--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/graphicsview/elasticnodes/graphwidget.d	Wed Jul 07 22:54:12 2010 +0100
@@ -0,0 +1,232 @@
+/****************************************************************************
+**
+** Copyright (C) 2010 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.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial Usage
+** Licensees holding valid Qt Commercial licenses may use this file in
+** accordance with the Qt Commercial License Agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Nokia.
+**
+** 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.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 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 the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import
+    std.math;
+
+import
+    qt.gui.QLinearGradient,
+    qt.gui.QGraphicsView,
+    qt.gui.QGraphicsScene;
+
+import
+    edge,
+    node;
+
+class GraphWidget : QGraphicsView
+{
+public:
+    this()
+    {
+        auto scene = new QGraphicsScene(this);
+        scene.setItemIndexMethod(QGraphicsScene.NoIndex);
+        scene.setSceneRect(-200, -200, 400, 400);
+        setScene(scene);
+        setCacheMode(CacheBackground);
+        setViewportUpdateMode(BoundingRectViewportUpdate);
+        setRenderHint(QPainter.Antialiasing);
+        setTransformationAnchor(AnchorUnderMouse);
+        setResizeAnchor(AnchorViewCenter);
+
+        Node node1 = new Node(this);
+        Node node2 = new Node(this);
+        Node node3 = new Node(this);
+        Node node4 = new Node(this);
+        centerNode = new Node(this);
+        Node node6 = new Node(this);
+        Node node7 = new Node(this);
+        Node node8 = new Node(this);
+        Node node9 = new Node(this);
+        scene.addItem(node1);
+        scene.addItem(node2);
+        scene.addItem(node3);
+        scene.addItem(node4);
+        scene.addItem(centerNode);
+        scene.addItem(node6);
+        scene.addItem(node7);
+        scene.addItem(node8);
+        scene.addItem(node9);
+        scene.addItem(new Edge(node1, node2));
+        scene.addItem(new Edge(node2, node3));
+        scene.addItem(new Edge(node2, centerNode));
+        scene.addItem(new Edge(node3, node6));
+        scene.addItem(new Edge(node4, node1));
+        scene.addItem(new Edge(node4, centerNode));
+        scene.addItem(new Edge(centerNode, node6));
+        scene.addItem(new Edge(centerNode, node8));
+        scene.addItem(new Edge(node6, node9));
+        scene.addItem(new Edge(node7, node4));
+        scene.addItem(new Edge(node8, node7));
+        scene.addItem(new Edge(node9, node8));
+
+        node1.setPos(-50, -50);
+        node2.setPos(0, -50);
+        node3.setPos(50, -50);
+        node4.setPos(-50, 0);
+        centerNode.setPos(0, 0);
+        node6.setPos(50, 0);
+        node7.setPos(-50, 50);
+        node8.setPos(0, 50);
+        node9.setPos(50, 50);
+
+        scale(0.8, 0.8);
+        setMinimumSize(400, 400);
+        setWindowTitle(tr("Elastic Nodes"));        
+    }
+
+    void itemMoved()
+    {    
+        if (!timerId)
+            timerId = startTimer(1000 / 25);
+    }
+    
+protected:
+    void keyPressEvent(QKeyEvent event)
+    {
+        switch (event.key()) {
+        case Qt.Key_Up:
+            centerNode.moveBy(0, -20);
+            break;
+        case Qt.Key_Down:
+            centerNode.moveBy(0, 20);
+            break;
+        case Qt.Key_Left:
+            centerNode.moveBy(-20, 0);
+            break;
+        case Qt.Key_Right:
+            centerNode.moveBy(20, 0);
+            break;
+        case Qt.Key_Plus:
+            scaleView(1.2);
+            break;
+        case Qt.Key_Minus:
+            scaleView(1 / 1.2);
+            break;
+        case Qt.Key_Space:
+        case Qt.Key_Enter:
+            foreach (IQGraphicsItem item; scene().items()) {
+                if (cast(Node)item)
+                    item.setPos(-150 + qrand() % 300, -150 + qrand() % 300);
+            }
+            break;
+        default:
+            super.keyPressEvent(event);
+        }
+    }
+    
+    void timerEvent(QTimerEvent event)
+    {
+        Node[] nodes;
+        foreach (IQGraphicsItem item; scene().items()) {
+            if (auto node = cast(Node)item)
+                nodes ~= node;
+        }
+
+        foreach (Node node; nodes)
+            node.calculateForces();
+
+        bool itemsMoved = false;
+        foreach (Node node; nodes) {
+            if (node.advance())
+                itemsMoved = true;
+        }
+
+        if (!itemsMoved) {
+            killTimer(timerId);
+            timerId = 0;
+        }
+    }
+
+    void wheelEvent(QWheelEvent event)
+    {
+        scaleView(pow(cast(float)2, cast(float)(-event.delta() / 240.0)));
+    }
+    
+    void drawBackground(QPainter painter, const QRectF rect)
+    {
+        // Shadow
+        QRectF sceneRect = this.sceneRect();
+        auto rightShadow = QRectF(sceneRect.right(), sceneRect.top() + 5, 5, sceneRect.height());
+        auto bottomShadow = QRectF(sceneRect.left() + 5, sceneRect.bottom(), sceneRect.width(), 5);
+        if (rightShadow.intersects(rect) || rightShadow.contains(rect))
+	    painter.fillRect(rightShadow, Qt.darkGray);
+        if (bottomShadow.intersects(rect) || bottomShadow.contains(rect))
+	    painter.fillRect(bottomShadow, Qt.darkGray);
+
+        // Fill
+        auto gradient = new QLinearGradient(sceneRect.topLeft(), sceneRect.bottomRight());
+        gradient.setColorAt(0, new QColor(Qt.white));
+        gradient.setColorAt(1, new QColor(Qt.lightGray));
+        painter.fillRect(rect.intersected(sceneRect), new QBrush(gradient));
+        painter.setBrush(Qt.NoBrush);
+        painter.drawRect(sceneRect);
+
+        // Text
+        auto textRect = QRectF(sceneRect.left() + 4, sceneRect.top() + 4,
+                        sceneRect.width() - 4, sceneRect.height() - 4);
+        string message = tr("Click and drag the nodes around, and zoom with the mouse "
+                           "wheel or the '+' and '-' keys");
+
+        QFont font = painter.font();
+        font.setBold(true);
+        font.setPointSize(14);
+        painter.setFont(font);
+        painter.setPen(new QColor(Qt.lightGray));
+        painter.drawText(textRect.translated(2, 2), message);
+        painter.setPen(new QColor(Qt.black));
+        painter.drawText(textRect, message);
+    }
+
+    void scaleView(qreal scaleFactor)
+    {
+        qreal factor = matrix().scale(scaleFactor, scaleFactor).mapRect(QRectF(0, 0, 1, 1)).width();
+        if (factor < 0.07 || factor > 100)
+            return;
+
+        scale(scaleFactor, scaleFactor);
+    }
+
+private:
+    int timerId;
+    Node centerNode;
+
+    mixin Q_OBJECT;
+};