chrome/browser/android/meta_tag_observer.h

   1 // Copyright 2014 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_ANDROID_META_TAG_OBSERVER_H_
   6 #define CHROME_BROWSER_ANDROID_META_TAG_OBSERVER_H_
   7
   8 #include "content/public/browser/web_contents_observer.h"
   9
  10 class GURL;
  11
  12 // Retrieves the content of a particular meta tag when a page has fully loaded.
  13 // Subclasses must implement |HandleMetaTagContent|, which gets called after
  14 // the DOM has been scanned for the tag.
  15 class MetaTagObserver : public content::WebContentsObserver {
  16  public:
  17   explicit MetaTagObserver(const std::string& meta_tag);
  18   virtual ~MetaTagObserver();
  19
  20   // content::WebContentsObserver overrides:
  21   virtual void DidFinishLoad(content::RenderFrameHost* render_frame_host,
  22                              const GURL& validated_url) OVERRIDE;
  23
  24   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
  25
  26  protected:
  27   // Called when the meta tag's content has been retrieved successfully.
  28   virtual void HandleMetaTagContent(const std::string& tag_content,
  29                                     const GURL& expected_url) = 0;
  30
  31  private:
  32   // Called when the renderer has returned information about the meta tag.
  33   void OnDidRetrieveMetaTagContent(bool success,
  34                                    const std::string& tag_name,
  35                                    const std::string& tag_content,
  36                                    const GURL& expected_url);
  37
  38   const std::string meta_tag_;
  39   GURL validated_url_;
  40
  41   DISALLOW_COPY_AND_ASSIGN(MetaTagObserver);
  42 };
  43
  44 #endif  // CHROME_BROWSER_ANDROID_META_TAG_OBSERVER_H_