icuSources/layout/LEInsertionList.h

   1 /*
   2  **********************************************************************
   3  *   Copyright (C) 1998-2014, International Business Machines
   4  *   Corporation and others.  All Rights Reserved.
   5  **********************************************************************
   6  */
   7
   8 #ifndef __LEINSERTIONLIST_H
   9 #define __LEINSERTIONLIST_H
  10
  11 #include "LETypes.h"
  12
  13 U_NAMESPACE_BEGIN
  14
  15 struct InsertionRecord;
  16
  17 #ifndef U_HIDE_INTERNAL_API
  18 /**
  19  * This class encapsulates the callback used by <code>LEInsertionList</code>
  20  * to apply an insertion from the insertion list.
  21  *
  22  * @internal
  23  */
  24 class U_LAYOUT_API LEInsertionCallback
  25 {
  26 public:
  27     /**
  28      * This method will be called by <code>LEInsertionList::applyInsertions</code> for each
  29      * entry on the insertion list.
  30      *
  31      * @param atPosition the position of the insertion
  32      * @param count the number of glyphs to insert
  33      * @param newGlyphs the address of the glyphs to insert
  34      *
  35      * @return <code>TRUE</code> if <code>LEInsertions::applyInsertions</code> should
  36      *         stop after applying this insertion.
  37      *
  38      * @internal
  39      */
  40     virtual le_bool applyInsertion(le_int32 atPosition, le_int32 count, LEGlyphID newGlyphs[]) = 0;
  41
  42     /**
  43      * The destructor
  44      */
  45      virtual ~LEInsertionCallback();
  46 };
  47
  48 /**
  49  * This class is used to keep track of insertions to an array of
  50  * <code>LEGlyphIDs</code>. The insertions are kept on a linked
  51  * list of <code>InsertionRecords</code> so that the glyph array
  52  * doesn't have to be grown for each insertion. The insertions are
  53  * stored on the list from leftmost to rightmost to make it easier
  54  * to do the insertions.
  55  *
  56  * The insertions are applied to the array by calling the
  57  * <code>applyInsertions</code> method, which calls a client
  58  * supplied <code>LEInsertionCallback</code> object to actually
  59  * apply the individual insertions.
  60  *
  61  * @internal
  62  */
  63 class LEInsertionList : public UObject
  64 {
  65 public:
  66     /**
  67      * Construct an empty insertion list.
  68      *
  69      * @param rightToLeft <code>TRUE</code> if the glyphs are stored
  70      *                    in the array in right to left order.
  71      *
  72      * @internal
  73      */
  74     LEInsertionList(le_bool rightToLeft);
  75
  76     /**
  77      * The destructor.
  78      */
  79     ~LEInsertionList();
  80
  81     /**
  82      * Add an entry to the insertion list.
  83      *
  84      * @param position the glyph at this position in the array will be
  85      *                 replaced by the new glyphs.
  86      * @param count the number of new glyphs
  87      * @param success set to an error code if the auxillary data cannot be retrieved.
  88      *
  89      * @return the address of an array in which to store the new glyphs. This will
  90      *         <em>not</em> be in the glyph array.
  91      *
  92      * @internal
  93      */
  94     LEGlyphID *insert(le_int32 position, le_int32 count, LEErrorCode &success);
  95
  96     /**
  97      * Return the number of new glyphs that have been inserted.
  98      *
  99      * @return the number of new glyphs which have been inserted
 100      *
 101      * @internal
 102      */
 103     le_int32 getGrowAmount();
 104
 105     /**
 106      * Call the <code>LEInsertionCallback</code> once for each
 107      * entry on the insertion list.
 108      *
 109      * @param callback the <code>LEInsertionCallback</code> to call for each insertion.
 110      *
 111      * @return <code>TRUE</code> if <code>callback</code> returned <code>TRUE</code> to
 112      *         terminate the insertion list processing.
 113      *
 114      * @internal
 115      */
 116     le_bool applyInsertions(LEInsertionCallback *callback);
 117
 118     /**
 119      * Empty the insertion list and free all associated
 120      * storage.
 121      *
 122      * @internal
 123      */
 124     void reset();
 125
 126     /**
 127      * ICU "poor man's RTTI", returns a UClassID for the actual class.
 128      *
 129      * @deprecated ICU 54. See {@link icu::LayoutEngine}
 130      */
 131     virtual UClassID getDynamicClassID() const;
 132
 133     /**
 134      * ICU "poor man's RTTI", returns a UClassID for this class.
 135      *
 136      * @deprecated ICU 54. See {@link icu::LayoutEngine}
 137      */
 138     static UClassID getStaticClassID();
 139
 140 private:
 141
 142     /**
 143      * The head of the insertion list.
 144      *
 145      * @internal
 146      */
 147     InsertionRecord *head;
 148
 149     /**
 150      * The tail of the insertion list.
 151      *
 152      * @internal
 153      */
 154     InsertionRecord *tail;
 155
 156     /**
 157      * The total number of new glyphs on the insertion list.
 158      *
 159      * @internal
 160      */
 161     le_int32 growAmount;
 162
 163     /**
 164      * Set to <code>TRUE</code> if the glyphs are in right
 165      * to left order. Since we want the rightmost insertion
 166      * to be first on the list, we need to append the
 167      * insertions in this case. Otherwise they're prepended.
 168      *
 169      * @internal
 170      */
 171     le_bool  append;
 172 };
 173 #endif  /* U_HIDE_INTERNAL_API */
 174
 175 U_NAMESPACE_END
 176 #endif
 177