QT real time graph has flickering problem - c++
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();
}
Related
How can I place Hex Data into a QT List Widget [duplicate]
Recently I am writing a debugger for my own hardware. I want to add a memory viewer widget like the eclipse or qt creator or other IDE. However, I have no idea what kind of widget to use. For example, tableWidget, is there some setting to make it like this:
The best option is to create a custom widget because the task is private and none of the widgets are accommodated to the task.
For this we will inherit from QAbstractScrollArea, from this class inherit QTableView, QListView, QListWidget and QTableWidget. It is designed to display data within a QScrollArea.
In addition documentation of this class tells us how to create a custom class.
When inheriting QAbstractScrollArea, you need to do the following:
Control the scroll bars by setting their range, value, page step, and
tracking their movements.
Draw the contents of the area in the
viewport according to the values of the scroll bars.
Handle events
received by the viewport in viewportEvent()
notably resize events.
Use viewport->update() to update the contents of the viewport instead
of update() as all painting operations take place on the viewport.
Taking that reference I created the following widget:
memoryviewer.h
#ifndef MEMORYVIEWER_H
#define MEMORYVIEWER_H
#include <QAbstractScrollArea>
#include <QBuffer>
class MemoryViewer : public QAbstractScrollArea
{
Q_OBJECT
public:
MemoryViewer(QWidget *parent = 0);
~MemoryViewer();
void setData(const QByteArray &ba);
bool setData(QIODevice &device);
protected:
void paintEvent(QPaintEvent *);
void resizeEvent(QResizeEvent *);
private:
void adjustContent();
void init();
int addressWidth();
int hexWidth();
int asciiWidth();
QByteArray data(qint64 pos=0, qint64 count=-1);
int nBlockAddress;
int mBytesPerLine;
int pxWidth;
int pxHeight;
qint64 startPos;
qint64 endPos;
int nRowsVisible;
QBuffer buffer;
QIODevice *ioDevice;
qint64 size;
QByteArray dataVisible;
QByteArray dataHex;
};
#endif // MEMORYVIEWER_H
memoryviewer.cpp
#include "memoryviewer.h"
#include <QPainter>
#include <QScrollBar>
MemoryViewer::MemoryViewer(QWidget *parent):QAbstractScrollArea(parent)
{
ioDevice = new QBuffer(this);
init();
connect(verticalScrollBar(), &QScrollBar::valueChanged, this, &MemoryViewer::adjustContent);
connect(horizontalScrollBar(), &QScrollBar::valueChanged, this, &MemoryViewer::adjustContent);
}
MemoryViewer::~MemoryViewer()
{
}
void MemoryViewer::init()
{
nBlockAddress = 2;
mBytesPerLine = 16;
pxWidth = fontMetrics().width(QChar('0'));
pxHeight = fontMetrics().height();
}
int MemoryViewer::addressWidth()
{
return (nBlockAddress*4+ nBlockAddress -1)*pxWidth;
}
int MemoryViewer::hexWidth()
{
return (mBytesPerLine*3+1)*pxWidth;
}
int MemoryViewer::asciiWidth()
{
return (mBytesPerLine*2 +1)*pxWidth;
}
QByteArray MemoryViewer::data(qint64 pos, qint64 count)
{
QByteArray buffer;
if (pos >= size)
return buffer;
if (count < 0)
count = size;
else
if ((pos + count) > size)
count = size - pos;
if(ioDevice->open(QIODevice::ReadOnly)){
ioDevice->seek(pos);
buffer = ioDevice->read(count);
ioDevice->close();
}
return buffer;
}
void MemoryViewer::setData(const QByteArray &ba)
{
buffer.setData(ba);
setData(buffer);
}
bool MemoryViewer::setData(QIODevice &device)
{
ioDevice = &device;
bool ok = ioDevice->open(QIODevice::ReadOnly);
if(ok){
size = ioDevice->size();
ioDevice->close();
}
else{
