[SOLVED]How to delete an item from the treeview by droping an item to pushbutton or to an group box

[Ratzz]

@mrjj
All drag drop events are handled in this. I am not aware how Bec, previous programmer has done it.

bool MessageModel::dropMimeData(const QMimeData *data, Qt::DropAction action, int row, int column, const QModelIndex &parent)
{
    if(action == Qt::CopyAction)
    {
//        QStringList format = data->formats();
        QByteArray encodedData = data->data("application/x-qabstractitemmodeldatalist");
        QDataStream stream(&encodedData, QIODevice::ReadOnly);
        QMap<int,  QVariant> roleDataMap;
//        roleDataMap.setInsertInOrder(true);
        QMap<int, QString> sortMsgs;

        while (!stream.atEnd())
        {
            int row, col;
            stream >> row >> col >> roleDataMap;
            QString tmp = roleDataMap.value(0).toString();
            //MsgId1.append(tmp);
            sortMsgs.insert(row,tmp);
        }
        QList < QString > MsgId1 = sortMsgs.values();

        if(parent.parent().isValid() && !parent.parent().parent().isValid())
        {
            QStandardItemModel::dropMimeData(data,action,row,column,parent);
            emit addFrameMessageIds(parent.row(), -1, MsgId1);
            return true;
        }
        if(parent.parent().parent().isValid() && column == -1)
        {
            QStandardItemModel::dropMimeData(data,action,parent.row() +1,column,parent.parent());
            emit addFrameMessageIds(parent.parent().row(),parent.row() +1, MsgId1);
            return true;
        }
        if(parent.parent().parent().isValid() && column == 0)
        {
            QStandardItemModel::dropMimeData(data,action,row,column,parent);
            emit addFrameMessageIds(parent.row(), row, MsgId1);
            return true;
        }
    }
    else if(action == Qt::MoveAction)
    {
        if(!parent.isValid())
        {
            return QStandardItemModel::dropMimeData(data,action,indexesLocal.row(),indexesLocal.column(),indexesLocal.parent());
        }
        if(indexesLocal.parent().parent().isValid() && !parent.parent().isValid() && column == -1)
        {
            //Msg is dropped on major frame
            return QStandardItemModel::dropMimeData(data,action,indexesLocal.row(),indexesLocal.column(),indexesLocal.parent());
        }
        if(indexesLocal.parent().parent().isValid() && !parent.parent().parent().isValid() && column == -1)
        {
            //Msg is dropped on minor frame
            if(indexesLocal.parent().row() != parent.row())
            {
                QStandardItemModel::dropMimeData(data,action,row,column,parent);
                emit moveFrameMessageIds(indexesLocal.parent().row(),parent.row(),indexesLocal.row(),-1);
                return true;
            }
            else
            {
                QStandardItemModel::dropMimeData(data,action, 0 ,column,parent);
                emit moveFrameMessageIds(indexesLocal.parent().row(),parent.row(),indexesLocal.row(),0);
                return true;
            }
        }
        if(indexesLocal.parent().parent().isValid() && parent.parent().parent().isValid() && column == -1)
        {
            //      Msg is dropped on another msg
            QStandardItemModel::dropMimeData(data,action,parent.row()+1,column,parent.parent());
            emit moveFrameMessageIds(indexesLocal.parent().row(),parent.parent().row(),indexesLocal.row(),parent.row()+1);
            return true;
        }
        if(indexesLocal.parent().isValid() && !(indexesLocal.parent().parent().isValid()) && !parent.parent().isValid() && column == -1)
        {
            //      Minor frame is dropped on Major frame
            QStandardItemModel::dropMimeData(data,action,0,indexesLocal.column(),indexesLocal.parent());
            emit moveFrame(indexesLocal.row(),0);
            return true;
        }
        if(indexesLocal.parent().isValid() && !(indexesLocal.parent().parent().isValid()) && parent.parent().isValid() && !(parent.parent().parent().isValid()) && column == -1)
        {
            // Minor frame is dropped on another minor frame
            int pre = indexesLocal.row();
            int cur = parent.row();
            QStandardItemModel::dropMimeData(data,action,parent.row()+1,column,parent.parent());
            emit moveFrame(indexesLocal.row(),parent.row());
            return true;
        }
        if(indexesLocal.parent().isValid() && !(indexesLocal.parent().parent().isValid()) && parent.parent().parent().isValid() && column == -1)
        {
            return QStandardItemModel::dropMimeData(data,action,indexesLocal.row(),indexesLocal.column(),indexesLocal.parent());
            //      Minor frame is dropped on msg
        }
        if(indexesLocal.parent().isValid() && !(indexesLocal.parent().parent().isValid()) && !parent.parent().isValid() && column == 0)
        {
            QStandardItemModel::dropMimeData(data,action,row,indexesLocal.column(),indexesLocal.parent());
            emit moveFrame(indexesLocal.row(),row);
            return true;
            //      Minor frame is dropped after minor
        }
        if(indexesLocal.parent().isValid() && !(indexesLocal.parent().parent().isValid()) && !parent.parent().parent().isValid() && column == 0)
        {
            return QStandardItemModel::dropMimeData(data,action,indexesLocal.row(),indexesLocal.column(),indexesLocal.parent());
            //      Minor frame is dropped after msg
        }
        if(indexesLocal.parent().parent().isValid() && parent.isValid() && !parent.parent().isValid() && column == 0)
        {
            return QStandardItemModel::dropMimeData(data,action,indexesLocal.row(),indexesLocal.column(),indexesLocal.parent());
            //      Msg is dropped after minor
        }
        if(indexesLocal.parent().parent().isValid() && parent.parent().isValid() && !parent.parent().parent().isValid() && column == 0)
        {
            QStandardItemModel::dropMimeData(data,action,row,parent.column(),parent);
            emit moveFrameMessageIds(indexesLocal.parent().row(),parent.row(),indexesLocal.row(),row);
            return true;
            //      Msg is dropped after msg
        }
}
}

