How to move an item on a GraphicsScene

[Holy]

hi,
Sorry for the posts and thanks for your answer.
i tried to do like you said namely:
------ MainGui.cpp

MainGui::MainGui(QWidget *parent): QWidget(parent)
{
...
}
void MainGui::timerEvent(QTimerEvent *e)
	{
		Q_UNUSED(e);
 
	QGraphicsItemAnimation anim;
anim.setItem(c1);
 
for(int i=0; i<200; i++)
{
anim.yTranslationAt(i/200.0);
 
}
		scene->advance();
		update();
 
	}

MainGui::MainGui(QWidget *parent): QWidget(parent)
{
...
}
void MainGui::timerEvent(QTimerEvent *e)
	{
		Q_UNUSED(e);

	QGraphicsItemAnimation anim;
anim.setItem(c1);

for(int i=0; i<200; i++)
{
anim.yTranslationAt(i/200.0);

}
		scene->advance();
		update();
		
	}

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but it doesn't work.
I also tried like this:

MainGui::MainGui(QWidget *parent): QWidget(parent)
{
 
	//QWidget *myWidget= new QWidget();
 
	scene = new Scene(this);
 
	Container *c1 = new Container(0, 0, 0);
 
QGraphicsItemAnimation anim;
QTimeLine *timeline = new QTimeLine(5000);
anim.setItem(c1);
for(qreal i=0.0;i<200.0;i++)
{
anim.setTranslationAt(i/200.0,i,i);
anim.yTranslationAt(i/200.0);
 
}
 
anim.setTimeLine(timeline);
timeline->setUpdateInterval(1000/3);
timeline->setLoopCount(0);
timeline->setDuration(5000);
timeline->start();
 
}

MainGui::MainGui(QWidget *parent): QWidget(parent)
{
	
	//QWidget *myWidget= new QWidget();

	scene = new Scene(this);
	
	Container *c1 = new Container(0, 0, 0);
	
QGraphicsItemAnimation anim;
QTimeLine *timeline = new QTimeLine(5000);
anim.setItem(c1);
for(qreal i=0.0;i<200.0;i++)
{
anim.setTranslationAt(i/200.0,i,i);
anim.yTranslationAt(i/200.0);

}

anim.setTimeLine(timeline);
timeline->setUpdateInterval(1000/3);
timeline->setLoopCount(0);
timeline->setDuration(5000);
timeline->start();

}

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the item doesn't move as well, please can you write it in the right way so that it can work?
thanks in advance

[jacek]

You create the animation object on the stack and it gets destroyed as soon as the constructor ends. Make it a member variable.

[Holy]

I did it, but there's no change, nothing moves.

can someone post me an example that works please?
what i want is to move the item upper in the vertical direction.
thanks for help.

[Holy]

it works now! thanks very much for the last idea!
but there's another problem, the item is moving down. How can i get it moving up first and then moving down and the movement should be inside the lines (i mean the item should remain inside the lines when moving) .
thanks for your help.

[jacek]

but there's another problem, the item is moving down. How can i get it moving up first and then moving down and the movement should be inside the lines

The movement is controlled by the animation object:

for( int i = 0; i < 50; ++i ) {
   anim.setTranslationAt( i / 100.0, 0, i );
}
for( int i = 50; i < 100; ++i ) {
   anim.setTranslationAt( i / 100.0, 0, 50 - i );
}

for( int i = 0; i < 50; ++i ) {
   anim.setTranslationAt( i / 100.0, 0, i );
}
for( int i = 50; i < 100; ++i ) {
   anim.setTranslationAt( i / 100.0, 0, 50 - i );
}

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[Holy]

thanks for your reply;
i have another problem , while inserting items in the scene all items are added at the same time but not one after another like i want them to be added, i've tried to controll this adding action of the scene by controlling the QTimeLine of Container :

something like this:
the variable QTimeLine timeline is declared public in the class container; i use it to controll the animation of the containers.

void MainGui::addnextContainer(int i, QGraphicsScene *scene1)
{
for(int i=0;i<containerNum; i++)
{
Container*[i];
scene1->addItem(c[i]);
c[i]->timeline->start();
c[i+1]->timeline->setPaused(true);
l_items(c[i]);
c[i]->timeline->stop();
scene1->addItem(c[i+1]);
c[i+1]->timeline->start();
l_items()
 
}
}

void MainGui::addnextContainer(int i, QGraphicsScene *scene1)
{
for(int i=0;i<containerNum; i++)
{
Container*[i];
scene1->addItem(c[i]);
c[i]->timeline->start();
c[i+1]->timeline->setPaused(true);
l_items(c[i]);
c[i]->timeline->stop();
scene1->addItem(c[i+1]);
c[i+1]->timeline->start();
l_items()

}
}

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puting the items in a range in the scene

QList<QGraphicsItem*>MainGui:: l_items(QGraphicsItem *item1)
{
QList<QGraphicsItem*>listing=scene->items();
listing.clear();
for(int i=0; i<listing.size();i++)
{
listing.append(item1);
 
}
return listing;
}

QList<QGraphicsItem*>MainGui:: l_items(QGraphicsItem *item1)
{
QList<QGraphicsItem*>listing=scene->items();
listing.clear();
for(int i=0; i<listing.size();i++)
{
listing.append(item1);

}
return listing;
}

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and i changed the MainGui.cpp

...
Scene scene= new Scene(this);
addnextContainer(5, scene)
...

...
Scene scene= new Scene(this);
addnextContainer(5, scene)
...

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can someone take a look at this code and tell me please what i'm doing wrong please? now i even cannot see any item anymore.
thanks in advance

[jacek]

What is l_items() method supposed to do? Now it just returns an empty list.

[Holy]

apology for the late reply, i did something else as i didn't get the solution of this problem.
back to your question.
the l_items() method is supposed to list the containers objects which are added to the scene. Can you also help me by controlling the addItem() method so that the containers should be added one by one and not all at the same time?
thanks in advance.

[jacek]

the l_items() method is supposed to list the containers objects which are added to the scene.

Lines 5--9 are never executed because you clear the list in line 4.

Can you also help me by controlling the addItem() method so that the containers should be added one by one and not all at the same time?

What do you mean by "one by one"? Do you want to have some kind of animation?

[Holy]

the items are already animated and it works very well, but what i need now is to get control over the addItem() method of scene, so that when i add n items in the scene for instance, i should get them added one after another and not as a group of n added of course as animation.
i also tried to remove listing.clear() completely but it doesn't do anything different.

[jacek]

the items are already animated and it works very well, but what i need now is to get control over the addItem() method of scene, so that when i add n items in the scene for instance, i should get them added one after another and not as a group of n added of course as animation.

Would it be enough if there was some delay between calls to addItem()?

i also tried to remove listing.clear() completely but it doesn't do anything different.

Better rewrite that method from scratch.

[Holy]

From Guru:Would it be enough if there was some delay between calls to addItem()?

i don't understand what you mean , can you please send me the example code to compile myself and see what you exactly mean with"some delay between calls to addItem()"

I have another question concerning Qt4.3 Network. There is an example named :"blockingFortuneclient" , i've tried to run that with eclipse on window(vista) but i cannot run it succesfully. wenn i try to input a port number it breaks, i mean it doesn't enable to input the port number.Can someone tell me please what is the problem.

Another question is : can i implement a middleware of RFID-System in the same way as this example to receive Data from a RFID-Reader?
or does someone know how to implement an RFID-receiver with Qt ? i will be very thankfull if someone send me an example code.
thanks for your reply.