QGraphicsView doesn't always update - c++

Hi I've got a GridLayout which has 64 GraphicsViews on it (I know it's alot but it's the only way i could think of doing this at this point in time).
Now i'm currently just drawing a random line on each of these graphics views on a timer tick. This works but only for the 8 of the Graphics,
Create Graphics Views
void Simulation::createGraphicsViews(){
for(int i = 0; i < 64; i++){
for(int j = 0; j < 8; j++){
graphicsScene[i] = new QGraphicsScene();
graphicsView[i] = new QGraphicsView(graphicsScene[i]);
simui->gridLayout->addWidget(graphicsView[i], i/8, j);
}
}
}
Random Line in each graphics view
for(int x = 0; x < 64; x++){
x1 = qrand()%(50+1) - 1;
y1 = qrand()%(50+1)-1;
x2 = qrand()%(50+1)-1;
y2 = qrand()%(50+1)-1;
graphicsScene[x]->addLine(x1,y1,x2,y2);
qDebug() << "adding line to" << x << "at" << x1 <<","<<y1<<","<<x2<<","<<y2;
}
show updated graphics view
for(int x = 0; x < 64; x++){
graphicsView[x]->show();
qDebug()<<"showing" << x;
}
I've looked through it for the last 2 hours trying multiple approaches none of which have fixed this problem, I'm assuming it's probably something stupid but I just can't figure it out
Any help is greatly appreciated
Thank you
Also if i try to update any of the Graphics Views other than the ones which work they still don't update.
https://gist.github.com/gazza126/f43d5b0377649782a35d -- Full Code (that does anything)


The below works. Make sure that you enable C++11 in your .pro file: add CONFIG += c++11 to the project file.
#include <QApplication>
#include <QGraphicsScene>
#include <QGraphicsView>
#include <QGraphicsLineItem>
#include <QGridLayout>
#include <QTime>
#include <QTimer>
#include <array>
class View : public QGraphicsView
{
public:
View(QWidget *parent = 0) : QGraphicsView(parent) {
setRenderHint(QPainter::Antialiasing);
}
void resizeEvent(QResizeEvent *) {
fitInView(-1, -1, 2, 2, Qt::KeepAspectRatio);
}
};
template <typename Container>
void updateScenes(Container & views)
{
auto angle = 360.0/1000.0 * (QTime::currentTime().msecsSinceStartOfDay() % 1000);
for (auto & view : views) {
auto scene = view.scene();
scene->clear();
auto * line = scene->addLine(-1, 0, 1, 0, QPen(Qt::darkBlue, 0.1));
line->setRotation(angle);
}
}
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QGraphicsScene s;
QTimer timer;
QWidget window;
QGridLayout layout(&window);
std::array<View, 64> views;
int i = 0;
for (auto & view : views) {
view.setScene(new QGraphicsScene(&view));
layout.addWidget(&view, i/8, i%8);
++ i;
}
QObject::connect(&timer, &QTimer::timeout, [&views]{ updateScenes(views); });
timer.start(50);
window.show();
return a.exec();
}

