printing/printed_document.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 PRINTING_PRINTED_DOCUMENT_H_
   6 #define PRINTING_PRINTED_DOCUMENT_H_
   7
   8 #include <map>
   9
  10 #include "base/memory/ref_counted.h"
  11 #include "base/string16.h"
  12 #include "base/synchronization/lock.h"
  13 #include "printing/print_settings.h"
  14 #include "ui/gfx/native_widget_types.h"
  15
  16 class MessageLoop;
  17
  18 namespace base {
  19 class FilePath;
  20 }
  21
  22 namespace printing {
  23
  24 class Metafile;
  25 class PrintedPage;
  26 class PrintedPagesSource;
  27 class PrintingContext;
  28
  29 // A collection of rendered pages. The settings are immutable. If the print
  30 // settings are changed, a new PrintedDocument must be created.
  31 // Warning: May be accessed from many threads at the same time. Only one thread
  32 // will have write access. Sensible functions are protected by a lock.
  33 // Warning: Once a page is loaded, it cannot be replaced. Pages may be discarded
  34 // under low memory conditions.
  35 class PRINTING_EXPORT PrintedDocument
  36     : public base::RefCountedThreadSafe<PrintedDocument> {
  37  public:
  38   // The cookie shall be unique and has a specific relationship with its
  39   // originating source and settings.
  40   PrintedDocument(const PrintSettings& settings,
  41                   PrintedPagesSource* source,
  42                   int cookie);
  43
  44   // Sets a page's data. 0-based. Takes metafile ownership.
  45   // Note: locks for a short amount of time.
  46   void SetPage(int page_number, Metafile* metafile, double shrink,
  47                const gfx::Size& paper_size, const gfx::Rect& page_rect);
  48
  49   // Retrieves a page. If the page is not available right now, it
  50   // requests to have this page be rendered and returns false.
  51   // Note: locks for a short amount of time.
  52   bool GetPage(int page_number, scoped_refptr<PrintedPage>* page);
  53
  54   // Draws the page in the context.
  55   // Note: locks for a short amount of time in debug only.
  56 #if defined(OS_WIN) || defined(OS_MACOSX) && !defined(USE_AURA)
  57   void RenderPrintedPage(const PrintedPage& page,
  58                          gfx::NativeDrawingContext context) const;
  59 #elif defined(OS_POSIX)
  60   void RenderPrintedPage(const PrintedPage& page,
  61                          PrintingContext* context) const;
  62 #endif
  63
  64   // Returns true if all the necessary pages for the settings are already
  65   // rendered.
  66   // Note: locks while parsing the whole tree.
  67   bool IsComplete() const;
  68
  69   // Disconnects the PrintedPage source (PrintedPagesSource). It is done when
  70   // the source is being destroyed.
  71   void DisconnectSource();
  72
  73   // Retrieves the current memory usage of the renderer pages.
  74   // Note: locks for a short amount of time.
  75   uint32 MemoryUsage() const;
  76
  77   // Sets the number of pages in the document to be rendered. Can only be set
  78   // once.
  79   // Note: locks for a short amount of time.
  80   void set_page_count(int max_page);
  81
  82   // Number of pages in the document. Used for headers/footers.
  83   // Note: locks for a short amount of time.
  84   int page_count() const;
  85
  86   // Returns the number of expected pages to be rendered. It is a non-linear
  87   // series if settings().ranges is not empty. It is the same value as
  88   // document_page_count() otherwise.
  89   // Note: locks for a short amount of time.
  90   int expected_page_count() const;
  91
  92   // Getters. All these items are immutable hence thread-safe.
  93   const PrintSettings& settings() const { return immutable_.settings_; }
  94   const string16& name() const { return immutable_.name_; }
  95   int cookie() const { return immutable_.cookie_; }
  96
  97   // Sets a path where to dump printing output files for debugging. If never set
  98   // no files are generated.
  99   static void set_debug_dump_path(const base::FilePath& debug_dump_path);
 100
 101   static const base::FilePath& debug_dump_path();
 102
 103  private:
 104   friend class base::RefCountedThreadSafe<PrintedDocument>;
 105
 106   virtual ~PrintedDocument();
 107
 108   // Array of data for each print previewed page.
 109   typedef std::map<int, scoped_refptr<PrintedPage> > PrintedPages;
 110
 111   // Contains all the mutable stuff. All this stuff MUST be accessed with the
 112   // lock held.
 113   struct Mutable {
 114     explicit Mutable(PrintedPagesSource* source);
 115     ~Mutable();
 116
 117     // Source that generates the PrintedPage's (i.e. a TabContents). It will be
 118     // set back to NULL if the source is deleted before this object.
 119     PrintedPagesSource* source_;
 120
 121     // Contains the pages' representation. This is a collection of PrintedPage.
 122     // Warning: Lock must be held when accessing this member.
 123     PrintedPages pages_;
 124
 125     // Number of expected pages to be rendered.
 126     // Warning: Lock must be held when accessing this member.
 127     int expected_page_count_;
 128
 129     // The total number of pages in the document.
 130     int page_count_;
 131
 132 #if defined(OS_POSIX) && !defined(OS_MACOSX)
 133     // Page number of the first page.
 134     int first_page;
 135 #endif
 136   };
 137
 138   // Contains all the immutable stuff. All this stuff can be accessed without
 139   // any lock held. This is because it can't be changed after the object's
 140   // construction.
 141   struct Immutable {
 142     Immutable(const PrintSettings& settings, PrintedPagesSource* source,
 143               int cookie);
 144     ~Immutable();
 145
 146     // Print settings used to generate this document. Immutable.
 147     PrintSettings settings_;
 148
 149     // Native thread for the render source.
 150     MessageLoop* source_message_loop_;
 151
 152     // Document name. Immutable.
 153     string16 name_;
 154
 155     // Cookie to uniquely identify this document. It is used to make sure that a
 156     // PrintedPage is correctly belonging to the PrintedDocument. Since
 157     // PrintedPage generation is completely asynchronous, it could be easy to
 158     // mess up and send the page to the wrong document. It can be viewed as a
 159     // simpler hash of PrintSettings since a new document is made each time the
 160     // print settings change.
 161     int cookie_;
 162   };
 163
 164   void DebugDump(const PrintedPage& page);
 165
 166   // All writable data member access must be guarded by this lock. Needs to be
 167   // mutable since it can be acquired from const member functions.
 168   mutable base::Lock lock_;
 169
 170   // All the mutable members.
 171   Mutable mutable_;
 172
 173   // All the immutable members.
 174   const Immutable immutable_;
 175
 176   DISALLOW_COPY_AND_ASSIGN(PrintedDocument);
 177 };
 178
 179 }  // namespace printing
 180
 181 #endif  // PRINTING_PRINTED_DOCUMENT_H_