examples/multitouch/knobs/knob.cpp
changeset 0 1918ee327afb
child 4 3b1da2848fc7
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/multitouch/knobs/knob.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,89 @@
+/****************************************************************************
+**
+** 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 "knob.h"
+
+#include <QBrush>
+#include <QTouchEvent>
+
+Knob::Knob()
+    : QGraphicsEllipseItem(-50, -50, 100, 100)
+{
+    setAcceptTouchEvents(true);
+    setBrush(Qt::lightGray);
+
+    QGraphicsEllipseItem *leftItem = new QGraphicsEllipseItem(0, 0, 20, 20, this);
+    leftItem->setPos(-40, -10);
+    leftItem->setBrush(Qt::darkGreen);
+
+    QGraphicsEllipseItem *rightItem = new QGraphicsEllipseItem(0, 0, 20, 20, this);
+    rightItem->setPos(20, -10);
+    rightItem->setBrush(Qt::darkRed);
+}
+
+bool Knob::sceneEvent(QEvent *event)
+{
+    switch (event->type()) {
+    case QEvent::TouchBegin:
+    case QEvent::TouchUpdate:
+    case QEvent::TouchEnd:
+    {
+        QTouchEvent *touchEvent = static_cast<QTouchEvent *>(event);
+
+        if (touchEvent->touchPoints().count() == 2) {
+            const QTouchEvent::TouchPoint &touchPoint1 = touchEvent->touchPoints().first();
+            const QTouchEvent::TouchPoint &touchPoint2 = touchEvent->touchPoints().last();
+
+            QLineF line1(touchPoint1.lastScenePos(), touchPoint2.lastScenePos());
+            QLineF line2(touchPoint1.scenePos(), touchPoint2.scenePos());
+
+            rotate(line2.angleTo(line1));
+        }
+
+        break;
+    }
+
+    default:
+        return QGraphicsItem::sceneEvent(event);
+    }
+
+    return true;
+}