C++/Qt/Drag Drop

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Drag and drop

  
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 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 the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef DRAGWIDGET_H
#define DRAGWIDGET_H
#include <QByteArray>
#include <QFrame>
#include <QString>
#include <QStringList>
class QComboBox;
class QFrame;
class QLabel;
class QTextBrowser;
class DragWidget : public QFrame
{
    Q_OBJECT
public:
    DragWidget(QWidget *parent);
    void setData(const QString &mimetype, const QByteArray &newData);
signals:
    void dragResult(const QString &actionText);
    void mimeTypes(const QStringList &types);
protected:
    void dragEnterEvent(QDragEnterEvent *event);
    void dropEvent(QDropEvent *event);
    void mouseMoveEvent(QMouseEvent *event);
    void mousePressEvent(QMouseEvent *event);
private:
    QByteArray data;
    QLabel *dragDropLabel;
    QPoint dragStartPosition;
    QString mimeType;
};
#endif




#include <QtGui>
#include "dragwidget.h"
DragWidget::DragWidget(QWidget *parent)
    : QFrame(parent)
{
    setFrameStyle(QFrame::StyledPanel | QFrame::Sunken);
    dragDropLabel = new QLabel("", this);
    dragDropLabel->setAlignment(Qt::AlignHCenter);
    QHBoxLayout *layout = new QHBoxLayout(this);
    layout->addStretch(0);
    layout->addWidget(dragDropLabel);
    layout->addStretch(0);
    setAcceptDrops(true);
}
// Accept all actions, but deal with them separately later.
void DragWidget::dragEnterEvent(QDragEnterEvent *event)
{
    event->acceptProposedAction();
}

void DragWidget::dropEvent(QDropEvent *event)
{
    if (event->source() == this && event->possibleActions() & Qt::MoveAction)
        return;

    if (event->proposedAction() == Qt::MoveAction) {
        event->acceptProposedAction();
        // Process the data from the event.
        emit dragResult(tr("The data was moved here."));
    } else if (event->proposedAction() == Qt::CopyAction) {
        event->acceptProposedAction();
        // Process the data from the event.
        emit dragResult(tr("The data was copied here."));
    } else {
        // Ignore the drop.
        return;
    }
    // End of quote
    emit mimeTypes(event->mimeData()->formats());
    setData(event->mimeData()->formats()[0],
            event->mimeData()->data(event->mimeData()->formats()[0]));
}

void DragWidget::mousePressEvent(QMouseEvent *event)
{
    if (event->button() == Qt::LeftButton)
        dragStartPosition = event->pos();
}

void DragWidget::mouseMoveEvent(QMouseEvent *event)
{
    if (!(event->buttons() & Qt::LeftButton))
        return;
    if ((event->pos() - dragStartPosition).manhattanLength()
         < QApplication::startDragDistance())
        return;
    QDrag *drag = new QDrag(this);
    QMimeData *mimeData = new QMimeData;
    mimeData->setData(mimeType, data);
    drag->setMimeData(mimeData);
    Qt::DropAction dropAction = drag->exec(Qt::CopyAction | Qt::MoveAction);

    switch (dropAction) {
        case Qt::CopyAction:
            emit dragResult(tr("The text was copied."));
            break;
        case Qt::MoveAction:
            emit dragResult(tr("The text was moved."));
            break;
        default:
            emit dragResult(tr("Unknown action."));
            break;
    }
}

void DragWidget::setData(const QString &mimetype, const QByteArray &newData)
{
    mimeType = mimetype;
    data = QByteArray(newData);
    dragDropLabel->setText(tr("%1 bytes").arg(data.size()));
    QStringList formats;
    formats << mimetype;
    emit mimeTypes(formats);
}





#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QPixmap>
#include <QPoint>
class QComboBox;
class QLabel;
class QLineEdit;
class QMouseEvent;
class QTextEdit;
class DragWidget;
class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    MainWindow(QWidget *parent = 0);
public slots:
    void setDragResult(const QString &actionText);
    void setMimeTypes(const QStringList &types);
private:
    QComboBox *mimeTypeCombo;
    DragWidget *dragWidget;
};
#endif



