Making GenericScopedHandle capable of handling handle types other than HANDLE.

printing/backend/win_helper.h

 // 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.
 
 #ifndef PRINTING_BACKEND_WIN_HELPER_H_
 #define PRINTING_BACKEND_WIN_HELPER_H_
 #pragma once
 
 #include <objidl.h>
 #include <winspool.h>
 #include <prntvpt.h>
 #include <xpsprint.h>
 
 #include "base/string16.h"
 #include "base/win/scoped_handle.h"
 #include "printing/printing_export.h"
 
 // These are helper functions for dealing with Windows Printing.
 namespace printing {
 
 class PrinterHandleTraits {

[Vitaly Buka (NO REVIEWS), 2012/03/05 18:52:14]

PrinterHandleTraits : public HandleTraits {

 CloseHandle

}

[alexeypa (please no reviews), 2012/03/05 18:56:58]

The same thing, trait classes are unrelated in this case.

  public:
+  typedef HANDLE Handle;
+
   static bool CloseHandle(HANDLE handle) {
     return ::ClosePrinter(handle) != FALSE;
   }
+
+  static bool IsHandleValid(HANDLE handle) {
+    return handle != NULL;
+  }
+
+  static HANDLE NullHandle() {
+    return NULL;
+  }
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(PrinterHandleTraits);
 };
 
 typedef base::win::GenericScopedHandle<PrinterHandleTraits> ScopedPrinterHandle;
 
 
 // Wrapper class to wrap the XPS APIs (PTxxx APIs). This is needed because these
 // APIs are not available by default on XP. We could delayload prntvpt.dll but
 // this would mean having to add that to every binary that links with
 // printing.lib (which is a LOT of binaries). So choosing the GetProcAddress
 // route instead).
@@ skipping 67 matching lines @@
       IXpsPrintJobStream **document_stream,
       IXpsPrintJobStream **print_ticket_stream);
  private:
   XPSPrintModule() { }
   static bool InitImpl();
 };
 
 }  // namespace printing
 
 #endif  // PRINTING_BACKEND_WIN_HELPER_H_