ios/web/webui/url_data_manager_ios.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 IOS_WEB_WEBUI_URL_DATA_MANAGER_IOS_H_
   6 #define IOS_WEB_WEBUI_URL_DATA_MANAGER_IOS_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/memory/ref_counted.h"
  12 #include "base/supports_user_data.h"
  13
  14 namespace web {
  15 class BrowserState;
  16 class URLDataSourceIOS;
  17 class URLDataSourceIOSImpl;
  18 class WebUIIOSDataSource;
  19
  20 // To serve dynamic data off of chrome: URLs, implement the
  21 // URLDataManagerIOS::DataSource interface and register your handler
  22 // with AddDataSource. DataSources must be added on the UI thread (they are also
  23 // deleted on the UI thread). Internally the DataSources are maintained by
  24 // URLDataManagerIOSBackend, see it for details.
  25 class URLDataManagerIOS : public base::SupportsUserData::Data {
  26  public:
  27   explicit URLDataManagerIOS(BrowserState* browser_state);
  28   ~URLDataManagerIOS() override;
  29
  30   // Adds a DataSource to the collection of data sources. This *must* be invoked
  31   // on the UI thread.
  32   //
  33   // If |AddDataSource| is called more than once for a particular name it will
  34   // release the old |DataSource|, most likely resulting in it getting deleted
  35   // as there are no other references to it. |DataSource| uses the
  36   // |DeleteOnUIThread| trait to insure that the destructor is called on the UI
  37   // thread. This is necessary as some |DataSource|s notably |FileIconSource|
  38   // and |FaviconSource|, have members that will DCHECK if they are not
  39   // destructed in the same thread as they are constructed (the UI thread).
  40   void AddDataSource(URLDataSourceIOSImpl* source);
  41
  42   // Deletes any data sources no longer referenced. This is normally invoked
  43   // for you, but can be invoked to force deletion (such as during shutdown).
  44   static void DeleteDataSources();
  45
  46   // Convenience wrapper function to add |source| to |browser_context|'s
  47   // |URLDataManagerIOS|. Creates a URLDataSourceIOSImpl to wrap the given
  48   // source.
  49   static void AddDataSource(BrowserState* browser_context,
  50                             URLDataSourceIOS* source);
  51
  52   // Adds a WebUI data source to |browser_context|'s |URLDataManagerIOS|.
  53   static void AddWebUIIOSDataSource(BrowserState* browser_state,
  54                                     WebUIIOSDataSource* source);
  55
  56  private:
  57   friend class URLDataSourceIOSImpl;
  58   friend struct DeleteURLDataSourceIOS;
  59   typedef std::vector<const URLDataSourceIOSImpl*> URLDataSources;
  60
  61   // Invoked on the IO thread to do the actual adding of the DataSource.
  62   static void AddDataSourceOnIOThread(
  63       BrowserState* browser_state,
  64       scoped_refptr<URLDataSourceIOSImpl> data_source);
  65
  66   // If invoked on the UI thread the DataSource is deleted immediatlye,
  67   // otherwise it is added to |data_sources_| and a task is scheduled to handle
  68   // deletion on the UI thread. See note abouve DeleteDataSource for more info.
  69   static void DeleteDataSource(const URLDataSourceIOSImpl* data_source);
  70
  71   // Returns true if |data_source| is scheduled for deletion (|DeleteDataSource|
  72   // was invoked).
  73   static bool IsScheduledForDeletion(const URLDataSourceIOSImpl* data_source);
  74
  75   BrowserState* browser_state_;
  76
  77   // |data_sources_| that are no longer referenced and scheduled for deletion.
  78   // Protected by g_delete_lock in the .cc file.
  79   static URLDataSources* data_sources_;
  80
  81   DISALLOW_COPY_AND_ASSIGN(URLDataManagerIOS);
  82 };
  83
  84 }  // namespace web
  85
  86 #endif  // IOS_WEB_WEBUI_URL_DATA_MANAGER_IOS_H_