chrome/browser/ui/search/instant_search_prerenderer.h

   1 // Copyright 2013 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_UI_SEARCH_INSTANT_SEARCH_PRERENDERER_H_
   6 #define CHROME_BROWSER_UI_SEARCH_INSTANT_SEARCH_PRERENDERER_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "base/strings/string16.h"
  11 #include "chrome/common/instant_types.h"
  12 #include "content/public/browser/navigation_controller.h"
  13
  14 class GURL;
  15 class Profile;
  16 struct AutocompleteMatch;
  17
  18 namespace chrome {
  19 struct NavigateParams;
  20 }
  21
  22 namespace content {
  23 class SessionStorageNamespace;
  24 class WebContents;
  25 }
  26
  27 namespace gfx {
  28 class Size;
  29 }
  30
  31 namespace prerender {
  32 class PrerenderHandle;
  33 }
  34
  35 // InstantSearchPrerenderer is responsible for prerendering the default search
  36 // provider Instant search base page URL to prefetch high-confidence search
  37 // suggestions. InstantSearchPrerenderer manages the prerender handle associated
  38 // with the prerendered contents.
  39 class InstantSearchPrerenderer {
  40  public:
  41   InstantSearchPrerenderer(Profile* profile, const GURL& url);
  42   ~InstantSearchPrerenderer();
  43
  44   // Returns the InstantSearchPrerenderer instance for the given |profile|.
  45   static InstantSearchPrerenderer* GetForProfile(Profile* profile);
  46
  47   // Prerender the |prerender_url_| contents. |session_storage_namespace| is
  48   // used to identify the namespace of the active tab at the time the prerender
  49   // is generated. The |size| gives the initial size for the target
  50   // prerender. InstantSearchPrerenderer will run at most one prerender at a
  51   // time, so launching a prerender will cancel the previous prerenders (if
  52   // any).
  53   void Init(content::SessionStorageNamespace* session_storage_namespace,
  54             const gfx::Size& size);
  55
  56   // Cancels the current request.
  57   void Cancel();
  58
  59   // Tells the Instant search base page to prerender |suggestion|.
  60   void Prerender(const InstantSuggestion& suggestion);
  61
  62   // Tells the Instant search base page to render the search results for the
  63   // given |query|.
  64   void Commit(const base::string16& query,
  65               const EmbeddedSearchRequestParams& params);
  66
  67   // Returns true if the prerendered page can be used to process the search for
  68   // the given |source|.
  69   bool CanCommitQuery(content::WebContents* source,
  70                       const base::string16& query) const;
  71
  72   // Returns true and updates |params->target_contents| if a prerendered page
  73   // exists for |url| and is swapped in.
  74   bool UsePrerenderedPage(const GURL& url, chrome::NavigateParams* params);
  75
  76   // Returns the last prefetched search query.
  77   const base::string16& get_last_query() const {
  78     return last_instant_suggestion_.text;
  79   }
  80
  81   // Returns true when prerendering is allowed for the given |source| and
  82   // |match|.
  83   bool IsAllowed(const AutocompleteMatch& match,
  84                  content::WebContents* source) const;
  85
  86  private:
  87   friend class InstantSearchPrerendererTest;
  88
  89   content::WebContents* prerender_contents() const;
  90
  91   // Returns true if the |query| matches the last prefetched search query or if
  92   // the 'reuse_instant_search_base_page' flag is enabled in the field trials.
  93   bool QueryMatchesPrefetch(const base::string16& query) const;
  94
  95   Profile* const profile_;
  96
  97   // Instant search base page URL.
  98   const GURL prerender_url_;
  99
 100   scoped_ptr<prerender::PrerenderHandle> prerender_handle_;
 101
 102   InstantSuggestion last_instant_suggestion_;
 103
 104   DISALLOW_COPY_AND_ASSIGN(InstantSearchPrerenderer);
 105 };
 106
 107 #endif  // CHROME_BROWSER_UI_SEARCH_INSTANT_SEARCH_PRERENDERER_H_