Step by Step solution about How to resolve the algorithm Simple windowed application step by step in the C++ programming language

The given code is written in C++ and implements a simple click counter widget. Here's a breakdown of what each part of the code does:

1. Header File (clickcounter.h):

   • Defines the Counter class as a subclass of QWidget.
   • Declares private member variables and public and private slots for the widget.

2. Implementation File (clickcounter.cpp):

   • Counter Constructor:
     • Initializes the widget with a default parent of 0.
     • Initializes private member variables:
       • number: Counts the number of clicks.
       • countLabel: A label to display the click count.
       • clicker: A push button that when clicked, increments the click count.
       • myLayout: A layout to arrange the widgets.
   • countClicks Slot:
     • When the clicker button is clicked, this slot is called.
     • Increments the number and updates the countLabel to display the new click count.

3. Main Function (main.cpp):

   • Creates an instance of the QApplication class to manage the application's GUI.
   • Creates an instance of the Counter class.
   • Calls show() on the counter widget to display it on the screen.
   • Calls exec() on the QApplication instance to start the event loop and run the application.

4. Layout:

   • The myLayout layout is a vertical box layout that arranges the countLabel and clicker widgets vertically within the counter widget.

When the application is run, a window containing the counter widget is displayed. Clicking the "click me" button increments the counter and updates the label to show the number of clicks.

#ifndef CLICKCOUNTER_H
#define CLICKCOUNTER_H

#include <QWidget>
class QLabel ;
class QPushButton ;
class QVBoxLayout ;

class Counter : public QWidget {
    Q_OBJECT
public :
   Counter( QWidget * parent = 0 ) ;
private :
   int number ;
   QLabel *countLabel ;
   QPushButton *clicker ;
   QVBoxLayout *myLayout ;
private slots :
   void countClicks( ) ;
} ;
#endif


#include <QPushButton>
#include <QLabel>
#include <QVBoxLayout>
#include "clickcounter.h" 

Counter::Counter( QWidget * parent ) : QWidget( parent ) {
   number = 0 ;
   countLabel = new QLabel( "There have been no clicks yet!" ) ;
   clicker = new QPushButton( "click me" ) ;
   connect ( clicker , SIGNAL( clicked( ) ) , this , SLOT( countClicks( ) ) ) ;
   myLayout = new QVBoxLayout ;
   myLayout->addWidget( countLabel ) ;
   myLayout->addWidget( clicker ) ;
   setLayout( myLayout ) ;
}

void Counter::countClicks( ) {
   number++ ;
   countLabel->setText( QString( "The button has been clicked %1 times!").arg( number ) ) ;
}


#include <QApplication>
#include "clickcounter.h"

int main( int argc , char *argv[ ] ) {
   QApplication app( argc , argv ) ;
   Counter counter ;
   counter.show( ) ;
   return app.exec( ) ;
}