#include <QtGui>
#include "dragwidget.h"
#include "mainwindow.h"
MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
    QFrame *centralWidget = new QFrame(this);
    QLabel *mimeTypeLabel = new QLabel(tr("MIME types:"), centralWidget);
    mimeTypeCombo = new QComboBox(centralWidget);
    QLabel *dataLabel = new QLabel(tr("Amount of data (bytes):"), centralWidget);
    dragWidget = new DragWidget(centralWidget);
    connect(dragWidget, SIGNAL(mimeTypes(const QStringList &)),
            this, SLOT(setMimeTypes(const QStringList &)));
    connect(dragWidget, SIGNAL(dragResult(const QString &)),
            this, SLOT(setDragResult(const QString &)));
    QVBoxLayout *mainLayout = new QVBoxLayout(centralWidget);
    mainLayout->addWidget(mimeTypeLabel);
    mainLayout->addWidget(mimeTypeCombo);
    mainLayout->addSpacing(32);
    mainLayout->addWidget(dataLabel);
    mainLayout->addWidget(dragWidget);
    statusBar();
    dragWidget->setData(QString("text/plain"), QByteArray("Hello world"));
    setCentralWidget(centralWidget);
    setWindowTitle(tr("Drag and Drop"));
}
void MainWindow::setDragResult(const QString &actionText)
{
    statusBar()->showMessage(actionText);
}
void MainWindow::setMimeTypes(const QStringList &types)
{
    mimeTypeCombo->clear();
    mimeTypeCombo->addItems(types);
}


#include <QtGui>
#include "mainwindow.h"
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    MainWindow *window1 = new MainWindow;
    MainWindow *window2 = new MainWindow;
    window1->show();
    window2->show();
    return app.exec();
}


Drag and drop text

  
  
  
  
/****************************************************************************  
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 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 the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QPixmap>
#include <QPoint>
class QLabel;
class QLineEdit;
class QMouseEvent;
class QTextEdit;
class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    MainWindow(QWidget *parent = 0);
protected:
    void mousePressEvent(QMouseEvent *event);
private:
    QLabel *iconLabel;
    QLineEdit *nameEdit;
    QPixmap iconPixmap;
    QPoint dragStartPosition;
    QTextEdit *commentEdit;
};
#endif




#include <QtGui>
#include "mainwindow.h"
MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
    QFrame *centralFrame = new QFrame(this);
    QLabel *nameLabel = new QLabel(tr("Comment:"), centralFrame);
    commentEdit = new QTextEdit(centralFrame);
    QLabel *dragLabel = new QLabel(tr("<p>Drag the icon to a filer "
                                      "window or the desktop background:</p>"),
                                      centralFrame);
    iconLabel = new QLabel(centralFrame);
    iconPixmap.load(":/images/file.png");
    iconLabel->setPixmap(iconPixmap);
    QGridLayout *grid = new QGridLayout(centralFrame);
    grid->addWidget(nameLabel, 0, 0);
    grid->addWidget(commentEdit, 1, 0, 1, 2);
    grid->addWidget(dragLabel, 2, 0);
    grid->addWidget(iconLabel, 2, 1);
    statusBar();
    setCentralWidget(centralFrame);
    setWindowTitle(tr("Dragging"));
}

void MainWindow::mousePressEvent(QMouseEvent *event)
{
    if (event->button() == Qt::LeftButton
        && iconLabel->geometry().contains(event->pos())) {
       QDrag *drag = new QDrag(this);
        QMimeData *mimeData = new QMimeData;
        mimeData->setText(commentEdit->toPlainText());
        drag->setMimeData(mimeData);
        drag->setPixmap(iconPixmap);
        Qt::DropAction dropAction = drag->exec();
        QString actionText;
        switch (dropAction) {
            case Qt::CopyAction:
                actionText = tr("The text was copied.");
                break;
            case Qt::MoveAction:
                actionText = tr("The text was moved.");
                break;
            case Qt::LinkAction:
                actionText = tr("The text was linked.");
                break;
            case Qt::IgnoreAction:
                actionText = tr("The drag was ignored.");
                break;
            default:
                actionText = tr("Unknown action.");
                break;
        }
        statusBar()->showMessage(actionText);
    }
}



