1// Copyright (C) 2016 The Qt Company Ltd.
2// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
3
4#include "qquickpathinterpolator_p.h"
5
6#include "qquickpath_p.h"
7
8QT_BEGIN_NAMESPACE
9
10/*!
11 \qmltype PathInterpolator
12 \nativetype QQuickPathInterpolator
13 \inqmlmodule QtQuick
14 \ingroup qtquick-animation-control
15 \brief Specifies how to manually animate along a path.
16
17 PathInterpolator provides \c x, \c y, and \c angle information for a particular \c progress
18 along a path.
19
20 In the following example, we animate a green rectangle along a bezier path.
21
22 \snippet qml/pathinterpolator.qml 0
23*/
24
25QQuickPathInterpolator::QQuickPathInterpolator(QObject *parent) :
26 QObject(parent), _path(nullptr), _x(0), _y(0), _angle(0), _progress(0)
27{
28}
29
30/*!
31 \qmlproperty Path QtQuick::PathInterpolator::path
32 This property holds the path to interpolate.
33
34 For more information on defining a path see the \l Path documentation.
35*/
36QQuickPath *QQuickPathInterpolator::path() const
37{
38 return _path;
39}
40
41void QQuickPathInterpolator::setPath(QQuickPath *path)
42{
43 if (_path == path)
44 return;
45 if (_path)
46 disconnect(sender: _path, SIGNAL(changed()), receiver: this, SLOT(_q_pathUpdated()));
47 _path = path;
48 connect(sender: _path, SIGNAL(changed()), receiver: this, SLOT(_q_pathUpdated()));
49 emit pathChanged();
50}
51
52/*!
53 \qmlproperty real QtQuick::PathInterpolator::progress
54 This property holds the current progress along the path.
55
56 Typical usage of PathInterpolator is to set the progress
57 (often via a NumberAnimation), and read the corresponding
58 values for x, y, and angle (often via bindings to these values).
59
60 Progress ranges from 0.0 to 1.0.
61*/
62qreal QQuickPathInterpolator::progress() const
63{
64 return _progress;
65}
66
67void QQuickPathInterpolator::setProgress(qreal progress)
68{
69 progress = qMin(a: qMax(a: progress, b: (qreal)0.0), b: (qreal)1.0);
70
71 if (progress == _progress)
72 return;
73 _progress = progress;
74 emit progressChanged();
75 _q_pathUpdated();
76}
77
78/*!
79 \qmlproperty real QtQuick::PathInterpolator::x
80 \qmlproperty real QtQuick::PathInterpolator::y
81
82 These properties hold the position of the path at \l progress.
83*/
84qreal QQuickPathInterpolator::x() const
85{
86 return _x;
87}
88
89qreal QQuickPathInterpolator::y() const
90{
91 return _y;
92}
93
94/*!
95 \qmlproperty real QtQuick::PathInterpolator::angle
96
97 This property holds the angle of the path tangent at \l progress.
98
99 Angles are reported clockwise, with zero degrees at the 3 o'clock position.
100*/
101qreal QQuickPathInterpolator::angle() const
102{
103 return _angle;
104}
105
106void QQuickPathInterpolator::_q_pathUpdated()
107{
108 if (! _path)
109 return;
110
111 qreal angle = 0;
112 const QPointF pt = _path->sequentialPointAt(p: _progress, angle: &angle);
113
114 if (_x != pt.x()) {
115 _x = pt.x();
116 emit xChanged();
117 }
118
119 if (_y != pt.y()) {
120 _y = pt.y();
121 emit yChanged();
122 }
123
124 //convert to clockwise
125 angle = qreal(360) - angle;
126 if (qFuzzyCompare(p1: angle, p2: qreal(360)))
127 angle = qreal(0);
128
129 if (angle != _angle) {
130 _angle = angle;
131 emit angleChanged();
132 }
133}
134
135QT_END_NAMESPACE
136
137#include "moc_qquickpathinterpolator_p.cpp"
138

source code of qtdeclarative/src/quick/util/qquickpathinterpolator.cpp