chrome/browser/extensions/api/declarative_content/content_condition.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_CONTENT_CONTENT_CONDITION_H_
   6 #define CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_CONTENT_CONTENT_CONDITION_H_
   7
   8 #include <map>
   9 #include <set>
  10 #include <string>
  11 #include <vector>
  12
  13 #include "base/containers/hash_tables.h"
  14 #include "base/memory/ref_counted.h"
  15 #include "base/memory/scoped_ptr.h"
  16 #include "base/values.h"
  17 #include "components/url_matcher/url_matcher.h"
  18 #include "extensions/browser/api/declarative/declarative_rule.h"
  19
  20 namespace extensions {
  21
  22 struct RendererContentMatchData {
  23   RendererContentMatchData();
  24   ~RendererContentMatchData();
  25   // Match IDs for the URL of the top-level page the renderer is
  26   // returning data for.
  27   std::set<url_matcher::URLMatcherConditionSet::ID> page_url_matches;
  28   // All watched CSS selectors that match on frames with the same
  29   // origin as the page's main frame.
  30   base::hash_set<std::string> css_selectors;
  31 };
  32
  33 // Representation of a condition in the Declarative Content API. A condition
  34 // consists of an optional URL and a list of CSS selectors. Each of these
  35 // attributes needs to be fulfilled in order for the condition to be fulfilled.
  36 //
  37 // We distinguish between two types of attributes:
  38 // - URL Matcher attributes are attributes that test the URL of a page.
  39 //   These are treated separately because we use a URLMatcher to efficiently
  40 //   test many of these attributes in parallel by using some advanced
  41 //   data structures. The URLMatcher tells us if all URL Matcher attributes
  42 //   are fulfilled for a ContentCondition.
  43 // - All other conditions are represented individually as fields in
  44 //   ContentCondition.  These conditions are probed linearly (only if the URL
  45 //   Matcher found a hit).
  46 //
  47 // TODO(battre) Consider making the URLMatcher an owner of the
  48 // URLMatcherConditionSet and only pass a pointer to URLMatcherConditionSet
  49 // in url_matcher_condition_set(). This saves some copying in
  50 // ContentConditionSet::GetURLMatcherConditionSets.
  51 class ContentCondition {
  52  public:
  53   typedef RendererContentMatchData MatchData;
  54
  55   ContentCondition(
  56       scoped_refptr<url_matcher::URLMatcherConditionSet> url_matcher_conditions,
  57       const std::vector<std::string>& css_selectors);
  58   ~ContentCondition();
  59
  60   // Factory method that instantiates a ContentCondition according to the
  61   // description |condition| passed by the extension API.  |condition| should be
  62   // an instance of declarativeContent.PageStateMatcher.
  63   static scoped_ptr<ContentCondition> Create(
  64       const Extension* extension,
  65       url_matcher::URLMatcherConditionFactory* url_matcher_condition_factory,
  66       const base::Value& condition,
  67       std::string* error);
  68
  69   // Returns whether the request is a match, given that the URLMatcher found
  70   // a match for |url_matcher_conditions_|.
  71   bool IsFulfilled(const RendererContentMatchData& renderer_data) const;
  72
  73   // Returns a URLMatcherConditionSet::ID which is the canonical representation
  74   // for all URL patterns that need to be matched by this ContentCondition.
  75   // This ID is registered in a URLMatcher that can inform us in case of a
  76   // match.
  77   url_matcher::URLMatcherConditionSet::ID url_matcher_condition_set_id() const {
  78     return url_matcher_conditions_->id();
  79   }
  80
  81   // If this Condition has a url filter, appends it to |condition_sets|.
  82   void GetURLMatcherConditionSets(
  83       url_matcher::URLMatcherConditionSet::Vector* condition_sets) const {
  84     if (url_matcher_conditions_.get())
  85       condition_sets->push_back(url_matcher_conditions_);
  86   }
  87
  88   // True if GetURLMatcherConditionSets would append anything to its
  89   // argument.
  90   bool has_url_matcher_condition_set() const {
  91     return url_matcher_conditions_.get() != NULL;
  92   }
  93
  94   // Returns the CSS selectors required to match by this condition.
  95   const std::vector<std::string>& css_selectors() const {
  96     return css_selectors_;
  97   }
  98
  99  private:
 100   scoped_refptr<url_matcher::URLMatcherConditionSet> url_matcher_conditions_;
 101   std::vector<std::string> css_selectors_;
 102
 103   DISALLOW_COPY_AND_ASSIGN(ContentCondition);
 104 };
 105
 106 typedef DeclarativeConditionSet<ContentCondition> ContentConditionSet;
 107
 108 }  // namespace extensions
 109
 110 #endif  // CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_CONTENT_CONTENT_CONDITION_H_