import java.util.Map;
import java.util.Set;
+import com.google.gwt.core.client.Duration;
import com.google.gwt.core.client.GWT;
import com.google.gwt.core.client.Scheduler;
import com.google.gwt.core.client.Scheduler.RepeatingCommand;
import com.google.gwt.dom.client.NodeList;
import com.google.gwt.dom.client.ObjectElement;
import com.google.gwt.dom.client.ScriptElement;
+import com.google.gwt.user.client.Timer;
/**
* ResourceLoader lets you dynamically include external scripts and styles on
*/
public interface ResourceLoadListener {
/**
- * Notified this ResourceLoadListener that a resource has been loaded
+ * Notifies this ResourceLoadListener that a resource has been loaded.
+ * Some browsers do not support any way of detecting load errors. In
+ * these cases, onLoad will be called regardless of the status.
*
* @see ResourceLoadEvent
*
* a resource load event with information about the loaded
* resource
*/
- public void onResourceLoad(ResourceLoadEvent event);
+ public void onLoad(ResourceLoadEvent event);
+
+ /**
+ * Notifies this ResourceLoadListener that a resource could not be
+ * loaded, e.g. because the file could not be found or because the
+ * server did not respond. Some browsers do not support any way of
+ * detecting load errors. In these cases, onLoad will be called
+ * regardless of the status.
+ *
+ * @see ResourceLoadEvent
+ *
+ * @param event
+ * a resource load event with information about the resource
+ * that could not be loaded.
+ */
+ public void onError(ResourceLoadEvent event);
}
private static final ResourceLoader INSTANCE = GWT
public void loadScript(final String scriptUrl,
final ResourceLoadListener resourceLoadListener) {
final String url = getAbsoluteUrl(scriptUrl);
+ ResourceLoadEvent event = new ResourceLoadEvent(this, url, false);
if (loadedResources.contains(url)) {
if (resourceLoadListener != null) {
- resourceLoadListener.onResourceLoad(new ResourceLoadEvent(this,
- url, false));
+ resourceLoadListener.onLoad(event);
}
return;
}
if (preloadListeners.containsKey(url)) {
+ // Preload going on, continue when preloaded
preloadResource(url, new ResourceLoadListener() {
- public void onResourceLoad(ResourceLoadEvent event) {
+ public void onLoad(ResourceLoadEvent event) {
loadScript(url, resourceLoadListener);
}
+
+ public void onError(ResourceLoadEvent event) {
+ // Preload failed -> signal error to own listener
+ if (resourceLoadListener != null) {
+ resourceLoadListener.onError(event);
+ }
+ }
});
return;
}
ScriptElement scriptTag = Document.get().createScriptElement();
scriptTag.setSrc(url);
scriptTag.setType("text/javascript");
- addOnloadHandler(scriptTag, url, false);
+ addOnloadHandler(scriptTag, new ResourceLoadListener() {
+ public void onLoad(ResourceLoadEvent event) {
+ fireLoad(event);
+ }
+
+ public void onError(ResourceLoadEvent event) {
+ fireError(event);
+ }
+ }, event);
head.appendChild(scriptTag);
}
}
public void preloadResource(String url,
ResourceLoadListener resourceLoadListener) {
url = getAbsoluteUrl(url);
+ ResourceLoadEvent event = new ResourceLoadEvent(this, url, true);
if (loadedResources.contains(url) || preloadedResources.contains(url)) {
+ // Already loaded or preloaded -> just fire listener
if (resourceLoadListener != null) {
- resourceLoadListener.onResourceLoad(new ResourceLoadEvent(this,
- url, !loadedResources.contains(url)));
+ resourceLoadListener.onLoad(event);
}
return;
}
// AND the resources isn't already being loaded in the normal way
Element element = getPreloadElement(url);
- addOnloadHandler(element, url, true);
+ addOnloadHandler(element, new ResourceLoadListener() {
+ public void onLoad(ResourceLoadEvent event) {
+ fireLoad(event);
+ }
+
+ public void onError(ResourceLoadEvent event) {
+ fireError(event);
+ }
+ }, event);
// TODO Remove object when loaded (without causing spinner in FF)
Document.get().getBody().appendChild(element);
}
}
- private native void addOnloadHandler(Element element, String url,
- boolean preload)
+ private native void addOnloadHandler(Element element,
+ ResourceLoadListener listener, ResourceLoadEvent event)
/*-{
- var self = this;
- var done = $entry(function() {
- element.onloadDone = true;
+ element.onload = $entry(function() {
element.onload = null;
+ element.onerror = null;
element.onreadystatechange = null;
- self.@com.vaadin.terminal.gwt.client.ResourceLoader::onResourceLoad(Ljava/lang/String;Z)(url, preload);
+ listener.@com.vaadin.terminal.gwt.client.ResourceLoader.ResourceLoadListener::onLoad(Lcom/vaadin/terminal/gwt/client/ResourceLoader$ResourceLoadEvent;)(event);
+ });
+ element.onerror = $entry(function() {
+ element.onload = null;
+ element.onerror = null;
+ element.onreadystatechange = null;
+ listener.@com.vaadin.terminal.gwt.client.ResourceLoader.ResourceLoadListener::onError(Lcom/vaadin/terminal/gwt/client/ResourceLoader$ResourceLoadEvent;)(event);
});
- element.onload = function() {
- if (!element.onloadDone) {
- done();
- }
- };
element.onreadystatechange = function() {
- if (("loaded" === element.readyState || "complete" === element.readyState) && !element.onloadDone ) {
- done();
