QGraphicsScene remove item selectively

gfxx

hi ... I try to delete some QGraphicsPixmapItem from my scenet .....

scenet->setItemIndexMethod(QGraphicsScene::NoIndex);
connect(ui->mybutton, SIGNAL(pressed()), this, SLOT(mycancelslot());

......

void Mainwindows::mycancelslot()
{
QList<QGraphicsItem*> ListPix = scenet->items();
        scenet->removeItem(ListPix.last());
}

these delete the item on scenet but in unordered way .... eplain my better:

in my app I add some items .... for last 5-15 QPixmapItem (user choose) ... under for statement:

for(int i=0; i<InUserChose; i++)
{
       QGraphicsPixmapItem* item = new QGraphicsPixmapItem();
               item->setPixmap(QPixmap::fromImage(myimage));
               item->setPos(mypoint);
               scenet->addItem(item);
}

at these point if i try to push "mybutton" the item is deleted, 1 item 1 button press OK, but disappear not only last QGraphicsPixmapItem, some other item too in unordered way ..... at last all item disappear & because my code is incomplete the app crash (I call removeitem but there is no item ... all deleted!!).

Finally it works but not understand the QList<QGraphicsItem*> ListPix order .... using QGraphicsScene::BspTreeIndex is bad choice ....

UPDATE: for remove last item use VRonin code as show in these post:
VRonin solution for remove last item

regards
giorgio

Asperamanca

The documentation on QGraphicsScene::items() explains how the list is ordered. This has nothing to do with the ItemIndexMethod.

gfxx

I struggled a bit 'to understand online documents ... that's why I looked for help .... but in the end I did it:

These code solve the problem (remove only the item with zvalue from 46 to 54):

void MainWindow::test_selective_clean()
{
    QList<QGraphicsItem*> citem = scene_Pallet->items();
    for (int ct = 0; ct < citem.size(); ct++)
    {
        if ((citem[ct]->zValue() > 45) && ((citem[ct]->zValue() < 55)))
        {
            scene_Pallet->removeItem(citem[ct]);
        }
    }
}

I hope these help someone in future.

regards
Giorgio

Solved QGraphicsScene remove item selectively