widget/nsPrinterListBase.h

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef nsPrinterListBase_h__
   7 #define nsPrinterListBase_h__
   8
   9 #include "nsIPrinterList.h"
  10
  11 #include "nsCycleCollectionParticipant.h"
  12 #include "nsISupportsImpl.h"
  13 #include "nsPaper.h"
  14 #include "nsString.h"
  15
  16 class nsPrinterListBase : public nsIPrinterList {
  17  public:
  18   using Promise = mozilla::dom::Promise;
  19
  20   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  21   NS_DECL_CYCLE_COLLECTION_CLASS(nsPrinterListBase)
  22   NS_IMETHOD GetSystemDefaultPrinterName(nsAString& aName) final {
  23     return SystemDefaultPrinterName(aName);
  24   }
  25   NS_IMETHOD GetPrinters(JSContext*, Promise**) final;
  26   NS_IMETHOD GetPrinterByName(const nsAString& aPrinterName, JSContext* aCx,
  27                               Promise** aResult) final;
  28   NS_IMETHOD GetPrinterBySystemName(const nsAString& aPrinterName,
  29                                     JSContext* aCx, Promise** aResult) final;
  30   NS_IMETHOD GetNamedOrDefaultPrinter(const nsAString& aPrinterName,
  31                                       JSContext* aCx, Promise** aResult) final;
  32   NS_IMETHOD GetFallbackPaperList(JSContext*, Promise**) final;
  33
  34   struct PrinterInfo {
  35     // Both windows and CUPS: The name of the printer.
  36     nsString mName;
  37     // CUPS only: Handle to owned cups_dest_t.
  38     void* mCupsHandle = nullptr;
  39   };
  40
  41   // Called off the main thread, collect information to create an appropriate
  42   // list of printers.
  43   virtual nsTArray<PrinterInfo> Printers() const = 0;
  44
  45   // Create an nsIPrinter object given the information we obtained from the
  46   // background thread.
  47   virtual RefPtr<nsIPrinter> CreatePrinter(PrinterInfo) const = 0;
  48
  49   mozilla::Maybe<PrinterInfo> NamedOrDefaultPrinter(nsString aName) const;
  50
  51   // No copy or move, we're an identity.
  52   nsPrinterListBase(const nsPrinterListBase&) = delete;
  53   nsPrinterListBase(nsPrinterListBase&&) = delete;
  54
  55  protected:
  56   nsPrinterListBase();
  57   virtual ~nsPrinterListBase();
  58
  59   // This could be implemented in terms of Printers() and then searching the
  60   // returned printer info for a printer of the given name, but we expect
  61   // backends to have more efficient methods of implementing this.
  62   virtual mozilla::Maybe<PrinterInfo> PrinterByName(nsString aName) const = 0;
  63
  64   // Same as NamedPrinter, but uses the system name.
  65   // Depending on whether or not there is a more efficient way to address the
  66   // printer for a given backend, this may or may not be equivalent to
  67   // NamedPrinter.
  68   virtual mozilla::Maybe<PrinterInfo> PrinterBySystemName(
  69       nsString aName) const = 0;
  70
  71   // This is implemented separately from the IDL interface version so that it
  72   // can be made const, which allows it to be used while resolving promises.
  73   virtual nsresult SystemDefaultPrinterName(nsAString&) const = 0;
  74
  75   // Return "paper" sizes to be supported by the Save to PDF destination;
  76   // for actual printer drivers the list is retrieved from nsIPrinter.
  77   nsTArray<RefPtr<nsPaper>> FallbackPaperList() const;
  78
  79   // Constructs mCommonPaperInfo by localizing the sizes in
  80   // nsPaper::kCommonPaperSizes and creating corresponding PaperInfo.
  81   void EnsureCommonPaperInfo(JSContext* aCx);
  82
  83   RefPtr<Promise> mPrintersPromise;
  84   // PaperInfo for our fallback sizes and common size localization.
  85   // This field contains the same data for every instance of this class.
  86   // It's unfortunate that this needs to be a member rather than static data
  87   // like nsPaper::kCommonPaperSizes, but that's because PaperInfo contains
  88   // localized data, and we need a JSContext to do the localization.
  89   RefPtr<const mozilla::CommonPaperInfoArray> mCommonPaperInfo;
  90 };
  91
  92 #endif