Draggable markers

[barbatus]

First of all, thanks for the awesome package.

Do you have plans to implement draggable markers soon?
I can help and contribute but not sure how much time it's gonna take.

[sebholstein]

@barbatus thanks for trying it out.

Draggable markers should be fairly easy to implement. Would be awesome if you can help out 👍

I think the API should look like this:

<sebm-google-map-marker 
  [latitude]="lat" [longitude]="lng" [isDraggable]="draggable">
</sebm-google-map-marker>

In addition to this, it should be possible to get the new position (lat/lng) of the marker after the dragging. I will create a seperate issue and plan this for the v0.6.0 milestone too.