| /* |
| * Copyright 2011 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.useragent.client; |
| |
| import com.google.gwt.core.client.EntryPoint; |
| import com.google.gwt.core.client.GWT; |
| |
| /** |
| * Helper class, which, during startup, asserts that the specified user.agent |
| * selection property value indeed matches the expected value for this browser / |
| * user agent, thus avoid long hours debugging strange error messages when a |
| * single user agent compile, typically created for testing purposes, ends up |
| * being executed in the wrong browser. |
| */ |
| public class UserAgentAsserter implements EntryPoint { |
| |
| /** |
| * Replacement for UserAgentAsserter to disable it. |
| */ |
| public static class UserAgentAsserterDisabled implements EntryPoint { |
| @Override |
| public void onModuleLoad() { /* Empty - no assertions */} |
| } |
| |
| @Override |
| public void onModuleLoad() { |
| scheduleUserAgentCheck(); |
| } |
| |
| private static native void scheduleUserAgentCheck() /*-{ |
| // Keeping minimal dependency to reduce risk of problems due to use of wrong permutation: |
| $wnd.setTimeout($entry(@com.google.gwt.useragent.client.UserAgentAsserter::assertCompileTimeUserAgent())); |
| }-*/; |
| |
| private static void assertCompileTimeUserAgent() { |
| UserAgent impl = GWT.create(UserAgent.class); |
| |
| String compileTimeValue = impl.getCompileTimeValue(); |
| String runtimeValue = impl.getRuntimeValue(); |
| |
| if (!compileTimeValue.equals(runtimeValue)) { |
| // Let it escape and get handled by UCEH: |
| throw new UserAgentAssertionError(compileTimeValue, runtimeValue); |
| } |
| } |
| |
| /** |
| * An error object that indicates that the user agent detected at runtime did |
| * not match the user agent that the module expected to find. |
| */ |
| public static class UserAgentAssertionError extends AssertionError { |
| /** |
| * Default constructor for serialization. |
| */ |
| public UserAgentAssertionError() { |
| } |
| |
| /** |
| * Creates an error with the given expected and actual user.agent value. |
| * |
| * @param compileTimeValue the compile time user.agent value, either in this |
| * permutation or soft permutation |
| * @param runtimeValue the detected user.agent value after the module started |
| */ |
| public UserAgentAssertionError(String compileTimeValue, String runtimeValue) { |
| super("Possible problem with your *.gwt.xml module file.\n" |
| + "The compile time user.agent value (" + compileTimeValue + ") " |
| + "does not match the runtime user.agent value (" + runtimeValue + ").\n" |
| + "Expect more errors."); |
| } |
| } |
| } |