Printing on Windows via PDF

chrome/utility/chrome_content_utility_client.cc

Index: chrome/utility/chrome_content_utility_client.cc
diff --git a/chrome/utility/chrome_content_utility_client.cc b/chrome/utility/chrome_content_utility_client.cc
index 777149dfcd26f006f44d4b09c2b3c85b09129d37..68bb36b1c14943d8d53fdccaf17439a5b39a144e 100644
--- a/chrome/utility/chrome_content_utility_client.cc
+++ b/chrome/utility/chrome_content_utility_client.cc
@@ -365,7 +365,7 @@ bool ChromeContentUtilityClient::OnMessageReceived(
                         OnParseUpdateManifest)
     IPC_MESSAGE_HANDLER(ChromeUtilityMsg_DecodeImage, OnDecodeImage)
     IPC_MESSAGE_HANDLER(ChromeUtilityMsg_DecodeImageBase64, OnDecodeImageBase64)
-    IPC_MESSAGE_HANDLER(ChromeUtilityMsg_RenderPDFPagesToMetafile,
+    IPC_MESSAGE_HANDLER(ChromeUtilityMsg_RenderPDFPagesToMetafiles,
                         OnRenderPDFPagesToMetafile)
     IPC_MESSAGE_HANDLER(ChromeUtilityMsg_RenderPDFPagesToPWGRaster,
                         OnRenderPDFPagesToPWGRaster)
@@ -567,23 +567,29 @@ void ChromeContentUtilityClient::OnCreateZipFile(
 #endif  // defined(OS_CHROMEOS)
 
 void ChromeContentUtilityClient::OnRenderPDFPagesToMetafile(
-    base::PlatformFile pdf_file,
+    IPC::PlatformFileForTransit pdf_transit,
     const base::FilePath& metafile_path,
     const printing::PdfRenderSettings& settings,
-    const std::vector<printing::PageRange>& page_ranges) {
+    const std::vector<printing::PageRange>& page_ranges_const) {
   bool succeeded = false;
 #if defined(OS_WIN)
+  base::PlatformFile pdf_file =
+      IPC::PlatformFileForTransitToPlatformFile(pdf_transit);
   int highest_rendered_page_number = 0;
   double scale_factor = 1.0;
+  std::vector<printing::PageRange> page_ranges = page_ranges_const;
   succeeded = RenderPDFToWinMetafile(pdf_file,
                                      metafile_path,
                                      settings,
-                                     page_ranges,
+                                     &page_ranges,
                                      &highest_rendered_page_number,
                                      &scale_factor);
   if (succeeded) {
-    Send(new ChromeUtilityHostMsg_RenderPDFPagesToMetafile_Succeeded(
-        highest_rendered_page_number, scale_factor));
+    // TODO(vitalybuka|scottmg): http://crbug.com/170859. These could
+    // potentially be sent as each page is converted so that the spool could
+    // start sooner.
+    Send(new ChromeUtilityHostMsg_RenderPDFPagesToMetafiles_Succeeded(
+        page_ranges, scale_factor));
   }
 #endif  // defined(OS_WIN)
   if (!succeeded) {
@@ -614,11 +620,12 @@ bool ChromeContentUtilityClient::RenderPDFToWinMetafile(
     base::PlatformFile pdf_file,
     const base::FilePath& metafile_path,
     const printing::PdfRenderSettings& settings,
-    const std::vector<printing::PageRange>& page_ranges,
+    std::vector<printing::PageRange>* page_ranges,
     int* highest_rendered_page_number,
     double* scale_factor) {
   *highest_rendered_page_number = -1;
   *scale_factor = 1.0;
+  CHECK(page_ranges);

[Lei Zhang, 2014/05/20 03:39:29]

DCHECK, put it as the first thing in this method

[scottmg, 2014/05/20 17:16:24]

Done.

   base::win::ScopedHandle file(pdf_file);
 
   if (!g_pdf_lib.Get().IsValid())
@@ -645,26 +652,37 @@ bool ChromeContentUtilityClient::RenderPDFToWinMetafile(
     return false;
   }
 
-  printing::Emf metafile;
-  metafile.InitToFile(metafile_path);
-  // We need to scale down DC to fit an entire page into DC available area.
-  // Current metafile is based on screen DC and have current screen size.
-  // Writing outside of those boundaries will result in the cut-off output.
-  // On metafiles (this is the case here), scaling down will still record
-  // original coordinates and we'll be able to print in full resolution.
-  // Before playback we'll need to counter the scaling up that will happen
-  // in the service (print_system_win.cc).
-  *scale_factor = gfx::CalculatePageScale(metafile.context(),
-                                          settings.area().right(),
-                                          settings.area().bottom());
-  gfx::ScaleDC(metafile.context(), *scale_factor);
+  // If no range supplied, do all pages.
+  if (page_ranges->empty()) {
+    printing::PageRange page_range_all;
+    page_range_all.from = 0;
+    page_range_all.to = total_page_count - 1;
+    page_ranges->push_back(page_range_all);
+  }
 
   bool ret = false;
   std::vector<printing::PageRange>::const_iterator iter;
-  for (iter = page_ranges.begin(); iter != page_ranges.end(); ++iter) {
+  for (iter = page_ranges->begin(); iter != page_ranges->end(); ++iter) {

[Lei Zhang, 2014/05/20 03:39:29]

(issue with existing code) Do we care about overlapping ranges?

[scottmg, 2014/05/20 17:16:24]

Yeah, I wondered about that too. I guess it's possible the user might actually
want to print pages repeatedly via overlapping ranges in the UI.

[[ In practice this code is less generally used than it appears it could be, in
particular there are only two ranges ever given, the empty range resulting in
all pages being printed per the change above, and a range consisting of one page
(from cloud print).

I believe the future intention was to pass larger batches for cloud print, which
should be possible now that all the pages wouldn't be rendered into one huge
output file. ]]

     for (int page_number = iter->from; page_number <= iter->to; ++page_number) {
       if (page_number >= total_page_count)
         break;
+
+      printing::Emf metafile;
+      metafile.InitToFile(metafile_path.InsertBeforeExtensionASCII(
+          base::StringPrintf(".%d", page_number)));
+
+      // We need to scale down DC to fit an entire page into DC available area.
+      // Current metafile is based on screen DC and have current screen size.
+      // Writing outside of those boundaries will result in the cut-off output.
+      // On metafiles (this is the case here), scaling down will still record
+      // original coordinates and we'll be able to print in full resolution.
+      // Before playback we'll need to counter the scaling up that will happen
+      // in the service (print_system_win.cc).
+      *scale_factor = gfx::CalculatePageScale(metafile.context(),
+                                              settings.area().right(),
+                                              settings.area().bottom());
+      gfx::ScaleDC(metafile.context(), *scale_factor);
+
       // The underlying metafile is of type Emf and ignores the arguments passed
       // to StartPage.
       metafile.StartPage(gfx::Size(), gfx::Rect(), 1);
@@ -679,9 +697,9 @@ bool ChromeContentUtilityClient::RenderPDFToWinMetafile(
         ret = true;
       }
       metafile.FinishPage();
+      metafile.FinishDocument();
     }
   }
-  metafile.FinishDocument();
   return ret;
 }
 #endif  // defined(OS_WIN)