Returns the offset at the specified x location in the specified line.
@param x x location of the mouse location
@param line line the mouse location is in
@return the offset at the specified x location in the specified line,
relative to the beginning of the document
Returns the offset at the specified x location in the specified line.
@param x x location of the mouse location @param line line the mouse location is in @return the offset at the specified x location in the specified line, relative to the beginning of the document