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_PRERENDER_PRERENDER_HANDLE_H_ 6 #define CHROME_BROWSER_PRERENDER_PRERENDER_HANDLE_H_ 7 8 #include "base/basictypes.h" 9 #include "base/memory/weak_ptr.h" 10 #include "base/threading/non_thread_safe.h" 11 #include "chrome/browser/prerender/prerender_manager.h" 12 13 class GURL; 14 15 namespace content { 16 class SessionStorageNamespace; 17 } 18 19 namespace prerender { 20 21 class PrerenderContents; 22 23 // A class representing a running prerender to a client of the PrerenderManager. 24 // Methods on PrerenderManager which start prerenders return a caller-owned 25 // PrerenderHandle* to the client (or NULL if they are unable to start a 26 // prerender). Calls on the handle of a prerender that is not running at no-ops. 27 // Destroying a handle before a prerender starts will prevent it from ever 28 // starting. Destroying a handle while a prerendering is running will stop the 29 // prerender, without making any calls to the observer. 30 class PrerenderHandle : public base::NonThreadSafe, 31 public PrerenderContents::Observer { 32 public: 33 class Observer { 34 public: 35 // Signals that the prerender has started running. 36 virtual void OnPrerenderStart(PrerenderHandle* handle) = 0; 37 38 // Signals that the prerender has had its load event. 39 virtual void OnPrerenderStopLoading(PrerenderHandle* handle) = 0; 40 41 // Signals that the prerender has stopped running. 42 virtual void OnPrerenderStop(PrerenderHandle* handle) = 0; 43 44 // Signals that this prerender has just become a MatchComplete replacement. 45 virtual void OnPrerenderCreatedMatchCompleteReplacement( 46 PrerenderHandle* handle) = 0; 47 48 protected: 49 Observer(); 50 virtual ~Observer(); 51 }; 52 53 // Before calling the destructor, the caller must invalidate the handle by 54 // calling either OnNavigateAway or OnCancel. 55 virtual ~PrerenderHandle(); 56 57 void SetObserver(Observer* observer); 58 59 // The launcher is navigating away from the context that launched this 60 // prerender. The prerender will likely stay alive briefly though, in case we 61 // are going through a redirect chain that will target it. 62 void OnNavigateAway(); 63 64 // The launcher has taken explicit action to remove this prerender (for 65 // instance, removing a link element from a document). This call invalidates 66 // the handle. If the prerender handle is already invalid, this call does 67 // nothing. 68 void OnCancel(); 69 70 // True if this prerender is currently active. 71 bool IsPrerendering() const; 72 73 // True if we started a prerender, and it has finished loading. 74 bool IsFinishedLoading() const; 75 76 PrerenderContents* contents() const; 77 78 // Returns whether the prerender matches the URL provided. 79 bool Matches( 80 const GURL& url, 81 const content::SessionStorageNamespace* session_storage_namespace) const; 82 83 // Returns whether this PrerenderHandle represents the same prerender as 84 // the other PrerenderHandle object specified. 85 bool RepresentingSamePrerenderAs(PrerenderHandle* other) const; 86 87 // Retrieves the SessionStorageNamespace of the underlying prerender, if 88 // available. 89 content::SessionStorageNamespace* GetSessionStorageNamespace() const; 90 91 // Returns the child id of the prerender. 92 int GetChildId() const; 93 94 private: 95 friend class PrerenderManager; 96 97 explicit PrerenderHandle(PrerenderManager::PrerenderData* prerender_data); 98 99 void AdoptPrerenderDataFrom(PrerenderHandle* other_handle); 100 101 // From PrerenderContents::Observer: 102 virtual void OnPrerenderStart(PrerenderContents* prerender_contents) OVERRIDE; 103 virtual void OnPrerenderStopLoading(PrerenderContents* prerender_contents) 104 OVERRIDE; 105 virtual void OnPrerenderStop(PrerenderContents* prerender_contents) OVERRIDE; 106 virtual void OnPrerenderCreatedMatchCompleteReplacement( 107 PrerenderContents* contents, PrerenderContents* replacement) OVERRIDE; 108 109 Observer* observer_; 110 111 base::WeakPtr<PrerenderManager::PrerenderData> prerender_data_; 112 base::WeakPtrFactory<PrerenderHandle> weak_ptr_factory_; 113 114 DISALLOW_COPY_AND_ASSIGN(PrerenderHandle); 115 }; 116 117 } // namespace prerender 118 119 #endif // CHROME_BROWSER_PRERENDER_PRERENDER_HANDLE_H_ 120