Tuesday, April 25, 2017

mobile touch gotcha

I once made an angular firebase demo site called Fridge Magnets With Friends.
You can move magnets around on a virtual fridge. This involves a lot of dragging elements.
One day mobile drag stopped working, even tho I employed the clever jquery ui touch punch.

I spent hours switching the whole thing to use ngDraggable, because their mobile demo did work in mobile. Altho using ngDraggable required me to take out jquery (actually it didn't, but some forums said that would help make it work in mobile) - so I spent a while redoing the angular app without jquery.
Moment of truth: no luck.

Finally I hijacked the browser with a little shim code:
        $document.on('touchstart', function(e){

Because for the life of me I couldn't figure out why my elements weren't receiving the touchstart event in mobile.
This way I could see what element the e event was pointing to.
Turns out my footer CSS was very improperly done and covering the entire screen, so the event for touchstart, which has to have a stoppropogate() for other reasons in mobile only, never made it to the dragable elements.
Took out the footer and both solutions started working; however, jquery-ui + touch-punch still worked better than ngDraggable, so in the end, 4 hours of work (work that was, admittedly, kind of fun) got reduced to commenting out a couple lines of html. At least I understand mobile touch events now.

facepalms: 9.5

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