Code editor display the line number in an area to the right

[Ramang]

I am just learning Qt. I want to show line number of QPlainTextEdit. I found this link http://doc.qt.io/qt-5/qtwidgets-widgets-codeeditor-example.html
and it worked. But now I want the editor displays the line numbers in an area to the RIGHTof the area for editing. I have been search google very much but i can't solve. How to solve? Thank you very much
[1]: http://i.stack.imgur.com/x4AKi.png

[Ginsengelf]

Hi, you can use the example and move the line number area to the right side. You just have to move some parameters in functions that define the position and size of the line number widget, e.g. CodeEditor::updateLineNumberAreaWidth()

Best regards,

Ginsengelf

[Ramang]

Thank for your reply.
I changed
CodeEditor::updateLineNumberAreaWidth(){
setViewportMargins(lineNumberAreaWidth(), 0, 0, 0);
}
but I cant't solve. I don't know which parameters have to move. Thank!