PrintPreview: Honor the print media page size and margin values.

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 14 matching lines @@
 using WebKit::WebFrame;
 
 void PrintWebViewHelper::PrintPageInternal(
     const PrintMsg_PrintPage_Params& params,
     const gfx::Size& canvas_size,
     WebFrame* frame) {
   printing::NativeMetafile metafile;
   if (!metafile.Init())
     return;
 
-  float scale_factor = frame->getPrintPageShrink(params.page_number);
+  double scale_factor = frame->getPrintPageShrink(params.page_number);
   int page_number = params.page_number;
 
   // Render page for printing.
+  printing::PageSizeMargins page_layout_in_points;
+  gfx::Size page_size(params.params.printable_size);
   gfx::Rect content_area(params.params.printable_size);
-  RenderPage(params.params.printable_size, content_area, scale_factor,
-             page_number, frame, false, &metafile);
+
+#if defined(USE_SKIA)

[vandebo (ex-Chrome), 2011/12/04 22:20:34]

I thought that the mac-skia flow was already different.  Is there a reason not
to use this new computation on the mac-cg flow?

[kmadhusu, 2011/12/05 09:06:54]

In the mac-cg workflow, we are doing some scaling and translation while
preparing a frame for printing. I will fix this issue later. Currently,  I have
made changes to support mac-skia workflow. 

+  GetPageSizeAndMarginsInPoints(print_preview_context_.frame(), page_number,
+                                print_pages_params_->params,
+                                ignore_frame_margins_css_, fit_to_page_,
+                                &scale_factor, &page_layout_in_points);
+  page_size = gfx::Size(

[vandebo (ex-Chrome), 2011/12/04 22:20:34]

Will this calculation of page_size come out to the same value as the previous
value of page_size?  I suspect it will, but I'm not sure.  If it will, then we
don't need to recompute it.  If it won't, I'll need some help understanding
what's going on.

[kmadhusu, 2011/12/05 09:06:54]

When source is html (with a special margin & size css) and the destination
printer is "PRINT_TO_PDF", the page_size is not the same as printer specified
default page size. That is the main reason for calculating the page size here. 

+      page_layout_in_points.content_width +
+      page_layout_in_points.margin_right +
+      page_layout_in_points.margin_left,
+      page_layout_in_points.content_height +
+      page_layout_in_points.margin_top +
+      page_layout_in_points.margin_bottom);
+  content_area = gfx::Rect(page_layout_in_points.margin_left,
+                         page_layout_in_points.margin_top,
+                         page_layout_in_points.content_width,
+                         page_layout_in_points.content_height);
+#else
+  GetPageSizeAndMarginsInPoints(print_preview_context_.frame(), page_number,
+                                print_pages_params_->params, false, false, NULL,
+                                &page_layout_in_points);
+#endif
+
+  RenderPage(page_size, content_area, scale_factor, page_number, frame, false,
+             &metafile, page_layout_in_points);
   metafile.FinishDocument();
 
   PrintHostMsg_DidPrintPage_Params page_params;
   page_params.data_size = metafile.GetDataSize();
   page_params.page_number = page_number;
   page_params.document_cookie = params.params.document_cookie;
   page_params.actual_shrink = scale_factor;
-  page_params.page_size = params.params.page_size;
-  page_params.content_area = gfx::Rect(params.params.margin_left,
-                                       params.params.margin_top,
-                                       params.params.printable_size.width(),
-                                       params.params.printable_size.height());
+  page_params.page_size = page_size;
+  page_params.content_area = content_area;
 
   // Ask the browser to create the shared memory for us.
   if (!CopyMetafileDataToSharedMem(&metafile,
                                    &(page_params.metafile_data_handle))) {
     page_params.data_size = 0;
   }
 
   Send(new PrintHostMsg_DidPrintPage(routing_id(), page_params));
 }
 
 bool PrintWebViewHelper::RenderPreviewPage(int page_number) {
-  float scale_factor = print_preview_context_.frame()->getPrintPageShrink(0);
+  double scale_factor = print_preview_context_.frame()->getPrintPageShrink(0);
   PrintMsg_Print_Params printParams = print_preview_context_.print_params();
+  printing::PageSizeMargins page_layout_in_points;
+  gfx::Size page_size(printParams.page_size);
   gfx::Rect content_area(printParams.margin_left, printParams.margin_top,
                          printParams.printable_size.width(),
                          printParams.printable_size.height());
 
+#if defined(USE_SKIA)

[vandebo (ex-Chrome), 2011/12/04 22:20:34]

Should this get pulled out into a common function?  Or should we just compute
content_area inside RenderPage?

[kmadhusu, 2011/12/05 09:06:54]

I created a helper function to update the page size and content area from
page_layout_in_points. In line #75 and #74, we are using the calculated values,
therefore I am little hesitant to have a common function.

+//  scale_factor = 1.0f;

[vandebo (ex-Chrome), 2011/12/04 22:20:34]

extra

[kmadhusu, 2011/12/05 09:06:54]

Removed.

