Qwidget Animation with Qtimer

[tissa]

I want to make an animation with two circlewidget in a scene. My purpose is to make the first widget with concentric circle animated for a periode of time and then stop it, after make the second widget animated also for a periode of time .

but I get blocked how to make such thing here is my code:

Main.cpp:

#include <QApplication>
 
#include <QTimer>
#include<unistd.h>
#include<QGraphicsScene>
#include<QGraphicsProxyWidget>
#include<QGraphicsView>
#include "circlewidget.h"
#include<QTimeLine>
 
 
int main(int argc, char *argv[])
{
 
QApplication app(argc, argv);
CircleWidget * circle= new CircleWidget();
CircleWidget * circl= new CircleWidget();
QGraphicsScene scene;
 
 
QGraphicsProxyWidget *proxy = new QGraphicsProxyWidget();
proxy->setWidget(circle);
proxy->setPos(0,1);
 
scene.addItem(proxy);
QTimer * time=new QTimer();
QTimer * timer=new QTimer();
 
QGraphicsProxyWidget *prox = new QGraphicsProxyWidget();
prox->setWidget(circl);
prox->setPos(200,100);
scene.addItem(prox);
 
/*QTimeLine *timer = new QTimeLine(5000);
timer->setFrameRange(0, 100);*/
 
QGraphicsView view(&scene);
 
 
 
QObject::connect(timer, SIGNAL(timeout()), circl, SLOT(nextAnimationFrame()));
timer->start();
sleep(5);
timer->stop();
QObject::connect(time, SIGNAL(timeout()),circle, SLOT(nextAnimationFrame()));
time->start();
view.show();
 
 
 
return app.exec();
 
}

#include <QApplication>

#include <QTimer>
#include<unistd.h>
#include<QGraphicsScene>
#include<QGraphicsProxyWidget>
#include<QGraphicsView>
#include "circlewidget.h"
#include<QTimeLine>


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

QApplication app(argc, argv);
CircleWidget * circle= new CircleWidget();
CircleWidget * circl= new CircleWidget();
QGraphicsScene scene;


QGraphicsProxyWidget *proxy = new QGraphicsProxyWidget();
proxy->setWidget(circle);
proxy->setPos(0,1);

scene.addItem(proxy);
QTimer * time=new QTimer();
QTimer * timer=new QTimer();

QGraphicsProxyWidget *prox = new QGraphicsProxyWidget();
prox->setWidget(circl);
prox->setPos(200,100);
scene.addItem(prox);

/*QTimeLine *timer = new QTimeLine(5000);
timer->setFrameRange(0, 100);*/

QGraphicsView view(&scene);



QObject::connect(timer, SIGNAL(timeout()), circl, SLOT(nextAnimationFrame()));
timer->start();
sleep(5);
timer->stop();
QObject::connect(time, SIGNAL(timeout()),circle, SLOT(nextAnimationFrame()));
time->start();
view.show();



return app.exec();

}

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circlewidget.cpp:

#include <QtGui>
 
#include "circlewidget.h"
#include<unistd.h>
#include <stdlib.h>
 
 CircleWidget::CircleWidget(QWidget *parent)
: QWidget(parent)
 {
 
 
setBackgroundRole(QPalette::Base);
setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
 
}
 
 
QSize CircleWidget::minimumSizeHint() const
{
return QSize(50, 50);
}
 
QSize CircleWidget::sizeHint() const
{
return QSize(180, 180);
}
 
void CircleWidget::nextAnimationFrame()
{
 
update();
++ frameNo;
 
}
 
 
void CircleWidget::paintEvent(QPaintEvent *)
{
QPainter painter(this);
painter.setRenderHint(QPainter::Antialiasing);
painter.translate(width() / 2, height() / 2);
 
for (int diameter = 0; diameter < 170; diameter += 6) {
 
    int delta = abs((frameNo %120) - diameter / 2);
    int alpha = 250 - (delta * delta) / 3 - diameter;
    if (alpha > 0) {
       painter.setPen(QPen(QColor(166, diameter / 2, 32, alpha), 5));
 
       painter.drawEllipse(QRectF(-diameter / 2.0, -diameter / 2.0,
                                  diameter, diameter));
 
    }
 
}
}

#include <QtGui>

#include "circlewidget.h"
#include<unistd.h>
#include <stdlib.h>

 CircleWidget::CircleWidget(QWidget *parent)
: QWidget(parent)
 {


setBackgroundRole(QPalette::Base);
setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);

}


QSize CircleWidget::minimumSizeHint() const
{
return QSize(50, 50);
}

QSize CircleWidget::sizeHint() const
{
return QSize(180, 180);
}

void CircleWidget::nextAnimationFrame()
{

update();
++ frameNo;

}


void CircleWidget::paintEvent(QPaintEvent *)
{
QPainter painter(this);
painter.setRenderHint(QPainter::Antialiasing);
painter.translate(width() / 2, height() / 2);

for (int diameter = 0; diameter < 170; diameter += 6) {

    int delta = abs((frameNo %120) - diameter / 2);
    int alpha = 250 - (delta * delta) / 3 - diameter;
    if (alpha > 0) {
       painter.setPen(QPen(QColor(166, diameter / 2, 32, alpha), 5));

       painter.drawEllipse(QRectF(-diameter / 2.0, -diameter / 2.0,
                                  diameter, diameter));

    }

}
}

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ciclewidget.h:

#ifndef CIRCLEWIDGET_H
#define CIRCLEWIDGET_H
 
#include <QWidget>
 
 class CircleWidget : public QWidget
 {
 Q_OBJECT
 
 public:
 
 CircleWidget(QWidget *parent = 0);
 QSize minimumSizeHint() const;
 QSize sizeHint() const;
 
 public slots:
 void nextAnimationFrame();
 
 protected:
 void paintEvent(QPaintEvent *event);
 
 private:
 
 int frameNo;
 };
 
 #endif

#ifndef CIRCLEWIDGET_H
#define CIRCLEWIDGET_H

#include <QWidget>

 class CircleWidget : public QWidget
 {
 Q_OBJECT

 public:

 CircleWidget(QWidget *parent = 0);
 QSize minimumSizeHint() const;
 QSize sizeHint() const;

 public slots:
 void nextAnimationFrame();

 protected:
 void paintEvent(QPaintEvent *event);

 private:

 int frameNo;
 };

 #endif

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[anda_skoa]

You start the timer but the pause the main thread for 5 seconds.
You then stop the timer.

So the timer never ever has a chance to actually run.

QtWidgets is an event based UI framework, so you need to run an event loop to let it process events, such as paint requests, user input or timers.

the line

return app.exec();

return app.exec();

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does that.

What you could do is to use QTimer::singleShot() to delay the start of the second timer.

Cheers,
_

[tissa]

thx for you're response,
I used the QTimer::singleShot() but the animation didn't want to start !

Qt Code:

QObject::connect(timer, SIGNAL(timeout()), circl, SLOT(nextAnimationFrame()));
timer->start();
QTimer::singleShot(20,circle,SLOT(nextAnimationFra me()));

view.show();

[wysota]

Please show your current main().