sendTextToFrame method

Future<void> sendTextToFrame(String text)

create the TextSpriteBlock for the specified text, then send the TSB header and line sprites one by one

Implementation

Future<void> sendTextToFrame(String text) async {
  if (text.isEmpty) {
    // just send a Clear Display message
    await frame!.sendMessage(TxCode(msgCode: 0x10));
    return;
  }

  var tsb = TxTextSpriteBlock(
    msgCode: 0x20,
    width: 620,
    fontSize: _textSizeValues[_textSizeIndex],
    maxDisplayRows: 10,
    textDirection: _textDir,
    textAlign: TextAlign.start,
    text: text,
  );

  // rasterize the text to sprites
  await tsb.rasterize(startLine: 0, endLine: tsb.numLines - 1);

  // send the TxTextSpriteBlock lines to Frame for display
  // block header first
  await frame!.sendMessage(tsb);

  // send over the lines one by one
  // note that the sprites have the same message code, so they need to be handled by the text_sprite_block parser
  for (var sprite in tsb.rasterizedSprites) {
    await frame!.sendMessage(sprite);
  }
}