qt5base-lts/examples/draganddrop/fridgemagnets/dragwidget.cpp

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/****************************************************************************
**
** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/
**
** 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 Nokia Corporation 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.
**
** 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
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include <QtWidgets>
#include "draglabel.h"
#include "dragwidget.h"
//! [0]
DragWidget::DragWidget(QWidget *parent)
: QWidget(parent)
{
QFile dictionaryFile(":/dictionary/words.txt");
dictionaryFile.open(QFile::ReadOnly);
QTextStream inputStream(&dictionaryFile);
//! [0]
//! [1]
int x = 5;
int y = 5;
while (!inputStream.atEnd()) {
QString word;
inputStream >> word;
if (!word.isEmpty()) {
DragLabel *wordLabel = new DragLabel(word, this);
wordLabel->move(x, y);
wordLabel->show();
wordLabel->setAttribute(Qt::WA_DeleteOnClose);
x += wordLabel->width() + 2;
if (x >= 245) {
x = 5;
y += wordLabel->height() + 2;
}
}
}
//! [1]
//! [2]
//Fridge magnets is used for demoing Qt on S60 and themed backgrounds look better than white
QPalette newPalette = palette();
newPalette.setColor(QPalette::Window, Qt::white);
setPalette(newPalette);
setMinimumSize(400, qMax(200, y));
setWindowTitle(tr("Fridge Magnets"));
//! [2] //! [3]
setAcceptDrops(true);
}
//! [3]
//! [4]
void DragWidget::dragEnterEvent(QDragEnterEvent *event)
{
//! [4] //! [5]
if (event->mimeData()->hasFormat("application/x-fridgemagnet")) {
if (children().contains(event->source())) {
event->setDropAction(Qt::MoveAction);
event->accept();
} else {
event->acceptProposedAction();
//! [5] //! [6]
}
//! [6] //! [7]
} else if (event->mimeData()->hasText()) {
event->acceptProposedAction();
} else {
event->ignore();
}
}
//! [7]
//! [8]
void DragWidget::dragMoveEvent(QDragMoveEvent *event)
{
if (event->mimeData()->hasFormat("application/x-fridgemagnet")) {
if (children().contains(event->source())) {
event->setDropAction(Qt::MoveAction);
event->accept();
} else {
event->acceptProposedAction();
}
} else if (event->mimeData()->hasText()) {
event->acceptProposedAction();
} else {
event->ignore();
}
}
//! [8]
//! [9]
void DragWidget::dropEvent(QDropEvent *event)
{
if (event->mimeData()->hasFormat("application/x-fridgemagnet")) {
const QMimeData *mime = event->mimeData();
//! [9] //! [10]
QByteArray itemData = mime->data("application/x-fridgemagnet");
QDataStream dataStream(&itemData, QIODevice::ReadOnly);
QString text;
QPoint offset;
dataStream >> text >> offset;
//! [10]
//! [11]
DragLabel *newLabel = new DragLabel(text, this);
newLabel->move(event->pos() - offset);
newLabel->show();
newLabel->setAttribute(Qt::WA_DeleteOnClose);
if (event->source() == this) {
event->setDropAction(Qt::MoveAction);
event->accept();
} else {
event->acceptProposedAction();
}
//! [11] //! [12]
} else if (event->mimeData()->hasText()) {
QStringList pieces = event->mimeData()->text().split(QRegExp("\\s+"),
QString::SkipEmptyParts);
QPoint position = event->pos();
foreach (QString piece, pieces) {
DragLabel *newLabel = new DragLabel(piece, this);
newLabel->move(position);
newLabel->show();
newLabel->setAttribute(Qt::WA_DeleteOnClose);
position += QPoint(newLabel->width(), 0);
}
event->acceptProposedAction();
} else {
event->ignore();
}
}
//! [12]
//! [13]
void DragWidget::mousePressEvent(QMouseEvent *event)
{
//! [13]
//! [14]
DragLabel *child = static_cast<DragLabel*>(childAt(event->pos()));
if (!child)
return;
QPoint hotSpot = event->pos() - child->pos();
QByteArray itemData;
QDataStream dataStream(&itemData, QIODevice::WriteOnly);
dataStream << child->labelText() << QPoint(hotSpot);
//! [14]
//! [15]
QMimeData *mimeData = new QMimeData;
mimeData->setData("application/x-fridgemagnet", itemData);
mimeData->setText(child->labelText());
//! [15]
//! [16]
QDrag *drag = new QDrag(this);
drag->setMimeData(mimeData);
drag->setPixmap(*child->pixmap());
drag->setHotSpot(hotSpot);
child->hide();
//! [16]
//! [17]
if (drag->exec(Qt::MoveAction | Qt::CopyAction, Qt::CopyAction) == Qt::MoveAction)
child->close();
else
child->show();
}
//! [17]