Related

QT real time graph has flickering problem

i am using openglseris (line) to display incoming data.
i edited the opengl series example given by the qt as per my needs.
How can I update the openglseris without flickering the display (smooth data update)? Because so far I have managed to display incoming data but the display is flickering every time it updates the value.
//***********datasource.h**********//
#ifndef DATASOURCE_H
#define DATASOURCE_H
#include <QtCore/QObject>
#include <QtCharts/QXYSeries>
#include <QtWidgets/QLabel>
#include <QtCore/QElapsedTimer>
#include <QtCore/QTimer>
QT_CHARTS_USE_NAMESPACE
class DataSource : public QObject
{
Q_OBJECT
public:
explicit DataSource(QObject *parent = 0);
void startUpdates(const QList<QXYSeries *> &seriesList, QLabel *fpsLabel);
public slots:
void generateData(int seriesCount, int rowCount, int colCount);
void update(QAbstractSeries *series, int seriesIndex);
void handleSceneChanged();
void updateAllSeries();
private:
QVector<QVector<QVector<QPointF> > > m_data;
int m_index;
QList<QXYSeries *> m_seriesList;
QLabel *m_fpsLabel;
QElapsedTimer m_fpsTimer;
QTimer m_dataUpdater;
};
#endif // DATASOURCE_H
//*************datasource.cpp*******************//
#include "datasource.h"
#include <QtCore/QtMath>
#include<QDebug>
QT_CHARTS_USE_NAMESPACE
int shift=0;
int c[2048]={50,149,143,148,151,151,150,150,149,149,152,148,148,147,146,152,149,150,147,151,150,149,148,149,152,150,148,150,147,149,149,149,149,151,152,151,149,148,151,147,151,147,150,147,151,150,154,150,151,151,151,151,154,154,150,152,148,151,150,148,150,151,149,151,150,156,155,159,158,154,154,151,152,154,155,150,154,149,150,149,154,152,155,150,154,152,155,150,149,154,150,156,154,150,151,150,151,155,151,157,151,152,150,151,148,150,150,157,150,156,150,147,155,150,155,155,152,150,154,151,152,151,150,152,151,157,151,152,150,149,154,152,154,154,151,151,150,150,157,154,154,155,150,155,157,150,152,151,156,151,150,152,152,154,155,150,155,150,150,156,154,149,152,154,154,154,151,150,156,148,150,157,150,154,150,154,154,154,156,150,150,155,156,155,156,154,154,150,154,155,158,151,154,154,150,150,156,151,148,150,151,150,154,150,156,150,154,151,154,150,150,157,154,155,154,157,155,156,152,155,155,157,154,159,156,156,154,155,154,156,156,151,152,150,150,156,154,152,159,150,150,158,150,155,156,155,156,155,155,154,154,154,155,155,155,154,149,156,150,156,150,155,155,156,157,150,157,157,151,157,157,158,152,150,156,155,154,154,155,156,154,154,156,150,157,154,150,157,157,152,155,155,154,154,155,154,156,156,150,155,154,157,155,156,156,150,155,157,154,157,154,161,155,155,155,158,156,156,150,154,155,155,157,157,157,152,155,156,159,155,154,154,155,157,151,159,154,157,154,157,158,154,155,155,155,159,155,156,156,157,154,158,155,160,157,157,158,158,155,158,155,155,155,150,159,156,157,158,156,157,156,154,156,158,157,156,159,156,157,158,155,157,154,157,155,157,156,157,157,159,156,157,156,162,158,155,159,156,156,159,155,157,155,158,155,162,156,157,154,163,157,158,156,161,157,156,157,156,154,158,159,160,156,159,159,157,159,155,162,159,156,155,157,154,155,156,157,156,157,155,159,157,160,150,157,158,152,157,155,154,158,155,158,158,158,155,158,156,156,157,159,156,159,156,157,157,156,156,158,155,155,160,150,158,154,159,157,154,157,155,157,159,154,157,150,155,155,155,152,155,159,158,155,155,158,156,154,154,155,157,157,154,158,155,159,155,160,156,159,157,155,150,160,156,150,154,157,150,158,155,150,154,157,155,158,160,158,154,159,157,157,157,155,156,159,154,157,160,154,155,157,156,150,156,157,156,158,150,156,156,154,157,156,159,158,158,156,155,156,155,156,155,160,155,156,158,157,154,150,158,157,155,157,155,158,156,159,156,157,159,157,156,157,159,154,160,158,158,160,156,155,154,161,159,160,157,156,154,155,154,156,159,158,155,154,150,158,162,156,156,155,154,160,159,162,160,159,158,161,150,159,156,155,160,158,159,158,155,161,155,157,154,154,156,150,156,163,154,149,160,160,155,159,155,156,155,150,157,158,157,157,154,157,155,158,155,156,156,156,155,150,156,157,155,155,155,157,157,157,157,155,157,157,155,159,158,150,156,157,155,158,156,158,155,154,157,157,156,155,156,155,160,157,159,150,158,155,162,157,159,159,155,156,154,155,158,157,161,156,158,157,155,156,158,158,157,156,158,157,154,155,150,158,156,160,160,160,156,157,154,155,150,159,156,152,156,160,158,157,154,158,158,158,155,156,160,160,155,156,157,158,157,159,157,161,155,152,157,158,154,157,160,156,158,155,158,158,156,155,155,150,154,156,155,158,155,155,157,156,158,154,155,158,162,156,159,158,157,159,154,155,160,157,158,154,155,157,158,159,158,158,157,155,156,159,159,155,155,158,155,155,158,155,160,161,157,159,159,156,155,150,156,155,150,156,157,155,155,158,155,156,159,156,158,162,155,160,154,158,158,158,157,160,156,155,157,152,156,160,158,160,155,158,155,155,157,155,156,159,154,155,157,157,160,159,156,157,162,158,156,157,154,160,157,156,159,159,156,155,159,158,157,156,162,160,158,157,162,157,158,157,157,163,156,156,160,161,154,155,156,159,157,156,158,159,157,155,157,162,157,160,158,159,155,156,155,160,158,157,155,160,159,156,157,157,160,155,157,158,157,157,156,160,155,157,156,157,159,159,160,159,160,157,162,157,157,154,157,157,159,161,155,160,155,155,157,160,156,158,158,161,159,156,156,158,160,160,158,155,157,161,154,160,156,155,156,160,158,156,157,150,155,154,160,157,154,155,155,160,155,154,158,157,155,160,155,156,160,154,157,154,158,157,159,157,155,152,155,156,156,155,155,155,155,156,156,159,159,157,160,155,158,158,157,157,150,155,156,155,156,156,155,159,150,161,155,159,156,156,158,161,155,157,156,159,155,150,155,156,161,155,156,156,154,157,155,157,158,156,158,160,155,161,158,156,159,157,156,159,155,158,162,155,160,158,161,160,156,158,164,156,158,159,158,154,161,158,157,157,156,156,160,157,155,156,160,160,155,158,156,162,160,160,158,157