Drag and Drop different item text in two QListWidgets

[Mr-Workalot]

@Bonnie i tried the above mimeData function , when i drag from one QListWIdget to another QListWidget, it only transfers "Pause Command" and not its data i.e"This is a Pause Command",

However, when i drag from QListWidget to QTextEdit , after dragging it shows "This is a Pause Command".

[VRonin]

No need to reimplement QListWidget::mimeData. See https://forum.qt.io/post/444126

[Mr-Workalot]

@VRonin Thanks for this, i got slight hope that my problem is solvable , but still kind of helpless here, in my case i want to drag item from one QListWidget-1 to QListWidget-2 but after dragging the text of that item in List widget -2 should change.

How can i acheive this ? , can you please provide code for Drop EVent ?

[SGaist]

Hi,

You have the code in the link @VRonin provided.

[Mr-Workalot]

@SGaist Okay, But in my case this function does not gets executed, so, before

void MainWindow::dropEvent(QDropEvent* event) 

gets invoked , do i need to enter any other function ??

[SGaist]

Why are you implementing that method for your MainWindow ?

[Bonnie]

@Mr-Workalot
Oh, sorry, I was misunderstanding your need, thinking you need to drop the text to a text edit.
If you reimplement dropEvent, I think you should create a new class for listwidget-2 and reimplement there.

[Mr-Workalot]

@SGaist Yeah, that's what, it kind of felt wrong to me, the place from where i am dragging is a modified QListWIdget,

std::map<QString, QString> commands;
bool first_time = true;

class ListWidget : public QListWidget {
private:

   //  map<QString, QString>::iterator it;
public:
   using QListWidget::QListWidget; 
protected: 
   QMimeData* mimeData(const QList<QListWidgetItem*> items) const
   {
       
       QMimeData* md = QListWidget::mimeData(items);
       QStringList texts;
       for (QListWidgetItem* item : selectedItems())
       {
         auto it = commands.find(item->text());
          texts << it->second;
       }
       if (first_time == true)
       {
           QString end = "</Script>";
           md->setText("<?xml version=\"1.0\" encoding=\"utf - 8\"?> \n <Script> \n"  + texts.join(QStringLiteral("\n")));
           first_time = false;
           return md;
       }
       else
       {
           md->setText(texts.join(QStringLiteral("\n")));
           return md;
       }
   }
};

and where i am dropping is a normal QListWidget,

should , i create a DropEvent for where i am dropping, right ??

and how do i create that , im very new to QT ?

[Mr-Workalot]

@Bonnie said in Drag and Drop different item text in two QListWidgets:

If you reimplement dropEvent, I think you should create a new class for listwidget-2 and reimplement there.

oh okay, thanks for clarifying. and how can i reimpliment drop event for listwidget-2 ??
what are the steps ??
, i know im asking too much but if you help me once, im gonna learn this for life.

[Bonnie]

@Mr-Workalot
Hmm..I tried to find an easiest way to handle this...
The QDataStream decode/encode thing may need to subclass the model, too.
So I think you just let it drop in the normal way, and then change it.

protected:
    bool dropMimeData(int index, const QMimeData *data, Qt::DropAction action)
    {
        if(QListWidget::dropMimeData(index, data, action)) {
            if(QListWidgetItem *dropped = item(index)) {
                dropped->setData(Qt::DisplayRole, dropped->data(Qt::UserRole));
            }
            return true;
        }
        return false;
    }

This is only working when you'll only accept drops from a item which you need to change its text to its Qt::UserRole.
If you want to accept drops from other items, you may need to add some conditional statements.