print_job_worker.h revision 5821806d5e7f356e8fa4b058a389a808ea183019 
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 "printing/page_number.h"
13#include "printing/print_destination_interface.h"
14#include "printing/printing_context.h"
15#include "printing/print_job_constants.h"
16#include "ui/gfx/native_widget_types.h"
17
18namespace base {
19class DictionaryValue;
20}
21
22namespace printing {
23
24class PrintedDocument;
25class PrintedPage;
26class PrintJob;
27class PrintJobWorkerOwner;
28
29// Worker thread code. All this code, except for the constructor, is executed in
30// the worker thread. It manages the PrintingContext, which can be blocking
31// and/or run a message loop. This is the object that generates most
32// NOTIFY_PRINT_JOB_EVENT notifications, but they are generated through a
33// NotificationTask task to be executed from the right thread, the UI thread.
34// PrintJob always outlives its worker instance.
35class PrintJobWorker : public base::Thread {
36 public:
37  explicit PrintJobWorker(PrintJobWorkerOwner* owner);
38  virtual ~PrintJobWorker();
39
40  void SetNewOwner(PrintJobWorkerOwner* new_owner);
41
42  // Set a destination for print.
43  // This supercedes the document's rendering destination.
44  void SetPrintDestination(PrintDestinationInterface* destination);
45
46  // Initializes the print settings. If |ask_user_for_settings| is true, a
47  // Print... dialog box will be shown to ask the user his preference.
48  void GetSettings(bool ask_user_for_settings,
49                   gfx::NativeView parent_view,
50                   int document_page_count,
51                   bool has_selection,
52                   MarginType margin_type);
53
54  // Set the new print settings. This function takes ownership of
55  // |new_settings|.
56  void SetSettings(const base::DictionaryValue* const new_settings);
57
58  // Starts the printing loop. Every pages are printed as soon as the data is
59  // available. Makes sure the new_document is the right one.
60  void StartPrinting(PrintedDocument* new_document);
61
62  // Updates the printed document.
63  void OnDocumentChanged(PrintedDocument* new_document);
64
65  // Dequeues waiting pages. Called when PrintJob receives a
66  // NOTIFY_PRINTED_DOCUMENT_UPDATED notification. It's time to look again if
67  // the next page can be printed.
68  void OnNewPage();
69
70  // This is the only function that can be called in a thread.
71  void Cancel();
72
73 protected:
74  // Retrieves the context for testing only.
75  PrintingContext* printing_context() { return printing_context_.get(); }
76
77 private:
78  // The shared NotificationService service can only be accessed from the UI
79  // thread, so this class encloses the necessary information to send the
80  // notification from the right thread. Most NOTIFY_PRINT_JOB_EVENT
81  // notifications are sent this way, except USER_INIT_DONE, USER_INIT_CANCELED
82  // and DEFAULT_INIT_DONE. These three are sent through PrintJob::InitDone().
83  class NotificationTask;
84
85  // Renders a page in the printer.
86  void SpoolPage(PrintedPage* page);
87
88  // Closes the job since spooling is done.
89  void OnDocumentDone();
90
91  // Discards the current document, the current page and cancels the printing
92  // context.
93  void OnFailure();
94
95  // Asks the user for print settings. Must be called on the UI thread.
96  // Required on Mac and Linux. Windows can display UI from non-main threads,
97  // but sticks with this for consistency.
98  void GetSettingsWithUI(gfx::NativeView parent_view,
99                         int document_page_count,
100                         bool has_selection);
101
102  // The callback used by PrintingContext::GetSettingsWithUI() to notify this
103  // object that the print settings are set.  This is needed in order to bounce
104  // back into the IO thread for GetSettingsDone().
105  void GetSettingsWithUIDone(PrintingContext::Result result);
106
107  // Called on the UI thread to update the print settings. This function takes
108  // the ownership of |new_settings|.
109  void UpdatePrintSettings(const base::DictionaryValue* const new_settings);
110
111  // Reports settings back to owner_.
112  void GetSettingsDone(PrintingContext::Result result);
113
114  // Use the default settings. When using GTK+ or Mac, this can still end up
115  // displaying a dialog. So this needs to happen from the UI thread on these
116  // systems.
117  void UseDefaultSettings();
118
119  // Information about the printer setting.
120  scoped_ptr<PrintingContext> printing_context_;
121
122  // The printed document. Only has read-only access.
123  scoped_refptr<PrintedDocument> document_;
124
125  // The print destination, may be NULL.
126  scoped_refptr<PrintDestinationInterface> destination_;
127
128  // The print job owning this worker thread. It is guaranteed to outlive this
129  // object.
130  PrintJobWorkerOwner* owner_;
131
132  // Current page number to print.
133  PageNumber page_number_;
134
135  // Used to generate a WeakPtr for callbacks.
136  base::WeakPtrFactory<PrintJobWorker> weak_factory_;
137
138  DISALLOW_COPY_AND_ASSIGN(PrintJobWorker);
139};
140
141}  // namespace printing
142
143#endif  // CHROME_BROWSER_PRINTING_PRINT_JOB_WORKER_H__
144