#include <QtGui>
#include "mainwindow.h"
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    MainWindow *window = new MainWindow;
    window->show();
    return app.exec();
}


Drag Drop List Model

  
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 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 the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of an example program for Qt.
** EDITIONS: NOLIMITS
**
****************************************************************************/
#ifndef MODEL_H
#define MODEL_H
#include <QObject>
#include <QStringListModel>
class DragDropListModel : public QStringListModel
{
    Q_OBJECT
public:
    DragDropListModel(const QStringList &strings, QObject *parent = 0);
    Qt::ItemFlags flags(const QModelIndex &index) const;
    bool dropMimeData(const QMimeData *data, Qt::DropAction action,
                      int row, int column, const QModelIndex &parent);
    QMimeData *mimeData(const QModelIndexList &indexes) const;
    QStringList mimeTypes() const;
    Qt::DropActions supportedDropActions() const;
};
#endif



/*
  model.cpp
  A simple model that uses a QStringList as its data source.
*/
#include <QtGui>
#include "model.h"
DragDropListModel::DragDropListModel(const QStringList &strings,
                                     QObject *parent)
    : QStringListModel(strings, parent)
{
}

bool DragDropListModel::dropMimeData(const QMimeData *data,
    Qt::DropAction action, int row, int column, const QModelIndex &parent)
{
    if (action == Qt::IgnoreAction)
        return true;
    if (!data->hasFormat("application/vnd.text.list"))
        return false;
    if (column > 0)
        return false;
    int beginRow;
    if (row != -1)
        beginRow = row;
    else if (parent.isValid())
        beginRow = parent.row();
    else
        beginRow = rowCount(QModelIndex());
    QByteArray encodedData = data->data("application/vnd.text.list");
    QDataStream stream(&encodedData, QIODevice::ReadOnly);
    QStringList newItems;
    int rows = 0;
    while (!stream.atEnd()) {
        QString text;
        stream >> text;
        newItems << text;
        ++rows;
    }
    insertRows(beginRow, rows, QModelIndex());
    foreach (QString text, newItems) {
        QModelIndex idx = index(beginRow, 0, QModelIndex());
        setData(idx, text);
        beginRow++;
    }
    return true;
}
Qt::ItemFlags DragDropListModel::flags(const QModelIndex &index) const
{
    Qt::ItemFlags defaultFlags = QStringListModel::flags(index);
    if (index.isValid())
        return Qt::ItemIsDragEnabled | Qt::ItemIsDropEnabled | defaultFlags;
    else
        return Qt::ItemIsDropEnabled | defaultFlags;
}
QMimeData *DragDropListModel::mimeData(const QModelIndexList &indexes) const
{
    QMimeData *mimeData = new QMimeData();
    QByteArray encodedData;
    QDataStream stream(&encodedData, QIODevice::WriteOnly);
    foreach (QModelIndex index, indexes) {
        if (index.isValid()) {
            QString text = data(index, Qt::DisplayRole).toString();
            stream << text;
        }
    }
    mimeData->setData("application/vnd.text.list", encodedData);
    return mimeData;
}
QStringList DragDropListModel::mimeTypes() const
{
    QStringList types;
    types << "application/vnd.text.list";
    return types;
}
Qt::DropActions DragDropListModel::supportedDropActions() const
{
    return Qt::CopyAction | Qt::MoveAction;
}




#ifndef WINDOW_H
#define WINDOW_H
#include <QMainWindow>
class QListView;
class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    MainWindow();
private:
    void setupListItems();
    QListView *listView;
};
#endif





