Hello. I want to layer widgets in such a way that you can see through them and interact with all layers. The obvious thing seemed to be to subclass QStackedLayout and override the hiding behaviour. So I came up with this:

viewlayout.hpp:
Qt Code: 
  1. class ViewLayout : public QStackedLayout {
  2. 	Q_OBJECT
  3. public:
  4. 	ViewLayout (QWidget * =0);
  5.  
  6. 	int addWidget (QWidget *);
  7. 	int insertWidget (int, QWidget *);
  8.  
  9. public slots:
  10. 	void setCurrentIndex (int);
  11. 	void setCurrentItem (QWidget *);
  12.  
  13. private:
  14. 	//! Shows everything in the widget.
  15. 	void show_all ();
  16. };
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viewlayout.cpp:
Qt Code: 
  1. ViewLayout :: ViewLayout (QWidget * parent) : QStackedLayout(parent) {
  2. }
  3.  
  4. int ViewLayout :: addWidget (QWidget * w) {
  5. 	int r = QStackedLayout :: addWidget (w);
  6. 	show_all ();
  7. 	return r;
  8. }
  9.  
  10. int ViewLayout :: insertWidget (int i, QWidget * w) {
  11. 	int r = QStackedLayout :: insertWidget (i, w);
  12. 	show_all ();
  13. 	return r;
  14. }
  15.  
  16. void ViewLayout :: setCurrentIndex (int) {
  17. 	// Do nothing. There is no notion of "current" item.
  18. }
  19.  
  20. void ViewLayout :: setCurrentItem (QWidget *) {
  21. 	// Do nothing. There is no notion of "current" item.
  22. }
  23.  
  24. void ViewLayout :: show_all () {
  25. 	for (int i=0; i<count(); i++) {
  26. 		itemAt(i)->widget()->raise();
  27. 		itemAt(i)->widget()->show();
  28. 	}
  29. }
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The widget that uses it:
view.hpp:
Qt Code: 
  1. class View : public QWidget {
  2. 	Q_OBJECT
  3. public:
  4. 	View (QWidget * =0);
  5.  
  6. 	//! Remove the window from the view but do not destroy it.
  7. 	void removeWidget (QWidget *);
  8.  
  9. 	//! \see QStackedLayout
  10. 	int addWidget (QWidget *);
  11.  
  12. 	//! \see QStackedLayout
  13. 	int insertWidget (int, QWidget *);
  14.  
  15. 	// \see QStackedLayout
  16. 	QWidget * widget (int) const;
  17. };
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view.cpp:
Qt Code: 
  1. View :: View (QWidget * parent) : QWidget(parent) {
  2. 	ViewLayout * l = new ViewLayout ();
  3. 	setLayout(l);
  4. }
  5.  
  6. void View :: removeWidget (QWidget * w) {
  7. 	layout() -> removeWidget (w);
  8. }
  9.  
  10. int View :: addWidget (QWidget * w) {
  11. 	ViewLayout * l = dynamic_cast<ViewLayout *>(layout());
  12. 	return l -> addWidget (w);
  13. }
  14.  
  15. int View :: insertWidget (int i, QWidget * w) {
  16. 	ViewLayout * l = dynamic_cast<ViewLayout *>(layout());
  17. 	return l -> insertWidget (i, w);
  18. }
  19.  
  20. QWidget * View :: widget (int i) const {
  21. 	ViewLayout * l = dynamic_cast<ViewLayout *>(layout());
  22. 	return l -> widget (i);
  23. }
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And here's a demo window to put into such a stack.
bouncetest.hpp:
Qt Code: 
  1. class BounceTest : public QFrame {
  2. 	Q_OBJECT
  3. public:
  4. 	BounceTest (QWidget * =0);
  5.  
  6. private:
  7. 	QWidget * obj;
  8. 	int vx;
  9. 	int vy;
  10.  
  11. private slots:
  12. 	void timeOut();
  13. };
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bouncetest.cpp:
Qt Code: 
  1. #include <stdlib.h>
  2.  
  3. namespace {unsigned int count = 0;}
  4.  
  5. BounceTest :: BounceTest (QWidget * parent) : QFrame(parent) {
  6. 	setFrameStyle(QFrame::Panel|QFrame::Plain);
  7. 	setLineWidth(3);
  8. 	QString s = "%1 %1 %1 %1\n%1 %1 %1 %1\n%1 %1 %1 %1\n%1 %1 %1 %1\n";
  9. 	obj = new QPushButton (s.arg(count++),this);
  10. 	obj->move(rand()%500,rand()%400);
  11. 	vx = 11;
  12. 	vy = 7;
  13. 	QTimer::singleShot(200,this,SLOT(timeOut()));
  14. }
  15.  
  16. void BounceTest :: timeOut () {
  17. 	int X = obj->x();
  18. 	int Y = obj->y();
  19. 	int W = width();
  20. 	int H = height();
  21. 	int Wo= obj->width();
  22. 	int Ho= obj->height();
  23. 	if ((X+Wo)>W || X<0)
  24. 		vx = -vx;
  25. 	if ((Y+Ho)>H || Y<0)
  26. 		vy = -vy;
  27. 	obj->move (X+vx,Y+vy);
  28. 	QTimer::singleShot(150,this,SLOT(timeOut()));
  29. }
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And finally, main.cpp:
Qt Code: 
  1. View * bt = new View ();
  2. 		bt->addWidget (new BounceTest());
  3. 		bt->addWidget (new BounceTest());
  4. 		bt->addWidget (new BounceTest());
  5. 		bt->addWidget (new BounceTest());
  6. 		bt->addWidget (new BounceTest());
  7. 	bt->resize(800,600);
  8. 	bt->show ();
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At first glance, it seems okay except not all the Views have been resized.

Also, you can press the topmost button but none of the others. How do I rewrite BounceTest such that any click or mouse move not hitting any of its children wil propagate to the lower levels?

Thanks for reading this far.