writeTextRange method
Implementation
void writeTextRange(int start, int end) {
if (end <= start) {
return;
}
final text = source.substring(start, end);
final nodes = _stack.last.children;
// If the previous node is text too, just append.
if (nodes.isNotEmpty && nodes.last is Text) {
final textNode = nodes.last as Text;
nodes[nodes.length - 1] = Text('${textNode.text}$text');
} else {
nodes.add(Text(text));
}
}