+  GetPageSizeAndMarginsInPoints(print_preview_context_.frame(), page_number,
+                                print_pages_params_->params,
+                                ignore_frame_margins_css_, fit_to_page_,
+                                &scale_factor, &page_layout_in_points);
+  page_size = gfx::Size(
+      page_layout_in_points.content_width +
+      page_layout_in_points.margin_right +
+      page_layout_in_points.margin_left,
+      page_layout_in_points.content_height +
+      page_layout_in_points.margin_top +
+      page_layout_in_points.margin_bottom);
+  content_area = gfx::Rect(page_layout_in_points.margin_left,
+                         page_layout_in_points.margin_top,
+                         page_layout_in_points.content_width,
+                         page_layout_in_points.content_height);
+#else
+  GetPageSizeAndMarginsInPoints(print_preview_context_.frame(), page_number,
+                                print_pages_params_->params, false, false, NULL,
+                                &page_layout_in_points);
+#endif
+
   scoped_ptr<printing::Metafile> draft_metafile;
   printing::Metafile* initial_render_metafile =
       print_preview_context_.metafile();
 
 #if defined(USE_SKIA)
   bool render_to_draft = print_preview_context_.IsModifiable() &&
                          is_print_ready_metafile_sent_;
 #else
   // If the page needs to be in both draft metafile and print ready metafile,
   // we should always render to the draft metafile first and then copy that
   // into the print ready metafile because CG does not allow us to do it in
   // the other order.
   bool render_to_draft = print_preview_context_.IsModifiable() &&
                          print_preview_context_.generate_draft_pages();
 #endif
 
   if (render_to_draft) {
     draft_metafile.reset(new printing::PreviewMetafile());
     if (!draft_metafile->Init()) {
       print_preview_context_.set_error(
           PREVIEW_ERROR_MAC_DRAFT_METAFILE_INIT_FAILED);
       LOG(ERROR) << "Draft PreviewMetafile Init failed";
       return false;
     }
     initial_render_metafile = draft_metafile.get();
   }
 
   base::TimeTicks begin_time = base::TimeTicks::Now();
-  RenderPage(printParams.page_size, content_area, scale_factor, page_number,
-             print_preview_context_.frame(), true, initial_render_metafile);
+  RenderPage(page_size, content_area, scale_factor, page_number,
+             print_preview_context_.frame(), true, initial_render_metafile,
+             page_layout_in_points);
   print_preview_context_.RenderedPreviewPage(
       base::TimeTicks::Now() - begin_time);
 
   if (draft_metafile.get()) {
     draft_metafile->FinishDocument();
 #if !defined(USE_SKIA)
     if (!is_print_ready_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 print ready document.  But the
       // document has already been scaled and adjusted for margins, so do a 1:1
       // drawing.
       printing::Metafile* print_ready_metafile =
           print_preview_context_.metafile();
-      bool success = print_ready_metafile->StartPage(
-          printParams.page_size, gfx::Rect(printParams.page_size), 1.0);
+      bool success = print_ready_metafile->StartPage(page_size,
+                                                     gfx::Rect(page_size), 1.0);
       DCHECK(success);
       // StartPage unconditionally flips the content over, flip it back since it
       // was already flipped in |draft_metafile|.
       CGContextTranslateCTM(print_ready_metafile->context(), 0,
-                            printParams.page_size.height());
+                            page_size.height());
       CGContextScaleCTM(print_ready_metafile->context(), 1.0, -1.0);
       draft_metafile->RenderPage(1,
                                  print_ready_metafile->context(),
                                  draft_metafile->GetPageBounds(1).ToCGRect(),
                                  false /* shrink_to_fit */,
                                  false /* stretch_to_fit */,
                                  true /* center_horizontally */,
                                  true /* center_vertically */);
       print_ready_metafile->FinishPage();
     }
 #endif
   } else {
 #if defined(USE_SKIA)
     if (print_preview_context_.IsModifiable() &&
         print_preview_context_.generate_draft_pages()) {
       DCHECK(!draft_metafile.get());
       draft_metafile.reset(
           print_preview_context_.metafile()->GetMetafileForCurrentPage());
     }
 #endif
   }
   return 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,
-    bool is_preview, printing::Metafile* metafile) {
+    const double& scale_factor, int page_number, WebFrame* frame,
+    bool is_preview, printing::Metafile* metafile,
+    printing::PageSizeMargins page_layout_in_points) {
 
   {
 #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* canvas_ptr = canvas.get();
     printing::MetafileSkiaWrapper::SetMetafileOnCanvas(*canvas, metafile);
     skia::SetIsDraftMode(*canvas, is_print_ready_metafile_sent_);
     skia::SetIsPreviewMetafile(*canvas, is_preview);
 #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 canvas_ptr = cgContext;
 #endif
 
-    printing::PageSizeMargins page_layout_in_points;
-    GetPageSizeAndMarginsInPoints(frame, page_number,
-                                  print_pages_params_->params,
-                                  &page_layout_in_points);
-
 #if !defined(USE_SKIA)
     // For CoreGraphics, print in the margins before printing in the content
     // area so that we don't spill over. Webkit draws a white background in the
     // content area and this acts as a clip.
     // TODO(aayushkumar): Combine the calls to PrintHeaderAndFooter once we
     // can draw in the margins safely in Skia in any order.
     if (print_pages_params_->params.display_header_footer) {
       PrintHeaderAndFooter(canvas_ptr, page_number + 1,
                            print_preview_context_.total_page_count(),
                            scale_factor, page_layout_in_points,
@@ skipping 10 matching lines @@
                            print_preview_context_.total_page_count(),
                            scale_factor, page_layout_in_points,
                            *header_footer_info_);
     }
 #endif  // defined(USE_SKIA)
   }
 
   // Done printing. Close the device context to retrieve the compiled metafile.
   metafile->FinishPage();
 }