChildView drawRect:] calls during normal browsing

Status: RESOLVED FIXED

(Core :: Widget: Cocoa, defect)

Description

[Markus Stange [:mstange]]

Attachment: dontinvalidatewhenmovingview

In the OMTC world, drawRect is expensive because it makes the main thread block while the compositor thread composites the window. We do this so that window resizing looks good.

So we should try to avoid all drawRect calls that don't come from resizing.

I've found two cases where drawRect is still called during normal browsing:
 (1) When scrolling a page with plugins and
 (2) when the window title changes, for example due to clicking a link.

This patch avoids invalidations in both scenarios and (for me) results in a noticeable improvement of scrolling smoothness on pages with plugins.

Comment 1

[Steven Michaud [:smichaud] (Retired)]

Comment on attachment 8356635 [details] [diff] [review]
dontinvalidatewhenmovingview

This looks promising, but of course we'll need to look out for unwanted side effects.

By the way, I checked and found that -[NSWindow _setNeedsDisplayInRect:] has been present since at least OS X 10.5.

Comment 2

[Markus Stange [:mstange]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/9bbdc400dc1f

Comment 3

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/9bbdc400dc1f