pieceslist.cpp Example File

draganddrop/puzzle/pieceslist.cpp
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#include "pieceslist.h" #include <QDrag> #include <QDragEnterEvent> #include <QMimeData> PiecesList::PiecesList(int pieceSize, QWidget *parent) : QListWidget(parent), m_PieceSize(pieceSize) { setDragEnabled(true); setViewMode(QListView::IconMode); setIconSize(QSize(m_PieceSize, m_PieceSize)); setSpacing(10); setAcceptDrops(true); setDropIndicatorShown(true); } void PiecesList::dragEnterEvent(QDragEnterEvent *event) { if (event->mimeData()->hasFormat(PiecesList::puzzleMimeType())) event->accept(); else event->ignore(); } void PiecesList::dragMoveEvent(QDragMoveEvent *event) { if (event->mimeData()->hasFormat(PiecesList::puzzleMimeType())) { event->setDropAction(Qt::MoveAction); event->accept(); } else { event->ignore(); } } void PiecesList::dropEvent(QDropEvent *event) { if (event->mimeData()->hasFormat(PiecesList::puzzleMimeType())) { QByteArray pieceData = event->mimeData()->data(PiecesList::puzzleMimeType()); QDataStream dataStream(&pieceData, QIODevice::ReadOnly); QPixmap pixmap; QPoint location; dataStream >> pixmap >> location; addPiece(pixmap, location); event->setDropAction(Qt::MoveAction); event->accept(); } else { event->ignore(); } } void PiecesList::addPiece(QPixmap pixmap, QPoint location) { QListWidgetItem *pieceItem = new QListWidgetItem(this); pieceItem->setIcon(QIcon(pixmap)); pieceItem->setData(Qt::UserRole, QVariant(pixmap)); pieceItem->setData(Qt::UserRole+1, location); pieceItem->setFlags(Qt::ItemIsEnabled | Qt::ItemIsSelectable | Qt::ItemIsDragEnabled); } void PiecesList::startDrag(Qt::DropActions /*supportedActions*/) { QListWidgetItem *item = currentItem(); QByteArray itemData; QDataStream dataStream(&itemData, QIODevice::WriteOnly); QPixmap pixmap = qvariant_cast<QPixmap>(item->data(Qt::UserRole)); QPoint location = item->data(Qt::UserRole+1).toPoint(); dataStream << pixmap << location; QMimeData *mimeData = new QMimeData; mimeData->setData(PiecesList::puzzleMimeType(), itemData); QDrag *drag = new QDrag(this); drag->setMimeData(mimeData); drag->setHotSpot(QPoint(pixmap.width()/2, pixmap.height()/2)); drag->setPixmap(pixmap); if (drag->exec(Qt::MoveAction) == Qt::MoveAction) delete takeItem(row(item)); }