Problem in updating listwidget of friend class

[stampede]

maybe show us Spam_MessagesWidget::additemS code.

[dipeshtech]

Here it goes:

void Spam_MessagesWidget :: additemS(QListWidgetItem* temp)
{
 
    m_messageListWidget->insertItem(0,temp);
 
    m_messageListWidget->update();
 
}

void Spam_MessagesWidget :: additemS(QListWidgetItem* temp)
{
   
    m_messageListWidget->insertItem(0,temp);
   
    m_messageListWidget->update();

}

To copy to clipboard, switch view to plain text mode 

[stampede]

You never call setLayout(m_layout) after creating layout objects, try to call this->setLayout(m_layout); after preparing ui elements.

[dipeshtech]

Still No Effect...!! I guess the function additemS() is not getting called from the RecentMessagesWidget class. I don't understand why the friend class function is not being called from here.

I am looking for a simple working example using friend classes or friend function that can update on the private members of both the classes. I started with this simple example.

[dipeshtech]

I guess the sole problem is here:

I am posing the problem in a different form:

//File recentmessageswidget.h [A simple class Containing 2 listwidgets]
 
class RecentMessagesWidget : public QWidget
{
    Q_OBJECT
public:
    explicit RecentMessagesWidget(QWidget *parent = 0);
    ~RecentMessagesWidget();
 
public:
    QListWidget* I_messageListWidget;
    QListWidget* S_messageListWidget;
 
public slots:
 
    void processResults();
    void reportAsSpam();
 
};
 
//recentmessageswidget.cpp
 
#include "recentmessageswidget.h"
 
RecentMessagesWidget::RecentMessagesWidget(QWidget *parent) :
    QWidget(parent)
{
    I_messageListWidget = new QListWidget(this);
    S_messageListWidget = new QListWidget(this);
    processResults();
}
RecentMessagesWidget::~RecentMessagesWidget()
{
 
}
 
void RecentMessagesWidget::processResults()
{
         //I_messageListWidget = new QListWidget(this);
          I_messageListWidget->addItem(new QListWidgetItem("I1"));
          I_messageListWidget->addItem(new QListWidgetItem("I2"));
          I_messageListWidget->addItem(new QListWidgetItem("I3"));
 
          //S_messageListWidget = new QListWidget(this);
           S_messageListWidget->addItem(new QListWidgetItem("S1"));
           S_messageListWidget->addItem(new QListWidgetItem("S2"));
           S_messageListWidget->addItem(new QListWidgetItem("S3"));
 
           S_messageListWidget->insertItem(4,QString("In fn PR")); //  added in the list 
 
}
void RecentMessagesWidget :: reportAsSpam()
{
        int cr = I_messageListWidget->currentRow();
        QListWidgetItem *temp = I_messageListWidget->takeItem(cr);
        //I_messageListWidget->update();
        //S_messageListWidget = new QListWidget(this);
        S_messageListWidget->insertItem(0,temp);                  // PROBLEM is here...
        S_messageListWidget->insertItem(5,QString("spm tab in fn")); // not added in the list 
 
        S_messageListWidget->update();
        I_messageListWidget->update();
 
}
 
 
//In file tabmain.h
 
class TabMain : public QMainWindow
{
    Q_OBJECT
public:
    TabMain(QWidget *parent = 0);
    ~TabMain();
private:
    void buildTabMenuBar(int index);
 
signals:
 
public slots:
    void activeTabChanged(int index);
private:
    QTabWidget* tabWidget;
 
};
 
class InBoxTab : public QWidget
{
Q_OBJECT
 
public:
    InBoxTab(QWidget *parent = 0);
    ~InBoxTab();
     void setupUi();
public slots:
    void hello();
    void rspam();
 private:
    RecentMessagesWidget* m_recentMessagesWidget;
};
 
class SpamBoxTab: public QWidget
{
Q_OBJECT
 
public:
    SpamBoxTab(QWidget *parent = 0);
    ~SpamBoxTab();
     void setupUi();
public slots:
    void hello();
private:
 
