New Signals and Slots Features in Qt 5

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Revision as of 11:21, 25 February 2015 by Maintenance script (talk | contribs)
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This small app (cross platform) demonstrates a few new features come with qt5. thats to ability connect c++ functor objects, non member outer class functions and c+11 lambda functions. main.cpp:

 #include "test.h"

 void outer_func(){std::printf("this is a test by outer class func;)");}
 void functor::operator() (bool) {std::printf("this is a test by functor;)");}

 int main(int argc,char* argv[]){
 QApplication app(argc, argv);
 Ui_Form ui;
 QWidget* form=new QWidget();
 ui.setupUi(form);
 form->show();
 return app.exec();
 }

test.h

 #ifndef TEST_H
 #define TEST_H

 #include <QtCore/QVariant>
 #include <QtWidgets/QAction>
 #include <QtWidgets/QApplication>
 #include <QtWidgets/QButtonGroup>
 #include <QtWidgets/QHeaderView>
 #include <QtWidgets/QPushButton>
 #include <QtWidgets/QWidget>
 #include <cstdio>

 void outer_func();
 class functor{public:void operator() (bool);};

 functor a_functor; // create an instance of functor

 class Ui_Form{

 public:
 QPushButton *pushButton;
 void setupUi(QWidget *Form){

 Form->setObjectName(QStringLiteral("Form"));
 Form->resize(600, 100);
 pushButton = new QPushButton(Form);
 pushButton->setObjectName(QStringLiteral("pushButton"));
 pushButton->setGeometry(QRect(10, 50, 580, 33));
 pushButton->connect(pushButton,&amp;QAbstractButton::clicked,outer_func);
 pushButton->connect(pushButton,&amp;QAbstractButton::clicked,a_functor);
 pushButton->connect(pushButton,&amp;QAbstractButton::clicked,[=] (bool){std::printf("This is a test by lambda;)");});

 Form->setWindowTitle(QString("Form"));
 pushButton->setText(QString("connect functor and outer class func simultaneously"));
 } // setupUi
 };
 #endif // TEST_H

and test.pro

TEMPLATE = app
TARGET = test
INCLUDEPATH= .
QT = widgets # mandatory needed for gui on qt5
QMAKE_CXXFLAGS= -std=c+11 # needed for lambda
HEADERS= test.h
SOURCES += main.cpp