,160,163,156,154,154,162,156,157,155,160,150,158,155,156,154,157,159,160,158,157,162,154,158,163,158,154,158,154,156,155,158,156,159,158,156,156,159,154,159,154,159,156,157,157,160,159,159,156,150,159,158,156,156,156,158,155,158,156,155,156,157,158,156,156,159,157,157,156,156,159,157,160,159,161,159,158,158,160,157,158,156,156,160,160,158,157,157,158,162,150,156,158,158,163,159,158,154,156,159,159,159,157,158,155,161,155,159,155,160,157,156,161,158,157,156,157,158,155,160,158,160,156,157,159,160,156,156,158,156,156,156,155,157,156,156,160,157,154,159,160,157,158,162,159,158,161,158,156,160,156,159,162,162,157,158,160,159,158,160,160,157,156,159,158,160,157,161,158,158,154,160,160,161,154,161,159,156,158,157,160,159,161,157,157,162,156,157,159,152,161,157,158,158,157,158,157,158,158,157,159,159,159,150,157,159,158,151,158,156,160,158,158,157,156,158,158,156,156,158,160,155,159,156,161,156,163,154,161,159,157,159,161,158,157,155,159,156,158,155,161,158,156,161,155,159,158,159,155,162,154,162,161,157,159,159,156,160,157,159,160,160,159,156,156,156,157,157,163,159,161,156,158,156,159,156,157,158,156,160,163,163,156,160,159,157,156,160,160,155,157,155,160,157,160,160,157,158,159,157,159,160,161,160,159,156,158,157,157,156,160,156,162,159,157,154,156,155,162,159,159,161,157,162,159,156,156,156,162,158,161,158,167,159,159,156,158,156,159,157,154,159,160,159,155,163,158,158,162,156,162,158,158,156,161,159,155,160,155,159,150,161,155,156,157,157,155,157,155,163,155,158,157,155,157,161,154,154,155,156,157,159,156,156,159,158,158,158,161,159,156,158,158,158,160,160,162,158,159,156,161,154,154,158,157,161,159,157,159,154,159,161,159,159,160,159,162,160,158,158,157,160,159,161,161,157,158,157,158,162,160,161,159,161,159,162,159,157,161,160,158,160,160,156,157,157,159,159,159,161,158,160,155,157,162,159,162,161,159,161,158,159,162,155,159,161,155,160,157,156,157,160,154,157,159,157,158,160,159,160,157,156,156,158,157,158,154,161,159,154,158,159,160,160,159,162,159,161,158,161,158,156,160,160,158,156,159,158,155,155,156,160,159,162,158,160,159,159,159,156,156,156,164,155,158,157,160,157,160,158,160,158,158,159,152,159,158,157,162,160,160,160,159,155,158,154,159,161,157,160,158,157,154,160,155,158,160,152,156,150,158,157,159,158,162,158,157,157,156,160,159,158,159,155,156,160,154,158,155,156,152,156,156,156,156,154,158,156,157,155,154,156,156,157,156,158,157,156,159,161,152,156,155,152,156,156,155,158,159,157,156,157,156,158,158,155,152,161,159,155,156,157,152,156,158,158,150,155,152,158,159,158,155,160,150,154,156,158,155,157,160,156,157,155,155,157,159,158,156,158,158,156,159,156,157,150,155,158,158,157,158,159,158,150,160,156,157,158,155,154,157,156,156,160,157,161,157,158,158,158,150,150,154,150,150,150,157,157,150,158,155,159,158,158,150,158,159,154,154,157,154,155,157,155,154,155,157,154,157,156,157,158,160,155,159,155,157,160,150,152,156,156,156,154,157,156,154,156,159,154,155,150,150,158,158,156,160,158,152,150,157,154,159,150,150,158,155,154,157,155,154,150,152,156,156,154,159,152,156,156,150,156,156,157,154,152,154,151,155,155,152,158,157,161,152,152,157,154,158,150,156,158,150,157,154,156,154,155,158,156,154,150,154,158,150,159,155,151,152,155,154,154,154,154,152,150,154,154,154,152,150,150,156,150,157,150,151,151,151,155,150,150,158,150,152,155,155,152,150,156,151,152,150,151,158,150,152,152,158,148,154,151,152,154,155,150,154,154,154,155,155,150,150,156,151,155,151,151,151,152,152,150,151,151,151,151,150,156,152,159,148,156,154,150,149,156,152,154,155,150,152,155,151,155,149,150,150,151,155,149,155,150,152,152,149,150,154,151,149,156,154,149,154,151,147,149,150,149,151,154,149,155,151,149,148,150,155,150,149,149,152,148,154,150,149,150,149,151,154,149,152,154,150,150,151,152,155,150,150,151,149,148,152,149};
int b[2048]={150,149,143,148,151,151,150,150,149,149,152,148,148,147,146,152,149,150,147,151,150,149,148,149,152,150,148,150,147,149,149,149,149,151,152,151,149,148,151,147,151,147,150,147,151,153,154,153,151,151,151,151,154,154,153,152,148,151,150,148,153,151,149,151,150,156,155,159,158,154,154,151,152,154,155,150,154,149,153,149,154,152,155,150,154,152,155,150,149,154,150,156,154,153,151,153,151,155,151,157,151,152,153,151,148,153,150,157,150,156,153,147,155,150,155,155,152,153,154,151,152,151,153,152,151,157,151,152,153,149,154,152,154,154,151,151,153,153,157,154,154,155,153,155,157,153,152,151,156,151,153,152,152,154,155,153,155,150,150,156,154,149,152,154,154,154,151,150,156,148,150,157,153,154,153,154,154,154,156,150,150,155,156,155,156,154,154,153,154,155,158,151,154,154,153,153,156,151,148,153,151,153,154,153,156,153,154,151,154,153,153,157,154,155,154,157,155,156,152,155,155,157,154,159,156,156,154,155,154,156,156,151,152,153,153,156,154,152,159,150,153,158,153,155,156,155,156,155,155,154,154,154,155,155,155,154,149,156,153,156,153,155,155,156,157,150,157,157,151,157,157,158,152,153,156,155,154,154,155,156,154,154,156,153,157,154,150,157,157,152,155,155,154,154,155,154,156,156,153,155,154,157,155,156,156,153,155,157,154,157,154,161,155,155,155,158,156,156,153,154,155,155,157,157,157,152,155,156,159,155,154,154,155,157,151,159,154,157,154,157,158,154,155,155,155,159,155,156,156,157,154,158,155,160,157,157,158,158,155,158,155,155,155,153,159,156,157,158,156,157,156,154,156,158,157,156,159,156,157,158,155,157,154,157,155,157,156,157,157,159,156,157,156,162,158,155,159,156,156,159,155,157,155,158,155,162,156,157,154,163,157,158,156,161,157,156,157,156,154,158,159,160,156,159,159,157,159,155,162,159,156,155,157,154,155,156,157,156,157,155,159,157,160,153,157,158,152,157,155,154,158,155,158,158,158,155,158,156,156,157,159,156,159,156,157,157,156,156,158,155,155,160,153,158,154,159,157,154,157,155,157,159,154,157,153,155,155,155,152,155,159,158,155