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

chrome/renderer/print_web_view_helper_win.cc

Index: chrome/renderer/print_web_view_helper_win.cc
diff --git a/chrome/renderer/print_web_view_helper_win.cc b/chrome/renderer/print_web_view_helper_win.cc
index 4ee351ba67cfc6c271a6d5aa113560abf9dac663..e1670b50ff920b9c7850c87947a808d080934355 100644
--- a/chrome/renderer/print_web_view_helper_win.cc
+++ b/chrome/renderer/print_web_view_helper_win.cc
@@ -109,12 +109,15 @@ void PrintWebViewHelper::PrintPageInternal(
   int page_number = params.page_number;
 
   // Calculate the dpi adjustment.
-  float scale_factor = static_cast<float>(params.params.desired_dpi /
-                                          params.params.dpi);
+  double scale_factor = static_cast<float>(params.params.desired_dpi /
+                                           params.params.dpi);
 
+  gfx::Size page_size_in_dpi;
+  gfx::Rect content_area_in_dpi;
   // Render page for printing.
-  metafile.reset(RenderPage(params.params, &scale_factor, page_number, false,
-                            frame, metafile.get()));
+  metafile.reset(RenderPage(params.params, page_number, false, frame,
+                            metafile.get(), &scale_factor, &page_size_in_dpi,
+                            &content_area_in_dpi));
 
   // Close the device context to retrieve the compiled metafile.
   if (!metafile->FinishDocument())
@@ -130,10 +133,8 @@ void PrintWebViewHelper::PrintPageInternal(
   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.content_size.width(),
-      params.params.content_size.height());
+  page_params.page_size = page_size_in_dpi;
+  page_params.content_area = content_area_in_dpi;
 
   if (!CopyMetafileDataToSharedMem(metafile.get(),
                                    &(page_params.metafile_data_handle))) {
@@ -146,8 +147,8 @@ void PrintWebViewHelper::PrintPageInternal(
 bool 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);
+  double scale_factor = static_cast<float>(print_params.desired_dpi /
+                                           print_params.dpi);
   scoped_ptr<Metafile> draft_metafile;
   printing::Metafile* initial_render_metafile =
       print_preview_context_.metafile();
@@ -159,8 +160,9 @@ bool PrintWebViewHelper::RenderPreviewPage(int page_number) {
 
   base::TimeTicks begin_time = base::TimeTicks::Now();
   printing::Metafile* render_page_result =
-      RenderPage(print_params, &scale_factor, page_number, true,
-                 print_preview_context_.frame(), initial_render_metafile);
+      RenderPage(print_params, page_number, true,
+                 print_preview_context_.frame(), initial_render_metafile,
+                 &scale_factor, NULL, NULL);
   // In the preview flow, RenderPage will never return a new metafile.
   DCHECK_EQ(render_page_result, initial_render_metafile);
   print_preview_context_.RenderedPreviewPage(
@@ -178,37 +180,52 @@ bool PrintWebViewHelper::RenderPreviewPage(int page_number) {
 }
 
 Metafile* PrintWebViewHelper::RenderPage(
-    const PrintMsg_Print_Params& params, float* scale_factor, int page_number,
-    bool is_preview, WebFrame* frame, Metafile* metafile) {
+    const PrintMsg_Print_Params& params, int page_number, bool is_preview,
+    WebFrame* frame, Metafile* metafile, double* scale_factor,

[vandebo (ex-Chrome), 2012/01/07 00:23:19]

Since there are a lot of factors, lets make the names a bit more explicit:
scale_factor -> actual_shrink or final_scale_factor
shrink_factor -> css_scale_factor

[kmadhusu, 2012/01/09 17:15:55]

Done.

+    gfx::Size* page_size_in_dpi, gfx::Rect* content_area_in_dpi) {
   printing::PageSizeMargins page_layout_in_points;
-  GetPageSizeAndMarginsInPoints(frame, page_number, params,
-                                &page_layout_in_points);
-
-  int width;
-  int height;
-  if (is_preview) {
+  double shrink_factor = 1.0f;
+  ComputePageLayoutInPoints(frame, page_number, params, ignore_css_margins_,
+                            fit_to_page_, &shrink_factor,
+                            &page_layout_in_points);
+  gfx::Size page_size;
+  gfx::Rect content_area;
+  GetPageSizeAndContentAreaFromPageLayout(page_layout_in_points, &page_size,
+                                          &content_area);
+  if (!is_preview) {

[vandebo (ex-Chrome), 2012/01/07 00:23:19]

Remove this if, since you already have the NULL protection.

