+ // Handle to the bidirectional info module in text-abstraction.
+ TextAbstraction::BidirectionalSupport bidirectionalSupport = TextAbstraction::BidirectionalSupport::Get();
+
+ // Resize the vector.
+ directions.Resize( totalNumberOfCharacters );
+
+ // Whether the current buffer is being updated or is set from scratch.
+ const bool updateCurrentBuffer = numberOfCharacters < totalNumberOfCharacters;
+
+ CharacterDirection* directionsBuffer = NULL;
+ Vector<CharacterDirection> newDirections;
+
+ if( updateCurrentBuffer )
+ {
+ newDirections.Resize( numberOfCharacters );
+ directionsBuffer = newDirections.Begin();
+ }
+ else
+ {
+ directionsBuffer = directions.Begin();
+ }
+
+ const CharacterIndex lastCharacter = startIndex + numberOfCharacters;
+ CharacterIndex index = startIndex;
+
+ for( Vector<BidirectionalParagraphInfoRun>::ConstIterator it = bidirectionalInfo.Begin(),
+ endIt = bidirectionalInfo.End();
+ it != endIt;
+ ++it )
+ {
+ const BidirectionalParagraphInfoRun& paragraph = *it;
+
+ if( index >= paragraph.characterRun.characterIndex + paragraph.characterRun.numberOfCharacters )
+ {
+ // Skip the paragraph as it has already been processed.
+ continue;
+ }
+
+ if( lastCharacter <= paragraph.characterRun.characterIndex )
+ {
+ // Do not get the character directions beyond startIndex + numberOfCharacters.
+ break;
+ }
+
+ // Set the directions of any previous left to right characters.
+ const Length numberOfLeftToRightCharacters = paragraph.characterRun.characterIndex - index;
+ if( numberOfLeftToRightCharacters > 0u )
+ {
+ memset( directionsBuffer + index - startIndex, false, numberOfLeftToRightCharacters * sizeof( bool ) );
+ }
+
+ // Set the directions of the bidirectional text.
+ bidirectionalSupport.GetCharactersDirection( paragraph.bidirectionalInfoIndex,
+ directionsBuffer + paragraph.characterRun.characterIndex - startIndex,
+ paragraph.characterRun.numberOfCharacters );
+
+ // Update the index.
+ index += paragraph.characterRun.numberOfCharacters + numberOfLeftToRightCharacters;
+ }
+
+ // Fills with left to right those paragraphs without right to left characters.
+ memset( directionsBuffer + index - startIndex, false, ( lastCharacter - index ) * sizeof( bool ) );
+
+ // If the direction info is updated, it needs to be inserted in the model.
+ if( updateCurrentBuffer )
+ {
+ // Insert the directions in the given buffer.
+ directions.Insert( directions.Begin() + startIndex,
+ newDirections.Begin(),
+ newDirections.End() );
+ directions.Resize( totalNumberOfCharacters );
+ }