     RecentMessagesWidget* sm_recentMessagesWidget;
 
 
};
 
 
 
TabMain::TabMain(QWidget *parent) :
    QMainWindow(parent)
{
    setContextMenuPolicy(Qt::NoContextMenu);
        this->setWindowTitle("SMSAssassin Alpha");
 
        tabWidget = new QTabWidget(this);
        tabWidget->setContextMenuPolicy(Qt::NoContextMenu);
 
        QObject::connect(tabWidget, SIGNAL(currentChanged(int)),this, SLOT(activeTabChanged(int)));
 
        InBoxTab* widget1 = new InBoxTab();
        tabWidget->addTab(widget1, "   INBOX   ");
        SpamBoxTab* widget2 = new SpamBoxTab();
        tabWidget->addTab(widget2, "   SPAMBOX   ");
        //adda();
        setCentralWidget(tabWidget);
 
 
 
    #ifdef Q_OS_SYMBIAN
        QWidgetList widgets = QApplication::allWidgets();
        QWidget* w = 0;
        foreach(w,widgets)
            {
                w->setContextMenuPolicy(Qt::NoContextMenu);
            }
    #endif
 
}
TabMain::~TabMain()
{
 
}
void TabMain::activeTabChanged(int index)
{
    buildTabMenuBar(index);
}
void TabMain::buildTabMenuBar(int index)
{
      QMenuBar* menubar = menuBar();
     menubar->clear();
 
     switch(index)
     {
     case 0:
         {
             menubar -> addAction("Inbox user Menu", tabWidget->widget(index),SLOT( hello() ) );
             menubar -> addAction("Report as Spam", tabWidget->widget(index), SLOT( rspam() ) );
             break;
         }
     case 1:
         {
             menubar -> addAction("SpamBox user Menu", tabWidget->widget(index), SLOT(hello()) );
             break;
 
         }
     default:
         {
             break;
         }
     }
}
 
InBoxTab::InBoxTab(QWidget *parent) :
        QWidget(parent),
        m_recentMessagesWidget(0)
{
    setupUi();
}
 
InBoxTab:: ~InBoxTab()
{
 
}
 
void InBoxTab::setupUi()
{
    QVBoxLayout* vbl = new QVBoxLayout(this);
    m_recentMessagesWidget = new RecentMessagesWidget(this);
    vbl->addWidget(m_recentMessagesWidget->I_messageListWidget);
    this->setLayout(vbl);
}
void InBoxTab :: rspam()
{
    m_recentMessagesWidget->reportAsSpam();
}
 
void InBoxTab::hello()
{
    QString message = QString("Hello from %1").arg(metaObject()->className());
    QMessageBox* messageBox = new QMessageBox(QMessageBox::Information, "QTabsExample", message,
        QMessageBox::Ok, this);
        messageBox->exec();
    delete messageBox;
    messageBox = 0;
}
 
 
SpamBoxTab::SpamBoxTab(QWidget *parent) :
        QWidget(parent)
{
    setupUi();
 
}
void SpamBoxTab::setupUi()
{
    QVBoxLayout* vbl = new QVBoxLayout(this);
    sm_recentMessagesWidget = new RecentMessagesWidget(this);
    vbl->addWidget(sm_recentMessagesWidget->S_messageListWidget);
    this->setLayout(vbl);
}
 
 
 
SpamBoxTab::~SpamBoxTab()
{
 
}
void SpamBoxTab::hello()
{
    QString message = QString("Hello from %1").arg(metaObject()->className());
    QMessageBox* messageBox = new QMessageBox(QMessageBox::Information, "QTabs", message,
        QMessageBox::Ok, this);
 
    messageBox->exec();
    delete messageBox;
    messageBox = 0;
}

//File recentmessageswidget.h [A simple class Containing 2 listwidgets]

class RecentMessagesWidget : public QWidget
{
    Q_OBJECT
public:
    explicit RecentMessagesWidget(QWidget *parent = 0);
    ~RecentMessagesWidget();

public:
    QListWidget* I_messageListWidget;
    QListWidget* S_messageListWidget;

public slots:

    void processResults();
    void reportAsSpam();

