How to show QGLWidget in full screen?

Question

I have a QGLWidget as part of the UI of my application. It is NOT a central widget, there are a lot of others widgets around it. I want to show it full screen on user clicks the button. Similar functionality like on youtube video flash player.

I have tried to use showFullScreen with no effect.

I have read how-to-fullscreen-a-qglwidget and fullscreen-widget, but they suggest using showFullScreen.

Qt documentation states that for using showFullScreen widget must be an independent window. So I assume there should be some trick for this.

score 2 · Accepted Answer · answered Nov 16 '11 at 09:37

The solution I found:

void MyApp::on_fullscreen_button_clicked() {
    QDialog *dlg = new QDialog(this);
    QHBoxLayout *dlg_layout = new QHBoxLayout(dlg);
    dlg_layout->setContentsMargins(0, 0, 0, 0);
    dlg_layout->addWidget(glwidget_);
    dlg->setLayout(dlg_layout);
    dlg->showFullScreen();

    bool r = connect(dlg, SIGNAL(rejected()), this, SLOT(showGlNormal()));
    assert(r);
    r = connect(dlg, SIGNAL(accepted()), this, SLOT(showGlNormal()));
    assert(r);
}

void MyApp::showGlNormal() {
    ui.glBox->layout()->addWidget(glwidget_);
}

score 0 · Answer 2 · answered Nov 04 '11 at 12:21

The showFullScreen function works only on windows. From the Qt documentation:

A window is a widget that isn't visually the child of any other widget and that usually has a frame and a window title.

A possible solution is the following:

When the user clicks the show full screen button

Create a new QGlWidget with no parent and set to it the contents of you QGlWidget
Use the showFullScreen function on it...

Maybe it is a better idea to subclass QGlWidget and pass in its constructor a pointer to another QGlWidget. The constructor should take the context of the provided widget and apply it to the new one.

On your subclass catch keyboard events. When the user press Esc emit a signal
In your base class catch this signal and connect it to a slot. In this slot hide the full screen QGlWidget and delete it.

How to show QGLWidget in full screen?

2 Answers2

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