printing/printed_document.h

   1 // Copyright (c) 2011 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/memory/scoped_ptr.h"
  12 #include "base/string16.h"
  13 #include "base/synchronization/lock.h"
  14 #include "printing/print_settings.h"
  15 #include "ui/gfx/native_widget_types.h"
  16
  17 class FilePath;
  18 class MessageLoop;
  19
  20 namespace printing {
  21
  22 class Metafile;
  23 class PrintedPage;
  24 class PrintedPagesSource;
  25 class PrintingContext;
  26
  27 // A collection of rendered pages. The settings are immutable. If the print
  28 // settings are changed, a new PrintedDocument must be created.
  29 // Warning: May be accessed from many threads at the same time. Only one thread
  30 // will have write access. Sensible functions are protected by a lock.
  31 // Warning: Once a page is loaded, it cannot be replaced. Pages may be discarded
  32 // under low memory conditions.
  33 class PRINTING_EXPORT PrintedDocument
  34     : public base::RefCountedThreadSafe<PrintedDocument> {
  35  public:
  36   // The cookie shall be unique and has a specific relationship with its
  37   // originating source and settings.
  38   PrintedDocument(const PrintSettings& settings,
  39                   PrintedPagesSource* source,
  40                   int cookie);
  41
  42   // Sets a page's data. 0-based. Takes metafile ownership.
  43   // Note: locks for a short amount of time.
  44   void SetPage(int page_number, Metafile* metafile, double shrink,
  45                const gfx::Size& paper_size, const gfx::Rect& page_rect);
  46
  47   // Retrieves a page. If the page is not available right now, it
  48   // requests to have this page be rendered and returns false.
  49   // Note: locks for a short amount of time.
  50   bool GetPage(int page_number, scoped_refptr<PrintedPage>* page);
  51
  52   // Draws the page in the context.
  53   // Note: locks for a short amount of time in debug only.
  54 #if defined(OS_WIN) || defined(OS_MACOSX) && !defined(USE_AURA)
  55   void RenderPrintedPage(const PrintedPage& page,
  56                          gfx::NativeDrawingContext context) const;
  57 #elif defined(OS_POSIX)
  58   void RenderPrintedPage(const PrintedPage& page,
  59                          PrintingContext* context) const;
  60 #endif
  61
  62   // Returns true if all the necessary pages for the settings are already
  63   // rendered.
  64   // Note: locks while parsing the whole tree.
  65   bool IsComplete() const;
  66
  67   // Disconnects the PrintedPage source (PrintedPagesSource). It is done when
  68   // the source is being destroyed.
  69   void DisconnectSource();
  70
  71   // Retrieves the current memory usage of the renderer pages.
  72   // Note: locks for a short amount of time.
  73   uint32 MemoryUsage() const;
  74
  75   // Sets the number of pages in the document to be rendered. Can only be set
  76   // once.
  77   // Note: locks for a short amount of time.
  78   void set_page_count(int max_page);
  79
  80   // Number of pages in the document. Used for headers/footers.
  81   // Note: locks for a short amount of time.
  82   int page_count() const;
  83
  84   // Returns the number of expected pages to be rendered. It is a non-linear
  85   // series if settings().ranges is not empty. It is the same value as
  86   // document_page_count() otherwise.
  87   // Note: locks for a short amount of time.
  88   int expected_page_count() const;
  89
  90   // Getters. All these items are immutable hence thread-safe.
  91   const PrintSettings& settings() const { return immutable_.settings_; }
  92   const string16& name() const { return immutable_.name_; }
  93   int cookie() const { return immutable_.cookie_; }
  94
  95   // Sets a path where to dump printing output files for debugging. If never set
  96   // no files are generated.
  97   static void set_debug_dump_path(const FilePath& debug_dump_path);
  98
  99   static const FilePath& debug_dump_path();
 100
 101  private:
 102   friend class base::RefCountedThreadSafe<PrintedDocument>;
 103
 104   virtual ~PrintedDocument();
 105
 106   // Array of data for each print previewed page.
 107   typedef std::map<int, scoped_refptr<PrintedPage> > PrintedPages;
 108
 109   // Contains all the mutable stuff. All this stuff MUST be accessed with the
 110   // lock held.
 111   struct Mutable {
 112     explicit Mutable(PrintedPagesSource* source);
 113     ~Mutable();
 114
 115     // Source that generates the PrintedPage's (i.e. a TabContents). It will be
 116     // set back to NULL if the source is deleted before this object.
 117     PrintedPagesSource* source_;
 118
 119     // Contains the pages' representation. This is a collection of PrintedPage.
 120     // Warning: Lock must be held when accessing this member.
 121     PrintedPages pages_;
 122
 123     // Number of expected pages to be rendered.
 124     // Warning: Lock must be held when accessing this member.
 125     int expected_page_count_;
 126
 127     // The total number of pages in the document.
 128     int page_count_;
 129
 130 #if defined(OS_POSIX) && !defined(OS_MACOSX)
 131     // Page number of the first page.
 132     int first_page;
 133 #endif
 134   };
 135
 136   // Contains all the immutable stuff. All this stuff can be accessed without
 137   // any lock held. This is because it can't be changed after the object's
 138   // construction.
 139   struct Immutable {
 140     Immutable(const PrintSettings& settings, PrintedPagesSource* source,
 141               int cookie);
 142     ~Immutable();
 143
 144     // Print settings used to generate this document. Immutable.
 145     PrintSettings settings_;
 146
 147     // Native thread for the render source.
 148     MessageLoop* source_message_loop_;
 149
 150     // Document name. Immutable.
 151     string16 name_;
 152
 153     // Cookie to uniquely identify this document. It is used to make sure that a
 154     // PrintedPage is correctly belonging to the PrintedDocument. Since
 155     // PrintedPage generation is completely asynchronous, it could be easy to
 156     // mess up and send the page to the wrong document. It can be viewed as a
 157     // simpler hash of PrintSettings since a new document is made each time the
 158     // print settings change.
 159     int cookie_;
 160   };
 161
 162   void DebugDump(const PrintedPage& page);
 163
 164   // All writable data member access must be guarded by this lock. Needs to be
 165   // mutable since it can be acquired from const member functions.
 166   mutable base::Lock lock_;
 167
 168   // All the mutable members.
 169   Mutable mutable_;
 170
 171   // All the immutable members.
 172   const Immutable immutable_;
 173
 174   DISALLOW_COPY_AND_ASSIGN(PrintedDocument);
 175 };
 176
 177 }  // namespace printing
 178
 179 #endif  // PRINTING_PRINTED_DOCUMENT_H_