dali-toolkit/internal/text/bidirectional-support.cpp

   1 /*
   2  * Copyright (c) 2015 Samsung Electronics Co., Ltd.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  *
  16  */
  17
  18 // FILE HEADER
  19 #include <dali-toolkit/internal/text/bidirectional-support.h>
  20
  21 // EXTERNAL INCLUDES
  22 #include <memory.h>
  23 #include <dali/devel-api/text-abstraction/bidirectional-support.h>
  24
  25 namespace Dali
  26 {
  27
  28 namespace Toolkit
  29 {
  30
  31 namespace Text
  32 {
  33
  34 namespace
  35 {
  36
  37 /**
  38  * @brief Get the lines of a paragraph.
  39  *
  40  * @param[in] paragraphInfo The paragraph.
  41  * @param[in] lines The lines.
  42  * @param[in] lineIndex Index pointing the first line to be checked.
  43  * @param[out] firstLine Index to the first line of the paragraph.
  44  * @param[out] numberOfLines The number of lines.
  45  */
  46 void GetLines( const BidirectionalParagraphInfoRun& paragraphInfo,
  47                const Vector<LineRun>& lines,
  48                unsigned int lineIndex,
  49                unsigned int& firstLine,
  50                unsigned int& numberOfLines )
  51 {
  52   firstLine = lineIndex;
  53   numberOfLines = 0u;
  54
  55   const CharacterIndex lastCharacterIndex = paragraphInfo.characterRun.characterIndex + paragraphInfo.characterRun.numberOfCharacters;
  56   bool firstLineFound = false;
  57
  58   for( Vector<LineRun>::ConstIterator it = lines.Begin() + lineIndex,
  59          endIt = lines.End();
  60        it != endIt;
  61        ++it )
  62   {
  63     const LineRun& line = *it;
  64
  65     if( ( line.characterRun.characterIndex + line.characterRun.numberOfCharacters > paragraphInfo.characterRun.characterIndex ) &&
  66         ( lastCharacterIndex > line.characterRun.characterIndex ) )
  67     {
  68       firstLineFound = true;
  69       ++numberOfLines;
  70     }
  71     else if( lastCharacterIndex <= line.characterRun.characterIndex )
  72     {
  73       // nothing else to do.
  74       break;
  75     }
  76
  77     if( !firstLineFound )
  78     {
  79       ++firstLine;
  80     }
  81   }
  82 }
  83
  84 } // namespace
  85
  86 void SetBidirectionalInfo( const Vector<Character>& text,
  87                            const Vector<ScriptRun>& scripts,
  88                            const Vector<LineBreakInfo>& lineBreakInfo,
  89                            Vector<BidirectionalParagraphInfoRun>& bidirectionalInfo )
  90 {
  91   // Traverse the script runs. If there is one with a right to left script, create the bidirectional info for the paragraph containing that script is needed.
  92   // From the bidirectional point of view, a paragraph is the piece of text between two LINE_MUST_BREAK.
  93
  94   // Index pointing the first character of the current paragraph.
  95   CharacterIndex paragraphCharacterIndex = 0u;
  96
  97   // Pointer to the text buffer.
  98   const Character* textBuffer = text.Begin();
  99
 100   // Pointer to the line break info buffer.
 101   const LineBreakInfo* lineBreakInfoBuffer = lineBreakInfo.Begin();
 102
 103   // The number of characters.
 104   const Length numberOfCharacters = text.Count();
 105
 106   // Handle to the bidirectional info module in text-abstraction.
 107   TextAbstraction::BidirectionalSupport bidirectionalSupport = TextAbstraction::BidirectionalSupport::Get();
 108
 109   for( Vector<ScriptRun>::ConstIterator it = scripts.Begin(),
 110          endIt = scripts.End();
 111        it != endIt;
 112        ++it )
 113   {
 114     const ScriptRun& scriptRun = *it;
 115     const CharacterIndex lastScriptRunIndex = scriptRun.characterRun.characterIndex + scriptRun.characterRun.numberOfCharacters;
 116
 117     if( TextAbstraction::IsRightToLeftScript( scriptRun.script ) && // The script is right to left.