QBuffer *buf = new QBuffer(this);
ioDevice = buf;
}
init();
adjustContent();
return ok;
}
void MemoryViewer::resizeEvent(QResizeEvent *)
{
adjustContent();
}
void MemoryViewer::paintEvent(QPaintEvent *)
{
QPainter painter(viewport());
int offsetX = horizontalScrollBar()->value();
int y = pxHeight;
QString address;
painter.setPen(viewport()->palette().color(QPalette::WindowText));
for(int row = 0; row <= dataVisible.size()/mBytesPerLine; row++){
QString str = QString("%1").arg(startPos + mBytesPerLine*row, nBlockAddress*4, 16, QChar('0')).toUpper();
int i = 0;
address = "";
while(i < nBlockAddress){
address += str.mid(i*4, 4) + ":";
i++;
}
address.remove(address.size()-1, 1);
painter.drawText(pxWidth/2 -offsetX , y, address);
y+=pxHeight;
}
int x;
int lx = addressWidth() +pxWidth;
painter.drawLine(lx-offsetX, 0, lx-offsetX, height());
lx += pxWidth/2;
y = pxHeight;
//hex data
x = lx-offsetX+3*pxWidth;
int w = 3*pxWidth;
for(int col =0; col < mBytesPerLine/2; col++){
painter.fillRect(x-pxWidth/2, 0, w, height(), viewport()->palette().color(QPalette::AlternateBase));
x+= 6*pxWidth;
}
int bPos = 0;
for(int row=0; row < nRowsVisible; row++){
x = lx-offsetX;
for(int col =0; (col < mBytesPerLine) && (bPos < dataHex.size()) ; col++){
QString str = dataHex.mid(bPos*2,2).toUpper();
painter.drawText(x, y, str);
x += 3*pxWidth;
bPos += 1;
}
y+= pxHeight;
}
lx = addressWidth() + hexWidth();
painter.drawLine(lx-offsetX, 0, lx-offsetX, height());
lx += pxWidth/2;
bPos = 0;
y = pxHeight ;
int ch;
for(int row=0; row < nRowsVisible; row++){
x = lx-offsetX;
for(int col =0; (col < mBytesPerLine) && (bPos < dataVisible.size()) ; col++){
ch = (uchar)dataVisible.at(bPos);
if ( ch < 0x20 )
ch = '.';
painter.drawText(x, y, QChar(ch));
x += 2*pxWidth;
bPos += 1;
}
y+= pxHeight;
}
}
void MemoryViewer::adjustContent()
{
int w = addressWidth() + hexWidth() + asciiWidth();
horizontalScrollBar()->setRange(0, w - viewport()->width());
horizontalScrollBar()->setPageStep(viewport()->width());
nRowsVisible = viewport()->height()/pxHeight;
int val = verticalScrollBar()->value();
startPos = (qint64)val*mBytesPerLine;
endPos = startPos + nRowsVisible*mBytesPerLine -1;
int lineCount = size/mBytesPerLine;
verticalScrollBar()->setRange(0, lineCount-nRowsVisible);
verticalScrollBar()->setPageStep(nRowsVisible);
if(endPos >= size){
endPos = size-1;
}
dataVisible = data(startPos, endPos-startPos + mBytesPerLine +1);
dataHex = dataVisible.toHex();
viewport()->update();
}
An advantage of the implementation is that you do not have to load all the bytes directly since you can pass an object that inherits from QIODevice such as QFile and read the data when the view needs it by eliminating the memory overhead. In addition you can pass a QByteArray
In the following link you will find an example
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();
}
QT how to use setPixmap skin.copy() for do an animation?
I want to do a little animation in my application. I have an asteroid and when he travel to the right the animation go to the right, when he go to the left animation go to the left,
the angle is between 0 and 360°.
I have add the tiles for you explain me how to cut it perfectly.
I have in the class an integer who have number bewteen 0 and 34 (asteroids on the image) I decrease -1 or add +1 to this variable at each animation.
The method that animates the asteroid:
void Asteroid::animation(){
int x = 1;
int y = 1;
int width = 5;
int height = 5;
// what should I add here?
