Not able to animate the ball at row 200 (solved)

houmingc

setPosAt sets the position of the item at the given step value to the point specified.
iterating i at row 200 not successful, why?
@ animation->setPosAt(0.2, QPointF(i,200));
@
Could not animate the ball rolling at bottom row.
It's seems to be moving at an acceleration??

@

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
QGraphicsItem *ball = new QGraphicsEllipseItem(0, 0, 20, 20);

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

QGraphicsItemAnimation *animation = new QGraphicsItemAnimation;
animation->setItem(ball);
animation->setTimeLine(timer);

for (int i = 0; i < 200; ++i)
animation->setPosAt(0.2, QPointF(i,200));

QGraphicsScene *scene = new QGraphicsScene();
scene->setSceneRect(0, 0, 250, 250);
scene->addItem(ball);

QGraphicsView *view = new QGraphicsView(scene);
view->show();

timer->start();

}

MainWindow::~MainWindow()
{
delete ui;
}

@

SGaist

Hi,

Looks like you are setting 200 times a different position but at the same point in time

houmingc

No. QPointF::QPointF(qreal x, qreal y)
i am iterating x and setting y at a constant value

@
for (int i = 0; i < 200; ++i)
animation->setPosAt(0.2, QPointF(i,200));
@

SGaist

So again, 200 different positions at the same point in time. You give 0.2 as the step for every position.

houmingc

can please show few line of code to meet the objective?

SGaist

Please, go read QGraphicsItemAnimation's documentation, it's explained in the Detailed Description with a code sample