 118         ( lastScriptRunIndex > paragraphCharacterIndex ) )          // It isn't part of a previous paragraph.
 119     {
 120       // Find the paragraphs which contains this script run.
 121       // Consider:
 122       //  1) Different paragraphs may contain this script run.
 123       //  ------||------------------- rtl sr ------------------------||-------------------
 124       //  --||----- p -----||------------------ p -------------||-------- p ------||------
 125       //
 126       //  2) The paragraph which contains this script run may contain other right to left script runs.
 127       //  -----||--- rtl sr ---||---- ltr sr ----||---------- rtl sr -----------||--------
 128       //  -----||---------------------------------- p -----------------------------------|
 129
 130       while( lastScriptRunIndex > paragraphCharacterIndex )
 131       {
 132         // There is a paragraph which contains the current script.
 133
 134         Length index = paragraphCharacterIndex;
 135         while( ( index < numberOfCharacters ) && ( paragraphCharacterIndex < lastScriptRunIndex ) )
 136         {
 137           if( TextAbstraction::LINE_MUST_BREAK == *( lineBreakInfoBuffer + index ) )
 138           {
 139             if( index >= scriptRun.characterRun.characterIndex )
 140             {
 141               // The Bidirectional run must have the same number of characters than the paragraph.
 142               BidirectionalParagraphInfoRun bidirectionalRun;
 143               bidirectionalRun.characterRun.characterIndex = paragraphCharacterIndex;
 144               bidirectionalRun.characterRun.numberOfCharacters = ( index - paragraphCharacterIndex ) + 1u; // The must break character is part of the paragrah.
 145
 146               // Create the bidirectional info for the whole paragraph and store the index to the table with this info in the run.
 147               bidirectionalRun.bidirectionalInfoIndex = bidirectionalSupport.CreateInfo( textBuffer + bidirectionalRun.characterRun.characterIndex,
 148                                                                                          bidirectionalRun.characterRun.numberOfCharacters );
 149
 150               bidirectionalInfo.PushBack( bidirectionalRun );
 151             }
 152
 153             // Update the character index of the next paragraph.
 154             paragraphCharacterIndex = index + 1u;
 155           }
 156           ++index;
 157         }
 158
 159         // The last character is always a must-break, so there is no need to check if there is characters left.
 160       }
 161     }
 162   }
 163 }
 164
 165 void ReorderLines( const Vector<BidirectionalParagraphInfoRun>& bidirectionalInfo,
 166                    Vector<LineRun>& lineRuns,
 167                    Vector<BidirectionalLineInfoRun>& lineInfoRuns )
 168 {
 169   // Handle to the bidirectional info module in text-abstraction.
 170   TextAbstraction::BidirectionalSupport bidirectionalSupport = TextAbstraction::BidirectionalSupport::Get();
 171
 172   // Keep an index to the first line to be checked if it's contained inside the paragraph.
 173   // Avoids check the lines from the beginning for each paragraph.
 174   unsigned int lineIndex = 0u;
 175
 176   for( Vector<BidirectionalParagraphInfoRun>::ConstIterator it = bidirectionalInfo.Begin(),
 177          endIt = bidirectionalInfo.End();
 178        it != endIt;
 179        ++it )
 180   {
 181     const BidirectionalParagraphInfoRun& paragraphInfo = *it;
 182     const CharacterDirection direction = bidirectionalSupport.GetParagraphDirection( paragraphInfo.bidirectionalInfoIndex );
 183
 184     // Get the lines for this paragraph.
 185     unsigned int firstLine = 0u;
 186     unsigned int numberOfLines = 0u;
 187
 188     // Get an index to the first line and the number of lines of the current paragraph.
