Print preview not showing if default print is invalid.

chrome/browser/printing/print_preview_message_handler.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 "chrome/browser/printing/print_preview_message_handler.h"
 
 #include <vector>
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/ref_counted_memory.h"
@@ skipping 193 matching lines @@
   PrintPreviewUI* print_preview_ui =
       static_cast<PrintPreviewUI*>(print_preview_tab->web_ui());
   print_preview_ui->OnDidGetDefaultPageLayout(page_layout_in_points);
 }
 
 void PrintPreviewMessageHandler::OnPrintPreviewCancelled(int document_cookie) {
   // Always need to stop the worker.
   StopWorker(document_cookie);
 }
 
+void PrintPreviewMessageHandler::OnInvalidPrinterSettings(int document_cookie) {
+  // Always need to stop the worker.
+  StopWorker(document_cookie);
+
+  TabContents* print_preview_tab = GetPrintPreviewTab();
+  if (!print_preview_tab)
+    return;
+
+  PrintPreviewUI* print_preview_ui =
+      static_cast<PrintPreviewUI*>(print_preview_tab->web_ui());

[kmadhusu, 2011/08/26 18:50:40]

If the preview tab is hidden for printing, we want to show an alert dialog with
an error message.

Refer to lines #187-190. 

[arthurhsu, 2011/08/29 22:53:16]

Done.

+  print_preview_ui->OnInvalidPrinterSettings();
+}
+
 bool PrintPreviewMessageHandler::OnMessageReceived(
     const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(PrintPreviewMessageHandler, message)
     IPC_MESSAGE_HANDLER(PrintHostMsg_RequestPrintPreview,
                         OnRequestPrintPreview)
     IPC_MESSAGE_HANDLER(PrintHostMsg_DidGetPreviewPageCount,
                         OnDidGetPreviewPageCount)
     IPC_MESSAGE_HANDLER(PrintHostMsg_DidPreviewPage,
                         OnDidPreviewPage)
     IPC_MESSAGE_HANDLER(PrintHostMsg_PagesReadyForPreview,
                         OnPagesReadyForPreview)
     IPC_MESSAGE_HANDLER(PrintHostMsg_PrintPreviewFailed,
                         OnPrintPreviewFailed)
     IPC_MESSAGE_HANDLER(PrintHostMsg_DidGetDefaultPageLayout,
                         OnDidGetDefaultPageLayout)
     IPC_MESSAGE_HANDLER(PrintHostMsg_PrintPreviewCancelled,
                         OnPrintPreviewCancelled)
+    IPC_MESSAGE_HANDLER(PrintHostMsg_PrintPreviewInvalidPrinterSettings,
+                        OnInvalidPrinterSettings)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
 void PrintPreviewMessageHandler::DidStartLoading() {
   if (tab_contents()->delegate() &&
       printing::PrintPreviewTabController::IsPrintPreviewTab(tab_contents())) {
     tab_contents()->SetContentRestrictions(CONTENT_RESTRICTION_PRINT);
   }
 }
 
 }  // namespace printing