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# droparea.cpp Example File

draganddrop/dropsite/droparea.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies).
     ** Contact: http://www.qt-project.org/legal
     **
     ** This file is part of the examples of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:BSD$
     ** You may use this file under the terms of the BSD license as follows:
     **
     ** "Redistribution and use in source and binary forms, with or without
     ** modification, are permitted provided that the following conditions are
     ** met:
     **   * Redistributions of source code must retain the above copyright
     **     notice, this list of conditions and the following disclaimer.
     **   * Redistributions in binary form must reproduce the above copyright
     **     notice, this list of conditions and the following disclaimer in
     **     the documentation and/or other materials provided with the
     **     distribution.
     **   * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
     **     of its contributors may be used to endorse or promote products derived
     **     from this software without specific prior written permission.
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     **
     ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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     ****************************************************************************/

     #include <QtGui>

     #include "droparea.h"

     DropArea::DropArea(QWidget *parent)
         : QLabel(parent)
     {
         setMinimumSize(200, 200);
         setFrameStyle(QFrame::Sunken | QFrame::StyledPanel);
         setAlignment(Qt::AlignCenter);
         setAcceptDrops(true);
         setAutoFillBackground(true);
         clear();
     }

     void DropArea::dragEnterEvent(QDragEnterEvent *event)
     {
         setText(tr("<drop content>"));
         setBackgroundRole(QPalette::Highlight);

         event->acceptProposedAction();
         emit changed(event->mimeData());
     }

     void DropArea::dragMoveEvent(QDragMoveEvent *event)
     {
         event->acceptProposedAction();
     }

     void DropArea::dropEvent(QDropEvent *event)
     {
         const QMimeData *mimeData = event->mimeData();

         if (mimeData->hasImage()) {
             setPixmap(qvariant_cast<QPixmap>(mimeData->imageData()));
         } else if (mimeData->hasHtml()) {
             setText(mimeData->html());
             setTextFormat(Qt::RichText);
         } else if (mimeData->hasText()) {
             setText(mimeData->text());
             setTextFormat(Qt::PlainText);
         } else if (mimeData->hasUrls()) {
             QList<QUrl> urlList = mimeData->urls();
             QString text;
             for (int i = 0; i < urlList.size() && i < 32; ++i) {
                 QString url = urlList.at(i).path();
                 text += url + QString("\n");
             }
             setText(text);
         } else {
             setText(tr("Cannot display data"));
         }

         setBackgroundRole(QPalette::Dark);
         event->acceptProposedAction();
     }

     void DropArea::dragLeaveEvent(QDragLeaveEvent *event)
     {
         clear();
         event->accept();
     }

     void DropArea::clear()
     {
         setText(tr("<drop content>"));
         setBackgroundRole(QPalette::Dark);

         emit changed();
     }