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/strings/string16.h"
  13 #include "base/synchronization/lock.h"
  14 #include "printing/print_settings.h"
  15 #include "ui/gfx/native_widget_types.h"
  16
  17 namespace base {
  18 class RefCountedMemory;
  19 class TaskRunner;
  20 }
  21
  22 namespace printing {
  23
  24 class Metafile;
  25 class PrintedPage;
  26 class PrintedPagesSource;
  27 class PrintingContext;
  28
  29 // A collection of rendered pages. The settings are immutable. If the print
  30 // settings are changed, a new PrintedDocument must be created.
  31 // Warning: May be accessed from many threads at the same time. Only one thread
  32 // will have write access. Sensible functions are protected by a lock.
  33 // Warning: Once a page is loaded, it cannot be replaced. Pages may be discarded
  34 // under low memory conditions.
  35 class PRINTING_EXPORT PrintedDocument
  36     : public base::RefCountedThreadSafe<PrintedDocument> {
  37  public:
  38   // The cookie shall be unique and has a specific relationship with its
  39   // originating source and settings.
  40   PrintedDocument(const PrintSettings& settings,
  41                   PrintedPagesSource* source,
  42                   int cookie,
  43                   base::TaskRunner* blocking_runner);
  44
  45   // Sets a page's data. 0-based. Takes metafile ownership.
  46   // Note: locks for a short amount of time.
  47   void SetPage(int page_number,
  48                Metafile* metafile,
  49 #if defined(OS_WIN)
  50                double shrink,
  51 #endif  // OS_WIN
  52                const gfx::Size& paper_size,
  53                const gfx::Rect& page_rect);
  54
  55   // Retrieves a page. If the page is not available right now, it
  56   // requests to have this page be rendered and returns NULL.
  57   // Note: locks for a short amount of time.
  58   scoped_refptr<PrintedPage> GetPage(int page_number);
  59
  60   // Draws the page in the context.
  61   // Note: locks for a short amount of time in debug only.
  62 #if defined(OS_WIN) || defined(OS_MACOSX) && !defined(USE_AURA)
  63   void RenderPrintedPage(const PrintedPage& page,
  64                          gfx::NativeDrawingContext context) const;
  65 #elif defined(OS_POSIX)
  66   void RenderPrintedPage(const PrintedPage& page,
  67                          PrintingContext* context) const;
  68 #endif
  69
  70   // Returns true if all the necessary pages for the settings are already
  71   // rendered.
  72   // Note: locks while parsing the whole tree.
  73   bool IsComplete() const;
  74
  75   // Disconnects the PrintedPage source (PrintedPagesSource). It is done when
  76   // the source is being destroyed.
  77   void DisconnectSource();
  78
  79   // Retrieves the current memory usage of the renderer pages.
  80   // Note: locks for a short amount of time.
  81   uint32 MemoryUsage() const;
  82
  83   // Sets the number of pages in the document to be rendered. Can only be set
  84   // once.
  85   // Note: locks for a short amount of time.
  86   void set_page_count(int max_page);
  87
  88   // Number of pages in the document. Used for headers/footers.
  89   // Note: locks for a short amount of time.
  90   int page_count() const;
  91
  92   // Returns the number of expected pages to be rendered. It is a non-linear
  93   // series if settings().ranges is not empty. It is the same value as
  94   // document_page_count() otherwise.
  95   // Note: locks for a short amount of time.
  96   int expected_page_count() const;
  97
  98   // Getters. All these items are immutable hence thread-safe.
  99   const PrintSettings& settings() const { return immutable_.settings_; }
 100   const base::string16& name() const { return immutable_.name_; }
 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 base::FilePath& debug_dump_path);
 106
 107   // Creates debug file name from given |document_name| and |extension|.
 108   // |extension| should include '.', example ".pdf"
 109   // Returns empty |base::FilePath| if debug dumps is not enabled.
 110   static base::FilePath CreateDebugDumpPath(
 111       const base::string16& document_name,
 112       const base::FilePath::StringType& extension);
 113
 114   // Dump data on blocking task runner if debug dumps enabled.
 115   void DebugDumpData(const base::RefCountedMemory* data,
 116                      const base::FilePath::StringType& extension);
 117
 118  private:
 119   friend class base::RefCountedThreadSafe<PrintedDocument>;
 120
 121   virtual ~PrintedDocument();
 122
 123   // Array of data for each print previewed page.
 124   typedef std::map<int, scoped_refptr<PrintedPage> > PrintedPages;
 125
 126   // Contains all the mutable stuff. All this stuff MUST be accessed with the
 127   // lock held.
 128   struct Mutable {
 129     explicit Mutable(PrintedPagesSource* source);
 130     ~Mutable();
 131
 132     // Source that generates the PrintedPage's (i.e. a TabContents). It will be
 133     // set back to NULL if the source is deleted before this object.
 134     PrintedPagesSource* source_;
 135
 136     // Contains the pages' representation. This is a collection of PrintedPage.
 137     // Warning: Lock must be held when accessing this member.
 138     PrintedPages pages_;
 139
 140     // Number of expected pages to be rendered.
 141     // Warning: Lock must be held when accessing this member.
 142     int expected_page_count_;
 143
 144     // The total number of pages in the document.
 145     int page_count_;
 146
 147 #if defined(OS_POSIX) && !defined(OS_MACOSX)
 148     // Page number of the first page.
 149     int first_page;
 150 #endif
 151   };
 152
 153   // Contains all the immutable stuff. All this stuff can be accessed without
 154   // any lock held. This is because it can't be changed after the object's
 155   // construction.
 156   struct Immutable {
 157     Immutable(const PrintSettings& settings,
 158               PrintedPagesSource* source,
 159               int cookie,
 160               base::TaskRunner* blocking_runner);
 161     ~Immutable();
 162
 163     // Print settings used to generate this document. Immutable.
 164     PrintSettings settings_;
 165
 166     // Document name. Immutable.
 167     base::string16 name_;
 168
 169     // Cookie to uniquely identify this document. It is used to make sure that a
 170     // PrintedPage is correctly belonging to the PrintedDocument. Since
 171     // PrintedPage generation is completely asynchronous, it could be easy to
 172     // mess up and send the page to the wrong document. It can be viewed as a
 173     // simpler hash of PrintSettings since a new document is made each time the
 174     // print settings change.
 175     int cookie_;
 176
 177     // Native thread for blocking operations, like file access.
 178     scoped_refptr<base::TaskRunner> blocking_runner_;
 179   };
 180
 181   // All writable data member access must be guarded by this lock. Needs to be
 182   // mutable since it can be acquired from const member functions.
 183   mutable base::Lock lock_;
 184
 185   // All the mutable members.
 186   Mutable mutable_;
 187
 188   // All the immutable members.
 189   const Immutable immutable_;
 190
 191   DISALLOW_COPY_AND_ASSIGN(PrintedDocument);
 192 };
 193
 194 }  // namespace printing
 195
 196 #endif  // PRINTING_PRINTED_DOCUMENT_H_