examples/draganddrop/draggableicons/dragwidget.cpp
changeset 0 1918ee327afb
child 4 3b1da2848fc7
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/draganddrop/draggableicons/dragwidget.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,169 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtGui>
+
+#include "dragwidget.h"
+
+//! [0]
+DragWidget::DragWidget(QWidget *parent)
+    : QFrame(parent)
+{
+    setMinimumSize(200, 200);
+    setFrameStyle(QFrame::Sunken | QFrame::StyledPanel);
+    setAcceptDrops(true);
+
+    QLabel *boatIcon = new QLabel(this);
+    boatIcon->setPixmap(QPixmap(":/images/boat.png"));
+    boatIcon->move(20, 20);
+    boatIcon->show();
+    boatIcon->setAttribute(Qt::WA_DeleteOnClose);
+
+    QLabel *carIcon = new QLabel(this);
+    carIcon->setPixmap(QPixmap(":/images/car.png"));
+    carIcon->move(120, 20);
+    carIcon->show();
+    carIcon->setAttribute(Qt::WA_DeleteOnClose);
+
+    QLabel *houseIcon = new QLabel(this);
+    houseIcon->setPixmap(QPixmap(":/images/house.png"));
+    houseIcon->move(20, 120);
+    houseIcon->show();
+    houseIcon->setAttribute(Qt::WA_DeleteOnClose);
+}
+//! [0]
+
+void DragWidget::dragEnterEvent(QDragEnterEvent *event)
+{
+    if (event->mimeData()->hasFormat("application/x-dnditemdata")) {
+        if (event->source() == this) {
+            event->setDropAction(Qt::MoveAction);
+            event->accept();
+        } else {
+            event->acceptProposedAction();
+        }
+    } else {
+        event->ignore();
+    }
+}
+
+void DragWidget::dragMoveEvent(QDragMoveEvent *event)
+{
+    if (event->mimeData()->hasFormat("application/x-dnditemdata")) {
+        if (event->source() == this) {
+            event->setDropAction(Qt::MoveAction);
+            event->accept();
+        } else {
+            event->acceptProposedAction();
+        }
+    } else {
+        event->ignore();
+    }
+}
+
+void DragWidget::dropEvent(QDropEvent *event)
+{
+    if (event->mimeData()->hasFormat("application/x-dnditemdata")) {
+        QByteArray itemData = event->mimeData()->data("application/x-dnditemdata");
+        QDataStream dataStream(&itemData, QIODevice::ReadOnly);
+        
+        QPixmap pixmap;
+        QPoint offset;
+        dataStream >> pixmap >> offset;
+
+        QLabel *newIcon = new QLabel(this);
+        newIcon->setPixmap(pixmap);
+        newIcon->move(event->pos() - offset);
+        newIcon->show();
+        newIcon->setAttribute(Qt::WA_DeleteOnClose);
+
+        if (event->source() == this) {
+            event->setDropAction(Qt::MoveAction);
+            event->accept();
+        } else {
+            event->acceptProposedAction();
+        }
+    } else {
+        event->ignore();
+    }
+}
+
+//! [1]
+void DragWidget::mousePressEvent(QMouseEvent *event)
+{
+    QLabel *child = static_cast<QLabel*>(childAt(event->pos()));
+    if (!child)
+        return;
+
+    QPixmap pixmap = *child->pixmap();
+
+    QByteArray itemData;
+    QDataStream dataStream(&itemData, QIODevice::WriteOnly);
+    dataStream << pixmap << QPoint(event->pos() - child->pos());
+//! [1]
+
+//! [2]
+    QMimeData *mimeData = new QMimeData;
+    mimeData->setData("application/x-dnditemdata", itemData);
+//! [2]
+        
+//! [3]
+    QDrag *drag = new QDrag(this);
+    drag->setMimeData(mimeData);
+    drag->setPixmap(pixmap);
+    drag->setHotSpot(event->pos() - child->pos());
+//! [3]
+
+    QPixmap tempPixmap = pixmap;
+    QPainter painter;
+    painter.begin(&tempPixmap);
+    painter.fillRect(pixmap.rect(), QColor(127, 127, 127, 127));
+    painter.end();
+
+    child->setPixmap(tempPixmap);
+
+    if (drag->exec(Qt::CopyAction | Qt::MoveAction, Qt::CopyAction) == Qt::MoveAction)
+        child->close();
+    else {
+        child->show();
+        child->setPixmap(pixmap);
+    }
+}