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