QTextBlockFormat resets by pressing the return key for empty block

[Koru]

I am making a rich text editor where each paragraph has a different background depending on its type. I set the background using this code:

    QTextCursor cursor(ui->textEdit->textCursor());
    QTextBlockFormat block_format = cursor.blockFormat();
    block_format.setBackground(Qt::yellow);
    cursor.setBlockFormat(block_format);
    ui->textEdit->setTextCursor(cursor);

This works well and sets the expected background for the paragraph. However, when I press enter on an empty block I noticed a weird behavior. Instead of adding a new paragraph after the existing one, the active block (the one where the cursor is set) resets its formatting. When the block is non-empty everything works as expected.
I want to leave the block format for the empty paragraph and add a new block by pressing the return key. What am I missing?

[Koru]

@SGaist thanks, I tried to find something but no luck.
However, I managed to find a workaround. I installed an event filter for the text widget that is listening for the return key and manually inserts a new block.
If someone is interested in the code:

    if (event->type() == QEvent::KeyPress && object == ui->textEdit)
    {
        QKeyEvent* key = static_cast<QKeyEvent*>(event);
        if (key->key() == Qt::Key_Return)
        {
            QTextCursor cursor = ui->textEdit->textCursor();
            cursor.insertBlock();
            ui->textEdit->setTextCursor(cursor);
            return true;
        }
        return false;
    }

[SGaist]

Hi,

If memory serves well, there was a report on the Qt bug tracker for something similar but when removing all blocks and starting to write again. You should check it.

[Koru]

@SGaist thanks, I tried to find something but no luck.
However, I managed to find a workaround. I installed an event filter for the text widget that is listening for the return key and manually inserts a new block.
If someone is interested in the code:

    if (event->type() == QEvent::KeyPress && object == ui->textEdit)
    {
        QKeyEvent* key = static_cast<QKeyEvent*>(event);
        if (key->key() == Qt::Key_Return)
        {
            QTextCursor cursor = ui->textEdit->textCursor();
            cursor.insertBlock();
            ui->textEdit->setTextCursor(cursor);
            return true;
        }
        return false;
    }