package com.googlecode.gwt.test.internal.resources;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import com.google.gwt.core.client.GWT;
import com.google.gwt.resources.client.ImageResource;
import com.google.gwt.resources.ext.DefaultExtensions;
import com.google.gwt.user.client.ui.AbstractImagePrototype;
import com.google.gwt.user.client.ui.ImageBundle;
import com.google.gwt.user.client.ui.ImageBundle.Resource;
import com.google.gwt.user.client.ui.impl.ClippedImagePrototype;
import com.googlecode.gwt.test.GwtCreateHandler;
import com.googlecode.gwt.test.exceptions.GwtTestResourcesException;
/**
* Class in charge of the instanciation of all {@link ImageBundle} sub-interfaces through deferred
* binding. <strong>For internal use only.</strong>
*
* @author Gael Lazzari
*
*/
@SuppressWarnings("deprecation")
public class ImageBundleCreateHandler implements GwtCreateHandler {
private static final String[] IMAGE_DEFAULT_EXTENSIONS = ImageResource.class.getAnnotation(
DefaultExtensions.class).value();
public Object create(Class<?> classLiteral) throws Exception {
if (!ImageBundle.class.isAssignableFrom(classLiteral)) {
return null;
}
return generateImageWrapper(classLiteral);
}
private Object generateImageWrapper(Class<?> clazz) {
InvocationHandler ih = new InvocationHandler() {
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
if (method.getReturnType() == AbstractImagePrototype.class) {
String url = getImageUrl(method);
return new ClippedImagePrototype(url, 0, 0, 0, 0);
}
throw new GwtTestResourcesException("Not managed return type for image bundle : "
+ method.getReturnType().getSimpleName());
}
private String computeFileSimpleName(Method method) {
String packagePath = method.getDeclaringClass().getPackage().getName().replaceAll(
"\\.", "/");
String relativePath = packagePath + "/" + method.getName();
for (String extension : IMAGE_DEFAULT_EXTENSIONS) {
String possiblePath = relativePath + extension;
if (this.getClass().getResource("/" + possiblePath) != null) {
return method.getName() + extension;
}
}
// should never happened
throw new GwtTestResourcesException("Cannot find an image with path relative to '"
+ relativePath + "'");
}
private String getImageUrl(Method method) {
String fileName;
Resource resource = method.getAnnotation(Resource.class);
if (resource != null) {
fileName = resource.value();
} else {
fileName = computeFileSimpleName(method);
}
return GWT.getModuleBaseURL() + fileName;
}
};
return Proxy.newProxyInstance(clazz.getClassLoader(), new Class<?>[]{clazz}, ih);
}
}