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
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
|
// Copyright (C) 2018 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
#include "qquicksinglepointhandler_p.h"
#include "qquicksinglepointhandler_p_p.h"
QT_BEGIN_NAMESPACE
Q_DECLARE_LOGGING_CATEGORY(lcTouchTarget)
/*!
\qmltype SinglePointHandler
\qmlabstract
\preliminary
\instantiates QQuickSinglePointHandler
\inherits PointerDeviceHandler
\inqmlmodule QtQuick
\brief Abstract handler for single-point Pointer Events.
An intermediate class (not registered as a QML type)
for the most common handlers: those which expect only a single point.
wantsPointerEvent() will choose the first point which is inside the
\l target item, and return true as long as the event contains that point.
Override handleEventPoint() to implement a single-point handler.
*/
QQuickSinglePointHandler::QQuickSinglePointHandler(QQuickItem *parent)
: QQuickPointerDeviceHandler(*(new QQuickSinglePointHandlerPrivate), parent)
{
}
QQuickSinglePointHandler::QQuickSinglePointHandler(QQuickSinglePointHandlerPrivate &dd, QQuickItem *parent)
: QQuickPointerDeviceHandler(dd, parent)
{
}
bool QQuickSinglePointHandler::wantsPointerEvent(QPointerEvent *event)
{
Q_D(QQuickSinglePointHandler);
if (!QQuickPointerDeviceHandler::wantsPointerEvent(event))
return false;
if (d->pointInfo.id() != -1) {
// We already know which one we want, so check whether it's there.
// It's expected to be an update or a release.
// If we no longer want it, cancel the grab.
int candidatePointCount = 0;
bool missing = true;
QEventPoint *point = nullptr;
for (int i = 0; i < event->pointCount(); ++i) {
auto &p = event->point(i);
const bool found = (p.id() == d->pointInfo.id());
if (found)
missing = false;
if (wantsEventPoint(event, p)) {
++candidatePointCount;
if (found)
point = &p;
}
}
if (missing) {
// Received a stray touch begin event => reset and start over.
if (event->type() == QEvent::TouchBegin && event->points().count() == 1) {
const QEventPoint &point = event->point(0);
qCDebug(lcTouchTarget) << this << "pointId" << Qt::hex << point.id()
<< "was received as a stray TouchBegin event. Canceling existing gesture"
" and starting over.";
d->pointInfo.reset(event, point);
return true;
} else {
qCWarning(lcTouchTarget) << this << "pointId" << Qt::hex << d->pointInfo.id()
<< "is missing from current event, but was neither canceled nor released."
" Ignoring:" << event->type();
}
}
if (point) {
if (candidatePointCount == 1 || (candidatePointCount > 1 && d->ignoreAdditionalPoints)) {
point->setAccepted();
return true;
} else {
cancelAllGrabs(event, *point);
}
} else {
return false;
}
} else {
// We have not yet chosen a point; choose the first one for which wantsEventPoint() returns true.
int candidatePointCount = 0;
QEventPoint *chosen = nullptr;
for (int i = 0; i < event->pointCount(); ++i) {
auto &p = event->point(i);
if (!event->exclusiveGrabber(p) && wantsEventPoint(event, p)) {
++candidatePointCount;
if (!chosen) {
chosen = &p;
break;
}
}
}
if (chosen && candidatePointCount == 1) {
setPointId(chosen->id());
chosen->setAccepted();
}
}
return d->pointInfo.id() != -1;
}
void QQuickSinglePointHandler::handlePointerEventImpl(QPointerEvent *event)
{
Q_D(QQuickSinglePointHandler);
QQuickPointerDeviceHandler::handlePointerEventImpl(event);
QEventPoint *currentPoint = const_cast<QEventPoint *>(event->pointById(d->pointInfo.id()));
Q_ASSERT(currentPoint);
d->pointInfo.reset(event, *currentPoint);
handleEventPoint(event, *currentPoint);
emit pointChanged();
}
void QQuickSinglePointHandler::handleEventPoint(QPointerEvent *event, QEventPoint &point)
{
if (point.state() == QEventPoint::Released) {
// If it's a mouse or tablet event, with buttons,
// do not deactivate unless all acceptable buttons are released.
if (event->isSinglePointEvent()) {
const Qt::MouseButtons releasedButtons = static_cast<QSinglePointEvent *>(event)->buttons();
if ((releasedButtons & acceptedButtons()) != Qt::NoButton)
return;
}
// Deactivate this handler on release
setExclusiveGrab(event, point, false);
d_func()->reset();
}
}
void QQuickSinglePointHandler::onGrabChanged(QQuickPointerHandler *grabber, QPointingDevice::GrabTransition transition, QPointerEvent *event, QEventPoint &point)
{
Q_D(QQuickSinglePointHandler);
if (grabber != this)
return;
switch (transition) {
case QPointingDevice::GrabExclusive:
d->pointInfo.m_sceneGrabPosition = point.sceneGrabPosition();
setActive(true);
QQuickPointerHandler::onGrabChanged(grabber, transition, event, point);
break;
case QPointingDevice::GrabPassive:
d->pointInfo.m_sceneGrabPosition = point.sceneGrabPosition();
QQuickPointerHandler::onGrabChanged(grabber, transition, event, point);
break;
case QPointingDevice::OverrideGrabPassive:
return; // don't emit
case QPointingDevice::UngrabPassive:
case QPointingDevice::UngrabExclusive:
case QPointingDevice::CancelGrabPassive:
case QPointingDevice::CancelGrabExclusive:
// the grab is lost or relinquished, so the point is no longer relevant
QQuickPointerHandler::onGrabChanged(grabber, transition, event, point);
d->reset();
break;
}
}
void QQuickSinglePointHandler::setIgnoreAdditionalPoints(bool v)
{
Q_D(QQuickSinglePointHandler);
d->ignoreAdditionalPoints = v;
}
void QQuickSinglePointHandler::moveTarget(QPointF pos, QEventPoint &point)
{
Q_D(QQuickSinglePointHandler);
target()->setPosition(pos);
d->pointInfo.m_scenePosition = point.scenePosition();
d->pointInfo.m_position = target()->mapFromScene(d->pointInfo.m_scenePosition);
}
void QQuickSinglePointHandler::setPointId(int id)
{
Q_D(QQuickSinglePointHandler);
d->pointInfo.m_id = id;
}
QQuickHandlerPoint QQuickSinglePointHandler::point() const
{
Q_D(const QQuickSinglePointHandler);
return d->pointInfo;
}
/*!
\readonly
\qmlproperty handlerPoint QtQuick::SinglePointHandler::point
The \l eventPoint currently being handled. When no point is currently being
handled, this object is reset to default values (all coordinates are 0).
*/
QQuickSinglePointHandlerPrivate::QQuickSinglePointHandlerPrivate()
: QQuickPointerDeviceHandlerPrivate()
{
}
void QQuickSinglePointHandlerPrivate::reset()
{
Q_Q(QQuickSinglePointHandler);
q->setActive(false);
pointInfo.reset();
}
QT_END_NAMESPACE
#include "moc_qquicksinglepointhandler_p.cpp"
|
