Change 367928 had a related patch set uploaded (by Dbrant; owner: Dbrant):
[apps/android/wikipedia@master] Fake out Explore toolbar overlap as one single bar.

https://gerrit.wikimedia.org/r/367928

@RHo I believe I've managed to create the expected behavior by following the last option noted in the description (manually adding/removing the elevation on the toolbar). Feel free to try out the patch listed above. As I mentioned, changing the behavior of the Search bar will be a separate matter entirely, and is currently rather prohibitive, based on my experimentation. I'll leave some more notes on that ticket.

Change 367928 merged by jenkins-bot:
[apps/android/wikipedia@master] Fake out Explore toolbar overlap as one single bar.

https://gerrit.wikimedia.org/r/367928

Looks really good and swiping up to collapse is pretty smooth!

However, here's an update on the overall feed toolbar spacing:

This seems to be looking great. I wanted to point out a little thing that I noticed. There's a possibility for the search bear to be partially under the hidden top bar in which case this doesn't seem to look pretty well. Not sure if it's that important.

In case this is considered for fixing, I guess T153573 could be considered parallely.

I pointed this out because, on seeing the Z-space diagram, side view found in the material design guideline for scrolling techniques, it seems the top bar should come above any other content on the screen. So, I thought the search bar should also be considered a content in this case.

In T170831#3486337, @Kaartic wrote:

I pointed this out because, on seeing the Z-space diagram, side view found in the material design guideline for scrolling techniques, it seems the top bar should come above any other content on the screen. So, I thought the search bar should also be considered a content in this case.

Hi @Kaartic - we are treating the search bar as part of the "flex space" described at the bottom of the scrolling techniques you mentioned, under "Flexible space with overlapping content". And yes, think the T153573 would be a separate bug.

In T170831#3486436, @RHo wrote:

Hi @Kaartic - we are treating the search bar as part of the "flex space" described at the bottom of the scrolling techniques you mentioned, under "Flexible space with overlapping content".

I see. I thought the search bar was a content. Didn't know you could consider the search bar as flex space. No issues.

Fortunately or Unfortunately, I happened to observe the odd behaviour depicted below.

I'm not pretty sure how to reproduce this but it seems to have occured as a result of a combination of events such as, switching from other apps and the wikipedia app and toggling the network connectivity on (or) off. I'll update the steps if I could find any.

BTW, it's a screenshot of the alpha dated 02-08-2017 on a moto g5 plus running android 7.0

+ @Dbrant - did you want to investigate this bug on this task or track separately?

That should be a separate task.

Hi @Kaartic - per the comment from @Dbrant I've created a separate bug ticket T172536 for the issue you're seeing.

In T170831#3501366, @RHo wrote:

Hi @Kaartic - per the comment from @Dbrant I've created a separate bug ticket T172536 for the issue you're seeing.

Thanks! I've updated the task with the Steps to reproduce

Same test as T171328, but check that upon scrolling, the search bar in that flex area should slide underneath the app bar.
open to view animated gif

Tested on a Nexus 4 with Android 5.1 and a Pixel with Android 7.1.1

Looks great