Media Grid: user feedback during content load

[Clorith]

When scrolling the media grid, there's no feedback to the end user that more content is loading beyond the spinner in the toolbar.

I found one oddity where infinite scroll is triggered, and we check if we are near the end of the page, then show the spinner in the toolbar, this is redundant as the toolbar will in most situations not even be visible at this point.

I think a spinner taking up the space of a grid element while loading should be introduced to the list and shown whenever we are loading more content (keep the spinner size, I'm just referencing the DOM area it should occupy at the time).

[michalzuber]

Tried with 400 images:

1. Had no infinite scroll
2. Only 79 items showed up in Media Grid instead 401 items as in List View

​https://youtu.be/3f2ckjflFM8

I created images with the following script and then just added them. Selected them all and multiple upload took approx. 2minutes to finish

#!/bin/bash

for (( i = 0; i < 400; i++ )); do
	cp wordpress-logo-square.png wordpress-$i.png
done

UPDATE: Tried also in FF 31. Both Chrome and FF issues admin-ajax.php request, during 2 minutes Chrome made over 400 requests ​http://i.imgur.com/xOEI8dM.png

[ocean90]

Duplicate of #28927?

[helen]

Duplicate of #28927.