I need to add capability to my Cesium app to drag-and-drop images(.png, .jpg, etc) onto it. Then, when the drop happens, I need to create a billboard with that image.
At first, I thought that the way to do it is to use Cesium.viewerDragDropMixin.
However it doesn't seem to have a way to specify function that is called when drop happens. I looked at the code for the Cesium.viewerDragDropMixinand saw a function handleDrop there which is specific to Czml.
When I tried to write my own mixin, using Cesium.viewerDragDropMixin as an example, Cesium crashed with message "Uncaught DeveloperError: mixin is required.".
So the questions I have are:
1. what is a proper way to implement Drag-andDrop
2. if I can use Cesium.viewerDragDropMixin, how do I specify function to process the drop?
3. If the proper way is to implement my own mixin, is there any tutorial on how to do it?
Thank you in advance,