chrome/browser/printing/printer_query.h

   1 // Copyright (c) 2012 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 CHROME_BROWSER_PRINTING_PRINTER_QUERY_H_
   6 #define CHROME_BROWSER_PRINTING_PRINTER_QUERY_H_
   7
   8 #include "base/callback.h"
   9 #include "base/compiler_specific.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "chrome/browser/printing/print_job_worker_owner.h"
  12 #include "printing/print_job_constants.h"
  13
  14 class PrintingUIWebContentsObserver;
  15
  16 namespace base {
  17 class DictionaryValue;
  18 class MessageLoop;
  19 }
  20
  21 namespace printing {
  22
  23 class PrintDestinationInterface;
  24 class PrintJobWorker;
  25
  26 // Query the printer for settings.
  27 class PrinterQuery : public PrintJobWorkerOwner {
  28  public:
  29   // GetSettings() UI parameter.
  30   enum GetSettingsAskParam {
  31     DEFAULTS,
  32     ASK_USER,
  33   };
  34
  35   PrinterQuery();
  36
  37   // PrintJobWorkerOwner implementation.
  38   virtual void GetSettingsDone(const PrintSettings& new_settings,
  39                                PrintingContext::Result result) OVERRIDE;
  40   virtual PrintJobWorker* DetachWorker(PrintJobWorkerOwner* new_owner) OVERRIDE;
  41   virtual base::MessageLoop* message_loop() OVERRIDE;
  42   virtual const PrintSettings& settings() const OVERRIDE;
  43   virtual int cookie() const OVERRIDE;
  44
  45   // Initializes the printing context. It is fine to call this function multiple
  46   // times to reinitialize the settings. |web_contents_observer| can be queried
  47   // to find the owner of the print setting dialog box. It is unused when
  48   // |ask_for_user_settings| is DEFAULTS.
  49   void GetSettings(
  50       GetSettingsAskParam ask_user_for_settings,
  51       scoped_ptr<PrintingUIWebContentsObserver> web_contents_observer,
  52       int expected_page_count,
  53       bool has_selection,
  54       MarginType margin_type,
  55       const base::Closure& callback);
  56
  57   // Updates the current settings with |new_settings| dictionary values.
  58   void SetSettings(const base::DictionaryValue& new_settings,
  59                    const base::Closure& callback);
  60
  61   // Set a destination for the worker.
  62   void SetWorkerDestination(PrintDestinationInterface* destination);
  63
  64   // Stops the worker thread since the client is done with this object.
  65   void StopWorker();
  66
  67   // Returns true if a GetSettings() call is pending completion.
  68   bool is_callback_pending() const;
  69
  70   PrintingContext::Result last_status() const { return last_status_; }
  71
  72   // Returns if a worker thread is still associated to this instance.
  73   bool is_valid() const;
  74
  75  private:
  76   virtual ~PrinterQuery();
  77
  78   // Lazy create the worker thread. There is one worker thread per print job.
  79   void StartWorker(const base::Closure& callback);
  80
  81   // Main message loop reference. Used to send notifications in the right
  82   // thread.
  83   base::MessageLoop* const io_message_loop_;
  84
  85   // All the UI is done in a worker thread because many Win32 print functions
  86   // are blocking and enters a message loop without your consent. There is one
  87   // worker thread per print job.
  88   scoped_ptr<PrintJobWorker> worker_;
  89
  90   // Cache of the print context settings for access in the UI thread.
  91   PrintSettings settings_;
  92
  93   // Is the Print... dialog box currently shown.
  94   bool is_print_dialog_box_shown_;
  95
  96   // Cookie that make this instance unique.
  97   int cookie_;
  98
  99   // Results from the last GetSettingsDone() callback.
 100   PrintingContext::Result last_status_;
 101
 102   // Callback waiting to be run.
 103   base::Closure callback_;
 104
 105   DISALLOW_COPY_AND_ASSIGN(PrinterQuery);
 106 };
 107
 108 }  // namespace printing
 109
 110 #endif  // CHROME_BROWSER_PRINTING_PRINTER_QUERY_H_