printing/printing_context.h

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef PRINTING_PRINTING_CONTEXT_H_
   6 #define PRINTING_PRINTING_CONTEXT_H_
   7
   8 #include <string>
   9
  10 #include "base/basictypes.h"
  11 #include "base/callback.h"
  12 #include "base/strings/string16.h"
  13 #include "printing/print_settings.h"
  14 #include "ui/gfx/native_widget_types.h"
  15
  16 namespace base {
  17 class DictionaryValue;
  18 }
  19
  20 namespace printing {
  21
  22 // An abstraction of a printer context, implemented by objects that describe the
  23 // user selected printing context. This includes the OS-dependent UI to ask the
  24 // user about the print settings. Concrete implementations directly talk to the
  25 // printer and manage the document and page breaks.
  26 class PRINTING_EXPORT PrintingContext {
  27  public:
  28   // Printing context delegate.
  29   class Delegate {
  30    public:
  31     Delegate() {};
  32     virtual ~Delegate() {};
  33
  34     // Returns parent view to use for modal dialogs.
  35     virtual gfx::NativeView GetParentView() = 0;
  36
  37     // Returns application locale.
  38     virtual std::string GetAppLocale() = 0;
  39   };
  40
  41   // Tri-state result for user behavior-dependent functions.
  42   enum Result {
  43     OK,
  44     CANCEL,
  45     FAILED,
  46   };
  47
  48   virtual ~PrintingContext();
  49
  50   // Callback of AskUserForSettings, used to notify the PrintJobWorker when
  51   // print settings are available.
  52   typedef base::Callback<void(Result)> PrintSettingsCallback;
  53
  54   // Asks the user what printer and format should be used to print. Updates the
  55   // context with the select device settings. The result of the call is returned
  56   // in the callback. This is necessary for Linux, which only has an
  57   // asynchronous printing API.
  58   virtual void AskUserForSettings(int max_pages,
  59                                   bool has_selection,
  60                                   const PrintSettingsCallback& callback) = 0;
  61
  62   // Selects the user's default printer and format. Updates the context with the
  63   // default device settings.
  64   virtual Result UseDefaultSettings() = 0;
  65
  66   // Updates the context with PDF printer settings.
  67   Result UsePdfSettings();
  68
  69   // Returns paper size to be used for PDF or Cloud Print in device units.
  70   virtual gfx::Size GetPdfPaperSizeDeviceUnits() = 0;
  71
  72   // Updates printer settings.
  73   // |external_preview| is true if pdf is going to be opened in external
  74   // preview. Used by MacOS only now to open Preview.app.
  75   virtual Result UpdatePrinterSettings(bool external_preview,
  76                                        bool show_system_dialog) = 0;
  77
  78   // Updates Print Settings. |job_settings| contains all print job
  79   // settings information. |ranges| has the new page range settings.
  80   Result UpdatePrintSettings(const base::DictionaryValue& job_settings);
  81
  82   // Initializes with predefined settings.
  83   virtual Result InitWithSettings(const PrintSettings& settings) = 0;
  84
  85   // Does platform specific setup of the printer before the printing. Signal the
  86   // printer that a document is about to be spooled.
  87   // Warning: This function enters a message loop. That may cause side effects
  88   // like IPC message processing! Some printers have side-effects on this call
  89   // like virtual printers that ask the user for the path of the saved document;
  90   // for example a PDF printer.
  91   virtual Result NewDocument(const base::string16& document_name) = 0;
  92
  93   // Starts a new page.
  94   virtual Result NewPage() = 0;
  95
  96   // Closes the printed page.
  97   virtual Result PageDone() = 0;
  98
  99   // Closes the printing job. After this call the object is ready to start a new
 100   // document.
 101   virtual Result DocumentDone() = 0;
 102
 103   // Cancels printing. Can be used in a multi-threaded context. Takes effect
 104   // immediately.
 105   virtual void Cancel() = 0;
 106
 107   // Releases the native printing context.
 108   virtual void ReleaseContext() = 0;
 109
 110   // Returns the native context used to print.
 111   virtual gfx::NativeDrawingContext context() const = 0;
 112
 113   // Creates an instance of this object. Implementers of this interface should
 114   // implement this method to create an object of their implementation.
 115   static scoped_ptr<PrintingContext> Create(Delegate* delegate);
 116
 117   void set_margin_type(MarginType type);
 118
 119   const PrintSettings& settings() const {
 120     return settings_;
 121   }
 122
 123  protected:
 124   explicit PrintingContext(Delegate* delegate);
 125
 126   // Reinitializes the settings for object reuse.
 127   void ResetSettings();
 128
 129   // Does bookkeeping when an error occurs.
 130   PrintingContext::Result OnError();
 131
 132   // Complete print context settings.
 133   PrintSettings settings_;
 134
 135   // Printing context delegate.
 136   Delegate* delegate_;
 137
 138   // The dialog box has been dismissed.
 139   volatile bool dialog_box_dismissed_;
 140
 141   // Is a print job being done.
 142   volatile bool in_print_job_;
 143
 144   // Did the user cancel the print job.
 145   volatile bool abort_printing_;
 146
 147  private:
 148   DISALLOW_COPY_AND_ASSIGN(PrintingContext);
 149 };
 150
 151 }  // namespace printing
 152
 153 #endif  // PRINTING_PRINTING_CONTEXT_H_