include/svl/IndexedStyleSheets.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  */
   9
  10 #ifndef INCLUDED_SVL_INDEXEDSTYLESHEETS_HXX
  11 #define INCLUDED_SVL_INDEXEDSTYLESHEETS_HXX
  12
  13 #include <svl/style.hxx>
  14 #include <rtl/ustring.hxx>
  15 #include <rtl/ref.hxx>
  16
  17 #include <svl/svldllapi.h>
  18
  19 #include <unordered_map>
  20 #include <vector>
  21
  22 namespace svl
  23 {
  24 /** Function object to check whether a style sheet a fulfills specific criteria.
  25  * Derive from this class and override the Check() method.
  26  */
  27 struct StyleSheetPredicate
  28 {
  29     virtual bool Check(const SfxStyleSheetBase& styleSheet) = 0;
  30     virtual ~StyleSheetPredicate() {}
  31 };
  32
  33 /** Function object for cleanup-Strategy for IndexedSfxStyleSheets::Clear().
  34  * Derive from it and do what is necessary to dispose of a style sheet in Dispose().
  35  */
  36 struct StyleSheetDisposer
  37 {
  38     virtual void Dispose(rtl::Reference<SfxStyleSheetBase> styleSheet) = 0;
  39     virtual ~StyleSheetDisposer() {}
  40 };
  41
  42 /** Function object to apply a method on all style sheets.
  43  * Derive from it and do whatever you want to with the style sheet in the DoIt() method.
  44  */
  45 struct StyleSheetCallback
  46 {
  47     virtual void DoIt(const SfxStyleSheetBase& styleSheet) = 0;
  48     virtual ~StyleSheetCallback() {}
  49 };
  50
  51 /** This class holds SfxStyleSheets and allows for access via an id and a name.
  52  *
  53  * @warning
  54  * The identification of style sheets happens by their name. If the name of a sheet changes,
  55  * it will not be found again! Please call Reindex() after changing a style sheet's name.
  56  *
  57  * @internal
  58  * This class was implemented to mitigate solve #fdo 30770.
  59  * The issue describes an Excel file which takes several hours to open.
  60  * An analysis revealed that the time is spent searching for style sheets with linear scans in an array.
  61  * This class implements access to the style sheets via their name in (usually) constant time.
  62  *
  63  * The return type for most methods is a vector of unsigned integers which denote the position
  64  * of the style sheets in the vector, and not of pointers to style sheets.
  65  * You will need a non-const StyleSheetPool to obtain the actual style sheets.
  66  *
  67  *
  68  * Index-based access is required in several code portions. Hence we have to store the style sheets
  69  * in a vector as well as in a map.
  70  */
  71 class SVL_DLLPUBLIC IndexedStyleSheets final
  72 {
  73 public:
  74     IndexedStyleSheets();
  75
  76     /** Destructor.
  77      *
  78      * @internal
  79      * Is explicit because it has to know how to dispose of SfxStyleSheetBase objects.
  80      */
  81     ~IndexedStyleSheets();
  82
  83     /** Adds a style sheet.
  84      *
  85      * If the style sheet is already contained, this call has no effect.
  86      */
  87     void AddStyleSheet(const rtl::Reference<SfxStyleSheetBase>& style);
  88
  89     /** Removes a style sheet. */
  90     bool RemoveStyleSheet(const rtl::Reference<SfxStyleSheetBase>& style);
  91
  92     /** Check whether a specified style sheet is stored. */
  93     bool HasStyleSheet(const rtl::Reference<SfxStyleSheetBase>& style) const;
  94
  95     /** Obtain the number of style sheets which are held */
  96     sal_Int32 GetNumberOfStyleSheets() const;
  97
  98     /** Obtain the number of style sheets for which a certain condition holds */
  99     sal_Int32 GetNumberOfStyleSheetsWithPredicate(StyleSheetPredicate& predicate) const;
 100
 101     /** Return the stylesheet by its position.
 102      * You can obtain the position by, e.g., FindStyleSheetPosition()
 103      * @internal
 104      * Method is not const because the returned style sheet is not const
 105      */
 106     SfxStyleSheetBase* GetStyleSheetByPosition(sal_Int32 pos);
 107
 108     /** Find the position of a provided style.
 109      *
 110      * @throws std::runtime_error if the style has not been found.
 111      */
 112     sal_Int32 FindStyleSheetPosition(const SfxStyleSheetBase& style) const;
 113
 114     /** Obtain the positions of all styles which have a given name
 115      */
 116     std::vector<sal_Int32> FindPositionsByName(const OUString& name) const;
 117
 118     enum class SearchBehavior
 119     {
 120         ReturnAll,
 121         ReturnFirst
 122     };
 123     /** Obtain the positions of all styles which have a certain name and fulfill a certain condition.
 124      *
 125      * This method is fast because it can use the name-based index
 126      */
 127     std::vector<sal_Int32>
 128     FindPositionsByNameAndPredicate(const OUString& name, StyleSheetPredicate& predicate,
 129                                     SearchBehavior behavior = SearchBehavior::ReturnAll) const;
 130
 131     /** Obtain the positions of all styles which fulfill a certain condition.
 132      *
 133      * This method is slow because it cannot use the name-based index
 134      */
 135     std::vector<sal_Int32> FindPositionsByPredicate(StyleSheetPredicate& predicate) const;
 136
 137     /** Execute a callback on all style sheets */
 138     void ApplyToAllStyleSheets(StyleSheetCallback& callback) const;
 139
 140     /** Clear the contents of the index.
 141      * The StyleSheetDisposer::Dispose() method is called on each style sheet, e.g., if you want to broadcast
 142      * changes.
 143      */
 144     void Clear(StyleSheetDisposer& cleanup);
 145
 146     void Reindex();
 147
 148     /** Warning: counting for n starts at 0, i.e., the 0th style sheet is the first that is found. */
 149     SfxStyleSheetBase* GetNthStyleSheetThatMatchesPredicate(sal_Int32 n,
 150                                                             StyleSheetPredicate& predicate,
 151                                                             sal_Int32 startAt = 0);
 152
 153     /** Get the positions of the style sheets which belong to a certain family.
 154      */
 155     const std::vector<sal_Int32>& GetStyleSheetPositionsByFamily(SfxStyleFamily) const;
 156
 157 private:
 158     /** Register the position of a styleName in the index */
 159     void Register(const SfxStyleSheetBase& style, sal_Int32 pos);
 160
 161     typedef std::vector<rtl::Reference<SfxStyleSheetBase>> VectorType;
 162     /** Vector with the stylesheets to allow for index-based access.
 163      */
 164     VectorType mStyleSheets;
 165
 166     /** The map type that is used to store the mapping from strings to ids in mStyleSheets
 167      *
 168      * @internal
 169      * Must be an unordered map. A regular map is too slow for some files. */
 170     typedef std::unordered_multimap<OUString, unsigned> MapType;
 171
 172     /** A map which stores the positions of style sheets by their name */
 173     MapType mPositionsByName;
 174
 175     std::vector<std::vector<sal_Int32>> mStyleSheetPositionsByFamily;
 176 };
 177
 178 } /* namespace svl */
 179
 180 #endif // INCLUDED_SVL_INDEXEDSTYLESHEETS_HXX
 181
 182 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */