1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
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;
}
|
