duplicate QStandardItem

shahriar25

Hi
I am working on a project and I have two QStandardModel(trackModel & queueModel) and I'm trying to copy items from one model to another:

QList<QStandardItem*> tempList= new QList<QStandardItem>;
for (int i=0; i<trackModel->rowCount(); ++i)
{
tempList->append(trackModel->item(i));
}
for (int i=0; i<trackModel->rowCount(); ++i)
{
queueModel->setItem(i, tempList->at(i));
}

But in queueModel I get empty items and this warnings in qdebugger:

QStandardItem::setChild: Ignoring duplicate insertion of item 0xec83e0
QStandardItem::setChild: Ignoring duplicate insertion of item 0x1947740
QStandardItem::setChild: Ignoring duplicate insertion of item 0xec85a0
QStandardItem::setChild: Ignoring duplicate insertion of item 0x19484d0
QStandardItem::setChild: Ignoring duplicate insertion of item 0x1947f50
QStandardItem::setChild: Ignoring duplicate insertion of item 0x19471d0
QStandardItem::setChild: Ignoring duplicate insertion of item 0x1948030
QStandardItem::setChild: Ignoring duplicate insertion of item 0x1948550
QStandardItem::setChild: Ignoring duplicate insertion of item 0x1948340
QStandardItem::setChild: Ignoring duplicate insertion of item 0x1948d00
QStandardItem::setChild: Ignoring duplicate insertion of item 0x1947e50

It ignores them all and I'm guessing because they already exist in ram.
I want the Items to remain in queueModel whent I call:
trackModel->clear();

How should I do this?

mrjj

hi
you must use TakeItem
http://doc.qt.io/qt-5.5/qstandarditemmodel.html#takeItem
else the model still owns it.

Also this line confuses me;
QList<QStandardItem*> tempList= new QList<QStandardItem>;
why not just
QList<QStandardItem*> tempList;
?

shahriar25

I can,t use takeItem() because I want the items to be on both Models.
And also i think if you use:

QWidgetItem item;
model.setItem(i, item)

the item gets deleted when the function ends and the the item is not in the model anymore. I tried it a few time and the model doesn't show the item. am I wrong?

mrjj

Hi

Im dont think the items can be in both models as each model thinks it owns it.
Cant you just make a function to fill the model and call it for each ?

I assume you mean
QStandardItem item;
model.setItem(i, item)

The model takes ownership of the item.
You should new it.
QStandardItem *item=new QStandardItem ();
Not sure it makes copy if u use non pointer.

SGaist

Hi,

What does each model represent ? Depending on that, you could also use proxy models to show the information you want.

Chris Kawa

After na item is inserted into a model it is owned by it, so it needs to be created on the heap (via new) and can't be shared across models.

You can create a duplicate of an item with clone(). This new item has no model assigned and can be used to insert it into the other model.

QList<QStandardItem*> tempList= new QList<QStandardItem>;

This makes no sense. On the left side is a list of pointers. On the right side you create a pointer to a list.

shahriar25

Hi

@SGaist : trackModel is to show the tracks in an album and the queueModel is to put all of the tracks in the
QmediaPlayer.playList()
And show them in queueModel in case the user wants to edit the queue

And yes I made a mistake in QList. You are right chris

shahriar25

Hi,
thank you chris clone() worked.
I have two other questions. You can drag the tems in a QListView anywhere in the listView. How can I disable that?

And also I want the QListView to resize the items when I press ctrl + "+" or ctrl + "-" or ctrl + mousewheel. How should I do that?

Chris Kawa

You can use setMovement to block item moves.

As for resize - what do you mean exactly? Change font size or the item rectangle size or what?

shahriar25

I mean changing the grid and the icon size. In general bigger Items (albums)