dragwidget.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

/****************************************************************************
**
** Copyright (C) 2005-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the example classes of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
** http://www.trolltech.com/products/qt/opensource.html
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://www.trolltech.com/products/qt/licensing.html or contact the
** sales department at [e-mail].
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

#include <QtGui>

#include "draglabel.h"
#include "dragwidget.h"

DragWidget::DragWidget(QWidget *parent)
    : QWidget(parent)
{
    QFile dictionaryFile(":/dictionary/words.txt");
    dictionaryFile.open(QFile::ReadOnly);
    QTextStream inputStream(&dictionaryFile);

    int x = 5;
    int y = 5;

    while (!inputStream.atEnd()) {
        QString word;
        inputStream >> word;
        if (!word.isEmpty()) {
            DragLabel *wordLabel = new DragLabel(word, this);
            wordLabel->move(x, y);
            wordLabel->show();
            x += wordLabel->width() + 2;
            if (x >= 245) {
                x = 5;
                y += wordLabel->height() + 2;
            }
        }
    }

    QPalette newPalette = palette();
    newPalette.setColor(QPalette::Background, Qt::white);
    setPalette(newPalette);

    setAcceptDrops(true);
    setMinimumSize(400, qMax(200, y));
    setWindowTitle(tr("Fridge Magnets"));
}

void DragWidget::dragEnterEvent(QDragEnterEvent *event)
{
    if (event->mimeData()->hasFormat("application/x-fridgemagnet")) {
        if (children().contains(event->source())) {
            event->setDropAction(Qt::MoveAction);
            event->accept();
        } else {
            event->acceptProposedAction();
        }
    } else if (event->mimeData()->hasText()) {
        event->acceptProposedAction();
    } else {
        event->ignore();
    }
}

void DragWidget::dragMoveEvent(QDragMoveEvent *event)
{
    if (event->mimeData()->hasFormat("application/x-fridgemagnet")) {
        if (children().contains(event->source())) {
            event->setDropAction(Qt::MoveAction);
            event->accept();
        } else {
            event->acceptProposedAction();
        }
    } else if (event->mimeData()->hasText()) {
        event->acceptProposedAction();
    } else {
        event->ignore();
    }
}

void DragWidget::dropEvent(QDropEvent *event)
{
    if (event->mimeData()->hasFormat("application/x-fridgemagnet")) {
        QByteArray itemData = event->mimeData()->data("application/x-fridgemagnet");
        QDataStream dataStream(&itemData, QIODevice::ReadOnly);
        
        QString text;
        QPoint offset;
        dataStream >> text >> offset;

        DragLabel *newLabel = new DragLabel(text, this);
        newLabel->move(event->pos() - offset);
        newLabel->show();

        if (children().contains(event->source())) {
            event->setDropAction(Qt::MoveAction);
            event->accept();
        } else {
            event->acceptProposedAction();
        }
    } else if (event->mimeData()->hasText()) {
        QStringList pieces = event->mimeData()->text().split(QRegExp("\\s+"),
                             QString::SkipEmptyParts);
        QPoint position = event->pos();

        foreach (QString piece, pieces) {
            DragLabel *newLabel = new DragLabel(piece, this);
            newLabel->move(position);
            newLabel->show();

            position += QPoint(newLabel->width(), 0);
        }

        event->acceptProposedAction();
    } else {
        event->ignore();
    }
}