question: public float textWidth ( String str ) { if ( textFont == null ) { defaultFontOrDeath ( "textWidth" ) ; } int length = str . length ( ) ; if ( length > textWidthBuffer . length ) { textWidthBuffer = new char [ length + 10 ] ; } str . getChars ( 0 , length , textWidthBuffer , 0 ) ; float wide = 0 ; int index = 0 ; int start = 0 ; while ( index < length ) { if ( textWidthBuffer [ index ] == '\n' ) { wide = Math . max ( wide , textWidthImpl ( textWidthBuffer , start , index ) ) ; start = index + 1 ; } index ++ ; } if ( start < length ) { wide = Math . max ( wide , textWidthImpl ( textWidthBuffer , start , index ) ) ; } return wide ; }
target:  Return the width of a line of text. If the text has multiple lines, this returns the length of the longest line.