Print Preview: Go from event driven print preview back to print preview with sync messages. The s...

chrome/browser/ui/webui/print_preview_ui.h

 // Copyright (c) 2011 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_PRINT_PREVIEW_UI_H_
 #define CHROME_BROWSER_UI_WEBUI_PRINT_PREVIEW_UI_H_
 #pragma once
 
 #include <string>
 
@@ skipping 23 matching lines @@
   // document.
   void SetPrintPreviewDataForIndex(int index, const RefCountedBytes* data);
 
   // Clear the existing print preview data.
   void ClearAllPreviewData();
 
   // Setters
   void SetInitiatorTabURLAndTitle(const std::string& initiator_url,
                                   const string16& initiator_tab_title);
 
-  // Notifies the Web UI that there is a print preview request. There should be
-  // a matching call to OnPreviewDataIsAvailable() or OnPrintPreviewFailed().
-  void OnPrintPreviewRequest();
+  // Determines whether to cancel a print preview request based on
+  // |preview_ui_id| and |request_id|.
+  // Only called on the IO thread. (thread safe)
+  static void GetCurrentPrintPreviewStatus(int preview_ui_id,
+                                           int request_id,
+                                           bool* cancel);
+
+  int uid() const;
+
+  // Notifies the Web UI of a print preview request with |request_id|.
+  void OnPrintPreviewRequest(int request_id);
 
   // Notifies the Web UI about the page count of the request preview.
   void OnDidGetPreviewPageCount(
       const PrintHostMsg_DidGetPreviewPageCount_Params& params);
 
   // Notifies the Web UI that the 0-based page |page_number| has been rendered.
   // |preview_request_id| indicates wich request resulted in this response.
   void OnDidPreviewPage(int page_number, int preview_request_id);
 
   // Notifies the Web UI renderer that preview data is available.
   // |expected_pages_count| specifies the total number of pages.
   // |preview_request_id| indicates which request resulted in this response.
   void OnPreviewDataIsAvailable(int expected_pages_count,
                                 int preview_request_id);
 
   void OnReusePreviewData(int preview_request_id);
 
   // Notifies the Web UI that preview tab is destroyed. This is the last chance
   // to communicate with the source tab before the association is erased.
   void OnTabDestroyed();
 
   // Notifies the Web UI that the print preview failed to render.
   void OnPrintPreviewFailed();
 
-  // Notifies the Web UI that the print preview request has been cancelled.
-  void OnPrintPreviewCancelled();
-
   // Notifies the Web UI that initiator tab is closed, so we can disable all the
   // controls that need the initiator tab for generating the preview data.
   void OnInitiatorTabClosed();
 
   // Notifies the Web UI that the initiator tab has crashed.
   void OnInitiatorTabCrashed();
 
   // Notifies the Web UI renderer that file selection has been cancelled.
   void OnFileSelectionCancelled();
 
-  // Returns true if there are pending requests.
-  bool HasPendingRequests();
-
-  int document_cookie();
-
  private:
   // Returns the Singleton instance of the PrintPreviewDataService.
   PrintPreviewDataService* print_preview_data_service();
 
-  void DecrementRequestCount();
-
   base::TimeTicks initial_preview_start_time_;
 
-  // Store the PrintPreviewUI address string.
+  // A unique id to identify this print preview tab.
+  int uid_;
+
+  // The |uid_| in string form.
   std::string preview_ui_addr_str_;
 
   // Weak pointer to the WebUI handler.
   PrintPreviewHandler* handler_;
 
-  // The number of print preview requests in flight.
-  uint32 request_count_;
-
-  // Document cookie from the initiator renderer.
-  int document_cookie_;
-
   // Store the |initiator_url| in order to display an accurate error message
   // when the initiator tab is closed/crashed.
   std::string initiator_url_;
 
   // Store the initiator tab title, used for populating the print preview tab
   // title.
   string16 initiator_tab_title_;
 
   DISALLOW_COPY_AND_ASSIGN(PrintPreviewUI);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_PRINT_PREVIEW_UI_H_