downloads: add the ability to undo download removal.

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>
 
@@ skipping 70 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);
 
+  // Callback for the "undoRemove" message. Undoes any previous removal.
+  void HandleUndoRemove(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);
 
   // Schedules a call to SendCurrentDownloads() in the next message loop
   // iteration. Protected rather than private for use in tests.
@@ skipping 16 matching lines @@
   void ShowDangerPrompt(content::DownloadItem* dangerous);
 
   // Conveys danger acceptance from the DownloadDangerPrompt to the
   // DownloadItem.
   void DangerPromptDone(int download_id, DownloadDangerPrompt::Action action);
 
   // Returns true if the records of any downloaded items are allowed (and able)
   // to be deleted.
   bool IsDeletingHistoryAllowed();
 
+  // Returns the download with ID of |download_id|.
+  content::DownloadItem* GetDownloadById(uint32 download_id);
+
   // Returns the download that is referred to in a given value.
   content::DownloadItem* GetDownloadByValue(const base::ListValue* args);
 
   // Current search terms.
   scoped_ptr<base::ListValue> search_terms_;
 
   // Notifies OnDownload*() and provides safe access to the DownloadManager.
   AllDownloadItemNotifier main_notifier_;
 
   // If |main_notifier_| observes an incognito profile, then this observes the
   // DownloadManager for the original profile; otherwise, this is NULL.
   scoped_ptr<AllDownloadItemNotifier> original_notifier_;
 
   // Whether a call to SendCurrentDownloads() is currently scheduled.
   bool update_scheduled_;
 
+  // IDs of downloads that have been removed from this page. These IDs are
+  // purged and the downloads are actually removed on destruction.
+  std::vector<uint32> removed_ids_;
+
   base::WeakPtrFactory<DownloadsDOMHandler> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadsDOMHandler);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_DOWNLOADS_DOM_HANDLER_H_