Add comments for the lat-lon field of editplace

gramps/gui/editors/editplace.py

@@ -186,6 +186,32 @@ class EditPlace(EditPrimary):
             self.db.readonly)
 
     def set_latlongitude(self, value):
+        """
+        This method is useful for directly copying the coordinates
+        of openstreetmap, googlemaps, and perhaps other if they
+        provide coordinates like it is define in conv_lat_lon
+        (see gramps/gen/utils/place.py)
+
+        To copy the coordinates:
+
+        - openstreetmap:
+         1 - choose the place where you want to save the coordinates.
+         2 - right click on this place
+         3 - select "show address"
+         4 - On the left side of the map, copy the coordinates of
+             "Result from internal"
+         5 - In the latlon field of the edit place window of gramps,
+             type <CTRL> V
+
+        - googlemap:
+         1 - choose the place where you want to save the coordinates.
+         2 - right click on this place
+         3 - select the coordinates at the top of the popup window.
+             They are automaticaly copied.
+         4 - In the latlon field of the edit place window of gramps,
+             type <CTRL> V
+
+        """
         try:
             # Bug 12349, 12374
             parts = value.split(', ')