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author | Lars Knoll <lars.knoll@nokia.com> | 2009-03-23 10:18:55 +0100 |
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committer | Simon Hausmann <simon.hausmann@nokia.com> | 2009-03-23 10:18:55 +0100 |
commit | e5fcad302d86d316390c6b0f62759a067313e8a9 (patch) | |
tree | c2afbf6f1066b6ce261f14341cf6d310e5595bc1 /doc/src/examples/calculatorbuilder.qdoc | |
download | qt4-tools-e5fcad302d86d316390c6b0f62759a067313e8a9.tar.gz |
Long live Qt 4.5!
Diffstat (limited to 'doc/src/examples/calculatorbuilder.qdoc')
-rw-r--r-- | doc/src/examples/calculatorbuilder.qdoc | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/doc/src/examples/calculatorbuilder.qdoc b/doc/src/examples/calculatorbuilder.qdoc new file mode 100644 index 0000000000..c63267e1e8 --- /dev/null +++ b/doc/src/examples/calculatorbuilder.qdoc @@ -0,0 +1,133 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (qt-info@nokia.com) +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** 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, Nokia gives you certain +** additional rights. These rights are described in the Nokia Qt LGPL +** Exception version 1.0, 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. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at qt-sales@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! + \example designer/calculatorbuilder + \title Calculator Builder Example + + The Calculator Builder example shows how to create a user interface from + a \QD form at run-time, using the QUiLoader class. + + \image calculatorbuilder-example.png + + We use the form created in the \l{designer/calculatorform}{Calculator Form} + example to show that the same user interface can be generated when the + application is executed or defined when the application is built. + + \section1 Preparation + + The \l{designer/calculatorform}{Calculator Form} example defines a user + interface that we can use without modification. In this example, we use a + \l{The Qt Resource System}{resource file} to contain the \c{calculatorform.ui} + file created in the previous example, but it could be stored on disk instead. + + To generate a form at run time, we need to link the example against the + \c QtUiTools module library. The project file we use contains all the + necessary information to do this: + + \snippet examples/designer/calculatorbuilder/calculatorbuilder.pro 0 + + All the other necessary files are declared as usual. + + \section1 CalculatorForm Class Definition + + The \c CalculatorForm class defines the widget used to host the form's + user interface: + + \snippet examples/designer/calculatorbuilder/calculatorform.h 0 + + Note that we do not need to include a header file to describe the user + interface. We only define two public slots, using the auto-connection + naming convention required by \c uic, and declare private variables + that we will use to access widgets provided by the form after they are + constructed. + + \section1 CalculatorForm Class Implementation + + We will need to use the QUiLoader class that is provided by the + \c libQtUiTools library, so we first ensure that we include the header + file for the module: + + \snippet examples/designer/calculatorbuilder/calculatorform.cpp 0 + + The constructor uses a form loader object to construct the user + interface that we retrieve, via a QFile object, from the example's + resources: + + \snippet examples/designer/calculatorbuilder/calculatorform.cpp 1 + + By including the user interface in the example's resources, we ensure + that it will be present when the example is run. The \c{loader.load()} + function takes the user interface description contained in the file + and constructs the form widget as a child widget of the \c{CalculatorForm}. + + We are interested in three widgets in the generated user interface: + two spin boxes and a label. For convenience, we retrieve pointers to + these widgets from the widget that was constructed by the \c FormBuilder, + and we record them for later use. The \c qFindChild() template function + allows us to query widgets in order to find named child widgets. + + \snippet examples/designer/calculatorbuilder/calculatorform.cpp 2 + + The widgets created by the form loader need to be connected to the + specially-named slots in the \c CalculatorForm object. We use Qt's + meta-object system to enable these connections: + + \snippet examples/designer/calculatorbuilder/calculatorform.cpp 3 + + The form widget is added to a layout, and the window title is set: + + \snippet examples/designer/calculatorbuilder/calculatorform.cpp 4 + + The two slots that modify widgets provided by the form are defined + in a similar way to those in the \l{designer/calculatorform}{Calculator + Form} example, except that we read the values from the spin boxes and + write the result to the output widget via the pointers we recorded in + the constructor: + + \snippet examples/designer/calculatorbuilder/calculatorform.cpp 5 + \codeline + \snippet examples/designer/calculatorbuilder/calculatorform.cpp 7 + + The advantage of this approach is that we can replace the form when the + application is run, but we can still manipulate the widgets it contains + as long as they are given appropriate names. +*/ |