Animation with Transformation in Qt

Article Metadata

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Tested with

Devices(s): 5800 xpress muzic

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Compatibility

Platform(s): S60 3rd Edition FP1, S60 3rd Edition FP2, S60 5th Edition

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Article

Keywords: QGraphicsItem,QGraphicsItemAnimation

Created: mind_freak (20 Jun 2009)

Last edited: hamishwillee (11 Oct 2012)

Overview

This article shows how to rotate and move a QGraphicsItem using the simple animation support provided by QGraphicsItemAnimation.

Preconditions

• Download and install the Qt SDK

Property

• Sets the Z-value, or the elevation, of the item, to z. The elevation decides the stacking order of sibling (neighboring) items

text->setZValue(5.0);

• Sets the rotation of the item at the given step value to the angle specified.

animation->setRotationAt(i / 300.0, i);

SourceCode

main.cpp

#include <QtGui/QApplication>
#include "animation.h"
#include<QGraphicsItemAnimation>
#include<QPointF>
#include<QTimeLine>
#include<QGraphicsItem>
#include<QGraphicsSimpleTextItem>
#include<QGraphicsScene>
#include<QGraphicsView>
#include<QHBoxLayout>
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
 
    QGraphicsItem *text = new QGraphicsSimpleTextItem("Viral");
    text->setAcceptDrops(1);
    //text->setOpacity(0.0);
    text->setAcceptHoverEvents(true);
    text->setZValue(5.0);
    QHBoxLayout *lay=new QHBoxLayout();
    QTimeLine *timer = new QTimeLine(5000);
    timer->setFrameRange(0, 100);
 
    QGraphicsItemAnimation *animation = new QGraphicsItemAnimation();
    animation->setItem(text);
    animation->setTimeLine(timer);
    int i;
    for (i = 0; i <= 250; ++i)//getting the coordinates
        animation->setPosAt(i/250.0,QPointF(i, i));//positioning the graphicsItem
 
        animation->setRotationAt(i / 300.0, i);//rotation of graphicsItem.
 
 
 
 
    QGraphicsScene *scene = new QGraphicsScene();
    scene->setSceneRect(0, 0, 250, 250);//rectuangular scene built
    scene->addItem(text);
 
    QGraphicsView *view = new QGraphicsView(scene);
    view->show();
 
   timer->start();//start timer to view animation 
 
   return a.exec();
}

ScreenShot