KML ROIs

ROIs could be stored as .kml (google-earth) files. Example:

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2" xmlns:gx="http://www.google.com/kml/ext/2.2" xmlns:kml="http://www.opengis.net/kml/2.2" xmlns:atom="http://www.w3.org/2005/Atom">
<Document>
	<name>dummy.kml</name>
	<open>1</open>
	<Style id="sn_ylw-pushpin">
		<IconStyle>
			<scale>1.1</scale>
			<Icon>
				<href>http://maps.google.com/mapfiles/kml/pushpin/ylw-pushpin.png</href>
			</Icon>
			<hotSpot x="20" y="2" xunits="pixels" yunits="pixels"/>
		</IconStyle>
		<LineStyle>
			<color>ffff717c</color>
			<width>3</width>
		</LineStyle>
	</Style>
	<StyleMap id="msn_ylw-pushpin">
		<Pair>
			<key>normal</key>
			<styleUrl>#sn_ylw-pushpin</styleUrl>
		</Pair>
		<Pair>
			<key>highlight</key>
			<styleUrl>#sn_ylw-pushpin2</styleUrl>
		</Pair>
	</StyleMap>
	<Folder>
		<name>Collection of ROIS</name>
		<description>Collection description</description>
		<Placemark>
			<name>Linear feature</name>
			<description>Linear feature description</description>
			<styleUrl>#msn_ylw-pushpin</styleUrl>
			<LineString>
				<extrude>1</extrude>
				<tessellate>1</tessellate>
				<altitudeMode>absolute</altitudeMode>
				<coordinates>
					110,-35,0 120,-30,0 130,-25,0
				</coordinates>
			</LineString>
		</Placemark>
		<Placemark>
			<name>Polygon feature</name>
			<description>Polygon feature description</description>
			<styleUrl>#msn_ylw-pushpin</styleUrl>
			<Polygon>
				<extrude>1</extrude>
				<tessellate>1</tessellate>
				<altitudeMode>absolute</altitudeMode>
				<outerBoundaryIs>
					<LinearRing>
						<coordinates>
							-90,30,0 -30,30,0 -30,0,0 -90,0,0 -90,30,0
						</coordinates>
					</LinearRing>
				</outerBoundaryIs>
			</Polygon>
		</Placemark>
	</Folder>
</Document>
</kml>

References: KML documentation

Usage proposal

KmlROIsCollection should be a ROIsCollectionWithCategories child:

>>> kml_rois = KmlROIsCollection('dummy.kml', target='Europa')
>>> kml_rois
<KmlROIsCollection> 2 rois | 1 category

>>> kml.categories
<CategoriesCollection> 1 category
 - Collection of ROIS

>>> kml.rois
<ROIsCollection> 2 rois
 - 1 / Linear feature
 - 2 / Polygon feature

Map display should be straightforward:

fig = plt.figure(figsize=(18, 9))
ax = fig.add_subplot(projection=EUROPA)

ax.add_collection(kml_rois);

Multiple files important should be supported and populate the collection with different categories based on the folder name and description:

>>> KmlROIsCollection('dummy.kml', 'foo.kml', 'bar.kml', target='Europa')
<KmlROIsCollection> 25 rois | 3 categories

Note

Support for Linear ROI intersection is not out of the scope of the this issue.