/**************************************************************************** ** ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). ** Contact: Nokia Corporation (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 Technology Preview License Agreement accompanying ** this package. ** ** 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 1.1, included in the file LGPL_EXCEPTION.txt in this ** package. ** ** If you have questions regarding the use of this file, please contact ** Nokia at qt-info@nokia.com. ** ** ** ** ** ** ** ** ** $QT_END_LICENSE$ ** ****************************************************************************/ //! [0] QT -= gui //! [0] //! [1] QT += network opengl sql qt3support //! [1] //! [2] CONFIG += uic3 //! [2] //! [3] #include //! [3] //! [4] #include #include #include //! [4] //! [5] #include //! [5] //! [6] #include //! [6] //! [7] using namespace Qt; //! [7] //! [8] QLabel *label1 = new QLabel("Hello", this); QLabel *label2 = new QLabel(this, "Hello"); //! [8] //! [9] MyWidget::MyWidget(QWidget *parent, const char *name) : QWidget(parent, name) { ... } //! [9] //! [10] // DEPRECATED if (obj->inherits("QPushButton")) { QPushButton *pushButton = (QPushButton *)obj; ... } //! [10] //! [11] QPushButton *pushButton = qobject_cast(obj); if (pushButton) { ... } //! [11] //! [12] QLabel *label = new QLabel; QPointer safeLabel = label; safeLabel->setText("Hello world!"); delete label; // safeLabel is now 0, whereas label is a dangling pointer //! [12] //! [13] QT += qt3support //! [13] //! [14] DEFINES += QT3_SUPPORT //! [14] //! [15] DEFINES += QT3_SUPPORT_WARNINGS //! [15] //! [16] DEFINES += QT3_SUPPORT //! [16]