* Added members for Ground Overlay tags.

* Implemented the altitude property and etree_element() functionality.

fastkml/kml.py

@@ -743,6 +743,72 @@ class GroundOverlay(_Overlay):
     """
     __name__ = 'GroundOverlay'
 
+    _altitude = None
+    # Specifies the distance above the earth's surface, in meters, and is
+    # interpreted according to the altitude mode.
+
+    _altitudeMode = None
+    # Specifies how the <altitude> is interpreted. Possible values are:
+    #   clampToGround -
+    #       (default) Indicates to ignore the altitude specification and drape
+    #       the overlay over the terrain.
+    #   absolute -
+    #       Sets the altitude of the overlay relative to sea level, regardless
+    #       of the actual elevation of the terrain beneath the element. For
+    #       example, if you set the altitude of an overlay to 10 meters with an
+    #       absolute altitude mode, the overlay will appear to be at ground
+    #       level if the terrain beneath is also 10 meters above sea level. If
+    #       the terrain is 3 meters above sea level, the overlay will appear
+    #       elevated above the terrain by 7 meters.
+
+    # - LatLonBox -
+    # Specifies where the top, bottom, right, and left sides of a bounding box
+    # for the ground overlay are aligned. Also, optionally the rotation of the
+    # overlay.
+
+    _north = None
+    # Specifies the latitude of the north edge of the bounding box, in decimal
+    # degrees from 0 to ±90.
+
+    _south = None
+    # Specifies the latitude of the south edge of the bounding box, in decimal
+    # degrees from 0 to ±90.
+
+    _east = None
+    # Specifies the longitude of the east edge of the bounding box, in decimal
+    # degrees from 0 to ±180. (For overlays that overlap the meridian of 180°
+    # longitude, values can extend beyond that range.)
+
+    _west = None
+    # Specifies the longitude of the west edge of the bounding box, in decimal
+    # degrees from 0 to ±180. (For overlays that overlap the meridian of 180°
+    # longitude, values can extend beyond that range.)
+
+    _rotation = None
+    # Specifies a rotation of the overlay about its center, in degrees. Values
+    # can be ±180. The default is 0 (north). Rotations are specified in a
+    # counterclockwise direction.
+
+
+    @property
+    def altitude(self):
+        return self._altitude
+
+    @altitude.setter
+    def altitude(self, value):
+        try:
+            float(value)
+        except (ValueError, TypeError):
+            self._altitude = None
+        else:
+            self._altitude = str(value)
+
+    def etree_element(self):
+        element = super(GroundOverlay, self).etree_element()
+        if self._altitude:
+            altitude = etree.SubElement(element, "%saltitude" % self.ns)
+            altitude.text = self._altitude
+        return element
 
 
 class Document(_Container):

fastkml/test_main.py

@@ -22,7 +22,7 @@ from fastkml import styles
 from fastkml import base
 from fastkml import atom
 from fastkml import config
-from fastkml import gx
+from fastkml import gx  # NOQA
 
 import datetime
 from dateutil.tz import tzutc, tzoffset
@@ -93,8 +93,8 @@ class BaseClassesTestCase(unittest.TestCase):
     def test_Container(self):
         f = kml._Container(name='A Container')
         # apparently you can add documents to containes
-        #d = kml.Document()
-        #self.assertRaises(TypeError, f.append, d)
+        # d = kml.Document()
+        # self.assertRaises(TypeError, f.append, d)
         p = kml.Placemark()
         f.append(p)
         self.assertRaises(NotImplementedError, f.etree_element)
@@ -2026,6 +2026,45 @@ class GroundOverlayTestCase(unittest.TestCase):
 
         self.assertEqual(g.to_string(prettyprint=False), expected)
 
+    def test_altitude_from_int(self):
+        g = kml.GroundOverlay()
+        g.altitude = 123
+
+        expected = (
+            '<kml:GroundOverlay xmlns:kml="http://www.opengis.net/kml/2.2">'
+            '<kml:visibility>1</kml:visibility>'
+            '<kml:altitude>123</kml:altitude>'
+            '</kml:GroundOverlay>'
+        )
+
+        self.assertEqual(g.to_string(prettyprint=False), expected)
+
+    def test_altitude_from_float(self):
+        g = kml.GroundOverlay()
+        g.altitude = 123.4
+
+        expected = (
+            '<kml:GroundOverlay xmlns:kml="http://www.opengis.net/kml/2.2">'
+            '<kml:visibility>1</kml:visibility>'
+            '<kml:altitude>123.4</kml:altitude>'
+            '</kml:GroundOverlay>'
+        )
+
+        self.assertEqual(g.to_string(prettyprint=False), expected)
+
+    def test_altitude_from_string(self):
+        g = kml.GroundOverlay()
+        g.altitude = '123.4'
+
+        expected = (
+            '<kml:GroundOverlay xmlns:kml="http://www.opengis.net/kml/2.2">'
+            '<kml:visibility>1</kml:visibility>'
+            '<kml:altitude>123.4</kml:altitude>'
+            '</kml:GroundOverlay>'
+        )
+
+        self.assertEqual(g.to_string(prettyprint=False), expected)
+
 
 def test_suite():
     suite = unittest.TestSuite()
@@ -2039,6 +2078,8 @@ def test_suite():
     suite.addTest(unittest.makeSuite(SetGeometryTestCase))
     suite.addTest(unittest.makeSuite(GetGeometryTestCase))
     suite.addTest(unittest.makeSuite(Force3DTestCase))
+    suite.addTest(unittest.makeSuite(BaseOverlayTestCase))
+    suite.addTest(unittest.makeSuite(GroundOverlayTestCase))
     return suite
 
 if __name__ == '__main__':