PrintPreview: [Win] Added a temporary hack to print blank pdf pages.

webkit/plugins/ppapi/ppapi_plugin_instance.cc

 // 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 "webkit/plugins/ppapi/ppapi_plugin_instance.h"
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 112 matching lines @@
 namespace ppapi {
 
 #if defined(OS_WIN)
 // Exported by pdf.dll
 typedef bool (*RenderPDFPageToDCProc)(
     const unsigned char* pdf_buffer, int buffer_size, int page_number, HDC dc,
     int dpi_x, int dpi_y, int bounds_origin_x, int bounds_origin_y,
     int bounds_width, int bounds_height, bool fit_to_bounds,
     bool stretch_to_bounds, bool keep_aspect_ratio, bool center_in_bounds,
     bool autorotate);
+
+void DrawEmptyRectangle(HDC dc) {
+  // TODO(sanjeevr): This is a temporary hack. If we output a JPEG
+  // to the EMF, the EnumEnhMetaFile call fails in the browser
+  // process. The failure also happens if we output nothing here.
+  // We need to investigate the reason for this failure and fix it.
+  // In the meantime this temporary hack of drawing an empty
+  // rectangle in the DC gets us by.
+  Rectangle(dc, 0, 0, 0, 0);
+}
 #endif  // defined(OS_WIN)
 
 namespace {
 
 #define COMPILE_ASSERT_MATCHING_ENUM(webkit_name, np_name) \
     COMPILE_ASSERT(static_cast<int>(WebCursorInfo::webkit_name) \
                        == static_cast<int>(np_name), \
                    mismatching_enums)
 
 COMPILE_ASSERT_MATCHING_ENUM(TypePointer, PP_CURSORTYPE_POINTER);
@@ skipping 1012 matching lines @@
   printing::Metafile* metafile =
     printing::MetafileSkiaWrapper::GetMetafileFromCanvas(*canvas);
   if (metafile) {
     // We only have a metafile when doing print preview, so we just want to
     // pass the PDF off to preview.
     ret = metafile->InitFromData(mapper.data(), mapper.size());
   } else {
     // On Windows, we now need to render the PDF to the DC that backs the
     // supplied canvas.
     HDC dc = skia::BeginPlatformPaint(canvas);
+    DrawEmptyRectangle(dc);
     gfx::Size size_in_pixels;
     size_in_pixels.set_width(printing::ConvertUnit(
         current_print_settings_.printable_area.size.width,
         static_cast<int>(printing::kPointsPerInch),
         current_print_settings_.dpi));
     size_in_pixels.set_height(printing::ConvertUnit(
         current_print_settings_.printable_area.size.height,
         static_cast<int>(printing::kPointsPerInch),
         current_print_settings_.dpi));
     // We need to render using the actual printer DPI (rendering to a smaller
@@ skipping 99 matching lines @@
       static_cast<int>(bitmap.rowBytes()), 100, &compressed_image);
   UMA_HISTOGRAM_TIMES("PepperPluginPrint.RasterBitmapCompressTime",
                       base::TimeTicks::Now() - start_time);
   if (!encoded) {
     NOTREACHED();
     return false;
   }
 
   skia::ScopedPlatformPaint scoped_platform_paint(canvas);
   HDC dc = scoped_platform_paint.GetPlatformSurface();
-  // TODO(sanjeevr): This is a temporary hack. If we output a JPEG
-  // to the EMF, the EnumEnhMetaFile call fails in the browser
-  // process. The failure also happens if we output nothing here.
-  // We need to investigate the reason for this failure and fix it.
-  // In the meantime this temporary hack of drawing an empty
-  // rectangle in the DC gets us by.
-  Rectangle(dc, 0, 0, 0, 0);
+  DrawEmptyRectangle(dc);
   BITMAPINFOHEADER bmi = {0};
   gfx::CreateBitmapHeader(bitmap.width(), bitmap.height(), &bmi);
   bmi.biCompression = BI_JPEG;
   bmi.biSizeImage = compressed_image.size();
   bmi.biHeight = -bmi.biHeight;
   StretchDIBits(dc, printable_area.x(), printable_area.y(),
                 printable_area.width(), printable_area.height(),
                 0, 0, bitmap.width(), bitmap.height(),
                 &compressed_image.front(),
                 reinterpret_cast<const BITMAPINFO*>(&bmi),
@@ skipping 505 matching lines @@
   }
   WebKit::WebDocument main_document =
       containing_document.frame()->view()->mainFrame()->document();
 
   return containing_document.securityOrigin().canAccess(
       main_document.securityOrigin());
 }
 
 }  // namespace ppapi
 }  // namespace webkit