package org.gwtopenmaps.openlayers.client;
import java.util.ArrayList;
import java.util.List;
import com.google.gwt.dom.client.Document;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.HeadElement;
import com.google.gwt.dom.client.ScriptElement;
/**
* Script injector that can inject script from a resource.
* @author fks/Frank Wynants
*
*/
public final class ScriptInjector
{
/** Keeps track if script was allready injected. */
private static List<String> scriptIsInjected = new ArrayList<String>();
/** The head element to inject in. */
private static HeadElement head;
// ===============================================================
/**
* Private utility class constructor.
*/
private ScriptInjector()
{
}
// ===============================================================
/**
* Inject public resource script file as a file.
* @param filename inject file name
*/
public static void injectResourceScriptAsFile(String filename)
{
if (!scriptIsInjected.contains(filename))
{
ScriptElement link = Document.get().createScriptElement();
link.setAttribute("language", "javascript");
link.setText(filename);
getHead().appendChild(link);
scriptIsInjected.add(filename);
}
}
// ================================================================
/**
* Get the head element.
* @return The update HeadElement
*/
private static HeadElement getHead()
{
if (head == null)
{
Element elt = Document.get().getElementsByTagName("head").getItem(0);
assert elt != null : "The host HTML page does not have a <head> element"
+ " which is required by StyleInjector";
head = HeadElement.as(elt);
}
return head;
}
}