deleteText method
Deletes the length
characters at the given index
.
Implementation
void deleteText(
Node node,
int index,
int length,
) {
final delta = node.delta;
if (delta == null) {
assert(false, 'The node must have a delta.');
return;
}
assert(
index + length <= delta.length && index >= 0 && length >= 0,
'The index($index) or length($length) is out of range or negative.',
);
final delete = Delta()
..retain(index)
..delete(length);
addDeltaToComposeMap(node, delete);
afterSelection = Selection.collapsed(
Position(path: node.path, offset: index),
);
}