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/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you 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 org.apache.myfaces.trinidadinternal.skin;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.regex.Matcher;

import java.util.regex.Pattern;

import org.apache.myfaces.trinidad.context.Version;
import org.apache.myfaces.trinidad.logging.TrinidadLogger;
import org.apache.myfaces.trinidadinternal.agent.TrinidadAgent;
import org.apache.myfaces.trinidadinternal.style.util.NameUtils;

/**
 * Threadsafe immutable class that stores the @agent rule for a particular @agent query string
 * from the skinning css file (e.g., @agent ie and (version:5), ie and (version:6), gecko {}).
 * This class is used to match the current agent against the @agent rule.
 * @see StyleSheetNode
 * @see NameUtils
 */
public final class AgentAtRuleMatcher
{

  /**
   * Enumeration representing the result of a call to match.
   * @see #match
   */
  public enum Match
  {
    /** The Match matched the agent applications */
    APPLICATION,
    /** The Match matched the agent version */
    VERSION,
    /** the Match matched capability touchScreen */
    CAP_TOUCH_SCREEN
  };

  /**
   * Creates an AgentAtRuleMatcher from an @agent query string.  if the @agent rule were
   * @agent ie and (version:8), gecko and (version:1.9) { .foo {background-color:red}}
   * the query string would be "ie and (version:8), gecko and (version:1.9)"
   * @param queryString String containing the query portion of the @agent at-rule
   */
  public AgentAtRuleMatcher(String queryString)
  {
    // split each of the comma-separated 'or' pieces into separate strings from processing
    this(queryString.split(","));
  }


  /**
   * Creates an AgentAtRuleMatcher from a decomposed array of @agent query selectors. With one
   * array entry for each comma-separated selector.
   * if the @agent rule were
   * @agent ie and (version:8), gecko and (version:1.9) { .foo {background-color:red}}
   * the decomposed selectors would be:
   * selector[0] = "ie and (version:8)"; selector[1] = "gecko and (version:1.9)";
   * @param selectors Array of query selectors with one selector for every or'ed rule
   */
  public AgentAtRuleMatcher(String[] selectors)
  {
    Map> selectorAgents = Collections.emptyMap();
    Set capTouchMatchers = new HashSet();

    // process each of the selectors to build the Map of the AgentMatchers to run for any
    // particular agent in this array of rules.
    for (int selectorIndex = 0; selectorIndex < selectors.length; selectorIndex++)
    {
      // parse the agent versions. Examples:
      // @agent ie and (version:6)
      // @agent ie and (version:6.*)
      // @agent ie and (version:5.0.*)
      // @agent ie and (min-version:5.*) and (max-version:6)
      // @agent ie and (version:6), ie and (version:7), gecko and (version:1.1)
      // @agent (touchScreen)
      // @agent (touchScreen:none)
      // @agent (touchScreen:none), ie and (version:6)
      // @agent webkit and (version:6), (touchScreen)
      // @agent webkit and (touchScreen:single)
      // @agent webkit and (version:9) and (touchScreen:multiple)

      String currSelector = selectors[selectorIndex].trim();
      if (currSelector.startsWith(TOUCH_SCREEN_RULE_STR))
      {
  	    capTouchMatchers.add(_getTouchScreenMatcher(currSelector));
        continue;
      }

      // split each of the sections between the "and"s.  For example
      // gecko and (min-version:1.5) and (max-version:1.9) would result in
      // {"gecko", "(min-version:1.5)", "(max-version:1.9)"}
      String[] sections = _AND_SPLITTER.split(currSelector);

      // the agent is always the first section and is required.
      // We trim because we are often passed strings with trailing whitespace
      String agentName = sections[0].trim();

      // convert the name of the agent to its TrinidadAgent.Application enum
      TrinidadAgent.Application browser = NameUtils.getAgentApplication(agentName);

      // turn the array of sections into the Set of AgentMatchers
      //
      if (browser != TrinidadAgent.Application.UNKNOWN)
      {
        int sectionCount = sections.length;

