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