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
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
|
/****************************************************************************
**
** Copyright (C) 2017 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtQuick module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
** Qt Foundation. The licenses are as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "qquicktaphandler_p.h"
#include <qpa/qplatformtheme.h>
#include <private/qguiapplication_p.h>
#include <QtGui/qstylehints.h>
QT_BEGIN_NAMESPACE
qreal QQuickTapHandler::m_multiTapInterval(0.0);
// single tap distance is the same as the drag threshold
int QQuickTapHandler::m_mouseMultiClickDistanceSquared(-1);
int QQuickTapHandler::m_touchMultiTapDistanceSquared(-1);
/*!
\qmltype TapHandler
\instantiates QQuickTapHandler
\inqmlmodule QtQuick
\ingroup qtquick-handlers
\brief Handler for taps and clicks
TapHandler is a handler for taps on a touchscreen or clicks on a mouse.
It requires that any movement between the press and release remains
less than the drag threshold for a single tap, and less than
QPlatformTheme::MouseDoubleClickDistance for multi-tap gestures
(double-tap, triple-tap, etc.) with the mouse, or 10 pixels with touch.
It also requires that the time between press and release remains
less than QStyleHints::mouseDoubleClickInterval() for a single tap,
and that the time from one press/release sequence to the next remains
less than QStyleHints::mouseDoubleClickInterval() for multi-tap gestures.
Note that buttons (such as QPushButton) are often implemented not to care
whether the press and release occur close together: if you press the button
and then change your mind, you need to drag all the way off the edge of the
button in order to cancel the click. If you want to achieve such behavior,
it's enough to use a PointerHandler and consider the button clicked on
every \l {QQuickPointerHandler:}{released} event. But TapHandler requires
that the events occur close together in both space and time, which is anyway
necessary to detect double clicks or multi-click gestures.
\sa MouseArea
*/
QQuickTapHandler::QQuickTapHandler(QObject *parent)
: QQuickPointerSingleHandler(parent)
, m_pressed(false)
, m_tapCount(0)
, m_lastTapTimestamp(0.0)
{
setAcceptedButtons(Qt::LeftButton);
if (m_mouseMultiClickDistanceSquared < 0) {
m_multiTapInterval = qApp->styleHints()->mouseDoubleClickInterval() / 1000.0;
m_mouseMultiClickDistanceSquared = QGuiApplicationPrivate::platformTheme()->
themeHint(QPlatformTheme::MouseDoubleClickDistance).toInt();
m_mouseMultiClickDistanceSquared *= m_mouseMultiClickDistanceSquared;
m_touchMultiTapDistanceSquared = QGuiApplicationPrivate::platformTheme()->
themeHint(QPlatformTheme::TouchDoubleTapDistance).toInt();
m_touchMultiTapDistanceSquared *= m_touchMultiTapDistanceSquared;
}
}
QQuickTapHandler::~QQuickTapHandler()
{
}
bool QQuickTapHandler::wantsEventPoint(QQuickEventPoint *point)
{
if (point->state() == QQuickEventPoint::Pressed && parentContains(point))
return true;
// If the user has not dragged too far, it could be a tap.
// Otherwise we want to give up the grab so that a competing handler
// (e.g. DragHandler) gets a chance to take over.
// Don't forget to emit released in case of a cancel.
return !point->isDraggedOverThreshold();
}
void QQuickTapHandler::handleEventPoint(QQuickEventPoint *point)
{
switch (point->state()) {
case QQuickEventPoint::Pressed:
setPressed(true, false, point);
break;
case QQuickEventPoint::Released:
if ((point->pointerEvent()->buttons() & m_acceptedButtons) == Qt::NoButton)
setPressed(false, false, point);
break;
default:
break;
}
}
void QQuickTapHandler::setPressed(bool press, bool cancel, QQuickEventPoint *point)
{
if (m_pressed != press) {
m_pressed = press;
if (!cancel && !press && point->timeHeld() < m_multiTapInterval) {
// Assuming here that pointerEvent()->timestamp() is in ms.
qreal ts = point->pointerEvent()->timestamp() / 1000.0;
if (ts - m_lastTapTimestamp < m_multiTapInterval &&
QVector2D(point->scenePos() - m_lastTapPos).lengthSquared() <
(point->pointerEvent()->device()->type() == QQuickPointerDevice::Mouse ?
m_mouseMultiClickDistanceSquared : m_touchMultiTapDistanceSquared))
++m_tapCount;
else
m_tapCount = 1;
emit tapped(point);
emit tapCountChanged();
m_lastTapTimestamp = ts;
m_lastTapPos = point->scenePos();
}
emit pressedChanged();
}
}
void QQuickTapHandler::handleGrabCancel(QQuickEventPoint *point)
{
QQuickPointerSingleHandler::handleGrabCancel(point);
setPressed(false, true, point);
}
/*!
\qmlproperty tapCount
The number of taps which have occurred within the time and space
constraints to be considered a single gesture. For example, to detect
a double-tap, you can write
\qml
Rectangle {
width: 100; height: 30
signal doubleTap
TapHandler {
acceptedButtons: Qt.AllButtons
onTapped: if (tapCount == 2) doubleTap()
}
}
*/
QT_END_NAMESPACE
|