        Set agentMatchers;

        if (sectionCount == 1)
        {
          // we only have the agent identifier, so no matchers
          agentMatchers = Collections.emptySet();
        }
        else
        {
          AgentMatcher newAgentMatcher;

          if (sectionCount > 2)
          {
            // we have multiple ands, so we need to build up the list of sections to pass to
            // to the AndMatcher, which will AND the results of each of the matches together
            List andedMatchers = new ArrayList(sectionCount - 1);

            // create agent matchers for each section
            // this could be version matcher or touchScreen matcher
            for (int sectionIndex = 1; sectionIndex < sectionCount; sectionIndex++)
            {
              andedMatchers.add(_getAgentMatcher(sections[sectionIndex]));
            }

            newAgentMatcher = new AndMatcher(andedMatchers);
          }
          else
          {
            // only a single and with a agent match, so return that matcher directly
            // this could be version matcher or touchScreen matcher
            newAgentMatcher = _getAgentMatcher(sections[1]);
          }

          // if you have selectors that repeat the browser, then get the agentMatchers that
          // you have so far for that browser so you can append to it.
          // @agent ie and (version: 6), ie and (version: 7), gecko and (version: 1.9)
          // Th comma ORs the rules together.
          agentMatchers = selectorAgents.get(browser);

          // create the Version Set if it doesn't already exist, or add the Version to the
          // current Version Set if it isn't already in there.  Since most Version entries are
          // a single value, we optimize for that case
          if ((agentMatchers == null) || agentMatchers.isEmpty())
            agentMatchers = Collections.singleton(newAgentMatcher);
          else if (!agentMatchers.contains(newAgentMatcher))
          {
            // we didn't already have an entry for this matcher.  If the old size is 1, then
            // the current set is going to be a Collections.singleton(), which is immutable,
            // so we need to copy the the singleton Set into a HashSet, which IS mutable
            if (agentMatchers.size() == 1)
              agentMatchers = new HashSet(agentMatchers);

            agentMatchers.add(newAgentMatcher);
          }
        }

        // optimize the size of the SelectorAgents Map when we add the new Versions
        if (selectorAgents.isEmpty())
          selectorAgents = Collections.singletonMap(browser, agentMatchers);
        else if (!agentMatchers.equals(selectorAgents.get(browser)))
        {
          if (selectorAgents.size() == 1)
          {
            // similar issue as with the Set case above.  If the Map currently has only one
            // entry, then we have an immutable singleton Map and we need to copy the single item
            // out into a new mutable Map.  Chances are, this map isn't going to be very big, so
            // a size of 3 seems a good start.
            Map> newSelectorAgents =
                                   new HashMap>(3);

            // get the single entry out of here so we can add it into the new mutable map
            Map.Entry> singleEntry =
                                                       selectorAgents.entrySet().iterator().next();

            newSelectorAgents.put(singleEntry.getKey(), singleEntry.getValue());

            selectorAgents = newSelectorAgents;
          }

          // add the new mapping
          selectorAgents.put(browser, agentMatchers);
        }
      }
    }

    _selectorAgents = selectorAgents;
    _capTouchMatchers = capTouchMatchers;
    _hashCode = _calculateStableHashCode(_selectorAgents, _capTouchMatchers);
  }

  /**
   * Parses touchScreen rule and creates appropriate AgentMatcher
   * @param currSelector
   */
  private TouchScreenCapabilityMatcher _getTouchScreenMatcher(String currSelector) {
    // split out the separate  and  parts of the property selector.  The
    //  will be in the first group, the  in the second.
    Matcher m = _PROPERTY_SPLITTER.matcher(currSelector);
    String[] capTouchArray = new String[]{};

    if (m.find())
    {
      String propName = m.group(1);
      String propValue = m.group(2);

