/**
* Create the objects described in an XML element containing layer and/or layer-list descriptions.
* Nested layer lists and included layers are created recursively.
*
* @param domElement an XML element describing the layers and/or layer lists.
* @param params any properties to apply when creating the included layers.
* @return a <code>Layer</code>, <code>LayerList</code> or array of <code>LayerList</code>s, as
* described by the specified description.
* @throws Exception if an exception occurs during creation. Exceptions occurring during creation
* of internal layers or layer lists are not re-thrown but are logged. The layer or layer list
* associated with the exception is not contained in the returned object.
*/
@Override
protected Object doCreateFromElement(Element domElement, AVList params) throws Exception {
Element[] elements = WWXML.getElements(domElement, "//LayerList", null);
if (elements != null && elements.length > 0) return createLayerLists(elements, params);
elements = WWXML.getElements(domElement, "./Layer", null);
if (elements != null && elements.length > 1) return createLayerList(elements, params);
if (elements != null && elements.length == 1)
return this.createFromLayerDocument(elements[0], params);
String localName = WWXML.getUnqualifiedName(domElement);
if (localName != null && localName.equals("Layer"))
return this.createFromLayerDocument(domElement, params);
return null;
}
/**
* Returns true if a specified DOM document should be accepted as an ElevationModel configuration
* document, and false otherwise.
*
* @param domElement the DOM document in question.
* @return true if the document is an ElevationModel configuration document; false otherwise.
* @throws IllegalArgumentException if document is null.
*/
public static boolean isElevationModelDocument(Element domElement) {
if (domElement == null) {
String message = Logging.getMessage("nullValue.DocumentIsNull");
Logging.logger().severe(message);
throw new IllegalArgumentException(message);
}
XPath xpath = WWXML.makeXPath();
Element[] elements = WWXML.getElements(domElement, "//ElevationModel", xpath);
return elements != null && elements.length > 0;
}
/**
* Create a collection of layer lists and their included layers described by an array of XML
* layer-list description elements.
*
* <p>Any exceptions occurring during creation of the layer lists or their included layers are
* logged and not re-thrown. The layers associated with the exceptions are not included in the
* returned layer list.
*
* @param elements the XML elements describing the layer lists to create.
* @param params any parameters to apply when creating the included layers.
* @return an array containing the specified layer lists.
*/
protected LayerList[] createLayerLists(Element[] elements, AVList params) {
ArrayList<LayerList> layerLists = new ArrayList<LayerList>();
for (Element element : elements) {
try {
String href = WWXML.getText(element, "@href");
if (href != null && href.length() > 0) {
Object o = this.createFromConfigSource(href, params);
if (o == null) continue;
if (o instanceof Layer) {
LayerList ll = new LayerList();
ll.add((Layer) o);
o = ll;
}
if (o instanceof LayerList) {
LayerList list = (LayerList) o;
if (list != null && list.size() > 0) layerLists.add(list);
} else if (o instanceof LayerList[]) {
LayerList[] lists = (LayerList[]) o;
if (lists != null && lists.length > 0) layerLists.addAll(Arrays.asList(lists));
} else {
String msg =
Logging.getMessage("LayerFactory.UnexpectedTypeForLayer", o.getClass().getName());
Logging.logger().log(java.util.logging.Level.WARNING, msg);
}
continue;
}
String title = WWXML.getText(element, "@title");
Element[] children = WWXML.getElements(element, "./Layer", null);
if (children != null && children.length > 0) {
LayerList list = this.createLayerList(children, params);
if (list != null && list.size() > 0) {
layerLists.add(list);
if (title != null && title.length() > 0) list.setValue(AVKey.DISPLAY_NAME, title);
}
}
} catch (Exception e) {
Logging.logger().log(java.util.logging.Level.WARNING, e.getMessage(), e);
// keep going to create other layers
}
}
return layerLists.toArray(new LayerList[layerLists.size()]);
}
