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();
-  scoped_ptr<printing::PreviewMetafile> draft_metafile;
-#if !defined(USE_SKIA)
-  if (print_preview_context_.IsModifiable()) {
-    draft_metafile.reset(new printing::PreviewMetafile);
+
+  if (print_preview_context_.IsModifiable() &&
+#if defined(USE_SKIA)

[vandebo (ex-Chrome), 2011/08/10 17:21:40]

The if inside an if is kind of hard to follow.  How about:
#if defines(USE_SKIA)
  bool need_draft_metafile = ...
#else
  bool need_draft_metafile = ...
#endif
if (need_draft_metafile) {...
?

[kmadhusu, 2011/08/10 19:01:13]

Done.

+      is_complete_metafile_sent_) {
+#else
+      print_preview_context_.generate_draft_pages()) {

[vandebo (ex-Chrome), 2011/08/10 17:21:40]

Maybe add a comment here says that for CG, if we want a draft metafile, we
render to that first and then copy that into the print ready metafile because CG
doesn't allow us to do it in the other order.

[kmadhusu, 2011/08/10 19:01:13]

Done.

+#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);
 
-  if (print_preview_context_.IsModifiable()) {
+  if (draft_metafile.get()) {
+    draft_metafile->FinishDocument();
+#if !defined(USE_SKIA)
+    if (!is_complete_metafile_sent_) {
+      // 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.  But the
+      // document has already been scaled and adjusted for margins, so do a 1:1
+      // drawing.
+      printing::Metafile* complete_metafile = print_preview_context_.metafile();
+      bool success = complete_metafile->StartPage(
+          printParams.page_size, gfx::Rect(printParams.page_size), 1.0);
+      DCHECK(success);
+      // StartPage unconditionally flips the content over, flip it back since it
+      // was already flipped in |draft_metafile|.
+      CGContextTranslateCTM(complete_metafile->context(), 0,
+                            printParams.page_size.height());
+      CGContextScaleCTM(complete_metafile->context(), 1.0, -1.0);
+      draft_metafile->RenderPage(1,
+                                 complete_metafile->context(),
+                                 draft_metafile->GetPageBounds(1).ToCGRect(),
+                                 false /* shrink_to_fit */,
+                                 false /* stretch_to_fit */,
+                                 true /* center_horizontally */,
+                                 true /* center_vertically */);
+      complete_metafile->FinishPage();
+    }
+#endif
+  } else if (print_preview_context_.IsModifiable() &&

[vandebo (ex-Chrome), 2011/08/10 17:21:40]

This if only has a body for the use skia case.  Can we put the entire thing
inside the use skia ifdef, i.e. including the if part?  It may be easier to make
it an if instead of an else if.

[kmadhusu, 2011/08/10 19:01:13]

Changed to:

if (draft_metafile.get()) {
..
} else {
#if defined(USE_SKIA)
  if (....) {
    ...
  }
#endif
}

+             print_preview_context_.generate_draft_pages()) {
 #if defined(USE_SKIA)
     DCHECK(!draft_metafile.get());
     draft_metafile.reset(
         print_preview_context_.metafile()->GetMetafileForCurrentPage());
-#else
-    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.  But the document
-    // has already been scaled and adjusted for margins, so do a 1:1 drawing.
-    printing::Metafile* complete_metafile = print_preview_context_.metafile();
-    bool success = complete_metafile->StartPage(
-        printParams.page_size, gfx::Rect(printParams.page_size), 1.0);
-    DCHECK(success);
-    // StartPage unconditionally flips the content over, flip it back since it
-    // was already flipped in |draft_metafile|.
-    CGContextTranslateCTM(complete_metafile->context(), 0,
-                          printParams.page_size.height());
-    CGContextScaleCTM(complete_metafile->context(), 1.0, -1.0);
-
-    draft_metafile->RenderPage(1,
-                               complete_metafile->context(),
-                               draft_metafile->GetPageBounds(1).ToCGRect(),
-                               false /* shrink_to_fit */,
-                               false /* stretch_to_fit */,
-                               true  /* center_horizontally */,
-                               true  /* center_vertically */);
-    complete_metafile->FinishPage();
 #endif
   }
-
   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();
 }