Displaying a QWidget with Transparent Background over a QMediaPlayer

[tmason202]

Hello,

I am trying to get a transparent QWidget to display over a QMediaPlayer object.

The goal is to have a semi-transparent QWidget that displays playback, volume, etc. controls over a QMediaPlayer widget.

As it stands now the control displays but there is no transparency over the QMediaPlayer object. What do I need to do to make that happen?

Thank you.

Here is the following code for the QWidget I am trying to make semi-transparent:

class QTSemiTransparentWidget : public QWidget {

	Q_OBJECT

public:

	explicit QTSemiTransparentWidget(QWidget* parent = NULL);
	~QTSemiTransparentWidget();

public slots:

signals:

protected:

private:

private slots :

	virtual void prepareUI();

};

And here is the implementation:

#include "QTSemiTransparentWidget.h"

QTSemiTransparentWidget::QTSemiTransparentWidget(QWidget* parent) : QWidget(parent) {

	prepareUI();

}

QTSemiTransparentWidget::~QTSemiTransparentWidget() {



}

void QTSemiTransparentWidget::prepareUI() {

	this->setWindowFlags(Qt::Window | Qt::FramelessWindowHint);
	this->setAttribute(Qt::WA_NoSystemBackground);
	this->setAttribute(Qt::WA_TranslucentBackground, true);
	this->setAttribute(Qt::WA_PaintOnScreen);
	this->setAttribute(Qt::WA_TransparentForMouseEvents);
	
	this->setWindowOpacity(0.5);

}

[Ruslan F.]

@tmason202 watch at QGraphicsOpacityEffect or reimplement paintEvent and use QPainter::setOpacity

[tmason202]

Hello!

This is what I tried:

this->setWindowFlags(Qt::Window | Qt::FramelessWindowHint);
	
	transparencyEffect = new QGraphicsOpacityEffect(this);
	transparencyEffect->setOpacity(0.5);

	this->setGraphicsEffect(transparencyEffect);

In the "prepareUI" function. But the transparency is still not applied to the class object.

What am I doing wrong?

Thank you.

[tmason202]

@Ruslan-F.

I also tried this:

void QTSemiTransparentWidget::paintEvent(QPaintEvent* event) {

	QPainter mainPainter(this);
	mainPainter.setOpacity(0.5);

}

But still no transparency.

[tmason202]

Hello,

So, I figured this out; what I ended up doing was creating a QGraphicsView and then have the QMediaPlayer display it's output to a QGraphicsVideoItem which was then attached to the scene.

I ended up getting transparency as I needed but it cost me a little bit of performance. I will be researching what I need to do to bump up performance.

Thank you for the help.

[Ruslan F.]

@tmason202 , try this one

void QTSemiTransparentWidget::paintEvent(QPaintEvent* event) {

    QPainter painter(this);
    painter.setOpacity(0.5);
    QStyleOption opt;
    opt.initFrom(this);
    QStyle* pStyle =  QApplication::style();
    pStyle->drawPrimitive(QStyle::PE_Widget, &opt, &painter, this);

}

at least you should draw something in paint event not to just set an opacity.