#include <QtGui>
#include "mainwindow.h"
#include "model.h"
MainWindow::MainWindow()
{
    QMenu *fileMenu = new QMenu(tr("&File"));
    QAction *quitAction = fileMenu->addAction(tr("E&xit"));
    quitAction->setShortcut(tr("Ctrl+Q"));
    menuBar()->addMenu(fileMenu);
//  For convenient quoting:
QListView *listView = new QListView(this);
listView->setSelectionMode(QAbstractItemView::ExtendedSelection);
listView->setDragEnabled(true);
listView->setAcceptDrops(true);
listView->setDropIndicatorShown(true);
    this->listView = listView;
    connect(quitAction, SIGNAL(triggered()), this, SLOT(close()));
    setupListItems();
    setCentralWidget(listView);
    setWindowTitle(tr("List View"));
}
void MainWindow::setupListItems()
{
    QStringList items;
    items << tr("Oak") << tr("Fir") << tr("Pine") << tr("Birch") << tr("Hazel")
          << tr("Redwood") << tr("Sycamore") << tr("Chestnut")
          << tr("Mahogany");
    DragDropListModel *model = new DragDropListModel(items, this);
    listView->setModel(model);
}


#include <QtGui>
#include "mainwindow.h"
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    MainWindow *window = new MainWindow;
    window->show();
    return app.exec();
}


Drop action

  
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 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 the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef WINDOW_H
#define WINDOW_H
#include <QString>
#include <QStringList>
#include <QWidget>
class QComboBox;
class QFrame;
class QTextBrowser;
class Window : public QWidget
{
    Q_OBJECT
public:
    Window(QWidget *parent = 0);
protected:
    void dragEnterEvent(QDragEnterEvent *event);
    void dropEvent(QDropEvent *event);
private:
    QComboBox *mimeTypeCombo;
    QFrame *dropFrame;
    QTextBrowser *textBrowser;
    QString oldText;
    QStringList oldMimeTypes;
};
#endif


#include <QtGui>
#include "window.h"
Window::Window(QWidget *parent)
    : QWidget(parent)
{
    QLabel *textLabel = new QLabel(tr("Data:"), this);
    textBrowser = new QTextBrowser(this);
    QLabel *mimeTypeLabel = new QLabel(tr("MIME types:"), this);
    mimeTypeCombo = new QComboBox(this);
    QVBoxLayout *layout = new QVBoxLayout(this);
    layout->addWidget(textLabel);
    layout->addWidget(textBrowser);
    layout->addWidget(mimeTypeLabel);
    layout->addWidget(mimeTypeCombo);
/*
    ...
    setAcceptDrops(true);
*/
    setAcceptDrops(true);
    setWindowTitle(tr("Drop Actions"));
}
void Window::dragEnterEvent(QDragEnterEvent *event)
{
    if (event->mimeData()->hasFormat("text/plain"))
        event->acceptProposedAction();
}
void Window::dropEvent(QDropEvent *event)
{
    QMenu actionMenu(this);
    QAction *copyAction = 0;
    QAction *moveAction = 0;
    QAction *linkAction = 0;
    QAction *ignoreAction = 0;
    if (event->possibleActions() & Qt::CopyAction)
        copyAction = actionMenu.addAction(tr("Copy"));
    if (event->possibleActions() & Qt::MoveAction)
        moveAction = actionMenu.addAction(tr("Move"));
    if (event->possibleActions() & Qt::LinkAction)
        linkAction = actionMenu.addAction(tr("Link"));
    if (event->possibleActions() & Qt::IgnoreAction)
        ignoreAction = actionMenu.addAction(tr("Ignore"));
    QAction *result = actionMenu.exec(QCursor::pos());
    if (copyAction && result == copyAction)
        event->setDropAction(Qt::CopyAction);
    else if (moveAction && result == moveAction)
        event->setDropAction(Qt::MoveAction);
    else if (linkAction && result == linkAction)
        event->setDropAction(Qt::LinkAction);
    else {
        event->setDropAction(Qt::IgnoreAction);
        return;
    }
    textBrowser->setPlainText(event->mimeData()->text());
    mimeTypeCombo->clear();
    mimeTypeCombo->addItems(event->mimeData()->formats());
}


