writeString method

void writeString(Font font, int size, String string, bool color, bool wrap, int linespacing,)

write text to the oled

Implementation

void writeString(Font font, int size, String string, bool color, bool wrap,
    int linespacing) {
  final wordArr = string.split(' ');

  final len = wordArr.length;

  // start x offset at cursor pos
  var offset = _cursor_x;
  var padding = 0;

  const letspace = 1;
  final leading = linespacing | 2;

  // loop through words
  for (var i = 0; i < len; i += 1) {
    // put the word space back in
    if (i < len - 1) wordArr[i] += ' ';

    final stringArr = wordArr[i].split('');
    final slen = stringArr.length;
    final compare = (font.width * size * slen) + (size * (len - 1));

    // wrap words if necessary
    if (wrap && len > 1 && (offset >= (width - compare))) {
      offset = 1;
      _cursor_y += (font.height * size) + size + leading;
      setCursor(offset, _cursor_y);
    }

    // loop through the array of each char to draw
    for (var i = 0; i < slen; i += 1) {
      // look up the position of the char, pull out the buffer slice
      final charBuf = _findCharBuf(font, stringArr[i]);
      // read the bits in the bytes that make up the char
      final charBytes = _readCharBytes(charBuf);
      // draw the entire charactei
      _drawChar(font, charBytes, size, color);

      // fills in background behind the text pixels so that it's easier to read the text
      fillRect(
          offset - padding, _cursor_y, padding, (font.height * size), !color);

      // calc new x position for the next char, add a touch of padding too if it's a non space char
      padding = (stringArr[i] == ' ') ? 0 : size + letspace;
      offset += (font.width * size) + padding;

      // wrap letters if necessary
      if (wrap && (offset >= (width - font.width - letspace))) {
        offset = 1;
        _cursor_y += (font.height * size) + size + leading;
      }
      // set the 'cursor' for the next char to be drawn, then loop again for next char
      setCursor(offset, _cursor_y);
    }
  }
}