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/****************************************************************************
**
** Copyright (C) 2014 Sze Howe Koh <szehowe.koh@gmail.com>
** Contact: http://www.qt.io/licensing/
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** You may use this file under the terms of the BSD license as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in
** the documentation and/or other materials provided with the
** distribution.
** * Neither the name of The Qt Company Ltd nor the names of its
** contributors may be used to endorse or promote products derived
** from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "signalslotsyntaxes.h"
#include <QQuickWidget>
#include <QQuickItem>
#include <QAudioInput>
void DemoWidget::demoImplicitConversion() {
//! [implicitconversion]
auto slider = new QSlider(this);
auto doubleSpinBox = new QDoubleSpinBox(this);
// OK: The compiler can convert an int into a double
connect(slider, &QSlider::valueChanged,
doubleSpinBox, &QDoubleSpinBox::setValue);
// ERROR: The string table doesn't contain conversion information
connect(slider, SIGNAL(valueChanged(int)),
doubleSpinBox, SLOT(setValue(double)));
//! [implicitconversion]
}
void DemoWidget::demoTypeResolution() {
//! [typeresolution]
auto audioInput = new QAudioInput(QAudioFormat(), this);
auto widget = new QWidget(this);
// OK
connect(audioInput, SIGNAL(stateChanged(QAudio::State)),
widget, SLOT(show()));
// ERROR: The strings "State" and "QAudio::State" don't match
using namespace QAudio;
connect(audioInput, SIGNAL(stateChanged(State)),
widget, SLOT(show()));
// ...
//! [typeresolution]
}
//! [lambda]
TextSender::TextSender(QWidget *parent) : QWidget(parent) {
lineEdit = new QLineEdit(this);
button = new QPushButton("Send", this);
connect(button, &QPushButton::clicked, [=] {
emit textCompleted(lineEdit->text());
});
// ...
}
//! [lambda]
void DemoWidget::demoCrossLanguageConnect()
{
//! [crosslanguage]
auto cppObj = new CppGui(this);
auto quickWidget = new QQuickWidget(QUrl("QmlGui.qml"), this);
auto qmlObj = quickWidget->rootObject();
// Connect QML signal to C++ slot
connect(qmlObj, SIGNAL(qmlSignal(QString)),
cppObj, SLOT(cppSlot(QString)));
// Connect C++ signal to QML slot
connect(cppObj, SIGNAL(cppSignal(QVariant)),
qmlObj, SLOT(qmlSlot(QVariant)));
//! [crosslanguage]
}
//! [defaultparams]
DemoWidget::DemoWidget(QWidget *parent) : QWidget(parent) {
// OK: printNumber() will be called with a default value of 42
connect(qApp, SIGNAL(aboutToQuit()),
this, SLOT(printNumber()));
// ERROR: Compiler requires compatible arguments
connect(qApp, &QApplication::aboutToQuit,
this, &DemoWidget::printNumber);
}
//! [defaultparams]
void DemoWidget::demoOverloadConnect()
{
//! [overload]
auto mapper = new QSignalMapper(this);
auto spinBox = new QSpinBox(this);
// String-based syntax
connect(mapper, SIGNAL(mapped(int)),
spinBox, SLOT(setValue(int)));
// Functor-based syntax, first alternative
connect(mapper, static_cast<void (QSignalMapper::*)(int)>(&QSignalMapper::mapped),
spinBox, &QSpinBox::setValue);
// Functor-based syntax, second alternative
void (QSignalMapper::*mySignal)(int) = &QSignalMapper::mapped;
connect(mapper, mySignal,
spinBox, &QSpinBox::setValue);
//! [overload]
}
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