dropsitewidget.cpp Example File
draganddrop/dropsite/dropsitewidget.cpp
/****************************************************************************
**
** Copyright (C) 2005-2005 Trolltech AS. All rights reserved.
**
** This file is part of the documentation 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
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** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
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****************************************************************************/
#include <QtGui>
#include "dropsitewidget.h"
#include "dropsitewindow.h"
DropSiteWidget::DropSiteWidget(QWidget *parent)
: QLabel(parent)
{
setMinimumSize(200, 200);
setFrameStyle(QFrame::Sunken | QFrame::StyledPanel);
setAcceptDrops(true);
setBackgroundRole(QPalette::Dark);
setText(tr("<drop content>"));
setAlignment(Qt::AlignCenter);
}
void DropSiteWidget::dragEnterEvent(QDragEnterEvent *event)
{
setText(tr("<drop content>"));
setBackgroundRole(QPalette::Light);
event->acceptProposedAction();
emit changed(event->mimeData());
}
void DropSiteWidget::dropEvent(QDropEvent *event)
{
const QMimeData *mimeData = event->mimeData();
QStringList formats = mimeData->formats();
foreach (QString format, formats)
{
if (format.startsWith("image/")) {
QPixmap pixmap = createPixmap(mimeData->data(format), format);
if (!pixmap.isNull()) {
setPixmap(pixmap);
break;
}
}
QString text = createPlainText(mimeData->data(format), format);
if (!text.isEmpty()) {
setText(text);
break;
} else {
setText(tr("No supported format"));
}
}
setBackgroundRole(QPalette::Dark);
event->acceptProposedAction();
}
void DropSiteWidget::dragLeaveEvent(QDragLeaveEvent *event)
{
clear();
event->accept();
}
void DropSiteWidget::clear()
{
setText(tr("<drop content>"));
setBackgroundRole(QPalette::Dark);
emit changed();
}
QPixmap DropSiteWidget::createPixmap(QByteArray data, QString format)
{
QList<QByteArray> imageFormats = QImageReader::supportedImageFormats();
QPixmap pixmap;
foreach (QByteArray imageFormat, imageFormats) {
if (format.mid(6) == QString(imageFormat)) {
pixmap.loadFromData(data, imageFormat);
break;
}
}
return pixmap;
}
QString DropSiteWidget::createPlainText(QByteArray data, QString format)
{
QString text = "";
if (format.startsWith("text/plain")) {
text.append(QString(data));
} else if (format.startsWith("text/plain;")) {
int index = format.indexOf('=');
if (index > 0) {
QTextCodec *codec = QTextCodec::codecForName(format.mid(index + 1).toAscii());
text.append(QString(codec->toUnicode(data)));
}
}
return text;
}