+ if ("loaded" === element.readyState || "complete" === element.readyState ) {
+ element.onload(arguments[0]);
}
};
}-*/;
public void loadStylesheet(final String stylesheetUrl,
final ResourceLoadListener resourceLoadListener) {
final String url = getAbsoluteUrl(stylesheetUrl);
+ final ResourceLoadEvent event = new ResourceLoadEvent(this, url, false);
if (loadedResources.contains(url)) {
if (resourceLoadListener != null) {
- resourceLoadListener.onResourceLoad(new ResourceLoadEvent(this,
- url, false));
+ resourceLoadListener.onLoad(event);
}
return;
}
if (preloadListeners.containsKey(url)) {
+ // Preload going on, continue when preloaded
preloadResource(url, new ResourceLoadListener() {
- public void onResourceLoad(ResourceLoadEvent event) {
+ public void onLoad(ResourceLoadEvent event) {
loadStylesheet(url, resourceLoadListener);
}
+
+ public void onError(ResourceLoadEvent event) {
+ // Preload failed -> signal error to own listener
+ if (resourceLoadListener != null) {
+ resourceLoadListener.onError(event);
+ }
+ }
});
return;
}
linkElement.setHref(url);
if (BrowserInfo.get().isSafari()) {
- // Safari doesn't fire onload events for link elements
+ // Safari doesn't fire any events for link elements
// See http://www.phpied.com/when-is-a-stylesheet-really-loaded/
- // TODO Stop checking after some timeout
Scheduler.get().scheduleFixedPeriod(new RepeatingCommand() {
+ private final Duration duration = new Duration();
+
public boolean execute() {
- if (isStyleSheetPresent(url)) {
- onResourceLoad(url, false);
+ int styleSheetLength = getStyleSheetLength(url);
+ if (getStyleSheetLength(url) > 0) {
+ fireLoad(event);
return false; // Stop repeating
+ } else if (styleSheetLength == 0) {
+ // "Loaded" empty sheet -> most likely 404 error
+ fireError(event);
+ return true;
+ } else if (duration.elapsedMillis() > 60 * 1000) {
+ fireError(event);
+ return false;
} else {
return true; // Continue repeating
}
}
}, 10);
} else {
- addOnloadHandler(linkElement, url, false);
+ addOnloadHandler(linkElement, new ResourceLoadListener() {
+ public void onLoad(ResourceLoadEvent event) {
+ // Chrome && IE fires load for errors, must check
+ // stylesheet data
+ if (BrowserInfo.get().isChrome()
+ || BrowserInfo.get().isIE()) {
+ int styleSheetLength = getStyleSheetLength(url);
+ // Error if there's an empty stylesheet
+ if (styleSheetLength == 0) {
+ fireError(event);
+ return;
+ }
+ }
+ fireLoad(event);
+ }
+
+ public void onError(ResourceLoadEvent event) {
+ fireError(event);
+ }
+ }, event);
+ if (BrowserInfo.get().isOpera()) {
+ // Opera onerror never fired, assume error if no onload in x
+ // seconds
+ new Timer() {
+ @Override
+ public void run() {
+ if (!loadedResources.contains(url)) {
+ fireError(event);
+ }
+ }
+ }.schedule(5 * 1000);
+ }
}
head.appendChild(linkElement);
}
}
- private static native boolean isStyleSheetPresent(String url)
+ private static native int getStyleSheetLength(String url)
/*-{
for(var i = 0; i < $doc.styleSheets.length; i++) {
if ($doc.styleSheets[i].href === url) {
- return true;
+ var sheet = $doc.styleSheets[i];
+ try {
+ var rules = sheet.cssRules
+ if (rules === undefined) {
+ rules = sheet.rules;
+ }
+
+ if (rules === null) {
+ // Style sheet loaded, but can't access length because of XSS -> assume there's something there
+ return 1;
+ }
+
+ // Return length so we can distinguish 0 (probably 404 error) from normal case.
+ return rules.length;
+ } catch (err) {
+ return 1;
+ }
}
}
- return false;
+ // No matching stylesheet found -> not yet loaded
+ return -1;
}-*/;
private static boolean addListener(String url,
}
}
- private void onResourceLoad(String resource, boolean preload) {
+ private void fireError(ResourceLoadEvent event) {
+ String resource = event.getResourceUrl();
+
+ Collection<ResourceLoadListener> listeners;
+ if (event.isPreload()) {
+ // Also fire error for load listeners
+ fireError(new ResourceLoadEvent(this, resource, false));
+ listeners = preloadListeners.remove(resource);
+ } else {
+ listeners = loadListeners.remove(resource);
+ }
+ if (listeners != null && !listeners.isEmpty()) {
+ for (ResourceLoadListener listener : listeners) {
+ if (listener != null) {
+ listener.onError(event);
+ }
+ }
+ }
+ }
+
+ private void fireLoad(ResourceLoadEvent event) {
+ String resource = event.getResourceUrl();
Collection<ResourceLoadListener> listeners;
- if (preload) {
+ if (event.isPreload()) {
preloadedResources.add(resource);
listeners = preloadListeners.remove(resource);
} else {
if (preloadListeners.containsKey(resource)) {
// Also fire preload events for potential listeners
- onResourceLoad(resource, true);
+ fireLoad(new ResourceLoadEvent(this, resource, true));
}
preloadedResources.remove(resource);
loadedResources.add(resource);
listeners = loadListeners.remove(resource);
}
if (listeners != null && !listeners.isEmpty()) {
- ResourceLoadEvent event = new ResourceLoadEvent(this, resource,
- preload);
for (ResourceLoadListener listener : listeners) {
if (listener != null) {
- listener.onResourceLoad(event);
+ listener.onLoad(event);
}
}
}
projects / vaadin-framework.git / commitdiff