if(this->angle >= 0 && this->angle < 180){
// cut image go to the right
setPixmap(this->skin.copy(x,y,width,height));
this->frame++;
if(frame > 34) this->frame = 1;
} else {
// cut image go to the left
setPixmap(this->skin.copy(x,y,width,height));
this->frame--;
if(frame < 1) this->frame = 34;
}
}
The contents of the skin pixmap:
Interface
#include <QGraphicsPixmapItem>
#include <QGraphicsScene>
#include <QPoint>
#include <QVector>
#include <QPixmap>
#include <QString>
#include <QTimer>
#include <QObject>
#include <time.h>
#include <QtCore/qmath.h>
#include "SettingsAsteroid.h"
class Asteroid : public QObject, public QGraphicsPixmapItem
{
Q_OBJECT
// Animation
QPixmap skin;
int frame; // 32 images
// Data
int speed;
int size;
int pv;
float angle;
public:
Asteroid(int size);
Asteroid(QPointF position, int size);
~Asteroid();
int getPosX();
int getPosY();
void setPosX(int newPos);
void setPosY(int newPos);
int getSpeed();
int getSize();
int getPV();
int getAngle();
// météorite détruite
void destroyed();
// toucher par un tir
void touched(int damage);
bool isDestroyed();
private slots:
// mouvement de la météorite
void move();
// animation de la météorite
void animation();
signals:
//void notKilled();
// transmet la taille du météorite détruit
void killed(int);
};
Implementation
#include "Asteroid.h"
Asteroid::Asteroid(int size)
{
this->skin = QPixmap(SettingsAsteroid::getRandomSkin());
this->speed = SettingsAsteroid::getRandomSpeed(4,8);
this->pv = SettingsAsteroid::getPV(size);
this->angle = SettingsAsteroid::getRandomAngle();
this->frame = 1;
// Position de départ random
QPointF position = QPointF(SettingsAsteroid::getRandomStartPosition());
this->setPos(position.x(), position.y());
this->size = size;
// mouvement de l'astéroide
QTimer* timer2 = new QTimer();
connect(timer2,SIGNAL(timeout()),this,SLOT(move()));
timer2->start(this->speed);
// animation de l'astéroide
QTimer* timer = new QTimer();
connect(timer,SIGNAL(timeout()),this,SLOT(animation()));
timer->start(100);
}
Asteroid::Asteroid(QPointF position, int size)
{
this->skin = QPixmap(SettingsAsteroid::getRandomSkin());
this->speed = SettingsAsteroid::getRandomSpeed(4,8);
this->pv = SettingsAsteroid::getPV(size);
this->angle = SettingsAsteroid::getRandomAngle();
this->frame = 1;
this->setPos(position.x(), position.y());
this->size = size;
QTimer* timer2 = new QTimer();
connect(timer2,SIGNAL(timeout()),this,SLOT(move()));
timer2->start(this->speed);
//Decoupe sprite et anmiation
QTimer* timer = new QTimer();
connect(timer,SIGNAL(timeout()),this,SLOT(animation()));
timer->start(150);
}
Asteroid::~Asteroid()
{
}
int Asteroid::getPosX(){
return this->pos().x();
}
int Asteroid::getPosY(){
return this->pos().y();
}
void Asteroid::setPosX(int newPos){
this->setPos(newPos, this->pos().y());
}
void Asteroid::setPosY(int newPos){
this->setPos(this->pos().x(), newPos);
}
int Asteroid::getSpeed(){
return this->speed;
}
int Asteroid::getSize(){
return this->size;
}
int Asteroid::getPV(){
return this->pv;
}
int Asteroid::getAngle(){
return this->angle;
}
bool Asteroid::isDestroyed(){
if(pv > 0) return false;
else return true;
}
void Asteroid::destroyed(){
// AVERTIR CLASSE PRINCIPALE QUE DETRUIT
}
void Asteroid::touched(int damage){
this->pv -= damage;
if(pv<=0) destroyed();
}
void Asteroid::move(){
double dx = getSpeed() * qCos(qDegreesToRadians(angle)) ;
double dy = getSpeed() * qSin(qDegreesToRadians(angle)) ;
setPos(QPointF(getPosX() + dx, getPosY() + dy)) ;
// place la météorite de l'autre coté de la scène
if (getPosX()<=0) setPosX(799);
else if (getPosY()<=0) setPosY(659);
else if (getPosX()>= 800) setPosX(1);
else if (getPosY()>= 600) setPosY(1);
}
void Asteroid::animation(){
// what add here?
int x = 1;
int y = 1;
int width = 5;
int height = 5;
if(this->angle >= 0 && this->angle < 180){
// cut image go to the right
setPixmap(this->skin.copy(x,y,width,height));
this->frame++;
if(frame > 34) this->frame = 1;
} else {
// cut image go to the left
setPixmap(this->skin.copy(x,y,width,height));
this->frame--;
if(frame < 1) this->frame = 34;
}
}
The angle is the direction of the Asteroid on the scene. There will be a spaceship who should destroyed the asteroid. I want make the animaton of the Asteroids who move on the scene
Assuming that the asteroid images in the skin are square, you can do as follows.
