Subclass a widget and augment its layout?

[Jugdish]

What's the best way to subclass an existing composite QWidget and make changes to its layout (for example, add an additional widget to it?)

Specifically, what I'm attempting to do is make my own subclass of QTreeView that has a page navigation widget at the bottom. I have tried this:

class MyTree : public QTreeView
{
public:
    MyTree(QWidget *parent = 0);
private:
    PageNavigatorWidget *pageNavigator;
}
 
MyTree::MyTree(QWidget *parent) : QTreeView(parent)
{
    pageNavigator = new PageNavigatorWidget(this);
 
    QVBoxLayout layout;
    layout.addWidget(this);
    layout.addWidget(pageNavigator);
    this->setLayout(layout);
}

class MyTree : public QTreeView
{
public:
    MyTree(QWidget *parent = 0);
private:
    PageNavigatorWidget *pageNavigator;
}

MyTree::MyTree(QWidget *parent) : QTreeView(parent)
{
    pageNavigator = new PageNavigatorWidget(this);

    QVBoxLayout layout;
    layout.addWidget(this);
    layout.addWidget(pageNavigator);
    this->setLayout(layout);
}

To copy to clipboard, switch view to plain text mode 

But this doesn't work.

The reason I'm trying to subclass QTreeView rather than just subclass QWidget and have a QTreeView as a data member is that I want my class to have all the same methods as QTreeView, so that it can be treated as one.

[spirit]

in this code

...
QVBoxLayout layout;
layout.addWidget(this);
layout.addWidget(pageNavigator);
this->setLayout(layout);
...

...
QVBoxLayout layout;
layout.addWidget(this);
layout.addWidget(pageNavigator);
this->setLayout(layout);
...

To copy to clipboard, switch view to plain text mode 

layout will be destroyed immediately after reaching "out of scope".
create a layout in the heap.

btw, I would not inherit QTreeView, I would inherit QWidget, then add a layout and put into it QTreeView and Navigator.

[Jugdish]

btw, I would not inherit QTreeView, I would inherit QWidget, then add a layout and put into it QTreeView and Navigator.

Yes, but then my widget could not be treated as a QTreeView -- i.e. it wouldn't inherit all of its methods, I would have to go through its data member for everything.

[spirit]

I don't understand you try to inherit QTreeView just for adding Navigator?