chrome/browser/ui/fast_unload_controller.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_FAST_UNLOAD_CONTROLLER_H_
   6 #define CHROME_BROWSER_UI_FAST_UNLOAD_CONTROLLER_H_
   7
   8 #include <set>
   9
  10 #include "base/callback.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "base/memory/weak_ptr.h"
  13 #include "base/strings/string_piece.h"
  14 #include "chrome/browser/ui/tabs/tab_strip_model_observer.h"
  15 #include "content/public/browser/notification_observer.h"
  16 #include "content/public/browser/notification_registrar.h"
  17
  18 class Browser;
  19 class TabStripModel;
  20
  21 namespace content {
  22 class NotificationSource;
  23 class NotificationDetails;
  24 class WebContents;
  25 }
  26
  27 namespace chrome {
  28 // FastUnloadController manages closing tabs and windows -- especially in
  29 // regards to beforeunload handlers (have proceed/cancel dialogs) and
  30 // unload handlers (have no user interaction).
  31 //
  32 // Typical flow of closing a tab:
  33 //  1. Browser calls CanCloseContents().
  34 //     If true, browser calls contents::CloseWebContents().
  35 //  2. WebContents notifies us via its delegate and BeforeUnloadFired()
  36 //     that the beforeunload handler was run. If the user allowed the
  37 //     close to continue, we detached the tab and hold onto it while the
  38 //     close finishes.
  39 //
  40 // Typical flow of closing a window:
  41 //  1. BrowserView::CanClose() calls TabsNeedBeforeUnloadFired().
  42 //     If beforeunload/unload handlers need to run, FastUnloadController returns
  43 //     true and calls ProcessPendingTabs() (private method).
  44 //  2. For each tab with a beforeunload/unload handler, ProcessPendingTabs()
  45 //        calls |CoreTabHelper::OnCloseStarted()|
  46 //        and   |web_contents->GetRenderViewHost()->FirePageBeforeUnload()|.
  47 //  3. If the user allowed the close to continue, we detach all the tabs with
  48 //     unload handlers, remove them from the tab strip, and finish closing
  49 //     the tabs in the background.
  50 //  4. The browser gets notified that the tab strip is empty and calls
  51 //     CloseFrame where the empty tab strip causes the window to hide.
  52 //     Once the detached tabs finish, the browser calls CloseFrame again and
  53 //     the window is finally closed.
  54 //
  55 class FastUnloadController : public content::NotificationObserver,
  56                              public TabStripModelObserver {
  57  public:
  58   explicit FastUnloadController(Browser* browser);
  59   ~FastUnloadController() override;
  60
  61   // Returns true if |contents| can be cleanly closed. When |browser_| is being
  62   // closed, this function will return false to indicate |contents| should not
  63   // be cleanly closed, since the fast shutdown path will just kill its
  64   // renderer.
  65   bool CanCloseContents(content::WebContents* contents);
  66
  67   // Returns true if we need to run unload events for the |contents|.
  68   static bool ShouldRunUnloadEventsHelper(content::WebContents* contents);
  69
  70   // Helper function to run beforeunload listeners on a WebContents.
  71   // Returns true if |contents| beforeunload listeners were invoked.
  72   static bool RunUnloadEventsHelper(content::WebContents* contents);
  73
  74   // Called when a BeforeUnload handler is fired for |contents|. |proceed|
  75   // indicates the user's response to the Y/N BeforeUnload handler dialog. If
  76   // this parameter is false, any pending attempt to close the whole browser
  77   // will be canceled. Returns true if Unload handlers should be fired. When the
  78   // |browser_| is being closed, Unload handlers for any particular WebContents
  79   // will not be run until every WebContents being closed has a chance to run
  80   // its BeforeUnloadHandler.
  81   bool BeforeUnloadFired(content::WebContents* contents, bool proceed);
  82
  83   bool is_attempting_to_close_browser() const {
  84     return is_attempting_to_close_browser_;
  85   }
  86
  87   // Called in response to a request to close |browser_|'s window. Returns true
  88   // when there are no remaining beforeunload handlers to be run.
  89   bool ShouldCloseWindow();
  90
  91   // Begins the process of confirming whether the associated browser can be
  92   // closed.
  93   bool CallBeforeUnloadHandlers(
  94       const base::Callback<void(bool)>& on_close_confirmed);
  95
  96   // Clears the results of any beforeunload confirmation dialogs triggered by a
  97   // CallBeforeUnloadHandlers call.