      // Needless to check if propName is touchScreen or not. It is already done in the caller side.
      if (propValue != null)
      {
        String capValue = propValue.trim();
        if (_ALL_TOUCH_CAPABILITIES.contains(capValue))
          capTouchArray = new String[] {capValue};
        else
        {
          _LOG.warning("INVALID_AGENT_PROPERTY", new Object[]{propName, capValue});
        }
      }
    }
    else
    {
      // when (touchScreen) is specified _PROPERTY_SPLITTER fails to match
      // in this case add single and multiple
      capTouchArray = _AFFIRMATIVE_TOUCH_CAPABILITIES;
    }

    if (capTouchArray.length > 0) {
      Set capTouchValues = Collections.unmodifiableSet(new HashSet(Arrays.asList(capTouchArray)));
      TouchScreenCapabilityMatcher matcher = new TouchScreenCapabilityMatcher(capTouchValues);
      return matcher;
    }

    // If touchScreen syntax was not parsed and no AgentMatcher was created.
    throw new IllegalArgumentException("Invalid @agent rule specified: " + currSelector);
  }



  /**
   * Because Enums don't have stable hash codes, we can't use their hash code directly.  Instead
   * we want to use the has code of the enum's name, which should be stable.  Here we essentially
   * duplicate the hash code calculation of Map, using the stable hash code instead
   * @return stable hash code
   */
  private static int _calculateStableHashCode(final Map> selectorAgents,
                                              final Set capTouchMatchers)
  {
    int hashCode = 0;

    // Map hash code is defined as the additive hash code of the entries
    for (Map.Entry> entry : selectorAgents.entrySet())
    {
      // use the enum's name to have a stable hash code
      int stableKeyHashCode = entry.getKey().name().hashCode();

      // entry hash code is defined as the XOR of the key and value.
      int entryHashCode = stableKeyHashCode ^ entry.getValue().hashCode();

      hashCode += entryHashCode;
    }

    hashCode += capTouchMatchers.hashCode();

    return hashCode;
  }

  private AgentMatcher _getAgentMatcher(String propertySelector)
  {
    propertySelector = propertySelector.trim();
    if (propertySelector.startsWith(TOUCH_SCREEN_RULE_STR))
    {
      return _getTouchScreenMatcher(propertySelector);
    } else
    {
      return _getVersionMatcher(propertySelector);
    }

  }

  /**
   * Given a property selector of the form
   * (:)
   * where "identifier" can be "min-version", "max-version" or "version" and "value" represents
   * a browser or HTML layout engine version number, return a VersionMatcher that will
   * perform the correct comparison against the current Agent.
   * @param propertySelector String containing the type of version comparison and version value
   * to match
   * @return VersionMatcher for the property selector
   */
  private VersionMatcher _getVersionMatcher(String propertySelector)
  {
    // split out the separate  and  parts of the property selector.  The
    //  will be in the first group, the  in the second.
    Matcher m = _PROPERTY_SPLITTER.matcher(propertySelector);

    if (m.find())
    {
      String propName = m.group(1);
      String version = m.group(2);

      // turn the property name--either "min-version", "max-version" or "version" into the
      // type of comparison to perform
      Comparison comparison = _COMPARISON_PARSER.get(propName);

      if (comparison == null)
      {
        throw new IllegalArgumentException("Invalid @agent property name: " + propName);
      }

      // create the new Version, padding the version number out with wildcards
      Version newVersion = new Version(version, "*");

      return new VersionMatcher(newVersion, comparison);
    }
    else
    {
      throw new IllegalArgumentException("Invalid @agent property selector: " + propertySelector);
    }
  }

  /**
   * 

* Called to actually determine if this AgentAtRuleMatcher applies to the current agent. The * result is a Set of Match constants indicating how precise the match is. While all anded * rules must match for the match to succeed, some callers need information regarding whether * the Version information was also necessary in order for the match to succeed. For example, * when generating CSS files, the version information is only part of the CSS name if the * generated CSS file for the agent contained version-dependent content. *

