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/****************************************************************************
**
** 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 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 http://qt.nokia.com/contact.
** $QT_END_LICENSE$
**
****************************************************************************/
//! [0]
QLineEdit *lineEdit = static_cast<QLineEdit *>(
qt_find_obj_child(myWidget, "QLineEdit", "my line edit"));
if (lineEdit)
lineEdit->setText("Default");
//! [0]
//! [1]
QObject *obj = new QPushButton;
obj->metaObject()->className(); // returns "QPushButton"
QPushButton::staticMetaObject.className(); // returns "QPushButton"
//! [1]
//! [2]
QPushButton::staticMetaObject.className(); // returns "QPushButton"
QObject *obj = new QPushButton;
obj->metaObject()->className(); // returns "QPushButton"
//! [2]
//! [3]
QObject *obj = new QTimer; // QTimer inherits QObject
QTimer *timer = qobject_cast<QTimer *>(obj);
// timer == (QObject *)obj
QAbstractButton *button = qobject_cast<QAbstractButton *>(obj);
// button == 0
//! [3]
//! [4]
QTimer *timer = new QTimer; // QTimer inherits QObject
timer->inherits("QTimer"); // returns true
timer->inherits("QObject"); // returns true
timer->inherits("QAbstractButton"); // returns false
// QVBoxLayout inherits QObject and QLayoutItem
QVBoxLayout *layout = new QVBoxLayout;
layout->inherits("QObject"); // returns true
layout->inherits("QLayoutItem"); // returns true (even though QLayoutItem is not a QObject)
//! [4]
//! [5]
qDebug("MyClass::setPrecision(): (%s) invalid precision %f",
qPrintable(objectName()), newPrecision);
//! [5]
//! [6]
class MainWindow : public QMainWindow
{
public:
MainWindow();
protected:
bool eventFilter(QObject *obj, QEvent *ev);
private:
QTextEdit *textEdit;
};
MainWindow::MainWindow()
{
textEdit = new QTextEdit;
setCentralWidget(textEdit);
textEdit->installEventFilter(this);
}
bool MainWindow::eventFilter(QObject *obj, QEvent *event)
{
if (obj == textEdit) {
if (event->type() == QEvent::KeyPress) {
QKeyEvent *keyEvent = static_cast<QKeyEvent*>(event);
qDebug() << "Ate key press" << keyEvent->key();
return true;
} else {
return false;
}
} else {
// pass the event on to the parent class
return QMainWindow::eventFilter(obj, event);
}
}
//! [6]
//! [7]
myObject->moveToThread(QApplication::instance()->thread());
//! [7]
//! [8]
class MyObject : public QObject
{
Q_OBJECT
public:
MyObject(QObject *parent = 0);
protected:
void timerEvent(QTimerEvent *event);
};
MyObject::MyObject(QObject *parent)
: QObject(parent)
{
startTimer(50); // 50-millisecond timer
startTimer(1000); // 1-second timer
startTimer(60000); // 1-minute timer
}
void MyObject::timerEvent(QTimerEvent *event)
{
qDebug() << "Timer ID:" << event->timerId();
}
//! [8]
//! [9]
QList<QObject *> list = window()->queryList("QAbstractButton"));
foreach (QObject *obj, list)
static_cast<QAbstractButton *>(obj)->setEnabled(false);
//! [9]
//! [10]
QPushButton *button = parentWidget->findChild<QPushButton *>("button1");
//! [10]
//! [11]
QListWidget *list = parentWidget->findChild<QListWidget *>();
//! [11]
//! [12]
QList<QWidget *> widgets = parentWidget.findChildren<QWidget *>("widgetname");
//! [12]
//! [13]
QList<QPushButton *> allPButtons = parentWidget.findChildren<QPushButton *>();
//! [13]
//! [14]
monitoredObj->installEventFilter(filterObj);
//! [14]
//! [15]
class KeyPressEater : public QObject
{
Q_OBJECT
...
protected:
bool eventFilter(QObject *obj, QEvent *event);
};
bool KeyPressEater::eventFilter(QObject *obj, QEvent *event)
{
if (event->type() == QEvent::KeyPress) {
QKeyEvent *keyEvent = static_cast<QKeyEvent *>(event);
qDebug("Ate key press %d", keyEvent->key());
return true;
} else {
// standard event processing
return QObject::eventFilter(obj, event);
}
}
//! [15]
//! [16]
KeyPressEater *keyPressEater = new KeyPressEater(this);
QPushButton *pushButton = new QPushButton(this);
QListView *listView = new QListView(this);
pushButton->installEventFilter(keyPressEater);
listView->installEventFilter(keyPressEater);
//! [16]
//! [17]
MyWindow::MyWindow()
{
QLabel *senderLabel = new QLabel(tr("Name:"));
QLabel *recipientLabel = new QLabel(tr("Name:", "recipient"));
...
