Item Views Puzzle Example

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#include "puzzlewidget.h" #include <QtWidgets> PuzzleWidget::PuzzleWidget(int imageSize, QWidget *parent) : QWidget(parent), m_ImageSize(imageSize) { setAcceptDrops(true); setMinimumSize(m_ImageSize, m_ImageSize); setMaximumSize(m_ImageSize, m_ImageSize); } void PuzzleWidget::clear() { pieces.clear(); highlightedRect = QRect(); inPlace = 0; update(); } void PuzzleWidget::dragEnterEvent(QDragEnterEvent *event) { if (event->mimeData()->hasFormat("image/x-puzzle-piece")) event->accept(); else event->ignore(); } void PuzzleWidget::dragLeaveEvent(QDragLeaveEvent *event) { QRect updateRect = highlightedRect; highlightedRect = QRect(); update(updateRect); event->accept(); } void PuzzleWidget::dragMoveEvent(QDragMoveEvent *event) { QRect updateRect = highlightedRect.united(targetSquare(event->pos())); if (event->mimeData()->hasFormat("image/x-puzzle-piece") && findPiece(targetSquare(event->pos())) == -1) { highlightedRect = targetSquare(event->pos()); event->setDropAction(Qt::MoveAction); event->accept(); } else { highlightedRect = QRect(); event->ignore(); } update(updateRect); } void PuzzleWidget::dropEvent(QDropEvent *event) { if (event->mimeData()->hasFormat("image/x-puzzle-piece") && findPiece(targetSquare(event->pos())) == -1) { QByteArray pieceData = event->mimeData()->data("image/x-puzzle-piece"); QDataStream dataStream(&pieceData, QIODevice::ReadOnly); Piece piece; piece.rect = targetSquare(event->pos()); dataStream >> piece.pixmap >> piece.location; pieces.append(piece); highlightedRect = QRect(); update(piece.rect); event->setDropAction(Qt::MoveAction); event->accept(); if (piece.location == piece.rect.topLeft() / pieceSize()) { inPlace++; if (inPlace == 25) emit puzzleCompleted(); } } else { highlightedRect = QRect(); event->ignore(); } } int PuzzleWidget::findPiece(const QRect &pieceRect) const { for (int i = 0, size = pieces.size(); i < size; ++i) { if (pieces.at(i).rect == pieceRect) return i; } return -1; } void PuzzleWidget::mousePressEvent(QMouseEvent *event) { QRect square = targetSquare(event->pos()); int found = findPiece(square); if (found == -1) return; Piece piece = pieces.takeAt(found); if (piece.location == square.topLeft() / pieceSize()) inPlace--; update(square); QByteArray itemData; QDataStream dataStream(&itemData, QIODevice::WriteOnly); dataStream << piece.pixmap << piece.location; QMimeData *mimeData = new QMimeData; mimeData->setData("image/x-puzzle-piece", itemData); QDrag *drag = new QDrag(this); drag->setMimeData(mimeData); drag->setHotSpot(event->pos() - square.topLeft()); drag->setPixmap(piece.pixmap); if (drag->exec(Qt::MoveAction) == Qt::IgnoreAction) { pieces.insert(found, piece); update(targetSquare(event->pos())); if (piece.location == QPoint(square.x() / pieceSize(), square.y() / pieceSize())) inPlace++; } } void PuzzleWidget::paintEvent(QPaintEvent *event) { QPainter painter(this); painter.fillRect(event->rect(), Qt::white); if (highlightedRect.isValid()) { painter.setBrush(QColor("#ffcccc")); painter.setPen(Qt::NoPen); painter.drawRect(highlightedRect.adjusted(0, 0, -1, -1)); } for (const Piece &piece : pieces) painter.drawPixmap(piece.rect, piece.pixmap); } const QRect PuzzleWidget::targetSquare(const QPoint &position) const { return QRect(position / pieceSize() * pieceSize(), QSize(pieceSize(), pieceSize())); } int PuzzleWidget::pieceSize() const { return m_ImageSize / 5; } int PuzzleWidget::imageSize() const { return m_ImageSize; }