Single Layer Opacity Slider Including Basemaps
Ooohhhh, I already made that Widget. Surely, I could get it ready for the public in like 15 minutes...
Much more than 15 minutes later...
Say you want to give your users the option to control the opacity of a layer. Well, you could use the Transparency option in the Map Layers Widget, but what if you aren't already using a Map Layers Widget? What if you want to make the option easier to find than buried in the Map Layer Widget? What if you wanted to change the basemap opacity?
This little slider can do that. And the 0% and 100% are buttons.
The default setting Control The Basemap is designed for controlling the basemap layers. The basemap may be made of many layers. It should adjust the opacity of all the basemap layers at the same time including the reference layers. If the user switches basemaps, this Widget should switch to controlling the new basemap and apply the current opacity.
If you turn off Control The Basemap, you can set the slider to control some other layer. If the user adjusts the opacity from the Map Layers Widget, this slider should move with it.
Known limitation: It cannot handle Group Layers. I just could not be bothered to figure out how to make that happen.
