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

   1 // Copyright 2015 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_DECLARATIVE_CONTENT_CSS_CONDITION_TRACKER_H_
   6 #define CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_CONTENT_DECLARATIVE_CONTENT_CSS_CONDITION_TRACKER_H_
   7
   8 #include <map>
   9 #include <set>
  10 #include <string>
  11 #include <vector>
  12
  13 #include "base/callback.h"
  14 #include "base/containers/hash_tables.h"
  15 #include "base/memory/linked_ptr.h"
  16 #include "content/public/browser/notification_observer.h"
  17 #include "content/public/browser/notification_registrar.h"
  18 #include "content/public/browser/web_contents_observer.h"
  19
  20
  21 namespace content {
  22 class BrowserContext;
  23 struct FrameNavigateParams;
  24 struct LoadCommittedDetails;
  25 class RenderProcessHost;
  26 class WebContents;
  27 }
  28
  29 namespace extensions {
  30
  31 class DeclarativeContentConditionTrackerDelegate;
  32
  33 // Supports watching of CSS selectors to across tab contents in a browser
  34 // context, and querying for the matching CSS selectors for a context.
  35 class DeclarativeContentCssConditionTracker
  36     : public content::NotificationObserver {
  37  public:
  38   DeclarativeContentCssConditionTracker(
  39       content::BrowserContext* context,
  40       DeclarativeContentConditionTrackerDelegate* delegate);
  41   ~DeclarativeContentCssConditionTracker() override;
  42
  43   // Sets the set of CSS selectors to watch for CSS condition evaluation.
  44   void SetWatchedCssSelectors(
  45       const std::set<std::string>& watched_css_selectors);
  46
  47   // Requests that CSS conditions be tracked for |contents|.
  48   void TrackForWebContents(content::WebContents* contents);
  49
  50   // Handles navigation of |contents|. We depend on the caller to notify us of
  51   // this event rather than listening for it ourselves, so that the caller can
  52   // coordinate evaluation with all the trackers that respond to it. If we
  53   // listened ourselves and requested rule evaluation before another tracker
  54   // received the notification, our conditions would be evaluated based on the
  55   // new URL while the other tracker's conditions would still be evaluated based
  56   // on the previous URL.
  57   void OnWebContentsNavigation(content::WebContents* contents,
  58                                const content::LoadCommittedDetails& details,
  59                                const content::FrameNavigateParams& params);
  60
  61   // Inserts the currently-matching CSS selectors into |css_selectors|. We use
  62   // hash_set for maximally efficient lookup.
  63   void GetMatchingCssSelectors(content::WebContents* contents,
  64                                base::hash_set<std::string>* css_selectors);
  65
  66   // TODO(wittman): Remove once DeclarativeChromeContentRulesRegistry no longer
  67   // depends on concrete condition implementations. At that point
  68   // DeclarativeChromeContentRulesRegistryTest.ActiveRulesDoesntGrow will be
  69   // able to use a test condition object and not need to depend on force setting
  70   // matching CSS seleectors.
  71   void UpdateMatchingCssSelectorsForTesting(
  72       content::WebContents* contents,
  73       const std::vector<std::string>& matching_css_selectors);
  74
  75  private:
  76   // Monitors CSS selector matching state on one WebContents.
  77   class PerWebContentsTracker : public content::WebContentsObserver {
  78    public:
  79     using RequestEvaluationCallback =
  80         base::Callback<void(content::WebContents*)>;
  81     using WebContentsDestroyedCallback =
  82         base::Callback<void(content::WebContents*)>;
  83
  84     PerWebContentsTracker(
  85         content::WebContents* contents,
  86         const RequestEvaluationCallback& request_evaluation,
  87         const WebContentsDestroyedCallback& web_contents_destroyed);
  88     ~PerWebContentsTracker() override;
  89
  90     void OnWebContentsNavigation(const content::LoadCommittedDetails& details,
  91                                  const content::FrameNavigateParams& params);
  92
  93     // See comment on similar function above.
  94     void UpdateMatchingCssSelectorsForTesting(
  95         const std::vector<std::string>& matching_css_selectors);
  96
  97     const std::vector<std::string>& matching_css_selectors() const {
  98       return matching_css_selectors_;
  99     }
 100
 101    private:
 102     // content::WebContentsObserver overrides.
 103     bool OnMessageReceived(const IPC::Message& message) override;
 104     void WebContentsDestroyed() override;
 105
 106     void OnWatchedPageChange(const std::vector<std::string>& css_selectors);
 107
 108     const RequestEvaluationCallback request_evaluation_;
 109     const WebContentsDestroyedCallback web_contents_destroyed_;
 110
 111     std::vector<std::string> matching_css_selectors_;
 112
 113     DISALLOW_COPY_AND_ASSIGN(PerWebContentsTracker);
 114   };
 115
 116   // content::NotificationObserver implementation.
 117   void Observe(int type,
 118                const content::NotificationSource& source,
 119                const content::NotificationDetails& details) override;
 120
 121   // If the renderer process is associated with our browser context, tells it
 122   // what page attributes to watch for using an ExtensionMsg_WatchPages.
 123   void InstructRenderProcessIfManagingBrowserContext(
 124       content::RenderProcessHost* process);
 125
 126   // Called by PerWebContentsTracker on web contents destruction.
 127   void DeletePerWebContentsTracker(content::WebContents* contents);
 128
 129   // The context whose state we're monitoring for evaluation.
 130   content::BrowserContext* context_;
 131
 132   // All CSS selectors that are watched for by any rule's conditions. This
 133   // vector is sorted by construction.
 134   std::vector<std::string> watched_css_selectors_;
 135
 136   // Maps WebContents to the tracker for that WebContents state.
 137   std::map<content::WebContents*, linked_ptr<PerWebContentsTracker>>
 138       per_web_contents_tracker_;
 139
 140   // Weak.
 141   DeclarativeContentConditionTrackerDelegate* delegate_;
 142
 143   // Manages our notification registrations.
 144   content::NotificationRegistrar registrar_;
 145
 146   DISALLOW_COPY_AND_ASSIGN(DeclarativeContentCssConditionTracker);
 147 };
 148
 149 }  // namespace extensions
 150
 151 #endif  // CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_CONTENT_DECLARATIVE_CONTENT_CSS_CONDITION_TRACKER_H_