Your skin has only 32 items, not 34, BTW.
void Asteroid::animation() {
int step = skin.height();
int N = skin.width() / step; // Number of images in the skin.
Q_ASSERT(skin.width() % step == 0); // ensure proper format of the skin
if (angle >= 0 && angle < 180) {
frame ++;
if (frame > N) frame -= N;
} else {
frame --;
if (frame < 1) frame += N;
}
int x = (frame - 1) * step;
setPixmap(skin.copy(x, 0, step, step));
}
QGraphicsView doesn't always update
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();
}
"QComboBox Pop-up" expanding and QtWebkit
In Firefox/Chrome/InternetExplorer/Safari/Opera pop-ups from the combobox expand as the content, see Firefox picture:
QComboBox pop-up does not expand the content. Pop-ups are limited by the size of QComboBox, see QWebView picture:
So I implemented the QComboBox::showPopup:
void newQComboBox::showPopup() {
int width = this->width();
this->view()->setTextElideMode( Qt::ElideNone );
const int iconSize = this->iconSize().width();
const QFontMetrics fontMetrics = this->fontMetrics();
const int j = this->count();
for( int i=0; i < j; ++i ) {
const int textWidth = fontMetrics.width( this->itemText(i) + "WWW" );
if (this->itemIcon(i).isNull()) {
width = qMax(width, textWidth);
} else {
width = qMax(width, textWidth + iconSize);
}
}
QStyleOptionComboBox opt;
this->initStyleOption(&opt);
QSize size(width, 0);
size = this->style()->sizeFromContents(QStyle::CT_ComboBox, &opt, size, this);
this->view()->setFixedWidth( width );
QComboBox::showPopup();
}
Is there any way to modify (reimplement) the QComboBox::showPopup of QWebViews (QtWebkit)?
Qt-BUG (suggestion): https://bugreports.qt.io/browse/QTBUG-35771
I solved using QProxyStyle class, example:
#include <QProxyStyle>
#include <QAbstractItemView>
#include <QComboBox>
class myProxyStyle : public QProxyStyle
{
public:
int styleHint(StyleHint hint, const QStyleOption *option, const QWidget *widget, QStyleHintReturn *returnData) const
{
if(hint == QStyle::SH_ComboBox_Popup) {
const QComboBox *combo = (QComboBox *) widget;//cast to QComboBox
const QObjectList a = combo->children();
const int j = a.count();
QAbstractItemView *view = 0;
QString className = "";
bool hasView = false;
/*
at this point I have not used combo->view() because he "crash" the application without explanation
so I had to make a loop to find the "view"
*/
for (int i = 0; i < j; ++i) {
const QObjectList b = a.at(i)->children();
const int y = b.count();
for (int x = 0; x < y; ++x) {
className = b.at(x)->metaObject()->className();
if (className == "QComboBoxListView") {
view = (QAbstractItemView *) b.at(x);
hasView = true;
break;
}
}
if (hasView) {
break;
}
}
if (hasView) {
const int iconSize = combo->iconSize().width();
const QFontMetrics fontMetrics1 = view->fontMetrics();
const QFontMetrics fontMetrics2 = combo->fontMetrics();
const int j = combo->count();
int width = combo->width(); //default width
for (int i = 0; i < j; ++i) {
const int textWidth = qMax(
fontMetrics1.width(combo->itemText(i) + "WW"),
fontMetrics2.width(combo->itemText(i) + "WW")
);
if(combo->itemIcon(i).isNull()) {
width = qMax(width, textWidth);
} else {
width = qMax(width, textWidth + iconSize);
}
}
view->setFixedWidth(width);
}
}
return QProxyStyle::styleHint(hint, option, widget, returnData);
}
};
how to use:
You must apply in QApplication (usually file main.cpp):
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
a.setStyle(new myProxyStyle);//set ProxyStyle
return a.exec();
}
#peppe thanks to your comment I got the solution
Please try to make use of the setMinimumWidth function and pass the max width you have calculated. it should work ui.comboBox->view()->setMinimumWidth(width); for more detail please go through https://qt-project.org/forums/viewthread/26388 link