PrintPreview: Hide/Show the header footer option based on print frame margins.

chrome/renderer/print_web_view_helper.cc

Index: chrome/renderer/print_web_view_helper.cc
diff --git a/chrome/renderer/print_web_view_helper.cc b/chrome/renderer/print_web_view_helper.cc
index 024ac9818771ad9ba0b97a7e1601d635da52ce6a..c3387f446fa252cbfe4b2a34b97ec78569dbd807 100644
--- a/chrome/renderer/print_web_view_helper.cc
+++ b/chrome/renderer/print_web_view_helper.cc
@@ -852,7 +852,11 @@ void PrintWebViewHelper::OnPrintPreview(const DictionaryValue& settings) {
   }
   print_preview_context_.set_generate_draft_pages(generate_draft_pages);
 
-  if (CreatePreviewDocument()) {
+  int margins_type = 0;
+  if (!settings.GetInteger(printing::kSettingMarginsType, &margins_type))
+    margins_type = printing::DEFAULT_MARGINS;
+
+  if (CreatePreviewDocument(margins_type)) {
     DidFinishPrinting(OK);
   } else {
     if (notify_browser_of_print_failure_)
@@ -861,7 +865,7 @@ void PrintWebViewHelper::OnPrintPreview(const DictionaryValue& settings) {
   }
 }
 
-bool PrintWebViewHelper::CreatePreviewDocument() {
+bool PrintWebViewHelper::CreatePreviewDocument(int margins_type) {
   PrintMsg_Print_Params print_params = print_pages_params_->params;
   const std::vector<int>& pages = print_pages_params_->pages;
   if (!print_preview_context_.CreatePreviewDocument(&print_params, pages,
@@ -874,20 +878,47 @@ bool PrintWebViewHelper::CreatePreviewDocument() {
   ComputePageLayoutInPointsForCss(print_preview_context_.frame(), 0,
                                   print_params, ignore_css_margins_,
                                   fit_to_page_, NULL, &default_page_layout);
+
+  bool preview_is_modifiable = print_preview_context_.IsModifiable();
   if (!old_print_pages_params_.get() ||
       !PageLayoutIsEqual(*old_print_pages_params_, *print_pages_params_)) {
     bool has_page_size_style = PrintingFrameHasPageSizeStyle(
         print_preview_context_.frame(),
         print_preview_context_.total_page_count());
+
+    bool header_footer_applies = true;
+    if (!preview_is_modifiable || margins_type == printing::NO_MARGINS) {
+      header_footer_applies = false;
+    } else if (margins_type != printing::PRINTABLE_AREA_MARGINS) {
+#if defined(OS_LINUX)
+    header_footer_applies =
+        (default_page_layout.margin_top > 0) ||
+        (default_page_layout.margin_bottom > 0);
+#else
+    int dpi = GetDPI(&print_params);
+    int non_printable_area_top = ConvertUnit(
+        print_pages_params_->params.printable_area.y(),
+            dpi, printing::kPointsPerInch);
+    int non_printable_area_bottom = ConvertUnit(
+        print_pages_params_->params.page_size.height() -
+            print_pages_params_->params.printable_area.y() -
+            print_pages_params_->params.printable_area.height(),
+        dpi, printing::kPointsPerInch);
+    header_footer_applies =
+        (default_page_layout.margin_top > non_printable_area_top) ||
+        (default_page_layout.margin_bottom > non_printable_area_bottom);
+#endif
+    }
     // Margins: Send default page layout to browser process.
     Send(new PrintHostMsg_DidGetDefaultPageLayout(routing_id(),
                                                   default_page_layout,
-                                                  has_page_size_style));
+                                                  has_page_size_style,
+                                                  header_footer_applies));
   }
 
   PrintHostMsg_DidGetPreviewPageCount_Params params;
   params.page_count = print_preview_context_.total_page_count();
-  params.is_modifiable = print_preview_context_.IsModifiable();
+  params.is_modifiable = preview_is_modifiable;
   params.document_cookie = print_pages_params_->params.document_cookie;
   params.preview_request_id = print_pages_params_->params.preview_request_id;
   params.clear_preview_data = print_preview_context_.generate_draft_pages();