 189     GetLines( paragraphInfo,
 190               lineRuns,
 191               lineIndex,
 192               firstLine,
 193               numberOfLines );
 194
 195     lineIndex = firstLine + numberOfLines;
 196
 197     // Traverse the lines and reorder them
 198     for( Vector<LineRun>::Iterator lineIt = lineRuns.Begin() + firstLine,
 199            endLineIt = lineRuns.Begin() + firstLine + numberOfLines;
 200            lineIt != endLineIt;
 201          ++lineIt )
 202     {
 203       LineRun& line = *lineIt;
 204
 205       // Sets the paragraph's direction.
 206       line.direction = direction;
 207
 208       // Creates a bidirectional info for the line run.
 209       BidirectionalLineInfoRun lineInfoRun;
 210       lineInfoRun.characterRun.characterIndex = line.characterRun.characterIndex;
 211       lineInfoRun.characterRun.numberOfCharacters = line.characterRun.numberOfCharacters;
 212       lineInfoRun.direction = direction;
 213
 214       // Allocate space for the conversion maps.
 215       // The memory is freed after the visual to logical to visual conversion tables are built in the logical model.
 216       lineInfoRun.visualToLogicalMap = reinterpret_cast<CharacterIndex*>( malloc( line.characterRun.numberOfCharacters * sizeof( CharacterIndex ) ) );
 217
 218       // Reorders the line.
 219       bidirectionalSupport.Reorder( paragraphInfo.bidirectionalInfoIndex,
 220                                     line.characterRun.characterIndex - paragraphInfo.characterRun.characterIndex,
 221                                     line.characterRun.numberOfCharacters,
 222                                     lineInfoRun.visualToLogicalMap );
 223
 224       // Push the run into the vector.
 225       lineInfoRuns.PushBack( lineInfoRun );
 226     }
 227   }
 228 }
 229
 230 bool GetMirroredText( const Vector<Character>& text,
 231                       Vector<Character>& mirroredText )
 232 {
 233   // Handle to the bidirectional info module in text-abstraction.
 234   TextAbstraction::BidirectionalSupport bidirectionalSupport = TextAbstraction::BidirectionalSupport::Get();
 235
 236   mirroredText = text;
 237
 238   return bidirectionalSupport.GetMirroredText( mirroredText.Begin(),
 239                                                mirroredText.Count() );
 240 }
 241
 242 void GetCharactersDirection( const Vector<BidirectionalParagraphInfoRun>& bidirectionalInfo,
 243                              Vector<CharacterDirection>& directions )
 244 {
 245   // Handle to the bidirectional info module in text-abstraction.
 246   TextAbstraction::BidirectionalSupport bidirectionalSupport = TextAbstraction::BidirectionalSupport::Get();
 247
 248   CharacterIndex index = 0u;
 249   CharacterDirection* directionsBuffer = directions.Begin();
 250   for( Vector<BidirectionalParagraphInfoRun>::ConstIterator it = bidirectionalInfo.Begin(),
 251          endIt = bidirectionalInfo.End();
 252        it != endIt;
 253        ++it )
 254   {
 255     const BidirectionalParagraphInfoRun& paragraph = *it;
 256
 257     // Fills with left to right those paragraphs without right to left characters.
 258     memset( directionsBuffer + index, false, ( paragraph.characterRun.characterIndex - index ) * sizeof( bool ) );
 259     index += paragraph.characterRun.numberOfCharacters;
 260
 261     bidirectionalSupport.GetCharactersDirection( paragraph.bidirectionalInfoIndex,
 262                                                  directionsBuffer + paragraph.characterRun.characterIndex,
 263                                                  paragraph.characterRun.numberOfCharacters );
 264   }
 265
 266   // Fills with left to right those paragraphs without right to left characters.
 267   memset( directionsBuffer + index, false, ( directions.Count() - index ) * sizeof( bool ) );
 268 }
 269
 270 } // namespace Text
 271
 272 } // namespace Toolkit
 273
 274 } // namespace Dali