@BzhAx hi,

@BzhAx said in Save whole context:

I don't know if this is the best way to do it..

it works ? do you have errors ?

You can have your TabButtons in ListModel and use this method :
https://stackoverflow.com/questions/48730166/how-to-save-and-restore-the-content-of-a-listmodel?rq=1

OH Thx a lot that was it. Without the const, it works.
So my code went from

void AnotherClass::showInfo(MyClass const *item) { // Same stuff as above (2nd post) }

to

void AnotherClass::showInfo(MyClass *item) { // Same stuff as above (2nd post) }

Out of curiosity, I implemented a QQuickPaintedItem-based PathMask type. The result looks like this:

PathMask

The code is:
pathmask.h

#ifndef PATHMASK_H #define PATHMASK_H #include <QObject> #include <QQuickItem> #include <QQuickPaintedItem> #include <QPainter> #include <QPainterPath> class PathMask : public QQuickPaintedItem { Q_OBJECT public: explicit PathMask(QQuickItem *parent = Q_NULLPTR); ~PathMask(); virtual void paint(QPainter *painter); Q_INVOKABLE void beginPath(); Q_INVOKABLE void moveTo(qreal x, qreal y); Q_INVOKABLE void lineTo(qreal x, qreal y); Q_INVOKABLE void closePath(); private: QPainterPath *m_path{Q_NULLPTR}; }; #endif // PATHMASK_H

pathmask.cpp

#include "pathmask.h" #include <QPainterPath> #include <QtMath> PathMask::PathMask(QQuickItem *parent) : QQuickPaintedItem(parent) { } PathMask::~PathMask() { delete m_path; } void PathMask::paint(QPainter *painter) { if (m_path) { painter->setRenderHint(QPainter::Antialiasing); painter->setBrush( QBrush(QColor("black")) ); painter->drawPath( *m_path ); } } void PathMask::beginPath() { delete m_path; m_path = new QPainterPath; update(); } void PathMask::moveTo(qreal x, qreal y) { Q_ASSERT(m_path); m_path->moveTo(x,y); } void PathMask::lineTo(qreal x, qreal y) { Q_ASSERT(m_path); m_path->lineTo(x, y); } void PathMask::closePath() { Q_ASSERT(m_path); m_path->closeSubpath(); update(); }

main.qml

import QtQuick 2.5 import QtQuick.Controls 2.0 import QtQuick.Controls.Material 2.0 import QtGraphicalEffects 1.0 import io.qt.forum 1.0 ApplicationWindow { title: "PathMask Demo" visible: true width: 400 height: 400 color: "black" Image { id: src anchors.fill: parent visible: false source: "file:///home/patrick/Downloads/f22.jpg" } PathMask { id: mask anchors.fill: parent visible: false } Component.onCompleted: { mask.beginPath() mask.moveTo(360, 200); var Pi = 3.141592653589793238463; for (var i = 1; i < 5; ++i) { mask.lineTo(200 + 160 * Math.cos(0.8 * i * Pi), 200 + 160 * Math.sin(0.8 * i * Pi)); } mask.closePath(); } OpacityMask { anchors.fill: src source: src maskSource: mask } }

@8Observer8 said in QOpenGLFunctions glGetString(GL_EXTENSIONS) is null:

I have a same question. I try to show OpenGL version but I get empty string:

I solved the problem. I activated a second video card on my laptop from code in main.cpp:

#ifdef _WIN32 #include <windows.h> extern "C" __declspec(dllexport) DWORD NvOptimusEnablement = 0x00000001; extern "C" __declspec(dllexport) DWORD AmdPowerXpressRequestHighPerformance = 0x00000001; #endif #include "Widget.h" #include <QApplication> int main(int argc, char *argv[]) { QApplication a(argc, argv); Widget w; w.show(); return a.exec(); }

It works too (without QString::fromLatin1):

qDebug() << (const char*)glGetString(GL_VERSION);