Stop QTextCursor from resetting undo stack

[dhamith93]

I have a function that check previous line and insert text to the QPlainTextEdit QTextCursor. Problem with my function is it resets the undo stack of the QPlainTextEdit. Is there a way to add my changes to the undo stack instead of resetting it?

This is how I'm currently doing it:

    QTextBlock textBlock = ui->noteText->textCursor().block();
    QString prevLine = textBlock.previous().text();

    if (checkListItem(prevLine)) {
        if (textBlock.text().length() == 0) {
            int spaceCount = getSpaceCount(prevLine);
            QString newLine = QString("").leftJustified(spaceCount, ' ');

            if (checkUnorderedListItem(prevLine)) {
                newLine += "* ";
            } else {
                newLine += getNextNumber(prevLine) + ". ";
            }

            ui->noteText->textCursor().insertText(newLine);
        }
    }

EDIT:

Because of how my function works, if the previous line checks true and current line is empty when undoing it inserts new text again into the current line.

I had to create an event filter and override ControlModifier + 'Z' event to make it work.