1 files changed, 92 insertions, 0 deletions
diff --git a/widget/nsPrinterListBase.h b/widget/nsPrinterListBase.h
new file mode 100644
index 0000000000..9f922d74b5
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+++ b/widget/nsPrinterListBase.h
@@ -0,0 +1,92 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 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 nsPrinterListBase_h__
+#define nsPrinterListBase_h__
+
+#include "nsIPrinterList.h"
+
+#include "nsCycleCollectionParticipant.h"
+#include "nsISupportsImpl.h"
+#include "nsPaper.h"
+#include "nsString.h"
+
+class nsPrinterListBase : public nsIPrinterList {
+ public:
+  using Promise = mozilla::dom::Promise;
+
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_CLASS(nsPrinterListBase)
+  NS_IMETHOD GetSystemDefaultPrinterName(nsAString& aName) final {
+    return SystemDefaultPrinterName(aName);
+  }
+  NS_IMETHOD GetPrinters(JSContext*, Promise**) final;
+  NS_IMETHOD GetPrinterByName(const nsAString& aPrinterName, JSContext* aCx,
+                              Promise** aResult) final;
+  NS_IMETHOD GetPrinterBySystemName(const nsAString& aPrinterName,
+                                    JSContext* aCx, Promise** aResult) final;
+  NS_IMETHOD GetNamedOrDefaultPrinter(const nsAString& aPrinterName,
+                                      JSContext* aCx, Promise** aResult) final;
+  NS_IMETHOD GetFallbackPaperList(JSContext*, Promise**) final;
+
+  struct PrinterInfo {
+    // Both windows and CUPS: The name of the printer.
+    nsString mName;
+    // CUPS only: Handle to owned cups_dest_t.
+    void* mCupsHandle = nullptr;
+  };
+
+  // Called off the main thread, collect information to create an appropriate
+  // list of printers.
+  virtual nsTArray<PrinterInfo> Printers() const = 0;
+
+  // Create an nsIPrinter object given the information we obtained from the
+  // background thread.
+  virtual RefPtr<nsIPrinter> CreatePrinter(PrinterInfo) const = 0;
+
+  mozilla::Maybe<PrinterInfo> NamedOrDefaultPrinter(nsString aName) const;
+
+  // No copy or move, we're an identity.
+  nsPrinterListBase(const nsPrinterListBase&) = delete;
+  nsPrinterListBase(nsPrinterListBase&&) = delete;
+
+ protected:
+  nsPrinterListBase();
+  virtual ~nsPrinterListBase();
+
+  // This could be implemented in terms of Printers() and then searching the
+  // returned printer info for a printer of the given name, but we expect
+  // backends to have more efficient methods of implementing this.
+  virtual mozilla::Maybe<PrinterInfo> PrinterByName(nsString aName) const = 0;
+
+  // Same as NamedPrinter, but uses the system name.
+  // Depending on whether or not there is a more efficient way to address the
+  // printer for a given backend, this may or may not be equivalent to
+  // NamedPrinter.
+  virtual mozilla::Maybe<PrinterInfo> PrinterBySystemName(
+      nsString aName) const = 0;
+
+  // This is implemented separately from the IDL interface version so that it
+  // can be made const, which allows it to be used while resolving promises.
+  virtual nsresult SystemDefaultPrinterName(nsAString&) const = 0;
+
+  // Return "paper" sizes to be supported by the Save to PDF destination;
+  // for actual printer drivers the list is retrieved from nsIPrinter.
+  nsTArray<RefPtr<nsPaper>> FallbackPaperList() const;
+
+  // Constructs mCommonPaperInfo by localizing the sizes in
+  // nsPaper::kCommonPaperSizes and creating corresponding PaperInfo.
+  void EnsureCommonPaperInfo(JSContext* aCx);
+
+  RefPtr<Promise> mPrintersPromise;
+  // PaperInfo for our fallback sizes and common size localization.
+  // This field contains the same data for every instance of this class.
+  // It's unfortunate that this needs to be a member rather than static data
+  // like nsPaper::kCommonPaperSizes, but that's because PaperInfo contains
+  // localized data, and we need a JSContext to do the localization.
+  RefPtr<const mozilla::CommonPaperInfoArray> mCommonPaperInfo;
+};
+
+#endif