*

* There are three possible return values *

    *
  1. An empty Set, indicating no match
  2. *
  3. A set containing Match.APPLICATION, indicating a match that only needed to * match against the agent Application
  4. *
  5. A set containing both Match.APPLICATION and Match.VERSION, * indicating that both the agent Application and its version needed to be matched against
  6. *
* @param agent Agent to test for compatibility with * @return the Set of successful matches, if any */ public Set match(TrinidadAgent agent) { Set matches = new HashSet(); // If we have browser exact match, compare versions TrinidadAgent.Application browser = agent.getAgentApplication(); if (_selectorAgents.containsKey(browser)) { matches.add(Match.APPLICATION); Set agentMatchers = _selectorAgents.get(browser); if (!agentMatchers.isEmpty()) { for (AgentMatcher currMatcher : agentMatchers) { if (currMatcher.match(agent)) { if (currMatcher instanceof VersionMatcher) matches.add(Match.VERSION); else if (currMatcher instanceof TouchScreenCapabilityMatcher) matches.add(Match.CAP_TOUCH_SCREEN); else if (currMatcher instanceof AndMatcher) { AndMatcher andMatcher = (AndMatcher) currMatcher; if (andMatcher.hasVersionMatcher()) matches.add(Match.VERSION); if (andMatcher.hasTouchScreenCapabilityMatcher()) matches.add(Match.CAP_TOUCH_SCREEN); } } } // Expect at least one match from the matchers if (!matches.contains(Match.CAP_TOUCH_SCREEN) && !matches.contains(Match.VERSION)) { // There were one or many matchers but none matched, so remove all matchers. matches.clear(); } } } // If touchScreen is already matched then no need to check further. if (!matches.contains(Match.CAP_TOUCH_SCREEN) && !_capTouchMatchers.isEmpty()) { for (AgentMatcher currMatcher : _capTouchMatchers) { if (currMatcher.match(agent)) { // If there is a capability matching then APPLICATION match should be by default. matches.add(Match.APPLICATION); matches.add(Match.CAP_TOUCH_SCREEN); break; } } } return Collections.unmodifiableSet(matches); } @Override public boolean equals(Object other) { if (this == other) return true; else { if (other instanceof AgentAtRuleMatcher) { AgentAtRuleMatcher otherAgentMatcher = (AgentAtRuleMatcher) other; return (_selectorAgents.equals(otherAgentMatcher._selectorAgents)) && (_capTouchMatchers.equals(otherAgentMatcher._capTouchMatchers)); } else { return false; } } } @Override public final int hashCode() { return _hashCode; } @Override public String toString() { return super.toString() + "agents=" + _selectorAgents.toString() + "touchScreenCap=" + _capTouchMatchers.toString(); } // the type of comparison to perform on the version private static enum Comparison { EQUALS, // Compared object must be equal MIN, // Compared object must be less than or equal to MAX}; // Compared object must be greater than or equal to /** *

* Abstract class that all matchers against Agents must implement. *

*

* match(TrinidadAgent) is called to determine if the match succeeds. *

*

* Since the AgentMatchers * are added to Maps (or sets that use Maps in the implementation), they are required to * implement equals and hashCode *

*

* While used to hide the differences between VersionMatchers and AndMatchers, * this class should be abstract enough to support any new types of Agent matchers that we might * want to add in the future. *