}
//! [17]
//! [18]
int n = messages.count();
showMessage(tr("%n message(s) saved", "", n));
//! [18]
//! [19]
n == 1 ? tr("%n message saved") : tr("%n messages saved")
//! [19]
//! [20]
label->setText(tr("F\374r \310lise"));
//! [20]
//! [21]
if (receivers(SIGNAL(valueChanged(QByteArray))) > 0) {
QByteArray data;
get_the_value(&data); // expensive operation
emit valueChanged(data);
}
//! [21]
//! [22]
QLabel *label = new QLabel;
QScrollBar *scrollBar = new QScrollBar;
QObject::connect(scrollBar, SIGNAL(valueChanged(int)),
label, SLOT(setNum(int)));
//! [22]
//! [23]
// WRONG
QObject::connect(scrollBar, SIGNAL(valueChanged(int value)),
label, SLOT(setNum(int value)));
//! [23]
//! [24]
class MyWidget : public QWidget
{
Q_OBJECT
public:
MyWidget();
signals:
void buttonClicked();
private:
QPushButton *myButton;
};
MyWidget::MyWidget()
{
myButton = new QPushButton(this);
connect(myButton, SIGNAL(clicked()),
this, SIGNAL(buttonClicked()));
}
//! [24]
//! [25]
QObject::connect: Cannot queue arguments of type 'MyType'
(Make sure 'MyType' is registered using qRegisterMetaType().)
//! [25]
//! [26]
disconnect(myObject, 0, 0, 0);
//! [26]
//! [27]
myObject->disconnect();
//! [27]
//! [28]
disconnect(myObject, SIGNAL(mySignal()), 0, 0);
//! [28]
//! [29]
myObject->disconnect(SIGNAL(mySignal()));
//! [29]
//! [30]
disconnect(myObject, 0, myReceiver, 0);
//! [30]
//! [31]
myObject->disconnect(myReceiver);
//! [31]
//! [32]
if (QLatin1String(signal) == SIGNAL(valueChanged(int))) {
// signal is valueChanged(int)
}
//! [32]
//! [33]
void on_<object name>_<signal name>(<signal parameters>);
//! [33]
//! [34]
void on_button1_clicked();
//! [34]
//! [35]
class MyClass : public QObject
{
Q_OBJECT
Q_CLASSINFO("Author", "Pierre Gendron")
Q_CLASSINFO("URL", "http://www.my-organization.qc.ca")
public:
...
};
//! [35]
//! [36]
Q_PROPERTY(type name
READ getFunction
[WRITE setFunction]
[RESET resetFunction]
[DESIGNABLE bool]
[SCRIPTABLE bool]
[STORED bool]
[USER bool])
//! [36]
//! [37]
Q_PROPERTY(QString title READ title WRITE setTitle USER true)
//! [37]
//! [38]
class MyClass : public QObject
{
Q_OBJECT
Q_ENUMS(Priority)
public:
MyClass(QObject *parent = 0);
~MyClass();
enum Priority { High, Low, VeryHigh, VeryLow };
void setPriority(Priority priority);
Priority priority() const;
};
//! [38]
//! [39]
Q_FLAGS(Options Alignment)
//! [39]
//! [40]
//: This name refers to a host name.
hostNameLabel->setText(tr("Name:"));
/*: This text refers to a C++ code example. */
QString example = tr("Example");
//! [40]
//! [meta data]
//: This is a comment for the translator.
//= qtn_foo_bar
//~ loc-layout_id foo_dialog
//~ loc-blank False
//~ magic-stuff This might mean something magic.
QString text = MyMagicClass::tr("Sim sala bim.");
//! [meta data]
//! [explicit tr context]
QString text = QScrollBar::tr("Page up");
//! [explicit tr context]
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