Refactor code in print_settings_intializer_win.cc

printing/print_settings_initializer_win.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 "printing/print_settings_initializer_win.h"
 
 #include <windows.h>
 
 #include "printing/print_settings.h"
 
 namespace printing {
 
 namespace {
 
-bool IsPrinterXPS(HDC hdc) {
-  int device_type = ::GetDeviceCaps(hdc, TECHNOLOGY);
-  if (device_type != DT_RASPRINTER)
+bool HasEscapeSupprt(HDC hdc, DWORD escape) {
+  const char* ptr = reinterpret_cast<const char*>(&escape);
+  return ExtEscape(hdc, QUERYESCSUPPORT, sizeof(escape), ptr, 0, nullptr) > 0;
+}
+
+bool IsTechnology(HDC hdc, const char* technology) {
+  if (::GetDeviceCaps(hdc, TECHNOLOGY) != DT_RASPRINTER)
     return false;
 
-  const DWORD escape = GETTECHNOLOGY;
-  const char* escape_ptr = reinterpret_cast<const char*>(&escape);
-  int ret =
-      ExtEscape(hdc, QUERYESCSUPPORT, sizeof(escape), escape_ptr, 0, nullptr);
-  if (ret <= 0)
+  if (!HasEscapeSupprt(hdc, GETTECHNOLOGY))
     return false;
 
-  char buffer[256];
-  memset(buffer, 0, sizeof(buffer));
-  ret = ExtEscape(hdc, GETTECHNOLOGY, 0, nullptr, sizeof(buffer) - 1, buffer);
-  if (ret <= 0)
+  char buf[256];
+  memset(buf, 0, sizeof(buf));
+  if (ExtEscape(hdc, GETTECHNOLOGY, 0, nullptr, sizeof(buf) - 1, buf) <= 0)
     return false;
+  return strcmp(buf, technology) == 0;
+}
 
-  static const char kXPSDriver[] = "http://schemas.microsoft.com/xps/2005/06";
-  return strcmp(buffer, kXPSDriver) == 0;
+bool IsPrinterXPS(HDC hdc) {
+  static constexpr char kXPSDriver[] =
+      "http://schemas.microsoft.com/xps/2005/06";
+  return IsTechnology(hdc, kXPSDriver);
 }
 
 }  // namespace
 
 // static
 void PrintSettingsInitializerWin::InitPrintSettings(
     HDC hdc,
     const DEVMODE& dev_mode,
     PrintSettings* print_settings) {
   DCHECK(hdc);
@@ skipping 34 matching lines @@
   }
   DCHECK_EQ(print_settings->device_units_per_inch(), dpi);
   print_settings->SetPrinterPrintableArea(physical_size_device_units,
                                           printable_area_device_units,
                                           false);
 
   print_settings->set_printer_is_xps(IsPrinterXPS(hdc));
 }
 
 }  // namespace printing