,155,158,156,154,154,155,157,157,154,158,155,159,155,160,156,159,157,155,153,160,156,150,154,157,153,158,155,153,154,157,155,158,160,158,154,159,157,157,157,155,156,159,154,157,160,154,155,157,156,153,156,157,156,158,153,156,156,154,157,156,159,158,158,156,155,156,155,156,155,160,155,156,158,157,154,153,158,157,155,157,155,158,156,159,156,157,159,157,156,157,159,154,160,158,158,160,156,155,154,161,159,160,157,156,154,155,154,156,159,158,155,154,153,158,162,156,156,155,154,160,159,162,160,159,158,161,153,159,156,155,160,158,159,158,155,161,155,157,154,154,156,153,156,163,154,149,160,160,155,159,155,156,155,153,157,158,157,157,154,157,155,158,155,156,156,156,155,153,156,157,155,155,155,157,157,157,157,155,157,157,155,159,158,153,156,157,155,158,156,158,155,154,157,157,156,155,156,155,160,157,159,153,158,155,162,157,159,159,155,156,154,155,158,157,161,156,158,157,155,156,158,158,157,156,158,157,154,155,153,158,156,160,160,160,156,157,154,155,153,159,156,152,156,160,158,157,154,158,158,158,155,156,160,160,155,156,157,158,157,159,157,161,155,152,157,158,154,157,160,156,158,155,158,158,156,155,155,153,154,156,155,158,155,155,157,156,158,154,155,158,162,156,159,158,157,159,154,155,160,157,158,154,155,157,158,159,158,158,157,155,156,159,159,155,155,158,155,155,158,155,160,161,157,159,159,156,155,153,156,155,153,156,157,155,155,158,155,156,159,156,158,162,155,160,154,158,158,158,157,160,156,155,157,152,156,160,158,160,155,158,155,155,157,155,156,159,154,155,157,157,160,159,156,157,162,158,156,157,154,160,157,156,159,159,156,155,159,158,157,156,162,160,158,157,162,157,158,157,157,163,156,156,160,161,154,155,156,159,157,156,158,159,157,155,157,162,157,160,158,159,155,156,155,160,158,157,155,160,159,156,157,157,160,155,157,158,157,157,156,160,155,157,156,157,159,159,160,159,160,157,162,157,157,154,157,157,159,161,155,160,155,155,157,160,156,158,158,161,159,156,156,158,160,160,158,155,157,161,154,160,156,155,156,160,158,156,157,153,155,154,160,157,154,155,155,160,155,154,158,157,155,160,155,156,160,154,157,154,158,157,159,157,155,152,155,156,156,155,155,155,155,156,156,159,159,157,160,155,158,158,157,157,153,155,156,155,156,156,155,159,153,161,155,159,156,156,158,161,155,157,156,159,155,153,155,156,161,155,156,156,154,157,155,157,158,156,158,160,155,161,158,156,159,157,156,159,155,158,162,155,160,158,161,160,156,158,164,156,158,159,158,154,161,158,157,157,156,156,160,157,155,156,160,160,155,158,156,162,160,160,158,157,160,163,156,154,154,162,156,157,155,160,153,158,155,156,154,157,159,160,158,157,162,154,158,163,158,154,158,154,156,155,158,156,159,158,156,156,159,154,159,154,159,156,157,157,160,159,159,156,153,159,158,156,156,156,158,155,158,156,155,156,157,158,156,156,159,157,157,156,156,159,157,160,159,161,159,158,158,160,157,158,156,156,160,160,158,157,157,158,162,153,156,158,158,163,159,158,154,156,159,159,159,157,158,155,161,155,159,155,160,157,156,161,158,157,156,157,158,155,160,158,160,156,157,159,160,156,156,158,156,156,156,155,157,156,156,160,157,154,159,160,157,158,162,159,158,161,158,156,160,156,159,162,162,157,158,160,159,158,160,160,157,156,159,158,160,157,161,158,158,154,160,160,161,154,161,159,156,158,157,160,159,161,157,157,162,156,157,159,152,161,157,158,158,157,158,157,158,158,157,159,159,159,153,157,159,158,151,158,156,160,158,158,157,156,158,158,156,156,158,160,155,159,156,161,156,163,154,161,159,157,159,161,158,157,155,159,156,158,155,161,158,156,161,155,159,158,159,155,162,154,162,161,157,159,159,156,160,157,159,160,160,159,156,156,156,157,157,163,159,161,156,158,156,159,156,157,158,156,160,163,163,156,160,159,157,156,160,160,155,157,155,160,157,160,160,157,158,159,157,159,160,161,160,159,156,158,157,157,156,160,156,162,159,157,154,156,155,162,159,159,161,157,162,159,156,156,156,162,158,161,158,167,159,159,156,158,156,159,157,154,159,160,159,155,163,158,158,162,156,162,158,158,156,161,159,155,160,155,159,153,161,155,156,157,157,155,157,155,163,155,158,157,155,157,161,154,154,155,156,157,159,156,156,159,158,158,158,161,159,156,158,158,158,160,160,162,158,159,156,161,154,154,158,157,161,159,157,159,154,159,161,159,159,160,159,162,160,158,158,157,160,159,161,161,157,158,157,158,162,160,161,159,161,159,162,159,157,161,160,158,160,160,156,157,157,159,159,159,161,158,160,155,157,162,159,162,161,159,161,158,159,162,155,159,161,155,160,157,156,157,160,154,157,159,157,158,160,159,160,157,156,156,158,157,158,154,161,159,154,158,159,160,160,159,162,159,161,158,161,158,156,160,160,158,156,159,158,155,155,156,160,159,162,158,160,159,159,159,156,156,156,164,155,158,157,160,157,160,158,160,158,158,159,152,159,158,157,162,160,160,160,159,155,158,154,159,161,157,160,158,157,154,160,155,158,160,152,156,153,158,157,159,158,162,158,157,157,156,160,159,158,159,155,156,160,154,158,155,156,152,156,156,156,156,154,158,156,157,155,154,156,156,157,156,158,157,156,159,161,152,156,155,152,156,156,155,158,159,157,156,157,156,158,158,155,152,161,159,155,156,157,152,156,158,158,150,155,152,158,159,158,155,160,150,154,156,158,155,157,160,156,157,155,155,157,159,158,156,158,158,156,159,156,157,153,155,158,158,157,158,159,158,153,160,156,157,158,155,154,157,156,156,160,157,161,157,158,158,158,153,153,154,153,153,153,157,157,150,158,155,159,158,158,153,158,159,154,154,157,154,155,157,155,154,155,157,154,157,156,157,158,160,155,159,155,157,160,153,152,156,156,156,154,157,156,154,156,159,154,155,153,153,158,158,156,160,158,152,153,157,154,159,153,153,158,155,154,157,155,154,153,152,156,156,154,159,152,156,156,153,156,156,157,154,152,154,151,155,155,152,158,157,161,152,152,157,154,158,153,156,158,153,157,154,156,154,155,158,156,154,153,154,158,153,159,155,151,152,155,154,154,154,154,152,153,154,154,154,152,153,153,156,153,157,153,151,151,151,155,153,153,158,153,152,155,155,152,153,156,151,152,153,151,158,153,152,152,158,148,154,151,152,154,155,153,154,154,154,155,155,153,153,156,151,155,151,151,151,152,152,150,151,151,151,151,150,156,152,159,148,156,154,150,149,156,152,154,155,153,152,155,151,155,149,153,150,151,155,149,155,153,152,152,149,153,154,151,149,156,154,149,154,151,147,149,153,149,151,154,149,155,151,149,148,150,155,150,149,149,152,148,154,153,149,150,149,151,154,149,152,154,153,150,151,152,155,153,150,151,149,148,152,149 };
