question: private String justifyTextLine ( TextPaint textPaint , String lineString , int textAreaWidth ) { int gapIndex = 0 ; float lineWidth = textPaint . measureText ( lineString ) ; while ( lineWidth < textAreaWidth && lineWidth > 0 ) { gapIndex = lineString . indexOf ( " " , gapIndex + 2 ) ; if ( gapIndex == - 1 ) { gapIndex = 0 ; gapIndex = lineString . indexOf ( " " , gapIndex + 1 ) ; if ( gapIndex == - 1 ) return lineString ; } lineString = lineString . substring ( 0 , gapIndex ) + "  " + lineString . substring ( gapIndex + 1 , lineString . length ( ) ) ; lineWidth = textPaint . measureText ( lineString ) ; } return lineString ; }
target:  this method add space in line until line width become equal to textAreaWidth