Print preview page selection should not require a rerendering of draft pages.

chrome/renderer/print_web_view_helper_win.cc

 // 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.
 
 #include "chrome/renderer/print_web_view_helper.h"
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/histogram.h"
 #include "base/process_util.h"
@@ skipping 112 matching lines @@
 
 void PrintWebViewHelper::RenderPreviewPage(int page_number) {
   PrintMsg_Print_Params print_params = print_preview_context_.print_params();
   // Calculate the dpi adjustment.
   float scale_factor = static_cast<float>(print_params.desired_dpi /
                                           print_params.dpi);
 
   // |metafile| is needed for RenderPage() below. |metafile| will not take the
   // ownership of |print_preview_context_| metafile.
   scoped_ptr<Metafile> metafile(print_preview_context_.metafile());
+  scoped_ptr<Metafile> draft_metafile;

[vandebo (ex-Chrome), 2011/08/08 20:11:46]

You probably need a rebase.

[kmadhusu, 2011/08/09 22:09:26]

Done.

+
+  if (print_preview_context_.IsModifiable() && is_complete_metafile_sent_)
+    draft_metafile.reset(new printing::PreviewMetafile);
 
   base::TimeTicks begin_time = base::TimeTicks::Now();
   RenderPage(print_params, &scale_factor, page_number, true,
-             print_preview_context_.frame(), &metafile);
+             print_preview_context_.frame(),
+             is_complete_metafile_sent_? &draft_metafile : &metafile);

[vandebo (ex-Chrome), 2011/08/08 20:11:46]

Hmm, this probably needs to be exactly the same condition as the init of
draft_metafile above.  But that is fragile. This will probably make it easier:
http://codereview.chromium.org/7491074/

[kmadhusu, 2011/08/09 22:09:26]

Rebased with your changes and made code changes accordingly.

 
   print_preview_context_.RenderedPreviewPage(
       base::TimeTicks::Now() - begin_time);
 
   // Release since |print_preview_context_| is the real owner.
   metafile.release();
-  printing::Metafile* page_metafile = NULL;
+
   if (print_preview_context_.IsModifiable()) {
-    page_metafile = reinterpret_cast<printing::PreviewMetafile*>(
-        print_preview_context_.metafile())->GetMetafileForCurrentPage();
+    if (draft_metafile.get()) {
+      draft_metafile->FinishDocument();
+    } else if (print_preview_context_.generate_draft_pages()){
+      draft_metafile.reset(reinterpret_cast<printing::PreviewMetafile*>(

[vandebo (ex-Chrome), 2011/08/08 20:11:46]

Add a DCHECK that draf_metafile is empty?

[kmadhusu, 2011/08/09 22:09:26]

Done.

+          print_preview_context_.metafile())->GetMetafileForCurrentPage());
+    }
   }
-  PreviewPageRendered(page_number, page_metafile);
+  PreviewPageRendered(page_number, draft_metafile.get());
 }
 
 void PrintWebViewHelper::RenderPage(
     const PrintMsg_Print_Params& params, float* scale_factor, int page_number,
     bool is_preview, WebFrame* frame, scoped_ptr<Metafile>* metafile) {
   PageSizeMargins page_layout_in_points;
   GetPageSizeAndMarginsInPoints(frame, page_number, params,
                                 &page_layout_in_points);
 
   int width;
@@ skipping 22 matching lines @@
   SkDevice* device = (*metafile)->StartPageForVectorCanvas(
       page_size, content_area, frame->getPrintPageShrink(page_number));
   DCHECK(device);
   // The printPage method may take a reference to the canvas we pass down, so it
   // can't be a stack object.
   SkRefPtr<skia::VectorCanvas> canvas = new skia::VectorCanvas(device);
   canvas->unref();  // SkRefPtr and new both took a reference.
   if (is_preview) {
     printing::MetafileSkiaWrapper::SetMetafileOnCanvas(canvas.get(),
                                                        metafile->get());
+    printing::MetafileSkiaWrapper::SetDraftMode(canvas.get(),
+                                                is_complete_metafile_sent_);
   }
 
   float webkit_scale_factor = frame->printPage(page_number, canvas.get());
   if (*scale_factor <= 0 || webkit_scale_factor <= 0) {
     NOTREACHED() << "Printing page " << page_number << " failed.";
   } else {
     // Update the dpi adjustment with the "page |scale_factor|" calculated in
     // webkit.
     *scale_factor /= webkit_scale_factor;
   }
@@ skipping 80 matching lines @@
     shared_buf.Unmap();
     return false;
   }
   shared_buf.GiveToProcess(base::GetCurrentProcessHandle(), shared_mem_handle);
   shared_buf.Unmap();
 
   Send(new PrintHostMsg_DuplicateSection(routing_id(), *shared_mem_handle,
                                          shared_mem_handle));
   return true;
 }