Dragging doesn't track well, breaks UI

[JonathanL]

When you drag any element except for the 0,0'th the dragged element will be some integer multiple offset of the mouse/finger location.

e.g. If you drag an element origin'ed at 0,1 then as dragging starts it will jump 1*N to the left, an element origin'ed at 0,3 then as dragging starts it will jump 3*N to the left, and everything shifts based on this offset.

The effect is also true in the Y direction, so 2,0 element will be 2*M up (unclear whether N=M), and an element a 1,3 will be 1*M up and 3*N left of the dragpoint.

It can be impossible to return to the original screen and some elements will be bumped off the screen and become invisible and because of the offset impossible to return.

I should note gridster has a demo which does not exhibit this behaviour so it is likely something atlasboard is doing.

Steps to reproduce

1. Open a dashboard with multiple rows and columns.
2. Drag a widget.

VP: Watch the widgets scatter.

Impact

Can destroy demos and teaches users to be fearful of touching widgets. Many widgets contain links which lead to further details so this is counterproductive.

Setup

• Atlasboard is 1.1.3, hosted on heroku or MacOS
• Running on Safari 10.0.2 on Sierra
• Seen also on MobileSafari on iOS 10

Workaround

Disable dragging by running this in the console:

$(".gridster ul").gridster().data('gridster').disable()

It could also be added to the page at the right point.

[Eric Hirlemann]

Very interesting, this deserves a PR. The client page is computed from with the help of ejs. The settings related to the grids are passed to Gridster here.