diff -r 000000000000 -r 1918ee327afb demos/qtdemo/guide.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/demos/qtdemo/guide.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,144 @@
+/****************************************************************************
+**
+** 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 demonstration applications 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 <cmath>
+#include "guide.h"
+#include "colors.h"
+
+Guide::Guide(Guide *follows)
+{
+    this->scaleX = 1.0;
+    this->scaleY = 1.0;
+
+    if (follows){
+        while (follows->nextGuide != follows->firstGuide) // append to end
+            follows = follows->nextGuide;
+
+        follows->nextGuide = this;
+        this->prevGuide = follows;
+        this->firstGuide = follows->firstGuide;
+        this->nextGuide = follows->firstGuide;
+        this->startLength = int(follows->startLength + follows->length()) + 1;
+    }
+    else{
+        this->prevGuide = this;
+        this->firstGuide = this;
+        this->nextGuide = this;
+        this->startLength = 0;
+    }
+}
+
+void Guide::setScale(float scaleX, float scaleY, bool all)
+{
+    this->scaleX = scaleX;
+    this->scaleY = scaleY;
+
+    if (all){
+        Guide *next = this->nextGuide;
+        while(next != this){
+            next->scaleX = scaleX;
+            next->scaleY = scaleY;
+            next = next->nextGuide;
+        }
+    }
+}
+
+void Guide::setFence(const QRectF &fence, bool all)
+{
+    this->fence = fence;
+
+    if (all){
+        Guide *next = this->nextGuide;
+        while(next != this){
+            next->fence = fence;
+            next = next->nextGuide;
+        }
+    }
+}
+
+Guide::~Guide()
+{
+    if (this != this->nextGuide && this->nextGuide != this->firstGuide)
+        delete this->nextGuide;
+}
+
+float Guide::lengthAll()
+{
+    float len = length();
+    Guide *next = this->nextGuide;
+    while(next != this){
+        len += next->length();
+        next = next->nextGuide;
+    }
+    return len;
+}
+
+void Guide::move(DemoItem *item, QPointF &dest, float moveSpeed)
+{
+    QLineF walkLine(item->getGuidedPos(), dest);
+    if (moveSpeed >= 0 && walkLine.length() > moveSpeed){
+        // The item is too far away from it's destination point.
+        // So we choose to move it towards it instead.
+        float dx = walkLine.dx();
+        float dy = walkLine.dy();
+
+        if (qAbs(dx) > qAbs(dy)){
+            // walk along x-axis
+            if (dx != 0){
+                float d = moveSpeed * dy / qAbs(dx);
+                float s = dx > 0 ? moveSpeed : -moveSpeed;
+                dest.setX(item->getGuidedPos().x() + s);
+                dest.setY(item->getGuidedPos().y() + d);
+            }
+        }
+        else{
+            // walk along y-axis
+            if (dy != 0){
+                float d = moveSpeed * dx / qAbs(dy);
+                float s = dy > 0 ? moveSpeed : -moveSpeed;
+                dest.setX(item->getGuidedPos().x() + d);
+                dest.setY(item->getGuidedPos().y() + s);
+            }
+        }
+    }
+
+    item->setGuidedPos(dest);
+}