And one more thing. If i drag items to pushbutton/group box the listview count is not getting updated.. ex:if i have 5 items and drag 1 item to pushbutton_delete then the count will be 5 . if i manually press delete button now then the list is getting updated to 3.

[mrjj]

@Ratzz said:

But i do not want the user to allow listview items to dragged to pushbutton/groupbox

So why can you not check there ?

also
http://doc.qt.io/qt-5/qtreewidget.html#dropMimeData
Seems to be when something is dropped on Tree and im confused what it has to do with the
Groupbox ?

[Ratzz]

@mrjj
Since the groupbox is deletes item as you suggested it also deletes listview items when dragged.

[mrjj]

@Ratzz
And the DragGBox do have
void dragEnterEvent(QDragEnterEvent* event) {
event->acceptProposedAction();
}

So why cant you just check that sender if the accepted one and then acccept or if not then
reject the drop?

[Ratzz]

@mrjj
dragEnterEvent shoud be used for main class?

[mrjj]

@mrjj said:
For the DropGroupBox class.
I assume you use that one?

[Ratzz]

@mrjj
yes i have used this one.
Since its different class how to pull the sender to it?
can you just drop me some piece of code.

[Ratzz]

@mrjj
Not it does not allow even the treeview items to drop

[mrjj]

STOP
sender() not working for events it seems.
So cannot work.
So its a no go.

[Ratzz]

@mrjj
ok fine.. what next?!

[mrjj]

@Ratzz
you can use
QWidget * QDropEvent::source() const

read here
http://doc.qt.io/qt-5.5/qdropevent.html#source

[Ratzz]

@mrjj
this way?

    void dragEnterEvent(QDragEnterEvent* event) {
        QWidget * theone= dynamic_cast<QWidget*>(event->source());
        if( theone == NULL )
        {
            event->acceptProposedAction();
        }
    }

[mrjj]

@Ratzz
almost but must be the type you want to allow
QTreeView * theone= dynamic_cast<QTreeView*>(event->source());
if( theone != NULL )
{
event->acceptProposedAction();
}

so it says if it IS a Treeview then say ok
For other types, it should not allow then. (red sign)
I hope :)

[Ratzz]

@mrjj
yes its working fine :)
i should implement for Pushbutton also .

[mrjj]

@Ratzz
Super :)

[Ratzz]

@mrjj
when i click delete button i do ui->label->setText(QString::number(parent->rowCount())); which gives me count of the number of rows. But if i drag the row will be deleted but count is not getting updated. how to update it ?
Should it be done on GroupDropBox??

[mrjj]

@Ratzz
GroupBox would not know about parent.
The Tree should update when the It is removed.

But then you drag, do you call the buttons on_click so the
ui->label->setText(QString::number(parent->rowCount()))
is executed ?
The groupBox example does not call anything as the Tree removes the item it self so
I assume that is why you dont see Count Changes.

[mrjj]

Hi
you could also cheat a bit and use a timer.

QTimer *timer = new QTimer(this);
connect(timer, SIGNAL(timeout()), this, SLOT(updateMinorFrameCount()));
timer->start(1000);

[Ratzz]

@mrjj
cheating works fine :)