1351336 - On print preview if you drag the scrollbar up and down creates some flicker

Status: RESOLVED DUPLICATE of bug 1251617

(Core :: Panning and Zooming, defect)

Description

[ovidiu boca[:Ovidiu]]

Tested on Nightly 55.0a1(2017-03-28) with Mac OS X 10.12, Ubuntu 14.04

STR: 

1. Go to http://conorlastowka.com/book/CitationNeededBook-Sample.pdf
2. Open print preview 
3. Drag the scrollbar up and down

Expected results:

The rendering is smooth without any issues. 

Actual results: 

Some flickers appear when you move up and down the scrollbar.  

Note: 

If I turn off from about:config the apz.drag pref. everything works as expected, this behavior can be obtained if you turn off the apz.allow_checkerboarding.

Comment 1

[Kartikaya Gupta (email:[e-mail])]

How do you open the print preview on OS X? As far as I know we never show the Firefox print preview window on OS X, since we use the OS-provided preview tool instead.

Comment 2

[ovidiu boca[:Ovidiu]]

Sorry, I wanted to say that is reproducible only on Ubuntu. You are right there is no print preview on OS X.

Comment 3

[Kartikaya Gupta (email:[e-mail])]

The flickering appears to be checkerboarding, so this is probably a dupe of bug 1251617. However I also notice that when scrolling the print preview window in Linux, the content seems to shift where it is on the preview "pages" depending on the scroll position. That's really weird. Seems to happen with and without apz.drag.enabled, and happens with wheel scrolling as well. That's probably worth a separate bug.

Comment 4

[Kartikaya Gupta (email:[e-mail])]

I filed https://bugzilla.mozilla.org/show_bug.cgi?id=1352083 for the other issue.

Comment 5

[Kartikaya Gupta (email:[e-mail])]

I'm going to dupe this to bug 1251617, which is what we're using to track checkerboarding during scrollbar drag.