};

//recentmessageswidget.cpp

#include "recentmessageswidget.h"

RecentMessagesWidget::RecentMessagesWidget(QWidget *parent) :
    QWidget(parent)
{
    I_messageListWidget = new QListWidget(this);
    S_messageListWidget = new QListWidget(this);
    processResults();
}
RecentMessagesWidget::~RecentMessagesWidget()
{

}

void RecentMessagesWidget::processResults()
{
         //I_messageListWidget = new QListWidget(this);
          I_messageListWidget->addItem(new QListWidgetItem("I1"));
          I_messageListWidget->addItem(new QListWidgetItem("I2"));
          I_messageListWidget->addItem(new QListWidgetItem("I3"));

          //S_messageListWidget = new QListWidget(this);
           S_messageListWidget->addItem(new QListWidgetItem("S1"));
           S_messageListWidget->addItem(new QListWidgetItem("S2"));
           S_messageListWidget->addItem(new QListWidgetItem("S3"));

           S_messageListWidget->insertItem(4,QString("In fn PR")); //  added in the list 

}
void RecentMessagesWidget :: reportAsSpam()
{
        int cr = I_messageListWidget->currentRow();
        QListWidgetItem *temp = I_messageListWidget->takeItem(cr);
        //I_messageListWidget->update();
        //S_messageListWidget = new QListWidget(this);
        S_messageListWidget->insertItem(0,temp);                  // PROBLEM is here...
        S_messageListWidget->insertItem(5,QString("spm tab in fn")); // not added in the list 

        S_messageListWidget->update();
        I_messageListWidget->update();

}


//In file tabmain.h

class TabMain : public QMainWindow
{
    Q_OBJECT
public:
    TabMain(QWidget *parent = 0);
    ~TabMain();
private:
    void buildTabMenuBar(int index);

signals:

public slots:
    void activeTabChanged(int index);
private:
    QTabWidget* tabWidget;

};

class InBoxTab : public QWidget
{
Q_OBJECT

public:
    InBoxTab(QWidget *parent = 0);
    ~InBoxTab();
     void setupUi();
public slots:
    void hello();
    void rspam();
 private:
    RecentMessagesWidget* m_recentMessagesWidget;
};

class SpamBoxTab: public QWidget
{
Q_OBJECT

public:
    SpamBoxTab(QWidget *parent = 0);
    ~SpamBoxTab();
     void setupUi();
public slots:
    void hello();
private:

     RecentMessagesWidget* sm_recentMessagesWidget;


};



TabMain::TabMain(QWidget *parent) :
    QMainWindow(parent)
{
    setContextMenuPolicy(Qt::NoContextMenu);
        this->setWindowTitle("SMSAssassin Alpha");

        tabWidget = new QTabWidget(this);
        tabWidget->setContextMenuPolicy(Qt::NoContextMenu);

        QObject::connect(tabWidget, SIGNAL(currentChanged(int)),this, SLOT(activeTabChanged(int)));

        InBoxTab* widget1 = new InBoxTab();
        tabWidget->addTab(widget1, "   INBOX   ");
        SpamBoxTab* widget2 = new SpamBoxTab();
        tabWidget->addTab(widget2, "   SPAMBOX   ");
        //adda();
        setCentralWidget(tabWidget);



    #ifdef Q_OS_SYMBIAN
        QWidgetList widgets = QApplication::allWidgets();
        QWidget* w = 0;
        foreach(w,widgets)
            {
                w->setContextMenuPolicy(Qt::NoContextMenu);
            }
    #endif

}
TabMain::~TabMain()
{

}
void TabMain::activeTabChanged(int index)
{
    buildTabMenuBar(index);
}
void TabMain::buildTabMenuBar(int index)
{
      QMenuBar* menubar = menuBar();
     menubar->clear();

     switch(index)
     {
     case 0:
         {
             menubar -> addAction("Inbox user Menu", tabWidget->widget(index),SLOT( hello() ) );
             menubar -> addAction("Report as Spam", tabWidget->widget(index), SLOT( rspam() ) );
             break;
         }
     case 1:
         {
             menubar -> addAction("SpamBox user Menu", tabWidget->widget(index), SLOT(hello()) );
             break;

