Qt Widget temporarily fullscreen - qt

Question

Consider a QWidget, normally a child in some Layout.
Supposed I want to make it fullScreen for a while, then have it return to it's old spot.
QWidget::setFullScreen() requires that the widget needs to be an independent window - any ideas how to work it out?

Answer 1

The simplest way I can see is to reparent to 0. Something like this:
#include <QApplication>
#include <QPushButton>
class MyButton : public QPushButton
{
public:
MyButton(QWidget* parent) : QPushButton(parent) {}
void mousePressEvent(QMouseEvent*) {
this->setParent(0);
this->showMaximized();
this->show();
}
};
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QWidget mainWidget;
MyButton button(&mainWidget);
mainWidget.show();
return a.exec();
}

Answer 2

I have modified the previous example. The previous example never goes back to normal screen.
Just copy paste the code and it will run.
#include <QApplication>
#include <QPushButton>
class MyButton : public QPushButton
{
public:
MyButton(QWidget* parent) : QPushButton(parent) {
m_pParent = parent;
maxMode = false;
}
QWidget * m_pParent;
bool maxMode;
Qt::WindowFlags m_enOrigWindowFlags;
QSize m_pSize;
void mousePressEvent(QMouseEvent*) {
if (maxMode== false)
{
m_enOrigWindowFlags = this->windowFlags();
m_pSize = this->size();
this->setParent(0);
this->setWindowFlags( Qt::FramelessWindowHint|Qt::WindowStaysOnTopHint);
this->showMaximized();
maxMode = true;
}
else
{
this->setParent(m_pParent);
this ->resize(m_pSize);
this->overrideWindowFlags(m_enOrigWindowFlags);
this->show();
maxMode = false;
}
}
};
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QWidget mainWidget;
MyButton button(&mainWidget);
mainWidget.show();
return a.exec();
}