paint central widget of a QMainWindow???

[Shuchi Agrawal]

Below are the codes. so can any1 check them n tel tht is it the right way to paint(draw line n a point) on the central widget on a menu click event?[i think its not the right way, though its working]

824

825

826

[wysota]

You should set an external central widget and paint on that widget and not on the main window itself.

By the way, how is this question related to Qt Designer?

[Shuchi Agrawal]

You should set an external central widget and paint on that widget and not on the main window itself.

so for this do i need QStackedWidget ? or simply a obj. of QWidget n set it as central widget???


By the way, how is this question related to Qt Designer?

sorry!! fm next time i wil take care..

[jpn]

so for this do i need QStackedWidget ? or simply a obj. of QWidget n set it as central widget???
The central widget can be anything inheriting from QWidget, but I think Qt Designer restricts it to be a QWidget. Just create any custom widget, reimplement the paintEvent(), add corresponding widget in the Designer and promote it (http://doc.trolltech.com/4.2/designer-using-custom-widgets.html#promoting-widgets).

As I have said previously:

Override QWidget::paintEvent() for the widget you want to paint on and use QPainter to draw the line. For example, if you want to paint on the central widget in a main window, you must reimplement the paintEvent() for the central widget, not for the main window.
So, in another words.
WRONG: "void MyMainWindow::paintEvent(QPaintEvent* event)"
CORRECT: "void MyCentralWidget::paintEvent(QPaintEvent* event)"