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
17namespace base {
18class DictionaryValue;
19}
20
21namespace printing {
22
23class PrintJob;
24class PrintJobWorkerOwner;
25class PrintedDocument;
26class 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.
33class 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_
160