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 <array>
  21 #include <vector>
  22
  23 namespace svl
  24 {
  25 /** Function object to check whether a style sheet a fulfills specific criteria.
  26  * Derive from this class and override the Check() method.
  27  */
  28 struct StyleSheetPredicate
  29 {
  30     virtual bool Check(const SfxStyleSheetBase& styleSheet) = 0;
  31     virtual ~StyleSheetPredicate() {}
  32 };
  33
  34 /** Function object for cleanup-Strategy for IndexedSfxStyleSheets::Clear().
  35  * Derive from it and do what is necessary to dispose of a style sheet in Dispose().
  36  */
  37 struct StyleSheetDisposer
  38 {
  39     virtual void Dispose(rtl::Reference<SfxStyleSheetBase> styleSheet) = 0;
  40     virtual ~StyleSheetDisposer() {}
  41 };
  42
  43 /** Function object to apply a method on all style sheets.
  44  * Derive from it and do whatever you want to with the style sheet in the DoIt() method.
  45  */
  46 struct StyleSheetCallback
  47 {
  48     virtual void DoIt(const SfxStyleSheetBase& styleSheet) = 0;
  49     virtual ~StyleSheetCallback() {}
  50 };
  51
  52 /** This class holds SfxStyleSheets and allows for access via an id and a name.
  53  *
  54  * @warning
  55  * The identification of style sheets happens by their name. If the name of a sheet changes,
  56  * it will not be found again! Please call Reindex() after changing a style sheet's name.
  57  *
  58  * @internal
  59  * This class was implemented to mitigate solve #fdo 30770.
  60  * The issue describes an Excel file which takes several hours to open.
  61  * An analysis revealed that the time is spent searching for style sheets with linear scans in an array.
  62  * This class implements access to the style sheets via their name in (usually) constant time.
  63  *
  64  * The return type for most methods is a vector of unsigned integers which denote the position
  65  * of the style sheets in the vector, and not of pointers to style sheets.
  66  * You will need a non-const StyleSheetPool to obtain the actual style sheets.
  67  *
  68  *
  69  * Index-based access is required in several code portions. Hence we have to store the style sheets
  70  * in a vector as well as in a map.
  71  */
  72 class SVL_DLLPUBLIC IndexedStyleSheets final
  73 {
  74 public:
  75     IndexedStyleSheets();
  76
  77     /** Destructor.
  78      *
  79      * @internal
  80      * Is explicit because it has to know how to dispose of SfxStyleSheetBase objects.
  81      */
  82     ~IndexedStyleSheets();
  83
  84     /** Adds a style sheet.
  85      *
  86      * If the style sheet is already contained, this call has no effect.
  87      */
  88     void AddStyleSheet(const rtl::Reference<SfxStyleSheetBase>& style);
  89
  90     /** Removes a style sheet. */
  91     bool RemoveStyleSheet(const rtl::Reference<SfxStyleSheetBase>& style);
  92
  93     /** Check whether a specified style sheet is stored. */
  94     bool HasStyleSheet(const rtl::Reference<SfxStyleSheetBase>& style) const;
  95
  96     /** Obtain the number of style sheets which are held */
  97     sal_Int32 GetNumberOfStyleSheets() const { return mStyleSheets.size(); }
  98
  99     /** Obtain the number of style sheets for which a certain condition holds */
 100     sal_Int32 GetNumberOfStyleSheetsWithPredicate(StyleSheetPredicate& predicate) const;
 101
 102     /** Return the stylesheet by its position.
 103      * You can obtain the position by, e.g., FindStyleSheetPosition()
 104      * @internal
 105      * Method is not const because the returned style sheet is not const
 106      */
 107     SfxStyleSheetBase* GetStyleSheetByPosition(sal_Int32 pos);
 108
 109     /** Find the position of a provided style.
 110      *
 111      * @throws std::runtime_error if the style has not been found.
 112      */
 113     sal_Int32 FindStyleSheetPosition(const SfxStyleSheetBase& style) const;
 114
 115     /** Obtain the positions of all styles which have a given name
 116      */
 117     std::vector<sal_Int32> FindPositionsByName(const OUString& name) const;
 118
 119     enum class SearchBehavior
 120     {
 121         ReturnAll,
 122         ReturnFirst
 123     };
 124     /** Obtain the positions of all styles which have a certain name and fulfill a certain condition.
 125      *
 126      * This method is fast because it can use the name-based index
 127      */
 128     std::vector<sal_Int32>
 129     FindPositionsByNameAndPredicate(const OUString& name, StyleSheetPredicate& predicate,
 130                                     SearchBehavior behavior = SearchBehavior::ReturnAll) const;
 131
 132     /** Obtain the positions of all styles which fulfill a certain condition.
 133      *
 134      * This method is slow because it cannot use the name-based index
 135      */
 136     std::vector<sal_Int32> FindPositionsByPredicate(StyleSheetPredicate& predicate) const;
 137
 138     /** Execute a callback on all style sheets */
 139     void ApplyToAllStyleSheets(StyleSheetCallback& callback) const;
 140
 141     /** Clear the contents of the index.
 142      * The StyleSheetDisposer::Dispose() method is called on each style sheet, e.g., if you want to broadcast
 143      * changes.
 144      */
 145     void Clear(StyleSheetDisposer& cleanup);
 146
 147     void Reindex();
 148     void ReindexOnNameChange(const SfxStyleSheetBase& style, const OUString& rOldName,
 149                              const OUString& rNewName);
 150
 151     /** Warning: counting for n starts at 0, i.e., the 0th style sheet is the first that is found.
 152         Returns a pointer if a stylesheet is found, and the position of the found stylesheet
 153      */
 154     std::pair<SfxStyleSheetBase*, sal_Int32>
 155     GetNthStyleSheetThatMatchesPredicate(sal_Int32 n, StyleSheetPredicate& predicate,
 156                                          sal_Int32 startAt = 0);
 157
 158     /** Get the positions of the style sheets which belong to a certain family.
 159      */
 160     const std::vector<SfxStyleSheetBase*>& GetStyleSheetsByFamily(SfxStyleFamily) const;
 161
 162 private:
 163     /** Register the position of a styleName in the index */
 164     void Register(SfxStyleSheetBase& style, sal_Int32 pos);
 165
 166     typedef std::vector<rtl::Reference<SfxStyleSheetBase>> VectorType;
 167     /** Vector with the stylesheets to allow for index-based access.
 168      */
 169     VectorType mStyleSheets;
 170
 171     /** The map type that is used to store the mapping from strings to ids in mStyleSheets
 172      *
 173      * @internal
 174      * Must be an unordered map. A regular map is too slow for some files. */
 175     typedef std::unordered_multimap<OUString, unsigned> MapType;
 176
 177     /** A map which stores the positions of style sheets by their name */
 178     MapType mPositionsByName;
 179
 180     static constexpr size_t NUMBER_OF_FAMILIES = 6;
 181
 182     std::array<std::vector<SfxStyleSheetBase*>, NUMBER_OF_FAMILIES> mStyleSheetsByFamily;
 183 };
 184
 185 } /* namespace svl */
 186
 187 #endif // INCLUDED_SVL_INDEXEDSTYLESHEETS_HXX
 188
 189 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */