/*
* Copyright 2009 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.gwt.gdata.client.impl;
import com.google.gwt.core.client.GWT;
import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.core.client.GWT.UncaughtExceptionHandler;
/**
* Provides utility methods for interacting with Callbacks in GWT.
*/
public class CallbackHelper {
/**
* Performs a call to a failure callback, with the supplied error.
* @param <T> The callback's return type
* @param cb The callback object
* @param error The error object
*/
public static <T extends JavaScriptObject> void handleFailureCallback(
Callback<T> cb, com.google.gwt.gdata.client.Error error) {
UncaughtExceptionHandler handler = GWT.getUncaughtExceptionHandler();
if (handler != null) {
try {
CallErrorException exc = new CallErrorException(error);
cb.onFailure(exc);
} catch (Throwable e) {
e.printStackTrace();
handler.onUncaughtException(e);
}
} else {
cb.onFailure(new CallErrorException(error));
}
}
/**
* Performs a call to a success callback, with the supplied return value.
* @param <T> The callback's return type
* @param cb The callback object
* @param arg The callback's return value
*/
public static <T extends JavaScriptObject> void handleSuccessCallback(
Callback<T> cb, T arg) {
UncaughtExceptionHandler handler = GWT.getUncaughtExceptionHandler();
if (handler != null) {
try {
cb.onSuccess(arg);
} catch (Throwable e) {
e.printStackTrace();
handler.onUncaughtException(e);
}
} else {
cb.onSuccess(arg);
}
}
}