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
|
// Copyright (C) 2017 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 "qquickcheckdelegate_p.h"
#include "qquickitemdelegate_p_p.h"
#include <QtGui/qpa/qplatformtheme.h>
#include <QtQml/qjsvalue.h>
QT_BEGIN_NAMESPACE
/*!
\qmltype CheckDelegate
\inherits ItemDelegate
//! \nativetype QQuickCheckDelegate
\inqmlmodule QtQuick.Controls
\since 5.7
\ingroup qtquickcontrols-delegates
\brief Item delegate with a check indicator that can be toggled on or off.
\image qtquickcontrols-checkdelegate.gif
CheckDelegate presents an item delegate that can be toggled on (checked) or
off (unchecked). Check delegates are typically used to select one or more
options from a set of options in a list. For smaller sets of options, or
for options that need to be uniquely identifiable, consider using
\l CheckBox instead.
CheckDelegate inherits its API from \l ItemDelegate, which is inherited
from AbstractButton. For instance, you can set \l {AbstractButton::text}{text},
and react to \l {AbstractButton::clicked}{clicks} using the AbstractButton
API. The state of the check delegate can be set with the
\l {AbstractButton::}{checked} property.
In addition to the checked and unchecked states, there is a third state:
partially checked. The partially checked state can be enabled using the
\l tristate property. This state indicates that the regular checked/unchecked
state can not be determined; generally because of other states that affect
the check delegate. This state is useful when several child nodes are selected
in a treeview, for example.
\code
ListView {
model: ["Option 1", "Option 2", "Option 3"]
delegate: CheckDelegate {
text: modelData
}
}
\endcode
\sa {Customizing CheckDelegate}, {Delegate Controls}, CheckBox
*/
class QQuickCheckDelegatePrivate : public QQuickItemDelegatePrivate
{
Q_DECLARE_PUBLIC(QQuickCheckDelegate)
public:
void setNextCheckState(const QJSValue &callback);
QPalette defaultPalette() const override { return QQuickTheme::palette(QQuickTheme::ListView); }
bool tristate = false;
Qt::CheckState checkState = Qt::Unchecked;
QJSValue nextCheckState;
};
void QQuickCheckDelegatePrivate::setNextCheckState(const QJSValue &callback)
{
Q_Q(QQuickCheckDelegate);
nextCheckState = callback;
emit q->nextCheckStateChanged();
}
QQuickCheckDelegate::QQuickCheckDelegate(QQuickItem *parent)
: QQuickItemDelegate(*(new QQuickCheckDelegatePrivate), parent)
{
setCheckable(true);
}
/*!
\qmlproperty bool QtQuick.Controls::CheckDelegate::tristate
This property determines whether the check delegate has three states.
In the animation below, the first checkdelegate is tri-state:
\image qtquickcontrols-checkdelegate-tristate.gif
The default is \c false, i.e., the delegate has only two states.
*/
bool QQuickCheckDelegate::isTristate() const
{
Q_D(const QQuickCheckDelegate);
return d->tristate;
}
void QQuickCheckDelegate::setTristate(bool tristate)
{
Q_D(QQuickCheckDelegate);
if (d->tristate == tristate)
return;
d->tristate = tristate;
emit tristateChanged();
}
/*!
\qmlproperty enumeration QtQuick.Controls::CheckDelegate::checkState
This property determines the check state of the check delegate.
Available states:
\value Qt.Unchecked The delegate is unchecked.
\value Qt.PartiallyChecked The delegate is partially checked. This state is only used when \l tristate is enabled.
\value Qt.Checked The delegate is checked.
\sa tristate, {AbstractButton::checked}{checked}
*/
Qt::CheckState QQuickCheckDelegate::checkState() const
{
Q_D(const QQuickCheckDelegate);
return d->checkState;
}
void QQuickCheckDelegate::setCheckState(Qt::CheckState state)
{
Q_D(QQuickCheckDelegate);
if (d->checkState == state)
return;
bool wasChecked = isChecked();
d->checked = state == Qt::Checked;
d->checkState = state;
emit checkStateChanged();
if (d->checked != wasChecked)
emit checkedChanged();
}
QFont QQuickCheckDelegate::defaultFont() const
{
return QQuickTheme::font(QQuickTheme::ListView);
}
void QQuickCheckDelegate::buttonChange(ButtonChange change)
{
if (change == ButtonCheckedChange)
setCheckState(isChecked() ? Qt::Checked : Qt::Unchecked);
else
QQuickAbstractButton::buttonChange(change);
}
/*!
\since QtQuick.Controls 2.4 (Qt 5.11)
\qmlproperty function QtQuick.Controls::CheckDelegate::nextCheckState
This property holds a callback function that is called to determine
the next check state whenever the check delegate is interactively toggled
by the user via touch, mouse, or keyboard.
By default, a normal check delegate cycles between \c Qt.Unchecked and
\c Qt.Checked states, and a tri-state check delegate cycles between
\c Qt.Unchecked, \c Qt.PartiallyChecked, and \c Qt.Checked states.
The \c nextCheckState callback function can override the default behavior.
The following example implements a tri-state check delegate that can present
a partially checked state depending on external conditions, but never
cycles to the partially checked state when interactively toggled by
the user.
\code
CheckDelegate {
tristate: true
checkState: allChildrenChecked ? Qt.Checked :
anyChildChecked ? Qt.PartiallyChecked : Qt.Unchecked
nextCheckState: function() {
if (checkState === Qt.Checked)
return Qt.Unchecked
else
return Qt.Checked
}
}
\endcode
*/
void QQuickCheckDelegate::nextCheckState()
{
Q_D(QQuickCheckDelegate);
if (d->nextCheckState.isCallable())
setCheckState(static_cast<Qt::CheckState>(d->nextCheckState.call().toInt()));
else if (d->tristate)
setCheckState(static_cast<Qt::CheckState>((d->checkState + 1) % 3));
else
QQuickItemDelegate::nextCheckState();
}
#if QT_CONFIG(accessibility)
QAccessible::Role QQuickCheckDelegate::accessibleRole() const
{
return QAccessible::CheckBox;
}
#endif
QT_END_NAMESPACE
#include "moc_qquickcheckdelegate_p.cpp"
|
