KML + Google Earth: Make a Polygon or GroundOverlay clickable?

Question

Pretty simple question.

I've got some Polygons and GroundOverlays defined in KML. Is there a way to specify that they should be clickable, and (in Google Earth, at least) pop up an info balloon or similar when they are clicked?

Similarly, is it possible to give polygons/GroundOverlays any sort of mouseover behavior? e.g. change the icon or color when moused over?

Lefthander

Answer 1

Yes. Giving the Placemark a name and description will make it a clickable object in Google Earth and will open with an info window showing both. You can create rollover/mouseover behavior using stylemaps, here is an example that does both:

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2">
<Document>
<name>Highlighted Icon</name>
<description>Place your mouse over the icon to see it display the new
      icon</description>
<StyleMap id="exampleStyleMap">
  <Pair>
    <key>normal</key>
    <!-- you could also use a <styleUrl> here instead of inlining -->
    <Style>
      <PolyStyle>
        <color>7dff0000</color>
      </PolyStyle>
    </Style>
  </Pair>
  <Pair>
    <key>highlight</key>
    <!-- you could also use a <styleUrl> here instead of inlining -->
    <Style>
      <PolyStyle>
        <color>7dffffff</color>
      </PolyStyle>
    </Style>
  </Pair>
</StyleMap>

<!-- and now, a Placemark that uses the StyleMap -->
<Placemark>
  <name>Roll over this polygon</name>
  <description>this will show up when clicked</description>
  <visibility>1</visibility>
  <styleUrl>#exampleStyleMap</styleUrl>
  <Polygon>
    <tessellate>1</tessellate>
    <altitudeMode>absolute</altitudeMode>
    <outerBoundaryIs>
      <LinearRing>
        <coordinates>
          -112.3372510731295,36.14888505105317,1784
          -112.3356128688403,36.14781540589019,1784
          -112.3368169371048,36.14658677734382,1784
          -112.3384408457543,36.14762778914076,1784
          -112.3372510731295,36.14888505105317,1784
        </coordinates>
      </LinearRing>
    </outerBoundaryIs>
  </Polygon>
</Placemark>
</Document>
</kml>

Flounce

One question: Can you do the two-part style for each placemark individually? e.g., have a library of 100 JPEG images, and have 100 solid-color polygons laid out on the map, where each time you mouse over one of them, one of the 100 images appears in its place? – Lefthander