[SOLVED] mainWidget()

I'd like to do this below but don't work....w is null (000000):

Code:

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MainForm* w;
w=(MainForm*) qApp->mainWidget()
cout << w;

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Why this?

So you never set main widget for your app before:)

Quote:

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Originally Posted by zlatko

So you never set main widget for your app before:)

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Or it's not type of MainWindow*..

Quote:

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Originally Posted by jpn

Or it's not type of MainWindow*..

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This would be true only in case of dynamic_cast<>.

the code above is in mywidget class;
I set mainWidget in main.cpp:

Code:

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int main( int argc, char ** argv )
{
    QApplication a( argc, argv );
 
    MainForm w;
	w.resize(600,500);
	a.setMainWidget(&w);
    w.show();
    a.connect( &a, SIGNAL( lastWindowClosed() ), &a, SLOT( quit() ) );
    return a.exec();
}

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Where do you invoke "qApp->mainWidget()"?

in mywidget.h (in constructor):

Code:

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MyWidget::MyWidget( QWidget *parent, const char *name)
        :  QGLWidget ( parent, name, shareWidget )
{	
	 setFormat(QGLFormat(DoubleBuffer | DepthBuffer));
	w=(MainForm*) qApp->mainWidget();
}

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Code:

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MainForm w; // <-- here you invoke qApp->mainWidget()
w.resize(600,500);
a.setMainWidget(&w); // <-- and here you set the main widget

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How do do you expect it to work?

Edit: You can use "this", instead of qApp->mainWidget().

this? In constructor widget? I don't understand; this below don't compile.

Code:

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w=(MainForm*) this->mainWidget();

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Do you say this?

Quote:

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Originally Posted by mickey

Do you say this?

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I meant:

Code:

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w = this;

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Edit: OK, I just noticed that you have MainForm and MyWidget. In this case you can probably use parent.

It compile but Bug error occurs....
Furthermore I must code this below.....and sender and receiver are the same and don't work connect....

Code:

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connect(this, SIGNAL(myUpdate()), w ,SLOT(updateWidgets()) );

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Quote:

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Originally Posted by mickey

It compile but Bug error occurs....
Furthermore I must code this below.....and sender and receiver are the same and don't work connect....

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Then try "w = parent" if the main window is the parent of your widget.

This don't work:

Quote:

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Originally Posted by jacek

Then try "w = parent" if the main window is the parent of your widget.

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( console says "parent" isn't the correct receiver() for my connect)
This works:

Code:

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w= (MainForm*)this->topLevelWidget();

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Thanks for help!