Handle rotation in plugins

[moovida]

I was wondering what the best practice would be in a plugin, to keep the graphics on screen even if the map rotates. For example the scalebar rotates with the map and therefore disappears.

I thought it would be simple as rotating back the drawing canvas of the same amount as the map.rotation, but it didn't work as expected.

Any hint? Thanks a ton.

[fluttercid]

I also want what you want.
There is any progress about it.
Thank you.

[moovida]

I assume this pull request will take care of it: #719

Well, most probably we will need a procedure that allows us to counter-rotate the plugins to have them kept right.

Also touch events will be an issue, if they are issued in plugins.

Most probably we will get (or we will implement :-) ) a rotation transformation from the map context to do this.

[maRci002]

#719 now implements this behavior: able to mix rotate and non rotate layers with a flag

Note: onTap, onLongPress still gives back the LatLng according to rotation.

I think I'll refactor to specify separately non rotate and rotate layers so rotate layers will be always the bottom one because rotating the whole layer tree is much faster than rotate one by one.

[maRci002]

PR updated now there are layers / nonRotatedLayers and children / nonRotatedChildren examples updated too.