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