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 "googleurl/src/gurl.h"
  15 #include "printing/print_settings.h"
  16 #include "ui/gfx/native_widget_types.h"
  17
  18 class FilePath;
  19 class MessageLoop;
  20
  21 namespace gfx {
  22 class Font;
  23 }
  24
  25 namespace printing {
  26
  27 class Metafile;
  28 class PrintedPage;
  29 class PrintedPagesSource;
  30 class PrintingContext;
  31
  32 // A collection of rendered pages. The settings are immutable. If the print
  33 // settings are changed, a new PrintedDocument must be created.
  34 // Warning: May be accessed from many threads at the same time. Only one thread
  35 // will have write access. Sensible functions are protected by a lock.
  36 // Warning: Once a page is loaded, it cannot be replaced. Pages may be discarded
  37 // under low memory conditions.
  38 class PrintedDocument : 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                bool has_visible_overlays);
  51
  52   // Retrieves a page. If the page is not available right now, it
  53   // requests to have this page be rendered and returns false.
  54   // Note: locks for a short amount of time.
  55   bool GetPage(int page_number, scoped_refptr<PrintedPage>* page);
  56
  57   // Draws the page in the context.
  58   // Note: locks for a short amount of time in debug only.
  59 #if defined(OS_WIN) || defined(OS_MACOSX)
  60   void RenderPrintedPage(const PrintedPage& page,
  61                          gfx::NativeDrawingContext context) const;
  62 #elif defined(OS_POSIX)
  63   void RenderPrintedPage(const PrintedPage& page,
  64                          PrintingContext* context) const;
  65 #endif
  66
  67   // Returns true if all the necessary pages for the settings are already
  68   // rendered.
  69   // Note: locks while parsing the whole tree.
  70   bool IsComplete() const;
  71
  72   // Disconnects the PrintedPage source (PrintedPagesSource). It is done when
  73   // the source is being destroyed.
  74   void DisconnectSource();
  75
  76   // Retrieves the current memory usage of the renderer pages.
  77   // Note: locks for a short amount of time.
  78   uint32 MemoryUsage() const;
  79
  80   // Sets the number of pages in the document to be rendered. Can only be set
  81   // once.
  82   // Note: locks for a short amount of time.
  83   void set_page_count(int max_page);
  84
  85   // Number of pages in the document. Used for headers/footers.
  86   // Note: locks for a short amount of time.
  87   int page_count() const;
  88
  89   // Returns the number of expected pages to be rendered. It is a non-linear
  90   // series if settings().ranges is not empty. It is the same value as
  91   // document_page_count() otherwise.
  92   // Note: locks for a short amount of time.
  93   int expected_page_count() const;
  94
  95   // Getters. All these items are immutable hence thread-safe.
  96   const PrintSettings& settings() const { return immutable_.settings_; }
  97   const string16& name() const {
  98     return immutable_.name_;
  99   }
 100   const GURL& url() const { return immutable_.url_; }
 101   int cookie() const { return immutable_.cookie_; }
 102
 103   // Sets a path where to dump printing output files for debugging. If never set
 104   // no files are generated.
 105   static void set_debug_dump_path(const FilePath& debug_dump_path);
 106
 107   static const FilePath& debug_dump_path();
 108
 109  private:
 110   friend class base::RefCountedThreadSafe<PrintedDocument>;
 111
 112   virtual ~PrintedDocument();
 113
 114   // Array of data for each print previewed page.
 115   typedef std::map<int, scoped_refptr<PrintedPage> > PrintedPages;
 116
 117   // Contains all the mutable stuff. All this stuff MUST be accessed with the
 118   // lock held.
 119   struct Mutable {
 120     explicit Mutable(PrintedPagesSource* source);
 121     ~Mutable();
 122
 123     // Source that generates the PrintedPage's (i.e. a TabContents). It will be
 124     // set back to NULL if the source is deleted before this object.
 125     PrintedPagesSource* source_;
 126
 127     // Contains the pages' representation. This is a collection of PrintedPage.
 128     // Warning: Lock must be held when accessing this member.
 129     PrintedPages pages_;
 130
 131     // Number of expected pages to be rendered.
 132     // Warning: Lock must be held when accessing this member.
 133     int expected_page_count_;
 134
 135     // The total number of pages in the document.
 136     int page_count_;
 137
 138     // Shrink done in comparison to desired_dpi.
 139     double shrink_factor;
 140
 141 #if defined(OS_POSIX) && !defined(OS_MACOSX)
 142     // Page number of the first page.
 143     int first_page;
 144 #endif
 145   };
 146
 147   // Contains all the immutable stuff. All this stuff can be accessed without
 148   // any lock held. This is because it can't be changed after the object's
 149   // construction.
 150   struct Immutable {
 151     Immutable(const PrintSettings& settings, PrintedPagesSource* source,
 152               int cookie);
 153     ~Immutable();
 154
 155     // Print settings used to generate this document. Immutable.
 156     PrintSettings settings_;
 157
 158     // Native thread for the render source.
 159     MessageLoop* source_message_loop_;
 160
 161     // Document name. Immutable.
 162     string16 name_;
 163
 164     // URL that generated this document. Immutable.
 165     GURL url_;
 166
 167     // Cookie to uniquely identify this document. It is used to make sure that a
 168     // PrintedPage is correctly belonging to the PrintedDocument. Since
 169     // PrintedPage generation is completely asynchronous, it could be easy to
 170     // mess up and send the page to the wrong document. It can be viewed as a
 171     // simpler hash of PrintSettings since a new document is made each time the
 172     // print settings change.
 173     int cookie_;
 174   };
 175
 176   void DebugDump(const PrintedPage& page);
 177
 178   // All writable data member access must be guarded by this lock. Needs to be
 179   // mutable since it can be acquired from const member functions.
 180   mutable base::Lock lock_;
 181
 182   // All the mutable members.
 183   Mutable mutable_;
 184
 185   // All the immutable members.
 186   const Immutable immutable_;
 187
 188   DISALLOW_COPY_AND_ASSIGN(PrintedDocument);
 189 };
 190
 191 }  // namespace printing
 192
 193 #endif  // PRINTING_PRINTED_DOCUMENT_H_