droparea.cpp Example File

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  #include "droparea.h"

  #include <QDragEnterEvent>
  #include <QMimeData>

  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)
              text += urlList.at(i).path() + QLatin1Char('\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();
  }