* @see #match */ private static abstract class AgentMatcher { /** * Returns true if the AgentMatcher matches the Agent * @param agent Agent to check against * @return true if the match succeeds */ public abstract boolean match(TrinidadAgent agent); @Override public abstract int hashCode(); @Override public abstract boolean equals(Object o); } /** * Immutable and thread-safe AgentMatcher that matches the supplied Version against the * version of a TrinidadAgent using the supplied, MAX, MIN, or EQUALS Comparison */ private static final class VersionMatcher extends AgentMatcher { /** * Creates a VersionMatcher * @param version Version to compare with * @param comparison Comparison to perform */ public VersionMatcher(Version version, Comparison comparison) { _version = version; _comparison = comparison; // cache the hash code. Because enums don't have stable hash codes, // we use the hash code of the name of the enum, which is stable _hashCode = _version.hashCode() * 37 + _comparison.name().hashCode(); } /** * Matches the Version of this VersionMatcher against the Version of the supplied Agent, * using the VersionMatcher's comparison * @param agent Agent to check the Version of * @return true if the comparison is successful */ @Override public boolean match(TrinidadAgent agent) { // use the Version's comparator int result = _version.compareTo(agent.getVersion()); // since MIN means less than or equal to and MAX means greater than or equal to, a result // of equality always means success if (result == 0) return true; else { switch (_comparison) { case MIN: return result < 0; // min version has to be less than current version case MAX: return result > 0; // max version has to be bigger than current version case EQUALS: return false; // if the result were equal, we wouldn't have gotten this far default: assert false : "Unknown comparison type " + _comparison; return false; // this should never happen, but the compiler doesn't know that } } } @Override public final int hashCode() { return _hashCode; } @Override public boolean equals(Object other) { if (this == other) return true; else { if (other instanceof VersionMatcher) { VersionMatcher otherVersionMatcher = (VersionMatcher)other; return _version.equals(otherVersionMatcher._version) && _comparison.equals(otherVersionMatcher._comparison); } else { return false; } } } @Override public String toString() { return super.toString() + ", version=" + _version + ", comparison=" + _comparison; } private final Version _version; private final Comparison _comparison; private final int _hashCode; } /** * AgentMatcher that ANDs the results of all calling match() on its AgentMatchers together, * short-circuiting on the first AgentMatcher.match() that returns false. */ private static class AndMatcher extends AgentMatcher { /** * Creates an AndMatcher * @param matchers List of AgentMatchers to AND together */ public AndMatcher(List matchers) { // =-= btsulliv should we do anything if matchers contains fewer than two items? The code // will still work, it just suggests a lack of optimization in the caller _matchers = matchers; // cache the hashcode so we don't traverse the list asking all of the other matchers for // their hash codes each time our hash code is called _hashCode = matchers.hashCode(); for (AgentMatcher matcher : matchers) { if (matcher instanceof VersionMatcher) hasVersionMatcher = true; if (matcher instanceof TouchScreenCapabilityMatcher) hasTouchScreenCapabilityMatcher = true; } } protected boolean hasTouchScreenCapabilityMatcher() { return hasTouchScreenCapabilityMatcher; } protected boolean hasVersionMatcher() { return hasVersionMatcher; } /** * @param agent Agent to match againt * @return true if all of the matchers matched the Agent */ @Override public boolean match(TrinidadAgent agent) { int matcherCount = _matchers.size(); for (int i = 0; i < matcherCount; i++) { // a matcher failed, so no sense in trying to match any more. Let's pick up our // ball and go home if (!