Backed out changeset a71e53a3e455 (bug 1657874) for CUPSPrinterList.h related bustage CLOSED TREE

widget/CUPSPrinterList.cpp

@@ -0,0 +1,41 @@
+/* -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 2; -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CUPSPrinterList.h"
+
+#include "mozilla/Assertions.h"
+
+namespace mozilla {
+
+CUPSPrinterList::~CUPSPrinterList() {
+  MOZ_ASSERT(mShim.IsInitialized());
+  // cupsFreeDests is safe to call on a zero-length or null array.
+  mShim.cupsFreeDests(mNumPrinters, mPrinters);
+}
+
+void CUPSPrinterList::Initialize() {
+  MOZ_ASSERT(mShim.IsInitialized());
+  mNumPrinters = mShim.cupsGetDests(&mPrinters);
+}
+
+cups_dest_t* CUPSPrinterList::FindPrinterByName(const char* aName) {
+  MOZ_ASSERT(aName);
+  return mShim.cupsGetDest(aName, /* instance */ nullptr, mNumPrinters,
+                           mPrinters);
+}
+
+cups_dest_t* CUPSPrinterList::GetPrinter(int i) {
+  if (i < 0 || i >= mNumPrinters)
+    MOZ_CRASH("CUPSPrinterList::GetPrinter out of range");
+  return mPrinters + i;
+}
+
+cups_dest_t* CUPSPrinterList::GetDefaultPrinter() {
+  // Passing in nullptr for the name will return the default, if any.
+  return mShim.cupsGetNamedDest(CUPS_HTTP_DEFAULT, /* name */ nullptr,
+                                /* instance */ nullptr);
+}
+
+}  // namespace mozilla

widget/CUPSPrinterList.h

@@ -0,0 +1,58 @@
+/* -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 2; -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsCUPSPrinterList_h___
+#define nsCUPSPrinterList_h___
+
+#include "nsCUPSShim.h"
+
+namespace mozilla {
+
+/**
+ * @brief Enumerates all CUPS printers and provides lookup by name.
+ */
+class CUPSPrinterList {
+ public:
+  CUPSPrinterList(const CUPSPrinterList&) = delete;
+  explicit CUPSPrinterList(const nsCUPSShim& aShim) : mShim(aShim) {}
+  ~CUPSPrinterList();
+
+  /**
+   * @brief fetches the printer list.
+   *
+   * This is a blocking call.
+   */
+  void Initialize();
+
+  /**
+   * @brief Looks up a printer by CUPS name.
+   */
+  cups_dest_t* FindPrinterByName(const char* name);
+
+  int NumPrinters() const { return mNumPrinters; }
+
+  /**
+   * @brief Gets a printer by index.
+   *
+   * This does NOT copy the printer's data.
+   */
+  cups_dest_t* GetPrinter(int i);
+
+  /**
+   * @brief Gets the system default printer.
+   *
+   * This does NOT copy the printer's data.
+   */
+  cups_dest_t* GetDefaultPrinter();
+
+ private:
+  const nsCUPSShim& mShim;
+  cups_dest_t* mPrinters = nullptr;
+  int mNumPrinters = 0;
+};
+
+}  // namespace mozilla
+
+#endif /* nsCUPSPrinter_h___ */

widget/moz.build

@@ -248,6 +248,7 @@ if CONFIG['MOZ_XUL'] and CONFIG['NS_PRINTING']:
 
     if toolkit in ('cocoa', 'gtk'):
         UNIFIED_SOURCES += [
+            'CUPSPrinterList.cpp',
             'nsCUPSShim.cpp',
             'nsPrinterCUPS.cpp',
             'nsPrinterListCUPS.cpp',

widget/nsPrinterListCUPS.cpp

@@ -4,10 +4,9 @@
 
 #include "nsPrinterListCUPS.h"
 
-#include "mozilla/IntegerRange.h"
+#include "CUPSPrinterList.h"
 #include "nsCUPSShim.h"
 #include "nsPrinterCUPS.h"
-#include "nsString.h"
 #include "prenv.h"
 
 static nsCUPSShim sCupsShim;
@@ -18,12 +17,12 @@ nsPrinterListCUPS::GetPrinters(nsTArray<RefPtr<nsIPrinter>>& aPrinters) {
     return NS_ERROR_FAILURE;
   }
 
-  cups_dest_t* printers = nullptr;
-  auto numPrinters = sCupsShim.cupsGetDests(&printers);
-  aPrinters.SetCapacity(numPrinters);
+  mozilla::CUPSPrinterList cupsPrinterList(sCupsShim);
+  cupsPrinterList.Initialize();
+  aPrinters.SetCapacity(cupsPrinterList.NumPrinters());
 
-  for (auto i : mozilla::IntegerRange(0, numPrinters)) {
-    cups_dest_t* dest = printers + i;
+  for (int i = 0; i < cupsPrinterList.NumPrinters(); i++) {
+    cups_dest_t* const dest = cupsPrinterList.GetPrinter(i);
 
     nsString displayName;
     GetDisplayNameForPrinter(*dest, displayName);
@@ -33,7 +32,6 @@ nsPrinterListCUPS::GetPrinters(nsTArray<RefPtr<nsIPrinter>>& aPrinters) {
     aPrinters.AppendElement(cupsPrinter);
   }
 
-  sCupsShim.cupsFreeDests(numPrinters, printers);
   return NS_OK;
 }
 
@@ -43,10 +41,10 @@ nsPrinterListCUPS::GetSystemDefaultPrinterName(nsAString& aName) {
     return NS_ERROR_FAILURE;
   }
 
-  // Passing in nullptr for the name will return the default, if any.
-  const cups_dest_t* dest =
-      sCupsShim.cupsGetNamedDest(CUPS_HTTP_DEFAULT, /* name */ nullptr,
-                                 /* instance */ nullptr);
+  mozilla::CUPSPrinterList cupsPrinterList(sCupsShim);
+  cupsPrinterList.Initialize();
+
+  cups_dest_t* const dest = cupsPrinterList.GetDefaultPrinter();
   if (!dest) {
     return NS_ERROR_GFX_PRINTER_NO_PRINTER_AVAILABLE;
   }