Drag & Drop using QTableWidget

[Israa]

Bump. ghorwin 'hijacked' my thread!

[ghorwin]

Israa: Sorry for hijacking, but you asked excactly the same question that I had, so figured opening a new thread would be non-sense.

Jpn: dragMoveEvent() is called correctly.

So it seems something prevents the dropping...

If I read the documentation correctly, only the widget itself, that should accept the drop, needs to call setAcceptDrop(), right? Or do I also have to tell the parent dialog to accept drops?

Anyway, I'm clueless. Should I post a simple test-program?

[jpn]

Jpn: dragMoveEvent() is called correctly.

Yes, but do you accept the event?

[ghorwin]

Guys, got it to work!!!

The trick is to call

setDragDropMode(QAbstractItemView::DropOnly);

setDragDropMode(QAbstractItemView::DropOnly);

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in addition to

setAcceptDrops(true);

setAcceptDrops(true);

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(wasn't mentioned in the docu, but I just went back to the abstract view class)...

Now dropEvent is called alright!

[ghorwin]

Still something strange about the dropping...

Explain that: When I reimplement the dragMoveEvent() (even with an empty function), I can drop anywhere in my table. If I don't reimplement it, I can only drop when the cursor is exactly on the frame around the content rows (so at the bottom of the header row and at the top of the horizontal scroll bar). That's weird, if you ask me.

So, the recipe for dropping on QTableWidget is:

1. setup your table in the constructor

setDragDropMode(QAbstractItemView::DropOnly);
setAcceptDrops(true);

setDragDropMode(QAbstractItemView::DropOnly);
setAcceptDrops(true);

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2. re-implement the functions dragEnterEvent(...), dragMoveEvent(...) and dropEvent(...), for example:

void MyTable::dragEnterEvent(QDragEnterEvent *event)
{
	if (event->mimeData()->hasUrls()) {
		event->acceptProposedAction();
	}
}
 
void MyTable::dragMoveEvent ( QDragMoveEvent * ) {
	// nothing to do, function just has to exist...
}
 
void MyTable::dropEvent(QDropEvent *event)
{
	if (event->mimeData()->hasUrls()) {
		QList<QUrl> urls = event->mimeData()->urls();
		for (int i=0; i<urls.count(); ++i) {
			int row = rowCount();
			insertRow(row);
			QTableWidgetItem *newItem = new QTableWidgetItem(urls[i].toString());
	    	setItem(row, 0, newItem);	
		}
 
		event->accept();
     }
}

void MyTable::dragEnterEvent(QDragEnterEvent *event)
{
	if (event->mimeData()->hasUrls()) {
		event->acceptProposedAction();
	}
}

void MyTable::dragMoveEvent ( QDragMoveEvent * ) {
	// nothing to do, function just has to exist...
}

void MyTable::dropEvent(QDropEvent *event)
{
	if (event->mimeData()->hasUrls()) {
		QList<QUrl> urls = event->mimeData()->urls();
		for (int i=0; i<urls.count(); ++i) {
			int row = rowCount();
			insertRow(row);
			QTableWidgetItem *newItem = new QTableWidgetItem(urls[i].toString());
	    	setItem(row, 0, newItem);	
		}
		
		event->accept();
     }
}

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At least that's what worked for me.

[Israa]

I still haven't gotten an answer to my question, would anyone know what I need to do to enable drag & drop to and from 2 QTableWidgets? I create a class that inherits QTableWidget and I place the two objects on either side of a QSplitter. I can drag & drop in the same table, but not to the other table.

[jpn]

Using Drag and Drop with Item Views - Using Convenience Views:

For example, we can enable drag and drop in a list widget with the following lines of code:

QListWidget *listWidget = new QListWidget(this);
listWidget->setSelectionMode(QAbstractItemView::SingleSelection);
listWidget->setDragEnabled(true);
listWidget->setAcceptDrops(true);
listWidget->setDropIndicatorShown(true);

QListWidget *listWidget = new QListWidget(this);
listWidget->setSelectionMode(QAbstractItemView::SingleSelection);
listWidget->setDragEnabled(true);
listWidget->setAcceptDrops(true);
listWidget->setDropIndicatorShown(true);

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The same applies for a table widget.

[para]

I still haven't gotten an answer to my question, would anyone know what I need to do to enable drag & drop to and from 2 QTableWidgets? I create a class that inherits QTableWidget and I place the two objects on either side of a QSplitter. I can drag & drop in the same table, but not to the other table.

I am having the same problem, trying to drag&drop from one table to another.

Using Drag and Drop with Item Views - Using Convenience Views:

The same applies for a table widget.

I am having trouble following the page you linked. I have tried the function calls that enable drag&drop functionality, but I am still having issues dropping to a different table than was dragged from. Is there any way some short example code could be provided? Nothing complicated, I'd just like to see a working example.

Thanks.

[jpn]

I am having the same problem, trying to drag&drop from one table to another.

Does this work for you?

#include <QtGui>
 
QTableWidget* createTableWidget(QWidget* parent)
{
   QTableWidget* tableWidget = new QTableWidget(4, 4, parent);
   tableWidget->setSelectionMode(QAbstractItemView::SingleSelection);
   tableWidget->setDragEnabled(true);
   tableWidget->setAcceptDrops(true);
   tableWidget->setDropIndicatorShown(true);
   return tableWidget;
}
 
int main(int argc, char* argv[])
{
   QApplication a(argc, argv);
   QSplitter splitter;
   splitter.addWidget(createTableWidget(&splitter));
   splitter.addWidget(createTableWidget(&splitter));
   splitter.show();
   return a.exec();
}

#include <QtGui>

QTableWidget* createTableWidget(QWidget* parent)
{
   QTableWidget* tableWidget = new QTableWidget(4, 4, parent);
   tableWidget->setSelectionMode(QAbstractItemView::SingleSelection);
   tableWidget->setDragEnabled(true);
   tableWidget->setAcceptDrops(true);
   tableWidget->setDropIndicatorShown(true);
   return tableWidget;
}

int main(int argc, char* argv[])
{
   QApplication a(argc, argv);
   QSplitter splitter;
   splitter.addWidget(createTableWidget(&splitter));
   splitter.addWidget(createTableWidget(&splitter));
   splitter.show();
   return a.exec();
}

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[para]

Does this work for you?

Yeah that worked, thanks a lot. I must have missed something.