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

chrome/renderer/print_web_view_helper_mac.mm

Index: chrome/renderer/print_web_view_helper_mac.mm
diff --git a/chrome/renderer/print_web_view_helper_mac.mm b/chrome/renderer/print_web_view_helper_mac.mm
index 95ccb7e69bf215ae5c209aa90778ffbca79b6649..2eb94d0fa21acc2720171b6cb8adae4ef8922dd5 100644
--- a/chrome/renderer/print_web_view_helper_mac.mm
+++ b/chrome/renderer/print_web_view_helper_mac.mm
@@ -66,19 +66,23 @@ void PrintWebViewHelper::RenderPreviewPage(int page_number) {
                          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,
@@ -86,38 +90,41 @@ void PrintWebViewHelper::RenderPreviewPage(int page_number) {
   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());
 }
 
@@ -137,6 +144,8 @@ void PrintWebViewHelper::RenderPage(
     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);