[kmadhusu, 2012/01/09 17:15:55]

Moved page_size_in_dpi and content_area_in_dpi out of if(!is_preview)

     int dpi = static_cast<int>(params.dpi);
-    int desired_dpi = printing::kPointsPerInch;
-    width = ConvertUnit(params.page_size.width(), dpi, desired_dpi);
-    height = ConvertUnit(params.page_size.height(), dpi, desired_dpi);
-  } else {
+    // Calculate the actual page size and content area in dpi.
+    if (page_size_in_dpi) {
+      *page_size_in_dpi = gfx::Size(
+          static_cast<int>(ConvertUnitDouble(
+              page_size.width(), printing::kPointsPerInch, dpi)),
+          static_cast<int>(ConvertUnitDouble(
+              page_size.height(), printing::kPointsPerInch, dpi)));
+    }
+    if (content_area_in_dpi) {
+      *content_area_in_dpi = gfx::Rect(
+          static_cast<int>(ConvertUnitDouble(content_area.x(),
+              printing::kPointsPerInch, dpi)),
+          static_cast<int>(ConvertUnitDouble(content_area.y(),
+              printing::kPointsPerInch, dpi)),
+          static_cast<int>(ConvertUnitDouble(content_area.width(),
+              printing::kPointsPerInch, dpi)),
+          static_cast<int>(ConvertUnitDouble(content_area.height(),
+              printing::kPointsPerInch, dpi)));
+    }
+
     // Since WebKit extends the page width depending on the magical scale factor
     // we make sure the canvas covers the worst case scenario (x2.0 currently).
     // PrintContext will then set the correct clipping region.
-    width = static_cast<int>(page_layout_in_points.content_width *
-                             params.max_shrink);
-    height = static_cast<int>(page_layout_in_points.content_height *
-                              params.max_shrink);
+    page_size = gfx::Size(
+        static_cast<int>(page_layout_in_points.content_width *
+                         params.max_shrink),
+        static_cast<int>(page_layout_in_points.content_height *
+                         params.max_shrink));
   }
-
-  gfx::Size page_size(width, height);
-  gfx::Rect content_area(
-      static_cast<int>(page_layout_in_points.margin_left),
-      static_cast<int>(page_layout_in_points.margin_top),
-      static_cast<int>(page_layout_in_points.content_width),
-      static_cast<int>(page_layout_in_points.content_height));
+  float webkit_page_shrink_factor = frame->getPrintPageShrink(page_number);
   SkDevice* device = metafile->StartPageForVectorCanvas(
-      page_size, content_area, frame->getPrintPageShrink(page_number));
+      page_size, content_area, shrink_factor * webkit_page_shrink_factor);
   DCHECK(device);
   // The printPage method may take a reference to the canvas we pass down, so it
   // can't be a stack object.
@@ -226,7 +243,8 @@ Metafile* PrintWebViewHelper::RenderPage(
     // |page_number| is 0-based, so 1 is added.
     PrintHeaderAndFooter(canvas.get(), page_number + 1,
                          print_preview_context_.total_page_count(),
-                         webkit_scale_factor, page_layout_in_points,
+                         shrink_factor * webkit_page_shrink_factor,
+                         page_layout_in_points,
                          *header_footer_info_);
   }
 
@@ -235,7 +253,7 @@ Metafile* PrintWebViewHelper::RenderPage(
   } else {
     // Update the dpi adjustment with the "page |scale_factor|" calculated in
     // webkit.
-    *scale_factor /= webkit_scale_factor;
+    *scale_factor /= (webkit_scale_factor * shrink_factor);
   }
 
   bool result = metafile->FinishPage();
@@ -264,14 +282,15 @@ Metafile* PrintWebViewHelper::RenderPage(
       SetGraphicsMode(bitmap_dc, GM_ADVANCED);
       void* bits = NULL;
       BITMAPINFO hdr;
-      gfx::CreateBitmapHeader(width, height, &hdr.bmiHeader);
+      gfx::CreateBitmapHeader(page_size.width(), page_size.height(),
+                              &hdr.bmiHeader);
       base::win::ScopedBitmap hbitmap(CreateDIBSection(
           bitmap_dc, &hdr, DIB_RGB_COLORS, &bits, NULL, 0));
       if (!hbitmap)
         NOTREACHED() << "Raster bitmap creation for printing failed";
 
       base::win::ScopedSelectObject selectBitmap(bitmap_dc, hbitmap);
-      RECT rect = {0, 0, width, height };
+      RECT rect = { 0, 0, page_size.width(), page_size.height() };
       HBRUSH whiteBrush = static_cast<HBRUSH>(GetStockObject(WHITE_BRUSH));
       FillRect(bitmap_dc, &rect, whiteBrush);