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

chrome/renderer/print_web_view_helper_mac.mm

 // 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"
 
 #import <AppKit/AppKit.h>
 
 #include "base/logging.h"
 #include "base/mac/scoped_nsautorelease_pool.h"
@@ skipping 48 matching lines @@
   Send(new PrintHostMsg_DidPrintPage(routing_id(), page_params));
 }
 
 void PrintWebViewHelper::RenderPreviewPage(int page_number) {
   float scale_factor = print_preview_context_.frame()->getPrintPageShrink(0);
   PrintMsg_Print_Params printParams = print_preview_context_.print_params();
   gfx::Rect content_area(printParams.margin_left, printParams.margin_top,
                          printParams.printable_size.width(),
                          printParams.printable_size.height());
 
+  scoped_ptr<printing::Metafile> draft_metafile;
   printing::Metafile* initial_render_metafile =
       print_preview_context_.metafile();
-#if !defined(USE_SKIA)
-  if (print_preview_context_.IsModifiable()) {
-    initial_render_metafile = new printing::PreviewMetafile();
-    if (!initial_render_metafile->Init()) {
+
+  if (print_preview_context_.IsModifiable() &&
+#if defined(USE_SKIA)
+      is_complete_metafile_sent_) {
+#else
+      print_preview_context_.generate_draft_pages()) {
+#endif
+    draft_metafile.reset(new printing::PreviewMetafile());
+    if (!draft_metafile->Init()) {
       DidFinishPrinting(FAIL_PREVIEW);
       return;
     }
+    initial_render_metafile = draft_metafile.get();
   }
-#endif
 
   base::TimeTicks begin_time = base::TimeTicks::Now();
   RenderPage(printParams.page_size, content_area, scale_factor, page_number,
              print_preview_context_.frame(), initial_render_metafile);
   print_preview_context_.RenderedPreviewPage(
       base::TimeTicks::Now() - begin_time);
 
-  printing::Metafile* draft_metafile = NULL;
   if (print_preview_context_.IsModifiable()) {

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

Not sure it if would be cleaner, but if you like, you could remove line 93 and
make the else on 115 be else if(modifiable && ppc_.generate_draft_pages())

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

Done.

+    if (draft_metafile.get()) {
+      draft_metafile->FinishDocument();
+#if !defined(USE_SKIA)
+      if (!is_complete_metafile_sent_) {
+        bool success = print_preview_context_.metafile()->StartPage(
+                           printParams.page_size, content_area, scale_factor);
+        DCHECK(success);
+        // With CG, we rendered into a new metafile so we could get it as a
+        // draft document.  Now we need to add it to complete document.
+        draft_metafile->RenderPage(1,
+                                  print_preview_context_.metafile()->context(),
+                                  CGRectMake(content_area.x(), content_area.y(),
+                                             content_area.width(),
+                                             content_area.height()),
+                                  false /*shrunk_to_fit*/,
+                                  false /*stretch_to_fit*/,
+                                  true /*center_horizontally*/,
+                                  true /*center_vertically*/);
+        print_preview_context_.metafile()->FinishPage();
+      }
+#endif
+    } else {

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

Actually, does this need to check ppc_generate_draft_metafile in either case?  I
suspect either this case or the Linux case is wrong or over constrained.

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

Yes, I need to check ppc_generate_draft_pages(), because on page selection, I
just want the complete metafile and not the draft pages.

 #if defined(USE_SKIA)
-    draft_metafile = reinterpret_cast<printing::PreviewMetafile*>(
-        print_preview_context_.metafile())->GetMetafileForCurrentPage();
-#else
-    draft_metafile = initial_render_metafile;
-    draft_metafile->FinishDocument();
-
-    // With CG, we rendered into a new metafile so we could get it as a draft
-    // document.  Now we need to add it to complete document.
-    draft_metafile->RenderPage(1,
-                               print_preview_context_.metafile()->context(),
-                               CGRectMake(content_area.x(), content_area.y(),
-                                          content_area.width(),
-                                          content_area.height()),
-                               false /*shrunk_to_fit*/,
-                               false /*stretch_to_fit*/,
-                               true /*center_horizontally*/,
-                               true /*center_vertically*/);
+    draft_metafile.reset(reinterpret_cast<printing::PreviewMetafile*>(
+        initial_render_metafile)->GetMetafileForCurrentPage());
 #endif
+    }
   }
 
-  PreviewPageRendered(page_number, draft_metafile);
+  PreviewPageRendered(page_number, draft_metafile.get());
 }
 
 void PrintWebViewHelper::RenderPage(
     const gfx::Size& page_size, const gfx::Rect& content_area,
     const float& scale_factor, int page_number, WebFrame* frame,
     printing::Metafile* metafile) {
 
   {
 #if defined(USE_SKIA)
     SkDevice* device = metafile->StartPageForVectorCanvas(
         page_size, content_area, scale_factor);
     if (!device)
       return;
 
     SkRefPtr<skia::VectorCanvas> canvas = new skia::VectorCanvas(device);
     canvas->unref();  // SkRefPtr and new both took a reference.
     WebKit::WebCanvas* canvasPtr = canvas.get();
     printing::MetafileSkiaWrapper::SetMetafileOnCanvas(canvasPtr, metafile);
+    printing::MetafileSkiaWrapper::SetDraftMode(canvasPtr,
+                                                is_complete_metafile_sent_);
 #else
     bool success = metafile->StartPage(page_size, content_area, scale_factor);
     DCHECK(success);
     // printPage can create autoreleased references to |context|. PDF contexts
     // don't write all their data until they are destroyed, so we need to make
     // certain that there are no lingering references.
     base::mac::ScopedNSAutoreleasePool pool;
     CGContextRef cgContext = metafile->context();
     CGContextRef canvasPtr = cgContext;
 #endif
     frame->printPage(page_number, canvasPtr);
   }
 
   // Done printing. Close the device context to retrieve the compiled metafile.
   metafile->FinishPage();
 }