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/****************************************************************************
**
** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
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** 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.
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** rights. These rights are described in the Digia Qt LGPL Exception
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** GNU General Public License Usage
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** 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
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****************************************************************************/
/*!
\example uitools/multipleinheritance
\title Multiple Inheritance Example
The Multiple Inheritance Example shows how to use a form created with \QD
in an application by subclassing both QWidget and the user interface
class, which is \c{Ui::CalculatorForm}.
\image multipleinheritance-example.png
To subclass the \c calculatorform.ui file and ensure that \c qmake
processes it with the \c uic, we have to include \c calculatorform.ui
in the \c .pro file, as shown below:
\snippet examples/uitools/multipleinheritance/multipleinheritance.pro 0
When the project is compiled, the \c uic will generate a corresponding
\c ui_calculatorform.h.
\section1 CalculatorForm Definition
In the \c CalculatorForm definition, we include the \c ui_calculatorform.h
that was generated earlier.
\snippet examples/uitools/multipleinheritance/calculatorform.h 0
As mentioned earlier, the class is a subclass of both QWidget and
\c{Ui::CalculatorForm}.
\snippet examples/uitools/multipleinheritance/calculatorform.h 1
Two slots are defined according to the \l{Automatic Connections}
{automatic connection} naming convention required by \c uic. This is
to ensure that \l{QMetaObject}'s auto-connection facilities connect
all the signals and slots involved automatically.
\section1 CalculatorForm Implementation
In the constructor, we call \c setupUi() to load the user interface file.
Note that we do not need the \c{ui} prefix as \c CalculatorForm is a
subclass of the user interface class.
\snippet examples/uitools/multipleinheritance/calculatorform.cpp 0
We include two slots, \c{on_inputSpinBox1_valueChanged()} and
\c{on_inputSpinBox2_valueChanged()}. These slots respond to the
\l{QSpinBox::valueChanged()}{valueChanged()} signal that both spin boxes
emit. Whenever there is a change in one spin box's value, we take that
value and add it to whatever value the other spin box has.
\snippet examples/uitools/multipleinheritance/calculatorform.cpp 1
\codeline
\snippet examples/uitools/multipleinheritance/calculatorform.cpp 2
\section1 \c main() Function
The \c main() function instantiates QApplication and \c CalculatorForm.
The \c calculator object is displayed by invoking the \l{QWidget::show()}
{show()} function.
\snippet examples/uitools/multipleinheritance/main.cpp 0
There are various approaches to include forms into applications. The
Multiple Inheritance approach is just one of them. See
\l{Using a Designer .ui File in Your Application} for more information on
the other approaches available.
*/
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