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/files/file_path.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/strings/string16.h"
  14 #include "base/synchronization/lock.h"
  15 #include "printing/print_settings.h"
  16 #include "ui/gfx/native_widget_types.h"
  17
  18 namespace base {
  19 class RefCountedMemory;
  20 class TaskRunner;
  21 }
  22
  23 namespace printing {
  24
  25 class MetafilePlayer;
  26 class PrintedPage;
  27 class PrintedPagesSource;
  28 class PrintingContext;
  29
  30 // A collection of rendered pages. The settings are immutable. If the print
  31 // settings are changed, a new PrintedDocument must be created.
  32 // Warning: May be accessed from many threads at the same time. Only one thread
  33 // will have write access. Sensible functions are protected by a lock.
  34 // Warning: Once a page is loaded, it cannot be replaced. Pages may be discarded
  35 // under low memory conditions.
  36 class PRINTING_EXPORT PrintedDocument
  37     : public base::RefCountedThreadSafe<PrintedDocument> {
  38  public:
  39   // The cookie shall be unique and has a specific relationship with its
  40   // originating source and settings.
  41   PrintedDocument(const PrintSettings& settings,
  42                   PrintedPagesSource* source,
  43                   int cookie,
  44                   base::TaskRunner* blocking_runner);
  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,
  49                scoped_ptr<MetafilePlayer> metafile,
  50 #if defined(OS_WIN)
  51                float shrink,
  52 #endif  // OS_WIN
  53                const gfx::Size& paper_size,
  54                const gfx::Rect& page_rect);
  55
  56   // Retrieves a page. If the page is not available right now, it
  57   // requests to have this page be rendered and returns NULL.
  58   // Note: locks for a short amount of time.
  59   scoped_refptr<PrintedPage> GetPage(int page_number);
  60
  61   // Draws the page in the context.
  62   // Note: locks for a short amount of time in debug only.
  63 #if defined(OS_WIN) || defined(OS_MACOSX) && !defined(USE_AURA)
  64   void RenderPrintedPage(const PrintedPage& page,
  65                          gfx::NativeDrawingContext context) const;
  66 #elif defined(OS_POSIX)
  67   void RenderPrintedPage(const PrintedPage& page,
  68                          PrintingContext* context) const;
  69 #endif
  70
  71   // Returns true if all the necessary pages for the settings are already
  72   // rendered.
  73   // Note: locks while parsing the whole tree.
  74   bool IsComplete() const;
  75
  76   // Disconnects the PrintedPage source (PrintedPagesSource). It is done when
  77   // the source is being destroyed.
  78   void DisconnectSource();
  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 base::string16& name() const { return immutable_.name_; }
  98   int cookie() const { return immutable_.cookie_; }
  99
 100   // Sets a path where to dump printing output files for debugging. If never set
 101   // no files are generated.
 102   static void set_debug_dump_path(const base::FilePath& debug_dump_path);
 103
 104   // Creates debug file name from given |document_name| and |extension|.
 105   // |extension| should include '.', example ".pdf"
 106   // Returns empty |base::FilePath| if debug dumps is not enabled.
 107   static base::FilePath CreateDebugDumpPath(
 108       const base::string16& document_name,
 109       const base::FilePath::StringType& extension);
 110
 111   // Dump data on blocking task runner if debug dumps enabled.
 112   void DebugDumpData(const base::RefCountedMemory* data,
 113                      const base::FilePath::StringType& extension);
 114
 115  private:
 116   friend class base::RefCountedThreadSafe<PrintedDocument>;
 117
 118   virtual ~PrintedDocument();
 119
 120   // Array of data for each print previewed page.
 121   typedef std::map<int, scoped_refptr<PrintedPage> > PrintedPages;
 122
 123   // Contains all the mutable stuff. All this stuff MUST be accessed with the
 124   // lock held.
 125   struct Mutable {
 126     explicit Mutable(PrintedPagesSource* source);
 127     ~Mutable();
 128
 129     // Source that generates the PrintedPage's (i.e. a TabContents). It will be
 130     // set back to NULL if the source is deleted before this object.
 131     PrintedPagesSource* source_;
 132
 133     // Contains the pages' representation. This is a collection of PrintedPage.
 134     // Warning: Lock must be held when accessing this member.
 135     PrintedPages pages_;
 136
 137     // Number of expected pages to be rendered.
 138     // Warning: Lock must be held when accessing this member.
 139     int expected_page_count_;
 140
 141     // The total number of pages in the document.
 142     int page_count_;
 143
 144 #if defined(OS_POSIX) && !defined(OS_MACOSX)
 145     // Page number of the first page.
 146     int first_page;
 147 #endif
 148   };
 149
 150   // Contains all the immutable stuff. All this stuff can be accessed without
 151   // any lock held. This is because it can't be changed after the object's
 152   // construction.
 153   struct Immutable {
 154     Immutable(const PrintSettings& settings,
 155               PrintedPagesSource* source,
 156               int cookie,
 157               base::TaskRunner* blocking_runner);
 158     ~Immutable();
 159
 160     // Print settings used to generate this document. Immutable.
 161     PrintSettings settings_;
 162
 163     // Document name. Immutable.
 164     base::string16 name_;
 165
 166     // Cookie to uniquely identify this document. It is used to make sure that a
 167     // PrintedPage is correctly belonging to the PrintedDocument. Since
 168     // PrintedPage generation is completely asynchronous, it could be easy to
 169     // mess up and send the page to the wrong document. It can be viewed as a
 170     // simpler hash of PrintSettings since a new document is made each time the
 171     // print settings change.
 172     int cookie_;
 173
 174     // Native thread for blocking operations, like file access.
 175     scoped_refptr<base::TaskRunner> blocking_runner_;
 176   };
 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_