559437 - Panning images inside overflow:auto elements (Google Reader) stops for some posts

Status: RESOLVED DUPLICATE of bug 618975

(Firefox for Android Graveyard :: Panning/Zooming, defect, P1)

Description

[Henrik Skupin [:whimboo][⌚️UTC+1]]

If a feed entry on Google Reader contains a big images no panning is possible. You can only try to pan the small empty border on the left side. But that's not the way it should work. Panning on the image should be possible. Looks like it's also related to overflow:auto? 

Steps:
1. Subscribe to http://djst.org/blog/feed/
2. Search for "Silicon Valley" from March 1st
3. Open the post and try to scroll down

Comment 1

[Aakash Desai [:aakashd]]

Can you mention what build id you're using, henrik?

Comment 2

[David Tenser [:djst]]

I love how my blog is unique enough to serve as multiple test cases. It's not just my fantastic writing style, I guess!

Comment 3

[Martijn Wargers (dead)]

Attachment: testcase

In this case, it's impossible to vertically scroll the red bordered block, from inside the blue bordered box.

Comment 4

[Martijn Wargers (dead)]

Matthew fixed bug 556414, so he might have a clue why this isn't working.

Comment 5

[Matt Brubeck (:mbrubeck)]

I think this is because we stop looking for scrollable elements as soon as we find one.  If two scrollable elements are nested, only the inner one will scroll.  Keyboard scrolling in desktop Firefox has the same problem.  (Click inside the red box in the testcase and use the arrow keys to scroll.)

To fix this we will need to build a chain of scrollable elements and walk through them with Browser._panScroller (like we do for the nested scrollboxes in the Fennec chrome).

Comment 6

[Benjamin Stover (:stechz)]

Work for this is currently being done in bug 618975.