droparea.cpp Example File
draganddrop/dropsite/droparea.cpp

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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();
 }