Drag and Drop inside QTableView with QStandardItemModel

[gig-raf]

Dear ALl,

I have a question that I am hoping someone in the Forum can help me with.

I have QtableView, using the QStandardItemModel. I need to be able to sort/arrange the content of the model by dragging and dropping its items. Is this possible with the QStandarItemModel and QTableView?
so in short I would be able to drag item2 and drop it on top of item1 - result should be that item1 and item2 swap place. I do not want to drop between, only on top of other items. No new lines should be created....

I am configuring the QTableView the following way.

...
    tableView->setContextMenuPolicy(Qt::CustomContextMenu);
    tableView->setSelectionBehavior(QAbstractItemView::SelectItems);
    tableView->setAlternatingRowColors(true);
    tableView->setDropIndicatorShown(true);
    tableView->setDragDropOverwriteMode(false);
    tableView->setDragEnabled(true);
    tableView->setDragDropMode(QAbstractItemView::InternalMove);
    tableView->setDragDropMode(QAbstractItemView::DragDrop);
...

...
    tableView->setContextMenuPolicy(Qt::CustomContextMenu);
    tableView->setSelectionBehavior(QAbstractItemView::SelectItems);
    tableView->setAlternatingRowColors(true);
    tableView->setDropIndicatorShown(true);
    tableView->setDragDropOverwriteMode(false);
    tableView->setDragEnabled(true);
    tableView->setDragDropMode(QAbstractItemView::InternalMove);
    tableView->setDragDropMode(QAbstractItemView::DragDrop);
...

To copy to clipboard, switch view to plain text mode 

BUt if I drag item1 and drop on item2 nothing happens. If I drag item1 and drop it between item2 and item3. item1 is appended to the model at the very bottom.??

Any help is most appreciated.

[d_stranz]

tableView->setDragDropMode(QAbstractItemView:: InternalMove);
tableView->setDragDropMode(QAbstractItemView:: DragDrop);

The second line cancels the first; it isn't an "OR" operation.

Have you read this?

[gig-raf]

Thanks for taking the time to answer me. True with the bottom two lines. I removed the bottom one, and left solely the InternalMove.

I can now drop item1 on item2, but then item1 is cleared (removed) and item2 remains unchanged. What I want is that item1 and item2 just swap place.

I will have a read at you link and see if I can progress with this tomorrow.

cheers!

[gig-raf]

Okay managed to get it working with QTableView and QStandardItems.

here for those who might have similar need:

The key for the success was setting the item.setFlags as below and the three drag options at the bottom.

model = new QStandardItemModel(0,1,this);
 
    // Attach the model to the view
    ui->downloadView->setModel(model);
    QStandardItem* itm = new QStandardItem();
    QList<QStandardItem*> data;
    itm = new QStandardItem("Breitner");
    itm->setFlags(itm->flags() & ~(Qt::ItemIsDropEnabled));
    data.append(itm);
    model->appendRow(data);
    data.clear();
    itm = new QStandardItem("Laudrup");
    itm->setFlags(itm->flags() & ~(Qt::ItemIsDropEnabled));
    data.append(itm);
    model->appendRow(data);
    data.clear();
    itm = new QStandardItem("Platini");
    itm->setFlags(itm->flags() & ~(Qt::ItemIsDropEnabled));
    data.append(itm);
    model->appendRow(data);
    data.clear();
    itm = new QStandardItem("Paolo Rossi");
    itm->setFlags(itm->flags() & ~(Qt::ItemIsDropEnabled));
    data.append(itm);
    model->appendRow(data);
    data.clear();
    itm = new QStandardItem("Lineker");
    itm->setFlags(itm->flags() & ~(Qt::ItemIsDropEnabled));
    data.append(itm);
    model->appendRow(data);
    data.clear();
 
    ui->downloadView->setDragDropOverwriteMode(false);
    ui->downloadView->setDragEnabled(true);
    ui->downloadView->setDragDropMode(QAbstractItemView::InternalMove);

model = new QStandardItemModel(0,1,this);

    // Attach the model to the view
    ui->downloadView->setModel(model);
    QStandardItem* itm = new QStandardItem();
    QList<QStandardItem*> data;
    itm = new QStandardItem("Breitner");
    itm->setFlags(itm->flags() & ~(Qt::ItemIsDropEnabled));
    data.append(itm);
    model->appendRow(data);
    data.clear();
    itm = new QStandardItem("Laudrup");
    itm->setFlags(itm->flags() & ~(Qt::ItemIsDropEnabled));
    data.append(itm);
    model->appendRow(data);
    data.clear();
    itm = new QStandardItem("Platini");
    itm->setFlags(itm->flags() & ~(Qt::ItemIsDropEnabled));
    data.append(itm);
    model->appendRow(data);
    data.clear();
    itm = new QStandardItem("Paolo Rossi");
    itm->setFlags(itm->flags() & ~(Qt::ItemIsDropEnabled));
    data.append(itm);
    model->appendRow(data);
    data.clear();
    itm = new QStandardItem("Lineker");
    itm->setFlags(itm->flags() & ~(Qt::ItemIsDropEnabled));
    data.append(itm);
    model->appendRow(data);
    data.clear();

    ui->downloadView->setDragDropOverwriteMode(false);
    ui->downloadView->setDragEnabled(true);
    ui->downloadView->setDragDropMode(QAbstractItemView::InternalMove);

To copy to clipboard, switch view to plain text mode 

[d_stranz]

QStandardItem* itm = new QStandardItem();
QList<QStandardItem*> data;
itm = new QStandardItem("Breitner");

The first line above is a memory leak because you create the item, do nothing with it, and then overwrite the pointer in the third line.

Thanks for sharing your solution.