PrintPreview: Preview generation should not block print button.

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 "base/memory/ref_counted.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/printing/print_job_manager.h"
 #include "chrome/browser/printing/print_preview_tab_controller.h"
@@ skipping 96 matching lines @@
 
 void PrintPreviewMessageHandler::OnPrintPreviewFailed(int document_cookie) {
   // Always need to stop the worker.
   StopWorker(document_cookie);
 
   // Inform the print preview tab of the failure.
   TabContents* print_preview_tab = GetPrintPreviewTab();
   // User might have closed it already.
   if (!print_preview_tab)
     return;
-  print_preview_tab->web_ui()->CallJavascriptFunction("printPreviewFailed");
+
+  PrintPreviewUI* print_preview_ui =
+      static_cast<PrintPreviewUI*>(print_preview_tab->web_ui());
+
+  if (print_preview_ui->isHidden()) {
+    // Preview tab was hidden to serve the print request.
+    RenderViewHost* rvh = tab_contents()->render_view_host();
+    rvh->Send(new PrintMsg_PrintingDone(rvh->routing_id(), false));

[Lei Zhang, 2011/06/09 09:54:55]

Why do you need this? If we failed to generate a print preview, then we haven't
even started printing yet.

[kmadhusu, 2011/06/09 18:11:44]

I am sending this message for 2 reasons.
(1) To display an alert dialog with an error message.  
(2) To release the acquired resources.

+    delete print_preview_tab;
+    return;
+  } else {
+    print_preview_ui->CallJavascriptFunction("printPreviewFailed");
+  }
 }
 
 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_PagesReadyForPreview,
                         OnPagesReadyForPreview)
     IPC_MESSAGE_HANDLER(PrintHostMsg_PrintPreviewFailed,
                         OnPrintPreviewFailed)
     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