1 // Copyright 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_UI_SEARCH_INSTANT_LOADER_H_ 6 #define CHROME_BROWSER_UI_SEARCH_INSTANT_LOADER_H_ 7 8 #include "base/basictypes.h" 9 #include "base/callback.h" 10 #include "base/compiler_specific.h" 11 #include "base/memory/scoped_ptr.h" 12 #include "base/timer/timer.h" 13 #include "chrome/browser/ui/tab_contents/core_tab_helper_delegate.h" 14 #include "content/public/browser/notification_observer.h" 15 #include "content/public/browser/notification_registrar.h" 16 #include "content/public/browser/web_contents_delegate.h" 17 18 class GURL; 19 class Profile; 20 21 namespace content { 22 struct OpenURLParams; 23 class WebContents; 24 } 25 26 // InstantLoader is used to create and maintain a WebContents where we can 27 // preload a page into. It is used by InstantNTP to preload an Instant page. 28 class InstantLoader : public content::NotificationObserver, 29 public content::WebContentsDelegate, 30 public CoreTabHelperDelegate { 31 public: 32 // InstantLoader calls these methods on its delegate in response to certain 33 // changes in the underlying contents. 34 class Delegate { 35 public: 36 // Called after someone has swapped in a different WebContents for ours. 37 virtual void OnSwappedContents() = 0; 38 39 // Called to open a URL using the underlying contents (see 40 // WebContentsDelegate::OpenURLFromTab). The Delegate should return the 41 // WebContents the URL is opened in, or NULL if the URL wasn't opened 42 // immediately. 43 virtual content::WebContents* OpenURLFromTab( 44 content::WebContents* source, 45 const content::OpenURLParams& params) = 0; 46 47 // Called when a main frame load is complete. 48 virtual void LoadCompletedMainFrame() = 0; 49 50 protected: 51 ~Delegate(); 52 }; 53 54 explicit InstantLoader(Delegate* delegate); 55 virtual ~InstantLoader(); 56 57 // Creates a new WebContents in the context of |profile| that will be used to 58 // load |instant_url|. The page is not actually loaded until Load() is 59 // called. |on_stale_callback| will be called after kStalePageTimeoutMS 60 // has elapsed after Load() being called. 61 void Init(const GURL& instant_url, 62 Profile* profile, 63 const base::Closure& on_stale_callback); 64 65 // Loads |instant_url_| in |contents_|. 66 void Load(); 67 68 // Returns the contents currently held. May be NULL. 69 content::WebContents* contents() const { return contents_.get(); } 70 71 // Replaces the contents held with |contents|. Any existing contents is 72 // deleted. The expiration timer is not restarted. 73 void SetContents(scoped_ptr<content::WebContents> contents); 74 75 // Releases the contents currently held. Must only be called if contents() is 76 // not NULL. 77 scoped_ptr<content::WebContents> ReleaseContents(); 78 79 private: 80 // Overridden from content::NotificationObserver: 81 virtual void Observe(int type, 82 const content::NotificationSource& source, 83 const content::NotificationDetails& details) OVERRIDE; 84 85 // Overridden from CoreTabHelperDelegate: 86 virtual void SwapTabContents(content::WebContents* old_contents, 87 content::WebContents* new_contents) OVERRIDE; 88 89 // Overridden from content::WebContentsDelegate: 90 virtual bool ShouldSuppressDialogs() OVERRIDE; 91 virtual bool ShouldFocusPageAfterCrash() OVERRIDE; 92 virtual void CanDownload(content::RenderViewHost* render_view_host, 93 int request_id, 94 const std::string& request_method, 95 const base::Callback<void(bool)>& callback) OVERRIDE; 96 virtual bool OnGoToEntryOffset(int offset) OVERRIDE; 97 virtual content::WebContents* OpenURLFromTab( 98 content::WebContents* source, 99 const content::OpenURLParams& params) OVERRIDE; 100 101 Delegate* const delegate_; 102 scoped_ptr<content::WebContents> contents_; 103 104 // The URL we will be loading. 105 GURL instant_url_; 106 107 // Called when |stale_page_timer_| fires. 108 base::Closure on_stale_callback_; 109 110 // Used to mark when the page is stale. 111 base::Timer stale_page_timer_; 112 113 // Used to get notifications about renderers. 114 content::NotificationRegistrar registrar_; 115 116 DISALLOW_COPY_AND_ASSIGN(InstantLoader); 117 }; 118 119 #endif // CHROME_BROWSER_UI_SEARCH_INSTANT_LOADER_H_ 120