#include <QtGui>
#include "window.h"
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    Window *window = new Window;
    window->show();
    return app.exec();
}


Drop event

  
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 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 the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef WINDOW_H
#define WINDOW_H
#include <QString>
#include <QStringList>
#include <QWidget>
class QComboBox;
class QFrame;
class QTextBrowser;
class Window : public QWidget
{
    Q_OBJECT
public:
    Window(QWidget *parent = 0);
protected:
    void dragEnterEvent(QDragEnterEvent *event);
    void dropEvent(QDropEvent *event);
private:
    QComboBox *mimeTypeCombo;
    QFrame *dropFrame;
    QTextBrowser *textBrowser;
    QString oldText;
    QStringList oldMimeTypes;
};
#endif


#include <QtGui>
#include "window.h"

Window::Window(QWidget *parent)
    : QWidget(parent)
{
    QLabel *textLabel = new QLabel(tr("Data:"), this);
    textBrowser = new QTextBrowser(this);
    QLabel *mimeTypeLabel = new QLabel(tr("MIME types:"), this);
    mimeTypeCombo = new QComboBox(this);
    QVBoxLayout *layout = new QVBoxLayout(this);
    layout->addWidget(textLabel);
    layout->addWidget(textBrowser);
    layout->addWidget(mimeTypeLabel);
    layout->addWidget(mimeTypeCombo);

    setAcceptDrops(true);
    setWindowTitle(tr("Drop Events"));
}

void Window::dragEnterEvent(QDragEnterEvent *event)
{
    if (event->mimeData()->hasFormat("text/plain"))
        event->acceptProposedAction();
}

void Window::dropEvent(QDropEvent *event)
{
    textBrowser->setPlainText(event->mimeData()->text());
    mimeTypeCombo->clear();
    mimeTypeCombo->addItems(event->mimeData()->formats());
    event->acceptProposedAction();
}





#include <QtGui>
#include "window.h"
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    Window *window = new Window;
    window->show();
    return app.exec();
}


Drop rectangle

  

/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 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 the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef WINDOW_H
#define WINDOW_H
#include <QString>
#include <QStringList>
#include <QWidget>
class QComboBox;
class QFrame;
class QTextBrowser;
class Window : public QWidget
{
    Q_OBJECT
public:
    Window(QWidget *parent = 0);
protected:
    void dragMoveEvent(QDragMoveEvent *event);
    void dropEvent(QDropEvent *event);
private:
    QComboBox *mimeTypeCombo;
    QFrame *dropFrame;
    QTextBrowser *textBrowser;
    QString oldText;
    QStringList oldMimeTypes;
};
#endif







#include <QtGui>
#include "window.h"
Window::Window(QWidget *parent)
    : QWidget(parent)
{
    QLabel *textLabel = new QLabel(tr("Data:"), this);
    textBrowser = new QTextBrowser(this);
    QLabel *mimeTypeLabel = new QLabel(tr("MIME types:"), this);
    mimeTypeCombo = new QComboBox(this);
    dropFrame = new QFrame(this);
    dropFrame->setFrameStyle(QFrame::StyledPanel | QFrame::Sunken);
    QLabel *dropLabel = new QLabel(tr("Drop items here"), dropFrame);
    dropLabel->setAlignment(Qt::AlignHCenter);
    QVBoxLayout *dropFrameLayout = new QVBoxLayout(dropFrame);
    dropFrameLayout->addWidget(dropLabel);
    QHBoxLayout *dropLayout = new QHBoxLayout;
    dropLayout->addStretch(0);
    dropLayout->addWidget(dropFrame);
    dropLayout->addStretch(0);
    QVBoxLayout *mainLayout = new QVBoxLayout(this);
    mainLayout->addWidget(textLabel);
    mainLayout->addWidget(textBrowser);
    mainLayout->addWidget(mimeTypeLabel);
    mainLayout->addWidget(mimeTypeCombo);
    mainLayout->addSpacing(32);
    mainLayout->addLayout(dropLayout);
    setAcceptDrops(true);
    setWindowTitle(tr("Drop Rectangle"));
}