DataSource::DataSource(QObject *parent) :
QObject(parent),
m_index(-1)
{
generateData(0, 0, 0);
}
void DataSource::update(QAbstractSeries *series, int seriesIndex)
{
if (series) {
QXYSeries *xySeries = static_cast<QXYSeries *>(series);
const QVector<QVector<QPointF> > &seriesData = m_data.at(seriesIndex);
if (seriesIndex == 0)
m_index++;
if (m_index > seriesData.count() - 1)
m_index = 0;
QVector<QPointF> points = seriesData.at(m_index);
// Use replace instead of clear + append, it's optimized for performance
xySeries->replace(points);
}
}
void DataSource::handleSceneChanged()
{
m_dataUpdater.start();
}
void DataSource::updateAllSeries()
{
static int frameCount = 0;
static QString labelText = QStringLiteral("FPS: %1");
for (int i = 0; i < m_seriesList.size(); i++)
update(m_seriesList[i], i);
frameCount++;
int elapsed = m_fpsTimer.elapsed();
if (elapsed >= 1000) {
elapsed = m_fpsTimer.restart();
qreal fps = qreal(0.1 * int(10000.0 * (qreal(frameCount) / qreal(elapsed))));
m_fpsLabel->setText(labelText.arg(QString::number(fps, 'f', 1)));
m_fpsLabel->adjustSize();
frameCount = 0;
}
m_data.clear();
// Append the new data depending on the type
QVector<QVector<QPointF> > seriesData;
QVector<QPointF> points;
// points.reserve(2048);
for (int j(0); j < 2048; j++) {
qreal x(0);
qreal y(0);
if(shift==0)
{
y = b[j] ;
x=j;
}else
{
y = c[j] ;
x=j;
}
points.append(QPointF(x, y));
}
seriesData.append(points);
m_data.append(seriesData);
if(shift==0)
{
shift=1;
}else
{
shift=0;
}
}
void DataSource::startUpdates(const QList<QXYSeries *> &seriesList, QLabel *fpsLabel)
{
m_seriesList = seriesList;
m_fpsLabel = fpsLabel;
m_dataUpdater.setInterval(500);
m_dataUpdater.setSingleShot(true);
QObject::connect(&m_dataUpdater, &QTimer::timeout,this, &DataSource::updateAllSeries);
m_fpsTimer.start();
updateAllSeries();
}
void DataSource::generateData(int seriesCount, int rowCount, int colCount)
{
// Remove previous data
foreach (QVector<QVector<QPointF> > seriesData, m_data) {
foreach (QVector<QPointF> row, seriesData)
row.clear();
}
m_data.clear();
// Append the new data depending on the type
for (int k(0); k < seriesCount; k++) {
QVector<QVector<QPointF> > seriesData;
for (int i(0); i < rowCount; i++) {
QVector<QPointF> points;
points.reserve(colCount);
for (int j(0); j < colCount; j++) {
qreal x(0);
qreal y(0);
if(shift==0)
{
y = a[j] ;
x=j;
}else
{
y = b[j] ;
x=j;
}
points.append(QPointF(x, y));
}
seriesData.append(points);
}
m_data.append(seriesData);
}
if(shift==0)
{
shift=1;
}else
{
shift=0;
}
qDebug()<<"test";
}
//***********main.cpp**********//
#include "datasource.h"
#include <QtWidgets/QApplication>
#include <QtWidgets/QMainWindow>
#include <QtCharts/QChartView>
#include <QtCharts/QLineSeries>
#include <QtCharts/QScatterSeries>
#include <QtCharts/QValueAxis>
#include <QtCharts/QLogValueAxis>
#include <QtWidgets/QLabel>
QT_CHARTS_USE_NAMESPACE
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QStringList colors;
colors << "red" << "blue" << "green" << "black";
QChart *chart = new QChart();
chart->legend()->hide();
QValueAxis *axisX = new QValueAxis;
QValueAxis *axisY = new QValueAxis;
chart->addAxis(axisX, Qt::AlignBottom);
chart->addAxis(axisY, Qt::AlignLeft);
const int seriesCount = 1;
const int pointCount = 2048;
chart->setTitle("OpenGL Accelerated Series");
QList<QXYSeries *> seriesList;
for (int i = 0; i < seriesCount; i++) {
QXYSeries *series = 0;
int colorIndex = i % colors.size();
if (i % 2) {
series = new QScatterSeries;
QScatterSeries *scatter = static_cast<QScatterSeries *>(series);
scatter->setColor(QColor(colors.at(colorIndex)));
scatter->setMarkerSize(qreal(colorIndex + 2) / 2.0);
// Scatter pen doesn't have affect in OpenGL drawing, but if you disable OpenGL drawing
// this makes the marker border visible and gives comparable marker size to OpenGL
// scatter points.
scatter->setPen(QPen("black"));
} else {
series = new QLineSeries;
series->setPen(QPen(QBrush(QColor(colors.at(colorIndex))),
qreal(colorIndex + 2) / 2.0));
}
seriesList.append(series);
//![1]
series->setUseOpenGL(true);
//![1]
chart->addSeries(series);
series->attachAxis(axisX);
series->attachAxis(axisY);
}
if (axisX->type() == QAbstractAxis::AxisTypeLogValue)
axisX->setRange(0.1, 2048.0);
else
axisX->setRange(0, 2048.0);
if (axisY->type() == QAbstractAxis::AxisTypeLogValue)
axisY->setRange(0.1, 255.0);
else
axisY->setRange(0, 255.0);
QChartView *chartView = new QChartView(chart);
QMainWindow window;
window.setCentralWidget(chartView);
window.resize(600, 400);
window.show();
DataSource dataSource;
dataSource.generateData(seriesCount, 1, pointCount);
QLabel *fpsLabel = new QLabel(&window);
QLabel *countLabel = new QLabel(&window);
QString countText = QStringLiteral("Total point count: %1");
countLabel->setText(countText.arg(pointCount * seriesCount));
countLabel->adjustSize();
fpsLabel->move(10, 2);
fpsLabel->adjustSize();
fpsLabel->raise();
fpsLabel->show();
countLabel->move(10, fpsLabel->height());
fpsLabel->raise();
countLabel->show();
// We can get more than one changed event per frame, so do async update.
// This also allows the application to be responsive.
QObject::connect(chart->scene(), &QGraphicsScene::changed,
&dataSource, &DataSource::handleSceneChanged);
dataSource.startUpdates(seriesList, fpsLabel);
return a.exec();
}

