Unsolved QListView & item movement
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Hi,
What do you mean by "they go into each other" ?
You can use the indexesMoved method to get the information and rebuild the playlist from there.
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@SGaist I mean when you move the Item in QListView you can drop the item between two items or on another item. when you drop it on another item the other item disappears and the moved item takes its place. I think it replaces the item's data
and also I need to know where the index is moved to. is that possible?
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Are you using the QListView in Icon mode or List mode ?
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@SGaist I'm using it in list mode
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Can you share how you setup your QListView ?
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@SGaist
I create a queueModel and set the listView's model to queue model. the Items in queueModel have a few userRole data. this is the slot that connets to doubleClicked signal on a track that I have in my trackModel:for (int i=0; i<trackModel->rowCount(); ++i)
{
queueModel->setItem(i, trackModel->item(i)->clone());const QPixmap *artWork = new QPixmap; artWork = ui->trackArtLabel->pixmap(); queueModel->item(i)->setIcon(QIcon(*artWork)); QString itemTitle=QString("%1\n%2\n%3") .arg(queueModel->item(i)->data(Qt::UserRole+3).toString()) .arg(queueModel->item(i)->data(Qt::UserRole+4).toString()) .arg(queueModel->item(i)->data(Qt::UserRole+6).toString()); queueModel->item(i)->setText(itemTitle); } for (int i=0; i<queueModel->rowCount(); ++i) { mediaPlayer.playlist()->addMedia(QMediaContent(QUrl::fromLocalFile(queueModel->item(i)->data(Qt::UserRole+1).toString()))); } playQueue(item.data(Qt::UserRole+7).toInt());
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You have a memory leak here. You allocate artWork on the heap and then directly replace its value by the one from trackArtLabel's pixmap. There's no need for that allocation.
Is your queueModel a custom model ?
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@SGaist
yes you are right. I'm using QStandardItemModel -
Any help would be appreciated.
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Again, can you show how you initialize your QListView and your model ?
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Hi, @SGaist I'm sorry I didn't get the question in the first place
the QListview is initialized from the ui with thesequeueView->setObjectName(QStringLiteral("queueView"));
queueView->setEnabled(true);
queueView->setFrameShape(QFrame::NoFrame);
queueView->setFrameShadow(QFrame::Plain);
queueView->setSizeAdjustPolicy(QAbstractScrollArea::AdjustIgnored);
queueView->setEditTriggers(QAbstractItemView::NoEditTriggers);
queueView->setDragEnabled(false);
queueView->setDragDropMode(QAbstractItemView::InternalMove);
queueView->setDefaultDropAction(Qt::TargetMoveAction);
queueView->setAlternatingRowColors(false);
queueView->setSelectionBehavior(QAbstractItemView::SelectItems);
queueView->setIconSize(QSize(150, 150));
queueView->setMovement(QListView::Snap);
queueView->setResizeMode(QListView::Adjust);
queueView->setSpacing(0);
queueView->setViewMode(QListView::ListMode);
queueView->setModelColumn(0);and the model:
QStandardItemModel *queueModel;
queueModel = new QStandardItemModel(this);
ui->queueView->setModel(queueModel);
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Ideally you want the dragged item to be placed between existing items, right? You can change standard item flags to disable drops. (ItemIsDropEnabled).
And for getting new index perhaps you can use itemChanged signal?
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Hi @asanka424
I tried the Qt::itemIsDropEnabled but the Items in the model get disabled. what should I do? -
@shahriar25
Hi,
Did you disable drops in QStandardItem or ListView? You have to disable drops in QStandardItem not in the view
setDropEnabled(false)BTW if you want to implement more custom behaviours I encourage to use QAbstractItemModel where you have more control over these operations.
Thanks
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@asanka424
Hi,
I did this in a "for" for every Item:queueModel->item(i)->setFlags(Qt::ItemIsDropEnabled);
And also I used QStandardModel in my app a lot but if this thing that I want can't be done in QStandardModel I will have to change the model. And also note that QListWidget doesn't have this problem
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this will enable drops in each item in your model. what you should do is disabling it like this
item->setFlags(item->flags() ^ Qt::ItemIsDropEnabled)
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Hi @asanka424 @SGaist
I was able to set the item flags correctly but now I'm having problem with item changed signal.
How do I know where was the Item (it's row) before it was moved? (I can set the item's data to hold the current row but isn't there a better way?)And also I was searching the QStandardItemModel's signals to find something useful and I found QStandardItemModel::rowsMoved(...) and QStandardItemModel::rowsAboutToBeMoved(...) and I tried them but they don't ge triggred when an item is moved. why is that?
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You can try dataChanged signal but it won't identify moves explicitly.
BTW does drag and drop work as you expected now?
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Hi @asanka424
Yes it does. if it won't work then I will have to set the user data every time an item moves. but I think there has to be another way. -
what you should do is disabling it like this
item->setFlags(item->flags() ^ Qt::ItemIsDropEnabled)
Beware of such handling of flags!
It's a very wrong way to do it. If the flag is not set you'll actually enable it, additionally it doesn't work with compound flags! Suppose you have (in binary)
a = 010
andb = 110
, thena ^ b == 100
which is very different from the expected000
.The proper way to remove a set of bits is to AND the inversion:
a & ~b == 000
/and this can be rigorously proven to be different froma ^ b
if you expand the xor in the other basic operationsa ^ b = (a & ~b) | (~a & b)
/