| /* |
| * 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.user.rebind; |
| |
| import com.google.gwt.core.ext.TreeLogger; |
| import com.google.gwt.core.ext.linker.ConfigurationProperty; |
| import com.google.gwt.core.ext.linker.PropertyProviderGenerator; |
| |
| import java.util.Arrays; |
| import java.util.List; |
| import java.util.SortedSet; |
| |
| /** |
| * Generator which writes out the JavaScript for determining the value of the |
| * <code>user.agent</code> selection property. |
| */ |
| public class UserAgentPropertyGenerator implements PropertyProviderGenerator { |
| |
| /** |
| * List of valid user agent selection property values, which helps ensure that |
| * UserAgent.gwt.xml stays in sync with the |
| * {@link #writeUserAgentPropertyJavaScript(SourceWriter)} method body of this |
| * class. |
| */ |
| private static final List<String> VALID_VALUES = Arrays.asList(new String[]{ |
| "ie6", "ie8", "gecko1_8", "safari", "opera", "ie9"}); |
| |
| /** |
| * List of predicates to identify user agent. |
| * The order of evaluation is from top to bottom, i.e., the first matching |
| * predicate will have the associated ua token returned. |
| * ua is defined in an outer scope and is therefore visible in |
| * the predicate javascript fragment. |
| */ |
| private static UserAgentPropertyGeneratorPredicate[] predicates = |
| new UserAgentPropertyGeneratorPredicate[] { |
| |
| // opera |
| new UserAgentPropertyGeneratorPredicate("opera") |
| .getPredicateBlock() |
| .println("return (ua.indexOf('opera') != -1);") |
| .returns("'opera'"), |
| |
| // webkit family |
| new UserAgentPropertyGeneratorPredicate("safari") |
| .getPredicateBlock() |
| .println("return (ua.indexOf('webkit') != -1);") |
| .returns("'safari'"), |
| |
| // IE9 |
| new UserAgentPropertyGeneratorPredicate("ie9") |
| .getPredicateBlock() |
| .println("return (ua.indexOf('msie') != -1 && ($doc.documentMode >= 9));") |
| .returns("'ie9'"), |
| |
| // IE8 |
| new UserAgentPropertyGeneratorPredicate("ie8") |
| .getPredicateBlock() |
| .println("return (ua.indexOf('msie') != -1 && ($doc.documentMode >= 8));") |
| .returns("'ie8'"), |
| |
| // IE6 |
| new UserAgentPropertyGeneratorPredicate("ie6") |
| .getPredicateBlock() |
| .println("var result = /msie ([0-9]+)\\.([0-9]+)/.exec(ua);") |
| .println("if (result && result.length == 3)") |
| .indent() |
| .println("return (makeVersion(result) >= 6000);") |
| .outdent() |
| .returns("'ie6'"), |
| |
| // gecko family |
| new UserAgentPropertyGeneratorPredicate("gecko1_8") |
| .getPredicateBlock() |
| .println("return (ua.indexOf('gecko') != -1);") |
| .returns("'gecko1_8'"), |
| }; |
| |
| /** |
| * Writes out the JavaScript function body for determining the value of the |
| * <code>user.agent</code> selection property. This method is used to create |
| * the selection script and by {@link UserAgentGenerator} to assert at runtime |
| * that the correct user agent permutation is executing. The list of |
| * <code>user.agent</code> values listed here should be kept in sync with |
| * {@link #VALID_VALUES} and <code>UserAgent.gwt.xml</code>. |
| */ |
| static void writeUserAgentPropertyJavaScript(SourceWriter body, |
| SortedSet<String> possibleValues) { |
| |
| // write preamble |
| body.println("var ua = navigator.userAgent.toLowerCase();"); |
| body.println("var makeVersion = function(result) {"); |
| body.indent(); |
| body.println("return (parseInt(result[1]) * 1000) + parseInt(result[2]);"); |
| body.outdent(); |
| body.println("};"); |
| |
| // write only selected user agents |
| for (int i = 0; i < predicates.length; i++) { |
| if (possibleValues.contains(predicates[i].getUserAgent())) { |
| body.println("if ((function() { "); |
| body.indent(); |
| body.print(predicates[i].toString()); |
| body.outdent(); |
| body.println("})()) return " + predicates[i].getReturnValue() + ";"); |
| } |
| } |
| |
| // default return |
| body.println("return 'unknown';"); |
| } |
| |
| public String generate(TreeLogger logger, SortedSet<String> possibleValues, |
| String fallback, SortedSet<ConfigurationProperty> configProperties) { |
| for (String value : possibleValues) { |
| if (!VALID_VALUES.contains(value)) { |
| logger.log(TreeLogger.WARN, "Unrecognized " |
| + UserAgentGenerator.PROPERTY_USER_AGENT + " property value '" |
| + value + "', possibly due to UserAgent.gwt.xml and " |
| + UserAgentPropertyGenerator.class.getName() |
| + " being out of sync." + " Use <set-configuration-property name=\"" |
| + UserAgentGenerator.PROPERTY_USER_AGENT_RUNTIME_WARNING |
| + "\" value=\"false\"/> to suppress this warning message."); |
| } |
| } |
| // make sure that the # of ua in VALID_VALUES |
| // is the same of predicates. maybe should iterate |
| // to make sure each one has a match. |
| assert predicates.length == VALID_VALUES.size(); |
| StringSourceWriter body = new StringSourceWriter(); |
| body.println("{"); |
| body.indent(); |
| writeUserAgentPropertyJavaScript(body, possibleValues); |
| body.outdent(); |
| body.println("}"); |
| |
| return body.toString(); |
| } |
| } |