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 gfx {
  21 class Font;
  22 }
  23
  24 namespace printing {
  25
  26 class Metafile;
  27 class PrintedPage;
  28 class PrintedPagesSource;
  29 class PrintingContext;
  30
  31 // A collection of rendered pages. The settings are immutable. If the print
  32 // settings are changed, a new PrintedDocument must be created.
  33 // Warning: May be accessed from many threads at the same time. Only one thread
  34 // will have write access. Sensible functions are protected by a lock.
  35 // Warning: Once a page is loaded, it cannot be replaced. Pages may be discarded
  36 // under low memory conditions.
  37 class PRINTING_EXPORT PrintedDocument
  38     : public base::RefCountedThreadSafe<PrintedDocument> {
  39  public:
  40   // The cookie shall be unique and has a specific relationship with its
  41   // originating source and settings.
  42   PrintedDocument(const PrintSettings& settings,
  43                   PrintedPagesSource* source,
  44                   int cookie);
  45
  46   // Sets a page's data. 0-based. Takes metafile ownership.
  47   // Note: locks for a short amount of time.
  48   void SetPage(int page_number, Metafile* metafile, double shrink,
  49                const gfx::Size& paper_size, const gfx::Rect& page_rect);
  50
  51   // Retrieves a page. If the page is not available right now, it
  52   // requests to have this page be rendered and returns false.
  53   // Note: locks for a short amount of time.
  54   bool GetPage(int page_number, scoped_refptr<PrintedPage>* page);
  55
  56   // Draws the page in the context.
  57   // Note: locks for a short amount of time in debug only.
  58 #if defined(OS_WIN) || defined(OS_MACOSX)
  59   void RenderPrintedPage(const PrintedPage& page,
  60                          gfx::NativeDrawingContext context) const;
  61 #elif defined(OS_POSIX)
  62   void RenderPrintedPage(const PrintedPage& page,
  63                          PrintingContext* context) const;
  64 #endif
  65
  66   // Returns true if all the necessary pages for the settings are already
  67   // rendered.
  68   // Note: locks while parsing the whole tree.
  69   bool IsComplete() const;
  70
  71   // Disconnects the PrintedPage source (PrintedPagesSource). It is done when
  72   // the source is being destroyed.
  73   void DisconnectSource();
  74
  75   // Retrieves the current memory usage of the renderer pages.
  76   // Note: locks for a short amount of time.
  77   uint32 MemoryUsage() const;
  78
  79   // Sets the number of pages in the document to be rendered. Can only be set
  80   // once.
  81   // Note: locks for a short amount of time.
  82   void set_page_count(int max_page);
  83
  84   // Number of pages in the document. Used for headers/footers.
  85   // Note: locks for a short amount of time.
  86   int page_count() const;
  87
  88   // Returns the number of expected pages to be rendered. It is a non-linear
  89   // series if settings().ranges is not empty. It is the same value as
  90   // document_page_count() otherwise.
  91   // Note: locks for a short amount of time.
  92   int expected_page_count() const;
  93
  94   // Getters. All these items are immutable hence thread-safe.
  95   const PrintSettings& settings() const { return immutable_.settings_; }
  96   const string16& name() const { return immutable_.name_; }
  97   int cookie() const { return immutable_.cookie_; }
  98
  99   // Sets a path where to dump printing output files for debugging. If never set
 100   // no files are generated.
 101   static void set_debug_dump_path(const FilePath& debug_dump_path);
 102
 103   static const FilePath& debug_dump_path();
 104
 105  private:
 106   friend class base::RefCountedThreadSafe<PrintedDocument>;
 107
 108   virtual ~PrintedDocument();
 109
 110   // Array of data for each print previewed page.
 111   typedef std::map<int, scoped_refptr<PrintedPage> > PrintedPages;
 112
 113   // Contains all the mutable stuff. All this stuff MUST be accessed with the
 114   // lock held.
 115   struct Mutable {
 116     explicit Mutable(PrintedPagesSource* source);
 117     ~Mutable();
 118
 119     // Source that generates the PrintedPage's (i.e. a TabContents). It will be
 120     // set back to NULL if the source is deleted before this object.
 121     PrintedPagesSource* source_;
 122
 123     // Contains the pages' representation. This is a collection of PrintedPage.
 124     // Warning: Lock must be held when accessing this member.
 125     PrintedPages pages_;
 126
 127     // Number of expected pages to be rendered.
 128     // Warning: Lock must be held when accessing this member.
 129     int expected_page_count_;
 130
 131     // The total number of pages in the document.
 132     int page_count_;
 133
 134     // Shrink done in comparison to desired_dpi.
 135     double shrink_factor;
 136
 137 #if defined(OS_POSIX) && !defined(OS_MACOSX)
 138     // Page number of the first page.
 139     int first_page;
 140 #endif
 141   };
 142
 143   // Contains all the immutable stuff. All this stuff can be accessed without
 144   // any lock held. This is because it can't be changed after the object's
 145   // construction.
 146   struct Immutable {
 147     Immutable(const PrintSettings& settings, PrintedPagesSource* source,
 148               int cookie);
 149     ~Immutable();
 150
 151     // Print settings used to generate this document. Immutable.
 152     PrintSettings settings_;
 153
 154     // Native thread for the render source.
 155     MessageLoop* source_message_loop_;
 156
 157     // Document name. Immutable.
 158     string16 name_;
 159
 160     // Cookie to uniquely identify this document. It is used to make sure that a
 161     // PrintedPage is correctly belonging to the PrintedDocument. Since
 162     // PrintedPage generation is completely asynchronous, it could be easy to
 163     // mess up and send the page to the wrong document. It can be viewed as a
 164     // simpler hash of PrintSettings since a new document is made each time the
 165     // print settings change.
 166     int cookie_;
 167   };
 168
 169   void DebugDump(const PrintedPage& page);
 170
 171   // All writable data member access must be guarded by this lock. Needs to be
 172   // mutable since it can be acquired from const member functions.
 173   mutable base::Lock lock_;
 174
 175   // All the mutable members.
 176   Mutable mutable_;
 177
 178   // All the immutable members.
 179   const Immutable immutable_;
 180
 181   DISALLOW_COPY_AND_ASSIGN(PrintedDocument);
 182 };
 183
 184 }  // namespace printing
 185
 186 #endif  // PRINTING_PRINTED_DOCUMENT_H_