850815 - [email] UI: Improve scrolling performance of message reader card for HTML messages (scaled and un-scaled)

Status: RESOLVED FIXED

(Firefox OS Graveyard :: Gaia::E-Mail, defect)

Description

[Andrew Sutherland [:asuth] (he/him)]

In bug 849924 Etienne provided me with an HTML newsletter (that does not trigger newsletter mode) that takes a very long time to load.  It also exhibited tremendously poor scrolling performance.  There are two inefficient things we are doing that we should avoid doing:
- setting scale(1) as a transform.  This is not the same as just setting the transform string to empty.
- setting overflow: hidden on the iframe.  Per input from roc, this has non-zero overhead, and in the case of the iframe, we simply don't need it.

In addition to significantly improving the responsiveness of scrolling, the load time of the HTML was reduced by slightly under 200ms, which seems like a large win.

Comment 1

[Andrew Sutherland [:asuth] (he/him)]

Attachment: Pointer to Github pull request: https://github.com/mozilla-b2g/gaia/pull/8627

Pointer to Github pull-request

Comment 2

[Andrew Sutherland [:asuth] (he/him)]

Comment on attachment 724563 [details]
Pointer to Github pull request: https://github.com/mozilla-b2g/gaia/pull/8627

Etienne, these fixes are the result of my investigation.  You seem appropriate to review.  Plus, good learning experience! :)

Comment 3

[Etienne Segonzac (:etienne)]

Comment on attachment 724563 [details]
Pointer to Github pull request: https://github.com/mozilla-b2g/gaia/pull/8627

cool, and now that I know how the zooming works I find it extremely fast ;)

Comment 4

[Andrew Sutherland [:asuth] (he/him)]

landed on gaia/master:
https://github.com/mozilla-b2g/gaia/pull/8627
https://github.com/mozilla-b2g/gaia/commit/447997ac8f15508f581d04e9913cd6b05aa8079d

Comment 5

[Julien Wajsberg [:julienw]]

Was landed in v1.0.1 as part of Bug 851124 big uplift.
Will land in v1-train tomorrow at the latest too.

Comment 6

[Julien Wajsberg [:julienw]]

Landed in v1-train as part of Bug 851124 big uplift.