Rewrite DownloadsDOMHandler

chrome/browser/ui/webui/downloads_dom_handler.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_UI_WEBUI_DOWNLOADS_DOM_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_DOWNLOADS_DOM_HANDLER_H_
 
+#include <set>
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/memory/weak_ptr.h"
 #include "content/public/browser/download_item.h"
 #include "content/public/browser/download_manager.h"
 #include "content/public/browser/web_ui_message_handler.h"
 
 namespace base {
 class ListValue;
 }
 
+namespace content {
+class WebContents;
+}
+
 // The handler for Javascript messages related to the "downloads" view,
 // also observes changes to the download manager.
 class DownloadsDOMHandler : public content::WebUIMessageHandler,
                             public content::DownloadManager::Observer,
                             public content::DownloadItem::Observer {
  public:
   explicit DownloadsDOMHandler(content::DownloadManager* dlm);
   virtual ~DownloadsDOMHandler();
 
   void Init();
 
   // WebUIMessageHandler implementation.
   virtual void RegisterMessages() OVERRIDE;
 
   // content::DownloadItem::Observer interface
-  virtual void OnDownloadUpdated(content::DownloadItem* download) OVERRIDE;
-  virtual void OnDownloadDestroyed(content::DownloadItem* download) OVERRIDE;
+  virtual void OnDownloadUpdated(
+      content::DownloadItem* download_item) OVERRIDE;
+  virtual void OnDownloadDestroyed(
+      content::DownloadItem* download_item) OVERRIDE;
 
   // content::DownloadManager::Observer interface
-  virtual void ModelChanged(content::DownloadManager* manager) OVERRIDE;
+  virtual void OnDownloadCreated(content::DownloadManager* manager,
+                                 content::DownloadItem* download_item) OVERRIDE;
   virtual void ManagerGoingDown(content::DownloadManager* manager) OVERRIDE;
 
   // Callback for the "onPageLoaded" message.
   void OnPageLoaded(const base::ListValue* args);
 
   // Callback for the "getDownloads" message.
   void HandleGetDownloads(const base::ListValue* args);
 
   // Callback for the "openFile" message - opens the file in the shell.
   void HandleOpenFile(const base::ListValue* args);
@@ skipping 22 matching lines @@
   // Callback for the "cancel" message - cancels the download.
   void HandleCancel(const base::ListValue* args);
 
   // Callback for the "clearAll" message - clears all the downloads.
   void HandleClearAll(const base::ListValue* args);
 
   // Callback for the "openDownloadsFolder" message - opens the downloads
   // folder.
   void HandleOpenDownloadsFolder(const base::ListValue* args);
 
+ protected:
+  // These methods are for mocking so that most of this class does not actually
+  // depend on WebUI. The other methods that depend on WebUI are
+  // RegisterMessages() and HandleDrag().
+  virtual content::WebContents* GetWebUIWebContents();
+  virtual void CallDownloadsList(const base::ListValue& downloads);
+  virtual void CallDownloadUpdated(const base::ListValue& download);
+
  private:
-  class OriginalDownloadManagerObserver;
+  // Shorthand for |observing_items_|, which tracks all items that this is
+  // observing so that RemoveObserver will be called for all of them.
+  typedef std::set<content::DownloadItem*> DownloadSet;
 
-  // Send the current list of downloads to the page.
+  // Schedules a call to SendCurrentDownloads() in the next message loop
+  // iteration.
+  void ScheduleSendCurrentDownloads();
+
+  // Sends the current list of downloads to the page.
   void SendCurrentDownloads();
 
-  // Clear all download items and their observers.
+  // Fills |downloads| with all the items for both DownloadManagers matching
+  // |search_text_|.
+  void SearchDownloads(content::DownloadManager::DownloadVector* downloads);
+
+  // Clears all download items and their observers.
   void ClearDownloadItems();
 
-  // Display a native prompt asking the user for confirmation after accepting
+  // Displays a native prompt asking the user for confirmation after accepting
   // the dangerous download specified by |dangerous|. The function returns
   // immediately, and will invoke DangerPromptAccepted() asynchronously if the
   // user accepts the dangerous download. The native prompt will observe
   // |dangerous| until either the dialog is dismissed or |dangerous| is no
   // longer an in-progress dangerous download.
   void ShowDangerPrompt(content::DownloadItem* dangerous);
 
-  // Called when the user accepts a dangerous download via the
-  // DownloadDangerPrompt invoked via ShowDangerPrompt().
+  // Conveys danger acceptance from the DownloadDangerPrompt to the
+  // DownloadItem.
   void DangerPromptAccepted(int download_id);
 
-  // Return the download that corresponds to a given id.
-  content::DownloadItem* GetDownloadById(int id);
-
-  // Return the download that is referred to in a given value.
+  // Returns the download that is referred to in a given value.
   content::DownloadItem* GetDownloadByValue(const base::ListValue* args);
 
   // Current search text.
-  std::wstring search_text_;
+  string16 search_text_;
+
+  // Keeps track of all items that this is observing so that RemoveObserver will
+  // be called for all of them.
+  DownloadSet observing_items_;
 
   // Our model
   content::DownloadManager* download_manager_;
 
-  // If |download_manager_| belongs to an incognito profile than this
+  // If |download_manager_| belongs to an incognito profile then this
   // is the DownloadManager for the original profile; otherwise, this is
   // NULL.
   content::DownloadManager* original_profile_download_manager_;
 
-  // True once the page has loaded the first time (it may load multiple times,
-  // e.g. on reload).
-  bool initialized_;
-
-  // The current set of visible DownloadItems for this view received from the
-  // DownloadManager. DownloadManager owns the DownloadItems. The vector is
-  // kept in order, sorted by ascending start time.
-  // Note that when a download item is removed, the entry in the vector becomes
-  // null.  This should only be a transient state, as a ModelChanged()
-  // notification should follow close on the heels of such a change.
-  typedef std::vector<content::DownloadItem*> OrderedDownloads;
-  OrderedDownloads download_items_;
+  // Whether a call to SendCurrentDownloads() is currently scheduled.
+  bool update_scheduled_;
 
   base::WeakPtrFactory<DownloadsDOMHandler> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadsDOMHandler);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_DOWNLOADS_DOM_HANDLER_H_