C++ - QMediaPlayer emits no sound

I'm trying to make a simple synth using Qt. A note is supposed to play when you left click a key but no sound is played. I've tried to search for a solution to the problem but I haven't found anything that helps.
Since I'm fairly new to Qt I believe that the problem is that I lack full understanding of how the framework works but I simply can't figure out why the sound wont play.
I've managed to emit sounds from the main.cpp and have included examples further down in the code when a sound is played and when it isn't.
Hope I've presented my problem well and thanks in advance.
//key.h
#ifndef KEY_H
#define KEY_H
#include <QGraphicsRectItem>
#include <QObject>
#include <QKeyEvent>
#include <QGraphicsSceneMouseEvent>
#include <QDebug>
#include <QBrush>
#include <QMediaPlayer>
enum Tune {A, B, C, D, E, F, G, ASS, BESS, DESS, ESS, GESS, MUTE}; // Key tune
class Key : public QObject, public QGraphicsRectItem {
Q_OBJECT
public:
Key(Tune t=MUTE);
void mousePressEvent(QGraphicsSceneMouseEvent *event);
void mouseMoveEvent(QGraphicsSceneMouseEvent *event);
void mouseReleaseEvent(QGraphicsSceneMouseEvent *event);
void paintPlayedKey();
void resetPaintedKey();
void setTone();
QMediaPlayer* getTone() {return tone;}
Tune getTune() {return tune;}
private:
Tune tune;
QMediaPlayer *tone;
};
#endif // KEY_H
//key.cpp
#include "key.h"
void Key::paintPlayedKey()
{
this->setBrush(* new QBrush(Qt::blue));
}
void Key::resetPaintedKey()
{
if(tune < 7)
this->setBrush(* new QBrush(Qt::white));
else
this->setBrush(* new QBrush(Qt::black));
}
void Key::setTone() // Sets sounds to tune
{
if(tune == 0)
tone->setMedia(QUrl("qrc:/keys/Pianosounds/TheKeys/a.wav"));
else if (tune == 1)
tone->setMedia(QUrl("qrc:/keys/Pianosounds/TheKeys/b.wav"));
else if (tune == 2)
tone->setMedia(QUrl("qrc:/keys/Pianosounds/TheKeys/c.wav"));
else if (tune == 3)
tone->setMedia(QUrl("qrc:/keys/Pianosounds/TheKeys/d.wav"));
else if (tune == 4)
tone->setMedia(QUrl("qrc:/keys/Pianosounds/TheKeys/e.wav"));
else if (tune == 5)
tone->setMedia(QUrl("qrc:/keys/Pianosounds/TheKeys/f.wav"));
else if (tune == 6)
tone->setMedia(QUrl("qrc:/keys/Pianosounds/TheKeys/g.wav"));
else if (tune == 7)
tone->setMedia(QUrl("qrc:/keys/Pianosounds/TheKeys/ab.wav"));
else if (tune == 8)
tone->setMedia(QUrl("qrc:/keys/Pianosounds/TheKeys/bb.wav"));
else if (tune == 9)
tone->setMedia(QUrl("qrc:/keys/Pianosounds/TheKeys/db.wav"));
else if (tune == 10)
tone->setMedia(QUrl("qrc:/keys/Pianosounds/TheKeys/eb.wav"));
else if (tune == 11)
tone->setMedia(QUrl("qrc:/keys/Pianosounds/TheKeys/gb.wav"));
}
Key::Key(Tune t)
{
tune = t;
tone = new QMediaPlayer();
setTone();
}
void Key::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
{
//Not sure if we wanna do anything here
}
void Key::mousePressEvent(QGraphicsSceneMouseEvent *event)
{
//play tune
if (event->buttons() == Qt::LeftButton) {
qDebug() << "Pressed";
paintPlayedKey();
if(tone->state() == QMediaPlayer::PlayingState) {
tone->setPosition(0);
qDebug() << "Have played?";
}
else if (tone->state() == QMediaPlayer::StoppedState) {
qDebug() << "Should play?"; // Well it doesn't :-)
tone->play();
}
}
}
void Key::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
{
//stop playing tune
resetPaintedKey();
tone->stop();
}
//main.cpp
#include <QApplication>
#include <QGraphicsScene>
#include <QGraphicsView>
#include <QBrush>
#include <QMediaPlayer>
#include <QTimer>
#include <iostream>
#include <vector>
#include "mainwindow.h"
#include "key.h"
using namespace std;
const int W_KEY_H = 150; // White Key width and height
const int W_KEY_W = 50;
const double B_KEY_H = 150 * 2/3; // White Key width and height
const double B_KEY_W = 50/2;
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
// create a scene
QGraphicsScene *scene = new QGraphicsScene();
// Create white keys of synth
Tune a = A, b = B, c = C, d = D, e = E, f = F, g = G;
Key *a1 = new Key(a);
Key *b1 = new Key(b);
Key *c1 = new Key(c);
Key *d1 = new Key(d);
Key *e1 = new Key(e);
Key *f1 = new Key(f);
Key *g1 = new Key(g);
vector<Key*> whites = {a1, b1, c1, d1, e1, f1, g1};
int x = 0;
for(int i = 0; i < whites.size(); i++, x+=W_KEY_W)
whites[i]->setRect(x, 0, W_KEY_W, W_KEY_H);
// add the keys to the scene
for(int i = 0; i < whites.size(); i++)
scene->addItem(whites[i]);
// focus keys
for(int i = 0; i < whites.size(); i++) {
whites[i]->setFlag(QGraphicsItem::ItemIsFocusable);
whites[i]->setFocus();
}
// Create black keys of synth
Tune ass = ASS, bess = BESS, dess = DESS, ess = ESS, gess = GESS;
Key *ass1 = new Key(ass);
Key *bess1 = new Key(bess);
Key *dess1 = new Key(dess);
Key *ess1 = new Key(ess);
Key *gess1 = new Key(gess);
Key *ass2 = new Key(ass);
vector<Key*> blacks = {ass1, bess1, dess1, ess1, gess1, ass2};
// For now...
ass1->setRect(a1->rect().x() - B_KEY_W/(double)2, 0, B_KEY_W, B_KEY_H);
bess1->setRect(b1->rect().x() - B_KEY_W/(double)2, 0, B_KEY_W, B_KEY_H);
dess1->setRect(d1->rect().x() - B_KEY_W/(double)2, 0, B_KEY_W, B_KEY_H);
ess1->setRect(e1->rect().x() - B_KEY_W/(double)2, 0, B_KEY_W, B_KEY_H);
gess1->setRect(g1->rect().x() - B_KEY_W/(double)2, 0, B_KEY_W, B_KEY_H);
ass2->setRect(g1->rect().x() + g1->rect().width() - B_KEY_W/(double)2, 0, B_KEY_W, B_KEY_H); // Nödlösning
//paint
for(int i=0; i<blacks.size(); i++)
blacks[i]->setBrush(* new QBrush(Qt::black));
// add the keys to the scene
for(int i = 0; i < blacks.size(); i++)
scene->addItem(blacks[i]);
// focus keys
for(int i = 0; i < blacks.size(); i++) {
blacks[i]->setFlag(QGraphicsItem::ItemIsFocusable);
blacks[i]->setFocus();
}
// add a view
QGraphicsView *view = new QGraphicsView(scene);
//show view
view->show();
//view->setFixedSize(800, 600);
//scene->setSceneRect(0, 0, 800, 600);
// Sound plays
QMediaPlayer *test = new QMediaPlayer();
test->setMedia(QUrl("qrc:/sounds/Pianosounds/TheKeys/a.wav"));
test->play();
// doesn't play
c1->getTone()->play();
return app.exec();
}

