qt6windows7/examples/widgets/draganddrop/puzzle/pieceslist.cpp
2023-10-29 23:33:08 +01:00

88 lines
2.5 KiB
C++

// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#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(const QPixmap &pixmap, const 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));
}