Bug 1657518 - Clean up nsCUPSPrinter GetName() Functionality r=emilio

- Add cupsGetOption function support to CUPSShim
- Improve performance on GetName() function to not copy string twice.
- Unify implementation of `GetDisplayNameForPrinter()`

Differential Revision: https://phabricator.services.mozilla.com/D86114

widget/cocoa/nsDeviceContextSpecX.mm

@@ -44,31 +44,6 @@ using mozilla::gfx::SurfaceFormat;
 
 static LazyLogModule sDeviceContextSpecXLog("DeviceContextSpecX");
 
-//----------------------------------------------------------------------
-// nsPrinterListX
-
-/**
- * Retrieves the display name of a printer.
- */
-void nsPrinterListCUPS::GetDisplayNameForPrinter(const cups_dest_t& aDest, nsAString& aName) {
-  NS_OBJC_BEGIN_TRY_ABORT_BLOCK;
-
-  // CUPS does not appear to have a native call to retrieve a display name for
-  // a printer, so we need to use cocoa to find a display name for the printer.
-  PMPrinter corePrinter = PMPrinterCreateFromPrinterID(
-      static_cast<CFStringRef>([NSString stringWithUTF8String:aDest.name]));
-
-  if (!corePrinter) {
-    return;
-  }
-
-  CFStringRef printerName = PMPrinterGetName(corePrinter);
-  nsCocoaUtils::GetStringForNSString(static_cast<NSString*>(printerName), aName);
-  PMRelease(corePrinter);
-
-  NS_OBJC_END_TRY_ABORT_BLOCK;
-}
-
 //----------------------------------------------------------------------
 // nsDeviceContentSpecX
 

widget/nsCUPSShim.h

@@ -37,6 +37,7 @@ class nsCUPSShim {
   X(cupsGetDest)               \
   X(cupsGetDests)              \
   X(cupsGetNamedDest)          \
+  X(cupsGetOption)             \
   X(cupsLocalizeDestMedia)     \
   X(cupsPrintFile)             \
   X(cupsTempFd)                \

widget/nsPrinterCUPS.cpp

@@ -23,7 +23,8 @@ nsPrinterCUPS::~nsPrinterCUPS() {
 NS_IMETHODIMP
 nsPrinterCUPS::GetName(nsAString& aName) {
   if (mDisplayName.IsEmpty()) {
-    aName = NS_ConvertUTF8toUTF16(mPrinter->name);
+    aName.Truncate();
+    CopyUTF8toUTF16(MakeStringSpan(mPrinter->name), aName);
   } else {
     aName = mDisplayName;
   }

widget/nsPrinterListCUPS.cpp

@@ -13,6 +13,23 @@
 static nsCUPSShim sCupsShim;
 using PrinterInfo = nsPrinterListBase::PrinterInfo;
 
+/**
+ * Retrieves a human-readable name for the printer from CUPS.
+ * https://www.cups.org/doc/cupspm.html#basic-destination-information
+ */
+static void GetDisplayNameForPrinter(const cups_dest_t& aDest,
+                                     nsAString& aName) {
+// macOS clients expect prettified printer names
+// while GTK clients expect non-prettified names.
+#ifdef XP_MACOSX
+  const char* displayName =
+      sCupsShim.cupsGetOption("printer-info", aDest.num_options, aDest.options);
+  if (displayName) {
+    CopyUTF8toUTF16(MakeStringSpan(displayName), aName);
+  }
+#endif
+}
+
 nsTArray<PrinterInfo> nsPrinterListCUPS::Printers() const {
   if (!sCupsShim.EnsureInitialized()) {
     return {};

widget/nsPrinterListCUPS.h

@@ -9,8 +9,6 @@
 #include "nsPrinterListBase.h"
 #include "nsStringFwd.h"
 
-struct cups_dest_s;
-
 class nsPrinterListCUPS final : public nsPrinterListBase {
   NS_IMETHOD InitPrintSettingsFromPrinter(const nsAString&,
                                           nsIPrintSettings*) final;
@@ -19,15 +17,6 @@ class nsPrinterListCUPS final : public nsPrinterListBase {
   nsTArray<PrinterInfo> Printers() const final;
   RefPtr<nsIPrinter> CreatePrinter(PrinterInfo) const final;
 
-#ifdef XP_MACOSX
-  // This is implemented in nsDeviceContextSpecX. We could add a new class to
-  // the class hierarchy instead and make this virtual, but it seems overkill
-  // just for this.
-  static void GetDisplayNameForPrinter(const cups_dest_s&, nsAString& aName);
-#else
-  static void GetDisplayNameForPrinter(const cups_dest_s&, nsAString& aName) {}
-#endif
-
  private:
   ~nsPrinterListCUPS() override = default;
 };