GTKMM buttons in a grid

just learned the concept of GTKMM and found out that I enjoyed this, compared to just C++, which is pretty boring just programming in the terminal. As I decided to create a code that will make a 8 x 8 buttons of table, I encountered a problem, which is how to set every button to my desired position, because the code I created just makes 64 buttons horizontally. Can anyone help me here? Thanks
examplewindow.h (The code the class attributes and methods)
#ifndef GTKMM_EXAMPLEWINDOW_H
#define GTKMM_EXAMPLEWINDOW_H
#include <gtkmm.h>
class ExampleWindow : public Gtk::Window
{
public:
ExampleWindow();
virtual ~ExampleWindow();
private:
// Signal handlers:
void on_button_numbered(const Glib::ustring& data);
// Child widgets:
Gtk::Grid m_grid;
Gtk::Button button[8][8];
};
#endif /* GTKMM_EXAMPLEWINDOW_H */
examplewindow.cc (The code for modifying the attributes and methods)
#include <iostream>
#include "examplewindow.h"
ExampleWindow::ExampleWindow()
{
set_title("Mr. Sandman");
set_border_width(12);
int i, j;
add(m_grid);
for (int i = 0; i < 8; i++)
{
for (int j = 0; j < 8; j++)
{
m_grid.add(button[i][j]);
}
}
for (int i = 0; i < 8; i++)
{
for (j = 0; j < 8; j++)
{
button[i][j].signal_clicked().connect(
sigc::bind<Glib::ustring>( sigc::mem_fun(*this,
&ExampleWindow::on_button_numbered), "button 1") );
}
}
m_grid.show_all();
}
ExampleWindow::~ExampleWindow()
{
}
void
ExampleWindow::on_button_numbered(const Glib::ustring& data)
{
std::cout << data << " was pressed" << std::endl;
}
main.cc (The main function)
#include "examplewindow.h"
#include <gtkmm/application.h>
int main(int argc, char *argv[])
{
Glib::RefPtr<Gtk::Application> app = Gtk::Application::create(argc, argv, "org.gtkmm.example");
ExampleWindow window;
// Shows the window and returns when it is closed.
return app->run(window);
}

instead of using m_Grid.add() try using attach() or attach_next_to()
so you can either give row/column position in your loop or attach button 9 below button 1 and button 2 to the right of button 1
https://developer.gnome.org/gtkmm/unstable/classGtk_1_1Grid.html#a9c425e95660daff60a77fc0cafc18115

