How to overlay transparent areas on a video widget

Quiccz

base on https://forum.qt.io/topic/151408/calling-the-hide-function-for-a-widget-only-hides-the-visual-representation-not-the-widget-itself?_=1698373724873

I want to overlay a transparent areas on a video widget, here is the layout.

Here is what i want：

But i find i cant do it unless use those layout：

Is there any method to achieve my goal with sibling layouts?

jsulm

@Quiccz You should post your relevant code.
"But i find i cant do it unless use those layout" - in what way it doesn't work?

Quiccz

@jsulm not work when they have same parent

#pragma once
#include <QWidget>
#include <QQuickWidget>
#include "VideoWidget.h"
#include "OpenGLWidget.h"
class MyWidget: public QWidget
{
public:
    MyWidget(QWidget *parent);
    void SetSubWidget();
};

#include "Mywidget.h"
MyWidget::MyWidget(QWidget* parent)
: QWidget(parent)
{
    this->setGeometry(0,0, 1920, 1080);
    this->setWindowFlags(Qt::FramelessWindowHint);
    QPalette palette;
    palette.setColor(QPalette::Window, Qt::GlobalColor::black);
    this->setAutoFillBackground(true);
    this->setPalette(palette);
    this->show();
}

void MyWidget::SetSubWidget()
{
    VideoWidget* videoWidget = new VideoWidget(this);
    videoWidget->setGeometry(0, 0, 512, 384);
    QPalette palette1;
    palette1.setColor(QPalette::Window, Qt::GlobalColor::red);
    videoWidget->setAutoFillBackground(true);
    videoWidget->setPalette(palette1);
    videoWidget->show();


    // not work
    QWidget* transparentWidget1 = new QWidget(this);
    transparentWidget1->setGeometry(0, 0, 100, 100);
    transparentWidget1->show();
    
    // work
    QWidget* transparentWidget2 = new QWidget(nullptr);
    transparentWidget2->setAttribute(Qt::WA_TranslucentBackground, true);
    transparentWidget2->setWindowFlags(Qt::FramelessWindowHint);
    transparentWidget2->setGeometry(100, 100, 100, 100);
    transparentWidget2->show();
    
    // work
    QWidget* transparentWidget3 = new QWidget(videoWidget);
    transparentWidget3->setGeometry(200, 200, 100, 100);
    transparentWidget3->show();
}

#pragma once
#include <QWidget>
#include <mpv/client.h>
class VideoWidget : public QWidget
{
Q_OBJECT
public:
	VideoWidget(QWidget* parent);
private:
	mpv_handle* mpv;
};

#include "VideoWidget.h"

VideoWidget::VideoWidget(QWidget* parent)
	:QWidget(parent)
{
    mpv = mpv_create();
    if (!mpv)
    {
        qDebug() << "could not create mpv context";
        throw std::runtime_error("could not create mpv context");
    }
    int64_t  wid = this->winId();
    mpv_set_property(mpv, "wid", MPV_FORMAT_INT64, &wid);

    qDebug() << "wid is " << wid;
    mpv_set_property_string(mpv, "hwdec", "auto");
    mpv_set_property_string(mpv, "loop-file", "inf");
    if (mpv_initialize(mpv) < 0)
    {
        qDebug() << "could not initialize mpv context";
        throw std::runtime_error("could not initialize mpv context");
    }
    const char* args[] = { "loadfile", "4k_60.mp4", NULL };
    mpv_command_async(mpv, 0, args);
}

#include <QWidget>
#include "Mywidget.h"
#include <QApplication>
#include <QTimer>


int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    MyWidget *mywidget = new MyWidget(nullptr);
    QTimer::singleShot(2000, mywidget, [&]() {
        mywidget->SetSubWidget();
        });
    return app.exec();;
}