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
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
|
/****************************************************************************
**
** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtGui 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 Digia. For licensing terms and
** conditions see http://qt.digia.com/licensing. For further information
** use the contact form at http://qt.digia.com/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 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, Digia gives you certain additional
** rights. These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "qwidgetaction.h"
#include "qdebug.h"
#ifndef QT_NO_ACTION
#include "qwidgetaction_p.h"
QT_BEGIN_NAMESPACE
/*!
\class QWidgetAction
\since 4.2
\brief The QWidgetAction class extends QAction by an interface
for inserting custom widgets into action based containers, such
as toolbars.
\ingroup mainwindow-classes
Most actions in an application are represented as items in menus or
buttons in toolbars. However sometimes more complex widgets are
necessary. For example a zoom action in a word processor may be
realized using a QComboBox in a QToolBar, presenting a range
of different zoom levels. QToolBar provides QToolBar::insertWidget()
as convenience function for inserting a single widget.
However if you want to implement an action that uses custom
widgets for visualization in multiple containers then you have to
subclass QWidgetAction.
If a QWidgetAction is added for example to a QToolBar then
QWidgetAction::createWidget() is called. Reimplementations of that
function should create a new custom widget with the specified parent.
If the action is removed from a container widget then
QWidgetAction::deleteWidget() is called with the previously created custom
widget as argument. The default implementation hides the widget and deletes
it using QObject::deleteLater().
If you have only one single custom widget then you can set it as default
widget using setDefaultWidget(). That widget will then be used if the
action is added to a QToolBar, or in general to an action container that
supports QWidgetAction. If a QWidgetAction with only a default widget is
added to two toolbars at the same time then the default widget is shown
only in the first toolbar the action was added to. QWidgetAction takes
over ownership of the default widget.
Note that it is up to the widget to activate the action, for example by
reimplementing mouse event handlers and calling QAction::trigger().
\bold {Mac OS X}: If you add a widget to a menu in the application's menu
bar on Mac OS X, the widget will be added and it will function but with some
limitations:
\list 1
\o The widget is reparented away from the QMenu to the native menu
view. If you show the menu in some other place (e.g. as a popup menu),
the widget will not be there.
\o Focus/Keyboard handling of the widget is not possible.
\o Due to Apple's design, mouse tracking on the widget currently does
not work.
\o Connecting the triggered() signal to a slot that opens a modal
dialog will cause a crash in Mac OS X 10.4 (known bug acknowledged
by Apple), a workaround is to use a QueuedConnection instead of a
DirectConnection.
\endlist
\sa QAction, QActionGroup, QWidget
*/
/*!
Constructs an action with \a parent.
*/
QWidgetAction::QWidgetAction(QObject *parent)
: QAction(*(new QWidgetActionPrivate), parent)
{
}
/*!
Destroys the object and frees allocated resources.
*/
QWidgetAction::~QWidgetAction()
{
Q_D(QWidgetAction);
for (int i = 0; i < d->createdWidgets.count(); ++i)
disconnect(d->createdWidgets.at(i), SIGNAL(destroyed(QObject*)),
this, SLOT(_q_widgetDestroyed(QObject*)));
QList<QWidget *> widgetsToDelete = d->createdWidgets;
d->createdWidgets.clear();
qDeleteAll(widgetsToDelete);
delete d->defaultWidget;
}
/*!
Sets \a widget to be the default widget. The ownership is
transferred to QWidgetAction. Unless createWidget() is
reimplemented by a subclass to return a new widget the default
widget is used when a container widget requests a widget through
requestWidget().
*/
void QWidgetAction::setDefaultWidget(QWidget *widget)
{
Q_D(QWidgetAction);
if (widget == d->defaultWidget || d->defaultWidgetInUse)
return;
delete d->defaultWidget;
d->defaultWidget = widget;
if (!widget)
return;
setVisible(!(widget->isHidden() && widget->testAttribute(Qt::WA_WState_ExplicitShowHide)));
d->defaultWidget->hide();
d->defaultWidget->setParent(0);
d->defaultWidgetInUse = false;
if (!isEnabled())
d->defaultWidget->setEnabled(false);
}
/*!
Returns the default widget.
*/
QWidget *QWidgetAction::defaultWidget() const
{
Q_D(const QWidgetAction);
return d->defaultWidget;
}
/*!
Returns a widget that represents the action, with the given \a
parent.
Container widgets that support actions can call this function to
request a widget as visual representation of the action.
\sa releaseWidget(), createWidget(), defaultWidget()
*/
QWidget *QWidgetAction::requestWidget(QWidget *parent)
{
Q_D(QWidgetAction);
QWidget *w = createWidget(parent);
if (!w) {
if (d->defaultWidgetInUse || !d->defaultWidget)
return 0;
d->defaultWidget->setParent(parent);
d->defaultWidgetInUse = true;
return d->defaultWidget;
}
connect(w, SIGNAL(destroyed(QObject*)),
this, SLOT(_q_widgetDestroyed(QObject*)));
d->createdWidgets.append(w);
return w;
}
/*!
Releases the specified \a widget.
Container widgets that support actions call this function when a widget
action is removed.
\sa requestWidget(), deleteWidget(), defaultWidget()
*/
void QWidgetAction::releaseWidget(QWidget *widget)
{
Q_D(QWidgetAction);
if (widget == d->defaultWidget) {
d->defaultWidget->hide();
d->defaultWidget->setParent(0);
d->defaultWidgetInUse = false;
return;
}
if (!d->createdWidgets.contains(widget))
return;
disconnect(widget, SIGNAL(destroyed(QObject*)),
this, SLOT(_q_widgetDestroyed(QObject*)));
d->createdWidgets.removeAll(widget);
deleteWidget(widget);
}
/*!
\reimp
*/
bool QWidgetAction::event(QEvent *event)
{
Q_D(QWidgetAction);
if (event->type() == QEvent::ActionChanged) {
if (d->defaultWidget)
d->defaultWidget->setEnabled(isEnabled());
for (int i = 0; i < d->createdWidgets.count(); ++i)
d->createdWidgets.at(i)->setEnabled(isEnabled());
}
return QAction::event(event);
}
/*!
\reimp
*/
bool QWidgetAction::eventFilter(QObject *obj, QEvent *event)
{
return QAction::eventFilter(obj,event);
}
/*!
This function is called whenever the action is added to a container widget
that supports custom widgets. If you don't want a custom widget to be
used as representation of the action in the specified \a parent widget then
0 should be returned.
\sa deleteWidget()
*/
QWidget *QWidgetAction::createWidget(QWidget *parent)
{
Q_UNUSED(parent)
return 0;
}
/*!
This function is called whenever the action is removed from a
container widget that displays the action using a custom \a
widget previously created using createWidget(). The default
implementation hides the \a widget and schedules it for deletion
using QObject::deleteLater().
\sa createWidget()
*/
void QWidgetAction::deleteWidget(QWidget *widget)
{
widget->hide();
widget->deleteLater();
}
/*!
Returns the list of widgets that have been using createWidget() and
are currently in use by widgets the action has been added to.
*/
QList<QWidget *> QWidgetAction::createdWidgets() const
{
Q_D(const QWidgetAction);
return d->createdWidgets;
}
QT_END_NAMESPACE
#include "moc_qwidgetaction.cpp"
#endif // QT_NO_ACTION
|