  98   void ResetBeforeUnloadHandlers();
  99
 100   // Returns true if |browser_| has any tabs that have BeforeUnload handlers
 101   // that have not been fired. This method is non-const because it builds a list
 102   // of tabs that need their BeforeUnloadHandlers fired.
 103   // TODO(beng): This seems like it could be private but it is used by
 104   //             AreAllBrowsersCloseable() in application_lifetime.cc. It seems
 105   //             very similar to ShouldCloseWindow() and some consolidation
 106   //             could be pursued.
 107   bool TabsNeedBeforeUnloadFired();
 108
 109   // Returns true if all tabs' beforeunload/unload events have fired.
 110   bool HasCompletedUnloadProcessing() const;
 111
 112   // Clears all the state associated with processing tabs' beforeunload/unload
 113   // events since the user cancelled closing the window.
 114   void CancelWindowClose();
 115
 116  private:
 117   // Overridden from content::NotificationObserver:
 118   void Observe(int type,
 119                const content::NotificationSource& source,
 120                const content::NotificationDetails& details) override;
 121
 122   // Overridden from TabStripModelObserver:
 123   void TabInsertedAt(content::WebContents* contents,
 124                      int index,
 125                      bool foreground) override;
 126   void TabDetachedAt(content::WebContents* contents, int index) override;
 127   void TabReplacedAt(TabStripModel* tab_strip_model,
 128                      content::WebContents* old_contents,
 129                      content::WebContents* new_contents,
 130                      int index) override;
 131   void TabStripEmpty() override;
 132
 133   void TabAttachedImpl(content::WebContents* contents);
 134   void TabDetachedImpl(content::WebContents* contents);
 135
 136   // Detach |contents| and wait for it to finish closing.
 137   // The close must be inititiated outside of this method.
 138   // Returns true if it succeeds.
 139   bool DetachWebContents(content::WebContents* contents);
 140
 141   // Processes the next tab that needs it's beforeunload/unload event fired.
 142   void ProcessPendingTabs();
 143
 144   // Cleans up state appropriately when we are trying to close the
 145   // browser or close a tab in the background. We also use this in the
 146   // cases where a tab crashes or hangs even if the
 147   // beforeunload/unload haven't successfully fired.
 148   void ClearUnloadState(content::WebContents* contents);
 149
 150   // Helper for |ClearUnloadState| to unwind stack before proceeding.
 151   void PostTaskForProcessPendingTabs();
 152
 153   // Log a step of the unload processing.
 154   void LogUnloadStep(const base::StringPiece& step_name,
 155                      content::WebContents* contents) const;
 156
 157   bool is_calling_before_unload_handlers() {
 158     return !on_close_confirmed_.is_null();
 159   }
 160
 161   Browser* browser_;
 162
 163   content::NotificationRegistrar registrar_;
 164
 165   typedef std::set<content::WebContents*> WebContentsSet;
 166
 167   // Tracks tabs that need their beforeunload event started.
 168   // Only gets populated when we try to close the browser.
 169   WebContentsSet tabs_needing_before_unload_;
 170
 171   // Tracks the tab that needs its beforeunload event result.
 172   // Only gets populated when we try to close the browser.
 173   content::WebContents* tab_needing_before_unload_ack_;
 174
 175   // Tracks tabs that need their unload event started.
 176   // Only gets populated when we try to close the browser.
 177   WebContentsSet tabs_needing_unload_;
 178
 179   // Tracks tabs that need to finish running their unload event.
 180   // Populated both when closing individual tabs and when closing the browser.
 181   WebContentsSet tabs_needing_unload_ack_;
 182
 183   // Whether we are processing the beforeunload and unload events of each tab
 184   // in preparation for closing the browser. FastUnloadController owns this
 185   // state rather than Browser because unload handlers are the only reason that
 186   // a Browser window isn't just immediately closed.
 187   bool is_attempting_to_close_browser_;
 188
 189   // A callback to call to report whether the user chose to close all tabs of
 190   // |browser_| that have beforeunload event handlers. This is set only if we
 191   // are currently confirming that the browser is closable.
 192   base::Callback<void(bool)> on_close_confirmed_;
 193
 194   // Manage tabs with beforeunload/unload handlers that close detached.
 195   class DetachedWebContentsDelegate;
 196   scoped_ptr<DetachedWebContentsDelegate> detached_delegate_;
 197
 198   base::WeakPtrFactory<FastUnloadController> weak_factory_;
 199
 200   DISALLOW_COPY_AND_ASSIGN(FastUnloadController);
 201 };
 202
 203 }  // namespace chrome
 204
 205 #endif  // CHROME_BROWSER_UI_FAST_UNLOAD_CONTROLLER_H_