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      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_
    154