QT QStandardItemModel segfaulting

I'm pretty new to QT, and I'm trying to take a list from a text file and output it into QT with nice formatting.
I managed to get the list printed on the window, but it has to be able to be sorted.
I have the radio buttons set up right now so that one of them displays the list and the other clears the list.
The problem is that when I switch from the list to the cleared list back to the list the program segfaults and I don't understand why.
The files are here.
winelist.cpp
#include "winelist.h"
#include "ui_winelist.h"
#include <QFile>
#include <QString>
#include <QStandardItemModel>
wineList::wineList(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::wineList)
{
ui->setupUi(this);
ui->ratingButton->setChecked(true);
fillList();
model->setHorizontalHeaderItem(0, new QStandardItem(QString("Wine Name")));
model->setHorizontalHeaderItem(1, new QStandardItem(QString("Vintage")));
model->setHorizontalHeaderItem(2, new QStandardItem(QString("Rating")));
model->setHorizontalHeaderItem(3, new QStandardItem(QString("Price")));
ui->listOutput->setModel(model);
}
wineList::~wineList()
{
delete ui;
}
void wineList::on_sortButton_clicked()
{
if( ui->ratingButton->isChecked())
{
for (int i = 0; i < 100; i++) {
model->setItem(i,0,wList[i].wineName);
model->setItem(i,1,wList[i].vintage);
model->setItem(i,2,wList[i].rating);
model->setItem(i,3,wList[i].price);
}
}
else
{
for(int i = 0; i < 100; i++) {
for(int j = 0; j < 4; j++) {
model->setItem(i, j, new QStandardItem(QString("")));
}
}
}
ui->listOutput->resizeColumnsToContents();
ui->listOutput->resizeRowsToContents();
}
void wineList::fillList()
{
Wine wine;
QString line;
QStringList lineElements;
QFile wineText(":/winelist.txt");
if (wineText.open(QIODevice::ReadOnly))
{
while ((line = line.fromUtf8(wineText.readLine())) != "")
{
lineElements = line.split(";");
lineElements[0].replace("\t", "");
lineElements[1].replace("\t", "");
wine.wineName = new QStandardItem(QString(lineElements.at(0)));
wine.vintage = new QStandardItem(QString(lineElements.at(1)));
wine.rating = new QStandardItem(QString::number(lineElements.at(2).toInt()));
wine.price = new QStandardItem(QString::number(lineElements.at(3).toInt()));
wList.append(wine);
}
}
wineText.close();
}
winelist.h
#ifndef WINELIST_H
#define WINELIST_H
#include <QMainWindow>
#include <QStandardItem>
#include <QStandardItemModel>
namespace Ui {
class wineList;
}
struct Wine {
QStandardItem* wineName;
QStandardItem* vintage;
QStandardItem* rating;
QStandardItem* price;
};
class wineList : public QMainWindow
{
Q_OBJECT
public:
explicit wineList(QWidget *parent = 0);
~wineList();
private slots:
void on_sortButton_clicked();
private:
Ui::wineList *ui;
QVarLengthArray<Wine> wList;
QStandardItemModel *model = new QStandardItemModel(100, 4, this);
void fillList();
void printList(QStandardItemModel *model);
};
#endif // WINELIST_H
main.cpp
#include "winelist.h"
#include <QApplication>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
wineList w;
w.show();
return a.exec();
}
Clicking sort the first time
Switching Radio Button and clicking sort again
Switching Radio Button back and clicking sort again
Any Help is appreciated, I am completely lost here.

In the on_sortButton_clicked you're trying to read data from a list, but not doing any range checks. Instead, you've hardcoded 100 there.
You should rewrite this:
for (int i = 0; i < 100; i++) {
model->setItem(i,0,wList[i].wineName);
to this:
for (int i = 0; i < wList.size(); i++) {
model->setItem(i,0,wList[i].wineName);
--upd---
When you initially populate your model, it takes ownership over items from wList. When you replace model items with empty ones, it deletes initial items from wList. After this your wList is no move valid, because it contains Wine structs with dangling pointers. That's why when you try to populate your model second time, it crashes.

QT Creator C++ not generating ui_.h file for one item

I've been working on my UI, and all that stuff compiles fine but I also wrote up the majority of my code then generated the header file for it part way through. But this header file will not compile - no errors. It just isn't in the build directory at all.
ink.h
#ifndef INK_H
#define INK_H
#include <QPaintDevice>
namespace Ui {
class Ink;
}
class Ink : public QPaintDevice
{
public:
explicit Ink(QWidget *parent = 0);
~Ink();
private:
Ui::Ink *ui;
};
#endif // INK_H
ink.cpp
#include "ink.h"
#include <QtCore>
#include <QtGui>
#include <QWidget>
#include <QPainter>
#include <QPaintEvent>
void ink()
{
QFile *brushInput; //takes raw 8 bit grayscale image, 8 bit values only
char *brushProto;
uchar *brushData;
brushInput = new QFile("x:\\Development\\InkPuppet\\brush.raw"); //open the raw file
brushInput->open(QIODevice::ReadOnly);
QDataStream in;
in.setDevice(brushInput);
int size = brushInput->size(); //set size to length of raw file
brushProto = new char[size];
in.readRawData(brushProto, size); //read file into prototype
brushData = new uchar[size];
for(int i = 0; i < size; ++i)
{
brushData[i] = (uchar)brushProto[i]; //copy char to uchar array
}
QImage test(brushData, 128, 128, QImage::Format_Indexed8);
QImage test2(128, 128, QImage::Format_ARGB32);
QVector<QRgb> vectorColors(256); //create color table
for(int c = 0; c < 256; c++)
{
vectorColors[c] = qRgb(c, c, c);
}
test.setColorTable(vectorColors);
for(int iX = 0; iX < 100; ++iX)
{
for(int iY = 0; iY < 100; ++iY)
{
test2.setPixel(iX, iY, qRgba(255 - (qrand() % 100), 0 + (qrand() % 100), 0 + (qrand() % 100), qAbs((int)test.pixel(iX, iY)-255)));
}
}
//final conversion for stencil and color brush
QPixmap testPixmap = QPixmap::fromImage(test2);
QPixmap testPixmap2 = QPixmap::fromImage(test);
QPainter painter(this);
painter.drawPixmap(150, 50, 100, 100, testPixmap);
painter.drawPixmap(50, 50, 100, 100, testPixmap2);
delete[] brushProto;
delete[] brushData;
delete brushInput;
}
main.cpp
#include "inkpuppet.h"
#include "ink.h"
#include <QApplication>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
InkPuppet w;
w.show();
return a.exec();
}

When you create a new form in QT creator you have to choose Qt Designer Form Class in order to generate the corresponding .cpp and .h files, otherwise it will only generate the .ui.