void Window::dragMoveEvent(QDragMoveEvent *event)
{
    if (event->mimeData()->hasFormat("text/plain")
        && event->answerRect().intersects(dropFrame->geometry()))
        event->acceptProposedAction();
}

void Window::dropEvent(QDropEvent *event)
{
    textBrowser->setPlainText(event->mimeData()->text());
    mimeTypeCombo->clear();
    mimeTypeCombo->addItems(event->mimeData()->formats());
    event->acceptProposedAction();
}


#include <QtGui>
#include "window.h"
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    Window *window = new Window;
    window->show();
    return app.exec();
}


Port for drop event

  
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 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 the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef WINDOW_H
#define WINDOW_H
#include <QString>
#include <QStringList>
#include <QWidget>
class QComboBox;
class QFrame;
class QLabel;
class MyWidget : public QWidget
{
    Q_OBJECT
public:
    MyWidget(QWidget *parent = 0);
protected:
    void dragEnterEvent(QDragEnterEvent *event);
    void dropEvent(QDropEvent *event);
    void mousePressEvent(QMouseEvent *event);
private:
    QComboBox *mimeTypeCombo;
    QFrame *dropFrame;
    QLabel *dataLabel;
    QString oldText;
    QStringList oldMimeTypes;
};
#endif


#include <QtGui>
#include "window.h"
MyWidget::MyWidget(QWidget *parent)
    : QWidget(parent)
{
    QLabel *textLabel = new QLabel(tr("Data:"), this);
    dataLabel = new QLabel(this);
    dataLabel->setFixedSize(200, 200);
    QVBoxLayout *layout = new QVBoxLayout(this);
    layout->addWidget(textLabel);
    layout->addWidget(dataLabel);
    setAcceptDrops(true);
    setWindowTitle(tr("Drop Events"));
}

void MyWidget::dragEnterEvent(QDragEnterEvent *event)
{
    if (event->mimeData()->hasText() || event->mimeData()->hasImage())
        event->acceptProposedAction();
}

void MyWidget::dropEvent(QDropEvent *event)
{
    if (event->mimeData()->hasText())
        dataLabel->setText(event->mimeData()->text());
    else if (event->mimeData()->hasImage()) {
        QVariant imageData = event->mimeData()->imageData();
        dataLabel->setPixmap(qvariant_cast<QPixmap>(imageData));
    }
    event->acceptProposedAction();
}

void MyWidget::mousePressEvent(QMouseEvent *event)
{
    QString text = dataLabel->text();
    QPixmap iconPixmap(32, 32);
    iconPixmap.fill(qRgba(255, 0, 0, 127));
    QImage image(100, 100, QImage::Format_RGB32);
    image.fill(qRgb(0, 0, 255));

    if (event->button() == Qt::LeftButton) {
        QDrag *drag = new QDrag(this);
        QMimeData *mimeData = new QMimeData;
        mimeData->setText(text);
        mimeData->setImageData(image);
        drag->setMimeData(mimeData);
        drag->setPixmap(iconPixmap);
        Qt::DropAction dropAction = drag->exec();
        // ...
        event->accept();
    }
    else if (event->button() == Qt::MidButton) {
        QDrag *drag = new QDrag(this);
        QMimeData *mimeData = new QMimeData;
        mimeData->setImageData(image);
        drag->setMimeData(mimeData);
        drag->setPixmap(iconPixmap);
        Qt::DropAction dropAction = drag->exec();
        // ...
        event->accept();
    }
}



#include <QtGui>
#include "window.h"
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    MyWidget window;
    window.show();
    return app.exec();
}