+ Dali::InputMethodContext::PreeditAttributeData data;
+ data.startIndex = 0;
+ data.endIndex = 0;
+
+ size_t visualCharacterIndex = 0;
+ size_t byteIndex = 0;
+
+ // iterate through null terminated string checking each character's position against the given byte position ( attr->end_index ).
+ const char leadByte = preEditString[byteIndex];
+ while( leadByte != '\0' )
+ {
+ // attr->end_index is provided as a byte position not character and we need to know the character position.
+ const size_t currentSequenceLength = Utf8SequenceLength( leadByte ); // returns number of bytes used to represent character.
+ if( byteIndex <= attr->start_index )
+ {
+ data.startIndex = visualCharacterIndex;
+ }
+ if ( byteIndex >= attr->end_index )
+ {
+ data.endIndex = visualCharacterIndex;
+ break;
+ // end loop as found cursor position that matches byte position
+ }
+ else
+ {
+ byteIndex += currentSequenceLength; // jump to next character
+ visualCharacterIndex++; // increment character count so we know our position for when we get a match
+ }
+ }
+