chrome/browser/printing/print_preview_data_service.cc

   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 #include "chrome/browser/printing/print_preview_data_service.h"
   6
   7 #include "base/memory/ref_counted_memory.h"
   8 #include "base/memory/singleton.h"
   9 #include "base/stl_util.h"
  10 #include "printing/print_job_constants.h"
  11
  12 // PrintPreviewDataStore stores data for preview workflow and preview printing
  13 // workflow.
  14 //
  15 // NOTE:
  16 //   This class stores a list of PDFs. The list |index| is zero-based and can
  17 // be |printing::COMPLETE_PREVIEW_DOCUMENT_INDEX| to represent complete preview
  18 // document. The PDF stored at |printing::COMPLETE_PREVIEW_DOCUMENT_INDEX| is
  19 // optimized with font subsetting, compression, etc. PDF's stored at all other
  20 // indices are unoptimized.
  21 //
  22 // PrintPreviewDataStore owns the data and is responsible for freeing it when
  23 // either:
  24 //    a) There is a new data.
  25 //    b) When PrintPreviewDataStore is destroyed.
  26 //
  27 class PrintPreviewDataStore : public base::RefCounted<PrintPreviewDataStore> {
  28  public:
  29   PrintPreviewDataStore() {}
  30
  31   // Get the preview page for the specified |index|.
  32   void GetPreviewDataForIndex(int index,
  33                               scoped_refptr<base::RefCountedBytes>* data) {
  34     if (IsInvalidIndex(index))
  35       return;
  36
  37     PreviewPageDataMap::iterator it = page_data_map_.find(index);
  38     if (it != page_data_map_.end())
  39       *data = it->second.get();
  40   }
  41
  42   // Set/Update the preview data entry for the specified |index|.
  43   void SetPreviewDataForIndex(int index, const base::RefCountedBytes* data) {
  44     if (IsInvalidIndex(index))
  45       return;
  46
  47     page_data_map_[index] = const_cast<base::RefCountedBytes*>(data);
  48   }
  49
  50   // Returns the available draft page count.
  51   int GetAvailableDraftPageCount() {
  52     int page_data_map_size = page_data_map_.size();
  53     if (ContainsKey(page_data_map_, printing::COMPLETE_PREVIEW_DOCUMENT_INDEX))
  54       page_data_map_size--;
  55     return page_data_map_size;
  56   }
  57
  58  private:
  59   friend class base::RefCounted<PrintPreviewDataStore>;
  60
  61   // 1:1 relationship between page index and its associated preview data.
  62   // Key: Page index is zero-based and can be
  63   // |printing::COMPLETE_PREVIEW_DOCUMENT_INDEX| to represent complete preview
  64   // document.
  65   // Value: Preview data.
  66   using PreviewPageDataMap =
  67       std::map<int, scoped_refptr<base::RefCountedBytes>>;
  68
  69   ~PrintPreviewDataStore() {}
  70
  71   static bool IsInvalidIndex(int index) {
  72     return (index != printing::COMPLETE_PREVIEW_DOCUMENT_INDEX &&
  73             index < printing::FIRST_PAGE_INDEX);
  74   }
  75
  76   PreviewPageDataMap page_data_map_;
  77
  78   DISALLOW_COPY_AND_ASSIGN(PrintPreviewDataStore);
  79 };
  80
  81 // static
  82 PrintPreviewDataService* PrintPreviewDataService::GetInstance() {
  83   return base::Singleton<PrintPreviewDataService>::get();
  84 }
  85
  86 PrintPreviewDataService::PrintPreviewDataService() {
  87 }
  88
  89 PrintPreviewDataService::~PrintPreviewDataService() {
  90 }
  91
  92 void PrintPreviewDataService::GetDataEntry(
  93     int32_t preview_ui_id,
  94     int index,
  95     scoped_refptr<base::RefCountedBytes>* data_bytes) {
  96   *data_bytes = nullptr;
  97   PreviewDataStoreMap::const_iterator it = data_store_map_.find(preview_ui_id);
  98   if (it != data_store_map_.end())
  99     it->second->GetPreviewDataForIndex(index, data_bytes);
 100 }
 101
 102 void PrintPreviewDataService::SetDataEntry(
 103     int32_t preview_ui_id,
 104     int index,
 105     const base::RefCountedBytes* data_bytes) {
 106   if (!ContainsKey(data_store_map_, preview_ui_id))
 107     data_store_map_[preview_ui_id] = new PrintPreviewDataStore();
 108
 109   data_store_map_[preview_ui_id]->SetPreviewDataForIndex(index, data_bytes);
 110 }
 111
 112 void PrintPreviewDataService::RemoveEntry(int32_t preview_ui_id) {
 113   data_store_map_.erase(preview_ui_id);
 114 }
 115
 116 int PrintPreviewDataService::GetAvailableDraftPageCount(int32_t preview_ui_id) {
 117   PreviewDataStoreMap::const_iterator it = data_store_map_.find(preview_ui_id);
 118   return (it == data_store_map_.end()) ?
 119       0 : it->second->GetAvailableDraftPageCount();
 120 }