Async frame preparation for Preview with support if selection.

chrome/renderer/printing/print_web_view_helper.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_RENDERER_PRINTING_PRINT_WEB_VIEW_HELPER_H_
 #define CHROME_RENDERER_PRINTING_PRINT_WEB_VIEW_HELPER_H_
 
 #include <vector>
 
 #include "base/gtest_prod_util.h"
@@ skipping 120 matching lines @@
       bool source_is_html,
       const base::DictionaryValue& job_settings,
       const PrintMsg_Print_Params& params);
 
   // Initiate print preview.
   void OnInitiatePrintPreview();
 
   // Start the process of generating a print preview using |settings|.
   void OnPrintPreview(const base::DictionaryValue& settings);
 
+  // Prepare frame for creating preview document.
+  void PrepareFrameForPreviewDocument();
+
+  // Continue creating preview document.
+  void OnFramePreparedForPreviewDocument();
+
   // Initialize the print preview document.
   bool CreatePreviewDocument();
 
   // Renders a print preview page. |page_number| is 0-based.
   // Returns true if print preview should continue, false on failure.
   bool RenderPreviewPage(int page_number,
                          const PrintMsg_Print_Params& print_params);
 
   // Finalize the print ready preview document.
   bool FinalizePrintReadyDocument();
@@ skipping 180 matching lines @@
   // True, when printing from print preview.
   bool print_for_preview_;
 
   scoped_ptr<PrintMsg_PrintPages_Params> old_print_pages_params_;
 
   // Strings generated by the browser process to be printed as headers and
   // footers if requested by the user.
   scoped_ptr<base::DictionaryValue> header_footer_info_;
 
   // Keeps track of the state of print preview between messages.
+  // TODO(vitalybuka): Create PrintPreviewContext when needed and delete after
+  // use. Now it's interaction with veriouse messages is confusing.

[Lei Zhang, 2013/01/29 01:40:47]

typo: veriouse -> various

[Vitaly Buka (NO REVIEWS), 2013/01/29 05:14:57]

Done.

   class PrintPreviewContext {
    public:
     PrintPreviewContext();
     ~PrintPreviewContext();
 
     // Initializes the print preview context. Need to be called to set
     // the |web_frame| / |web_node| to generate the print preview for.
     void InitWithFrame(WebKit::WebFrame* web_frame);
     void InitWithNode(const WebKit::WebNode& web_node);
 
     // Does bookkeeping at the beginning of print preview.
     void OnPrintPreview();
 
     // Create the print preview document. |pages| is empty to print all pages.
-    bool CreatePreviewDocument(const PrintMsg_Print_Params& params,
-                               const std::vector<int>& pages,
-                               bool ignore_css_margins);
+    // Takes ownership of |prepared_frame|.
+    bool CreatePreviewDocument(PrepareFrameAndViewForPrint* prepared_frame,
+                               const std::vector<int>& pages);
 
     // Called after a page gets rendered. |page_time| is how long the
     // rendering took.
     void RenderedPreviewPage(const base::TimeDelta& page_time);
 
     // Updates the print preview context when the required pages are rendered.
     void AllPagesRendered();
 
     // Finalizes the print ready preview document.
     void FinalizePrintReadyDocument();
 
     // Cleanup after print preview finishes.
     void Finished();
 
     // Cleanup after print preview fails.
     void Failed(bool report_error);
 
     // Helper functions
     int GetNextPageNumber();
     bool IsRendering() const;
     bool IsModifiable() const;
     bool IsLastPageOfPrintReadyMetafile() const;
     bool IsFinalPageRendered() const;
 
     // Setters
     void set_generate_draft_pages(bool generate_draft_pages);
     void set_error(enum PrintPreviewErrorBuckets error);
 
     // Getters
-    WebKit::WebFrame* frame();
-    const WebKit::WebNode& node() const;
+    // Original frame for which preview was requested.
+    WebKit::WebFrame* source_frame();
+    // Original node for which preview was requested.
+    const WebKit::WebNode& source_node() const;
+
+    // Frame to be use to render preview. May be the same as source_frame(), or
+    // generated from it, e.g. copy of selected block.
+    WebKit::WebFrame* prepared_frame();
+    // Node to be use to render preview. May be the same as source_node(), or
+    // generated from it, e.g. copy of selected block.
+    const WebKit::WebNode& prepared_node() const;
+
     int total_page_count() const;
     bool generate_draft_pages() const;
     PreviewMetafile* metafile();
     gfx::Size GetPrintCanvasSize() const;
     int last_error() const;
 
    private:
     enum State {
       UNINITIALIZED,  // Not ready to render.
       INITIALIZED,    // Ready to render.
       RENDERING,      // Rendering.
       DONE            // Finished rendering.
     };
 
     // Reset some of the internal rendering context.
     void ClearContext();
 
     // Specifies what to render for print preview.
-    WebKit::WebFrame* frame_;
-    WebKit::WebNode node_;
+    WebKit::WebFrame* source_frame_;
+    WebKit::WebNode source_node_;
 
     scoped_ptr<PrepareFrameAndViewForPrint> prep_frame_view_;
     scoped_ptr<PreviewMetafile> metafile_;
 
     // Total page count in the renderer.
     int total_page_count_;
 
     // The current page to render.
     int current_page_index_;
 
@@ skipping 15 matching lines @@
   };
 
   bool print_node_in_progress_;
   PrintPreviewContext print_preview_context_;
   DISALLOW_COPY_AND_ASSIGN(PrintWebViewHelper);
 };
 
 }  // namespace printing
 
 #endif  // CHROME_RENDERER_PRINTING_PRINT_WEB_VIEW_HELPER_H_