mainwindow.cpp Example File
^{draganddrop/puzzle/mainwindow.cpp}

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    **
    ** Copyright (C) 2005-2006 Trolltech ASA. All rights reserved.
    **
    ** This file is part of the documentation of the Qt Toolkit.
    **
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    ** License version 2.0 as published by the Free Software Foundation
    ** and appearing in the file LICENSE.GPL included in the packaging of
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    #include <QtGui>
    #include <stdlib.h>

    #include "mainwindow.h"
    #include "pieceslist.h"
    #include "puzzlewidget.h"

    MainWindow::MainWindow(QWidget *parent)
        : QMainWindow(parent)
    {
        setupMenus();
        setupWidgets();

        setSizePolicy(QSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed));
        setWindowTitle(tr("Puzzle"));
    }

    void MainWindow::openImage(const QString &path)
    {
        QString fileName = path;

        if (fileName.isNull())
            fileName = QFileDialog::getOpenFileName(this,
                tr("Open Image"), "", "Image Files (*.png *.jpg *.bmp)");

        if (!fileName.isEmpty()) {
            QPixmap newImage;
            if (!newImage.load(fileName)) {
                QMessageBox::warning(this, tr("Open Image"),
                                     tr("The image file could not be loaded."),
                                     QMessageBox::Cancel, QMessageBox::NoButton);
                return;
            }
            puzzleImage = newImage;
            setupPuzzle();
        }
    }

    void MainWindow::setCompleted()
    {
        QMessageBox::information(this, tr("Puzzle Completed"),
            tr("Congratulations! You have completed the puzzle!\n"
               "Click OK to start again."),
            QMessageBox::Ok);

        setupPuzzle();
    }

    void MainWindow::setupPuzzle()
    {
        int size = qMin(puzzleImage.width(), puzzleImage.height());
        puzzleImage = puzzleImage.copy((puzzleImage.width() - size)/2,
            (puzzleImage.height() - size)/2, size, size).scaled(400,
                400, Qt::IgnoreAspectRatio, Qt::SmoothTransformation);

        piecesList->clear();

        for (int y = 0; y < 5; ++y) {
            for (int x = 0; x < 5; ++x) {
                QPixmap pieceImage = puzzleImage.copy(x*80, y*80, 80, 80);
                piecesList->addPiece(pieceImage, QPoint(x, y));
            }
        }

        srand(QCursor::pos().x() ^ QCursor::pos().y());

        for (int i = 0; i < piecesList->count(); ++i) {
            if (int(2.0*rand()/(RAND_MAX+1.0)) == 1) {
                QListWidgetItem *item = piecesList->takeItem(i);
                piecesList->insertItem(0, item);
            }
        }

        puzzleWidget->clear();
    }

    void MainWindow::setupMenus()
    {
        QMenu *fileMenu = menuBar()->addMenu(tr("&File"));

        QAction *openAction = fileMenu->addAction(tr("&Open..."));
        openAction->setShortcut(QKeySequence(tr("Ctrl+O")));

        QAction *exitAction = fileMenu->addAction(tr("E&xit"));
        exitAction->setShortcut(QKeySequence(tr("Ctrl+Q")));

        QMenu *gameMenu = menuBar()->addMenu(tr("&Game"));

        QAction *restartAction = gameMenu->addAction(tr("&Restart"));

        connect(openAction, SIGNAL(triggered()), this, SLOT(openImage()));
        connect(exitAction, SIGNAL(triggered()), qApp, SLOT(quit()));
        connect(restartAction, SIGNAL(triggered()), this, SLOT(setupPuzzle()));
    }

    void MainWindow::setupWidgets()
    {
        QFrame *frame = new QFrame;
        QHBoxLayout *frameLayout = new QHBoxLayout(frame);

        piecesList = new PiecesList;
        puzzleWidget = new PuzzleWidget;

        connect(puzzleWidget, SIGNAL(puzzleCompleted()),
                this, SLOT(setCompleted()), Qt::QueuedConnection);

        frameLayout->addWidget(piecesList);
        frameLayout->addWidget(puzzleWidget);
        setCentralWidget(frame);
    }