07-advanced-connections/main.cpp

An example of how to use the KDBindings::Signal::connect() overloaded function for advanced slot connections.

The output of this example is:

Hello World!
Emitted value: 5
true

/*
  This file is part of KDBindings.
 
  SPDX-FileCopyrightText: 2021 Klarälvdalens Datakonsult AB, a KDAB Group company <info@kdab.com>
  Author: Leon Matthes <leon.matthes@kdab.com>
 
  SPDX-License-Identifier: MIT
 
  Contact KDAB at <info@kdab.com> for commercial licensing options.
*/
 
#include <ios>
#include <kdbindings/signal.h>
 
#include <iostream>
#include <string>
 
using namespace KDBindings;
 
void display()
{
    std::cout << "Hello World!" << std::endl;
}
 
void displayLabelled(const std::string &label, int value)
{
    std::cout << label << ": " << value << std::endl;
}
 
class SignalHandler
{
public:
    bool received = 0;
 
    void receive()
    {
        received = true;
    }
};
 
int main()
{
    Signal<int> signal;
    std::vector<ConnectionHandle> connections;
 
    // Signal::connect allows connecting functions that take too few arguments.
    connections.emplace_back(signal.connect(display));
 
    // As well as functions with too many arguments, as long as default values are provided.
    connections.emplace_back(signal.connect(displayLabelled, "Emitted value"));
 
    // This is very useful to connect member functions, where the first implicit argument
    // is a pointer to the "this" object.
    SignalHandler handler;
    connections.emplace_back(signal.connect(&SignalHandler::receive, &handler));
 
    // This will print "Hello World!" and "Emitted value: 5" in an unspecified order.
    // It will also set handler.received to true
    signal.emit(5);
 
    std::cout << std::boolalpha << handler.received << std::endl;
 
    for (auto &connection : connections) {
        connection.disconnect();
    }
 
    return 0;
}