chrome/browser/printing/print_job_worker.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_PRINT_JOB_WORKER_H_
   6 #define CHROME_BROWSER_PRINTING_PRINT_JOB_WORKER_H_
   7
   8 #include "base/memory/ref_counted.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "base/memory/weak_ptr.h"
  11 #include "base/threading/thread.h"
  12 #include "content/public/browser/browser_thread.h"
  13 #include "printing/page_number.h"
  14 #include "printing/print_job_constants.h"
  15 #include "printing/printing_context.h"
  16
  17 namespace base {
  18 class DictionaryValue;
  19 }
  20
  21 namespace printing {
  22
  23 class PrintJob;
  24 class PrintJobWorkerOwner;
  25 class PrintedDocument;
  26 class PrintedPage;
  27
  28 // Worker thread code. It manages the PrintingContext, which can be blocking
  29 // and/or run a message loop. This is the object that generates most
  30 // NOTIFY_PRINT_JOB_EVENT notifications, but they are generated through a
  31 // NotificationTask task to be executed from the right thread, the UI thread.
  32 // PrintJob always outlives its worker instance.
  33 class PrintJobWorker {
  34  public:
  35   PrintJobWorker(int render_process_id,
  36                  int render_view_id,
  37                  PrintJobWorkerOwner* owner);
  38   virtual ~PrintJobWorker();
  39
  40   void SetNewOwner(PrintJobWorkerOwner* new_owner);
  41
  42   // Initializes the print settings. If |ask_user_for_settings| is true, a
  43   // Print... dialog box will be shown to ask the user his preference.
  44   void GetSettings(
  45       bool ask_user_for_settings,
  46       int document_page_count,
  47       bool has_selection,
  48       MarginType margin_type);
  49
  50   // Set the new print settings.
  51   void SetSettings(scoped_ptr<base::DictionaryValue> new_settings);
  52
  53   // Starts the printing loop. Every pages are printed as soon as the data is
  54   // available. Makes sure the new_document is the right one.
  55   void StartPrinting(PrintedDocument* new_document);
  56
  57   // Updates the printed document.
  58   void OnDocumentChanged(PrintedDocument* new_document);
  59
  60   // Dequeues waiting pages. Called when PrintJob receives a
  61   // NOTIFY_PRINTED_DOCUMENT_UPDATED notification. It's time to look again if
  62   // the next page can be printed.
  63   void OnNewPage();
  64
  65   // This is the only function that can be called in a thread.
  66   void Cancel();
  67
  68   // Returns true if the thread has been started, and not yet stopped.
  69   bool IsRunning() const;
  70
  71   // Posts the given task to be run.
  72   bool PostTask(const tracked_objects::Location& from_here,
  73                 const base::Closure& task);
  74
  75   // Signals the thread to exit in the near future.
  76   void StopSoon();
  77
  78   // Signals the thread to exit and returns once the thread has exited.
  79   void Stop();
  80
  81   // Starts the thread.
  82   bool Start();
  83
  84  protected:
  85   // Retrieves the context for testing only.
  86   PrintingContext* printing_context() { return printing_context_.get(); }
  87
  88  private:
  89   // The shared NotificationService service can only be accessed from the UI
  90   // thread, so this class encloses the necessary information to send the
  91   // notification from the right thread. Most NOTIFY_PRINT_JOB_EVENT
  92   // notifications are sent this way, except USER_INIT_DONE, USER_INIT_CANCELED
  93   // and DEFAULT_INIT_DONE. These three are sent through PrintJob::InitDone().
  94   class NotificationTask;
  95
  96   // Renders a page in the printer.
  97   void SpoolPage(PrintedPage* page);
  98
  99   // Closes the job since spooling is done.
 100   void OnDocumentDone();
 101
 102   // Discards the current document, the current page and cancels the printing
 103   // context.
 104   void OnFailure();
 105
 106   // Asks the user for print settings. Must be called on the UI thread.
 107   // Required on Mac and Linux. Windows can display UI from non-main threads,
 108   // but sticks with this for consistency.
 109   void GetSettingsWithUI(
 110       int document_page_count,
 111       bool has_selection);
 112
 113   // The callback used by PrintingContext::GetSettingsWithUI() to notify this
 114   // object that the print settings are set.  This is needed in order to bounce
 115   // back into the IO thread for GetSettingsDone().
 116   void GetSettingsWithUIDone(PrintingContext::Result result);
 117
 118   // Called on the UI thread to update the print settings.
 119   void UpdatePrintSettings(scoped_ptr<base::DictionaryValue> new_settings);
 120
 121   // Reports settings back to owner_.
 122   void GetSettingsDone(PrintingContext::Result result);
 123
 124   // Use the default settings. When using GTK+ or Mac, this can still end up
 125   // displaying a dialog. So this needs to happen from the UI thread on these
 126   // systems.
 127   void UseDefaultSettings();
 128
 129   // Printing context delegate.
 130   scoped_ptr<PrintingContext::Delegate> printing_context_delegate_;
 131
 132   // Information about the printer setting.
 133   scoped_ptr<PrintingContext> printing_context_;
 134
 135   // The printed document. Only has read-only access.
 136   scoped_refptr<PrintedDocument> document_;
 137
 138   // The print job owning this worker thread. It is guaranteed to outlive this
 139   // object.
 140   PrintJobWorkerOwner* owner_;
 141
 142   // Current page number to print.
 143   PageNumber page_number_;
 144
 145   // Thread to run worker tasks.
 146   base::Thread thread_;
 147
 148   // Tread-safe pointer to task runner of the |thread_|.
 149   scoped_refptr<base::SequencedTaskRunner> task_runner_;
 150
 151   // Used to generate a WeakPtr for callbacks.
 152   base::WeakPtrFactory<PrintJobWorker> weak_factory_;
 153
 154   DISALLOW_COPY_AND_ASSIGN(PrintJobWorker);
 155 };
 156
 157 }  // namespace printing
 158
 159 #endif  // CHROME_BROWSER_PRINTING_PRINT_JOB_WORKER_H_