_matchers.get(i).match(agent)) return false; } // all of the matchers matched. Yay! return true; } @Override public int hashCode() { return _hashCode; } @Override public boolean equals(Object other) { if (this == other) return true; else { if (other instanceof AndMatcher) { return _matchers.equals(((AndMatcher)other)._matchers); } else { return false; } } } @Override public String toString() { return super.toString() + ", matchers=" + _matchers; } private final List _matchers; private final int _hashCode; private boolean hasVersionMatcher; private boolean hasTouchScreenCapabilityMatcher; } /** * Immutable and thread-safe AgentMatcher that matches the supplied touchScreen capability against the * that of the agent's. */ private static final class TouchScreenCapabilityMatcher extends AgentMatcher { /** * Creates a TouchScreenCapabilityMatcher * @param touchCapabilities */ public TouchScreenCapabilityMatcher(Set touchCapabilities) { if (touchCapabilities == null) throw new NullPointerException("touchCapabilities must be non-null"); _touchCapabilities = touchCapabilities; _hashCode = _touchCapabilities.hashCode(); } /** * Matches the TouchScreenCapabilityMatcher against the touchScreen capability of the supplied Agent * @param agent Agent to check the touchScreen capability of * @return true if the comparison is successful */ @Override public boolean match(TrinidadAgent agent) { String capTouchScreen = (String) agent.getCapabilities().get(TrinidadAgent.CAP_TOUCH_SCREEN); for (String touchCap : _touchCapabilities) { if (capTouchScreen.equals(touchCap)) { return true; } } return false; } @Override public final int hashCode() { return _hashCode; } @Override public boolean equals(Object other) { if (this == other) return true; else { if (other instanceof TouchScreenCapabilityMatcher) { TouchScreenCapabilityMatcher otherMatcher = (TouchScreenCapabilityMatcher)other; return _touchCapabilities.equals(otherMatcher._touchCapabilities); } else { return false; } } } @Override public String toString() { return super.toString() + ", touchCapabilities=" + _touchCapabilities; } private final Set _touchCapabilities; private final int _hashCode; } // RegExp Pattern used to breaking apart the property selectors into a separate property name // and value. The property selectors are in the form: // (:) // This isn't as complicated as it seems at first. Taking it from outside-in // 1) The double backslashes are because Java Strings already use backslashes for escaping, so // a double backslash is necessary in order to generate the single backslash needed for RegExp, // so this is really the RegExp pattern // \(\s*([A-Za-z0-9_-]+)\s*:\s*(\S+)\s*\) // 2) We are using parentheses for both exact character matching (the parentheses at the ends of // the RegExp), and for RegExp grouping (so that we can extract the property name and value. // Notice that since we need to exactly match the parentheses at the ends, they are escaped. // Removing these gives us: // \s*([A-Za-z0-9_-]+)\s*:\s*(\S+)\s* // 3) The \s* represent the option white space, removing these gives us the grouping expressions // for the property name:([A-Za-z0-9_-]+) and property value (\S+) // The property name is allowed to contain one or more word characters, plush the character '-' // (needed for min-version and max-version), while the property value can contain any // non-whitespace character private static final Pattern _PROPERTY_SPLITTER = Pattern.compile("\\(\\s*([A-Za-z0-9_-]+)\\s*:\\s*(\\S+)\\s*\\)"); // used for splitting up the agenet selectors between the "and"s. Just in case a "sand" operator // is added later, we require the "and" to be surrounded with whitespace. private static final Pattern _AND_SPLITTER = Pattern.compile("\\s+and\\s+"); private static final String[] _AFFIRMATIVE_TOUCH_CAPABILITIES = new String[] { TrinidadAgent.TOUCH_SCREEN_MULTIPLE.toString(), TrinidadAgent.TOUCH_SCREEN_SINGLE.toString() }; private static final Set _ALL_TOUCH_CAPABILITIES = new HashSet(Arrays.asList(new String[] { TrinidadAgent.TOUCH_SCREEN_MULTIPLE.toString(), TrinidadAgent.TOUCH_SCREEN_SINGLE.toString(), TrinidadAgent.TOUCH_SCREEN_NONE.toString() })); // map of property names to the types of comparison to use for each name private static final Map _COMPARISON_PARSER; static { // initialize property-name to Comparison type Map. Thread-safe because the Map is not // modified after initialization _COMPARISON_PARSER = new HashMap(4); _COMPARISON_PARSER.put("version", Comparison.EQUALS); _COMPARISON_PARSER.put("max-version", Comparison.MAX); _COMPARISON_PARSER.put("min-version", Comparison.MIN); } // As we need to be able to have multiple version matching rules for the same agent: // @agent ie and (version:5), ie and (version:6), gecko. // We store a map of agents and their version sets private final Map> _selectorAgents; private final Set _capTouchMatchers; // cached hash code private final int _hashCode; private static final TrinidadLogger _LOG = TrinidadLogger.createTrinidadLogger(AgentAtRuleMatcher.class); private static final String TOUCH_SCREEN_RULE_STR = "(" + TrinidadAgent.CAP_TOUCH_SCREEN.getCapabilityName(); }




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