1819848 - Additional hardening of the compositor thumb size calculation

Status: RESOLVED FIXED

(Core :: Panning and Zooming, task, P2)

Description

[Botond Ballo [:botond]]

Spinning out the initial fix idea for bug 1818702 from bug 1818702 comment 14, which is really a hardening against other possible minor mismatches between the main-thread and compositor calculations, into this bug.

Comment 1

[Botond Ballo [:botond]]

Attachment: Bug 1819848 - Only scale the thumb in the compositor if we are async-zoomed. r=rzvncj

In principle, the calculated scale should be 1.0 if we are not async-zoomed,
but sometimes things like rounding error can cause the scale to be slightly
off.

Comment 2

[Botond Ballo [:botond]]

Attachment: Bug 1819848 - If we don't scale the thumb, use the unscaled length in the position calculation. r=rzvncj

Depends on D171437

Comment 3

[Botond Ballo [:botond]]

Attachment: Bug 1819848 - Move calculations that are only needed for the 'if (haveAsyncZoom)' branch into that branch. r=rzvncj

Depends on D171438

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/3e1124bfbcbd
Only scale the thumb in the compositor if we are async-zoomed. r=rzvncj
https://hg.mozilla.org/integration/autoland/rev/367f1d038bea
If we don't scale the thumb, use the unscaled length in the position calculation. r=rzvncj
https://hg.mozilla.org/integration/autoland/rev/222a3e2f0f2e
Move calculations that are only needed for the 'if (haveAsyncZoom)' branch into that branch. r=rzvncj

Comment 5

[Norisz Fay [:noriszfay]]

https://hg.mozilla.org/mozilla-central/rev/3e1124bfbcbd
https://hg.mozilla.org/mozilla-central/rev/367f1d038bea
https://hg.mozilla.org/mozilla-central/rev/222a3e2f0f2e