Print Preview: Support the duplex preset in PDFs.

components/printing/renderer/print_web_view_helper.cc

 // Copyright (c) 2012 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 "components/printing/renderer/print_web_view_helper.h"
 
 #include <string>
 
 #include "base/auto_reset.h"
 #include "base/json/json_writer.h"
@@ skipping 31 matching lines @@
 #include "third_party/WebKit/public/web/WebView.h"
 #include "third_party/WebKit/public/web/WebViewClient.h"
 #include "ui/base/resource/resource_bundle.h"
 
 using content::WebPreferences;
 
 namespace printing {
 
 namespace {
 
+#define STATIC_ASSERT_PP_MATCHING_ENUM(a, b)                  \
+    static_assert(static_cast<int>(a) == static_cast<int>(b), \
+                  "mismatching enums: " #a)
+
+// Check blink::WebDuplexMode and printing::DuplexMode are kept in sync.
+STATIC_ASSERT_PP_MATCHING_ENUM(blink::WebUnknownDuplexMode,
+                               UNKNOWN_DUPLEX_MODE);
+STATIC_ASSERT_PP_MATCHING_ENUM(blink::WebSimplex, SIMPLEX);
+STATIC_ASSERT_PP_MATCHING_ENUM(blink::WebLongEdge, LONG_EDGE);
+STATIC_ASSERT_PP_MATCHING_ENUM(blink::WebShortEdge, SHORT_EDGE);
+
 enum PrintPreviewHelperEvents {
   PREVIEW_EVENT_REQUESTED,
   PREVIEW_EVENT_CACHE_HIT,  // Unused
   PREVIEW_EVENT_CREATE_DOCUMENT,
   PREVIEW_EVENT_NEW_SETTINGS,  // Unused
   PREVIEW_EVENT_MAX,
 };
 
 const double kMinDpi = 1.0;
 
@@ skipping 936 matching lines @@
       notify_browser_of_print_failure_ = false;  // Already sent.
     }
     DidFinishPrinting(FAIL_PREVIEW);
     return;
   }
 
   // Set the options from document if we are previewing a pdf and send a
   // message to browser.
   if (print_pages_params_->params.is_first_request &&
       !print_preview_context_.IsModifiable()) {
-    PrintHostMsg_SetOptionsFromDocument_Params params;
-    SetOptionsFromDocument(params);
-    Send(new PrintHostMsg_SetOptionsFromDocument(routing_id(), params));
+    PrintHostMsg_SetOptionsFromDocument_Params options;
+    SetOptionsFromPdfDocument(&options);
+    Send(new PrintHostMsg_SetOptionsFromDocument(routing_id(), options));
   }
 
   is_print_ready_metafile_sent_ = false;
 
   // PDF printer device supports alpha blending.
   print_pages_params_->params.supports_alpha_blend = true;
 
   bool generate_draft_pages = false;
   if (!settings.GetBoolean(kSettingGenerateDraftData, &generate_draft_pages)) {
     NOTREACHED();
@@ skipping 404 matching lines @@
   }
 
   const PrintMsg_Print_Params& params = print_pages_params_->params;
   PrepareFrameAndViewForPrint prepare(params, frame, node, ignore_css_margins_);
   prepare.StartPrinting();
 
   *number_of_pages = prepare.GetExpectedPageCount();
   return true;
 }
 
-void PrintWebViewHelper::SetOptionsFromDocument(
-    PrintHostMsg_SetOptionsFromDocument_Params& params) {
+void PrintWebViewHelper::SetOptionsFromPdfDocument(
+    PrintHostMsg_SetOptionsFromDocument_Params* options) {
   blink::WebLocalFrame* source_frame = print_preview_context_.source_frame();
   const blink::WebNode& source_node = print_preview_context_.source_node();
 
   blink::WebPrintPresetOptions preset_options;
   if (!source_frame->getPrintPresetOptionsForPlugin(source_node,
                                                     &preset_options)) {
     return;
   }
 
-  params.is_scaling_disabled = preset_options.isScalingDisabled;
-  params.copies = preset_options.copies;
+  options->is_scaling_disabled = preset_options.isScalingDisabled;
+  options->copies = preset_options.copies;
+
+  // TODO(thestig) This should be a straight pass-through, but print preview
+  // does not currently support short-edge printing.
+  switch (preset_options.duplexMode) {
+    case blink::WebSimplex:
+      options->duplex = SIMPLEX;
+      break;
+    case blink::WebLongEdge:
+      options->duplex = LONG_EDGE;
+      break;
+    default:
+      options->duplex = UNKNOWN_DUPLEX_MODE;
+      break;
+  }
 }
 
 bool PrintWebViewHelper::UpdatePrintSettings(
     blink::WebLocalFrame* frame,
     const blink::WebNode& node,
     const base::DictionaryValue& passed_job_settings) {
   const base::DictionaryValue* job_settings = &passed_job_settings;
   base::DictionaryValue modified_job_settings;
   if (job_settings->empty()) {
     if (!print_for_preview_)
@@ skipping 551 matching lines @@
       blink::WebConsoleMessage::LevelWarning, message));
   return false;
 }
 
 void PrintWebViewHelper::ScriptingThrottler::Reset() {
   // Reset counter on successful print.
   count_ = 0;
 }
 
 }  // namespace printing