         }
     default:
         {
             break;
         }
     }
}

InBoxTab::InBoxTab(QWidget *parent) :
        QWidget(parent),
        m_recentMessagesWidget(0)
{
    setupUi();
}

InBoxTab:: ~InBoxTab()
{

}

void InBoxTab::setupUi()
{
    QVBoxLayout* vbl = new QVBoxLayout(this);
    m_recentMessagesWidget = new RecentMessagesWidget(this);
    vbl->addWidget(m_recentMessagesWidget->I_messageListWidget);
    this->setLayout(vbl);
}
void InBoxTab :: rspam()
{
    m_recentMessagesWidget->reportAsSpam();
}

void InBoxTab::hello()
{
    QString message = QString("Hello from %1").arg(metaObject()->className());
    QMessageBox* messageBox = new QMessageBox(QMessageBox::Information, "QTabsExample", message,
        QMessageBox::Ok, this);
        messageBox->exec();
    delete messageBox;
    messageBox = 0;
}


SpamBoxTab::SpamBoxTab(QWidget *parent) :
        QWidget(parent)
{
    setupUi();

}
void SpamBoxTab::setupUi()
{
    QVBoxLayout* vbl = new QVBoxLayout(this);
    sm_recentMessagesWidget = new RecentMessagesWidget(this);
    vbl->addWidget(sm_recentMessagesWidget->S_messageListWidget);
    this->setLayout(vbl);
}



SpamBoxTab::~SpamBoxTab()
{

}
void SpamBoxTab::hello()
{
    QString message = QString("Hello from %1").arg(metaObject()->className());
    QMessageBox* messageBox = new QMessageBox(QMessageBox::Information, "QTabs", message,
        QMessageBox::Ok, this);

    messageBox->exec();
    delete messageBox;
    messageBox = 0;
}

To copy to clipboard, switch view to plain text mode 

The problem is same, item is removed from one tab but not gets added to other tab.

[Rhayader]

Attached is a very minimalist example of two listWidgets that shows that the code you think is problematic, is actually working. I don't know where and why there is an error in your program but you have to look for it somewhere else.

[dipeshtech]

In my case the problem is that on selection the item is removed from one Listwidget of one TAB but doesn't get added in other TAB.

May be my problem is due to the TAB thing. Attached is my project, You can check it, It doesn't work but doesn't throws any error too.

[Rhayader]

Besides your title and I don't see anywhere in your code to be declared a friend (as in C++ friend) class.
Your main widget is a tabBar that creates InBoxTar and SpamBoxTab both of type RecentMessageWidget. Now, in the RecentMessageWidget's constructor there are created two list widget (I_.. and S_...)
So what you have is
Tabbar----InBoxTab------RecentMessageWidget's ---I_messageListWidget (1)+S_messageListWidget (2)
Tabbar----SpamBoxTab---RecentMessageWidget's---I_messageListWidget (3)+S_messageListWidget (4)
(2) and (3) are invisible because they are not added in the layout, but does not mean they don't exist. What you are doing is a connection between (1) and (2), though what you want is a connection between (1) and (4) which simply exist in different objects.

My suggestion: Create only one listWidget. Maybe it's better RecentMessage to be a subclass of QListWidget. Add a method that returns the currentItem, and a method that reports this QListWidgetItem.

QListWidgetItem* RecentMessagesWidget::getCurrentItem();
void RecentMessagesWidget::reportAsSpam(QListWidgetItem *temp);

QListWidgetItem* RecentMessagesWidget::getCurrentItem();
void RecentMessagesWidget::reportAsSpam(QListWidgetItem *temp);

To copy to clipboard, switch view to plain text mode 

So in your tabBar class you can call something like

spamBox->reportAsSpam(inBox->getCurrentItem());

spamBox->reportAsSpam(inBox->getCurrentItem());

To copy to clipboard, switch view to plain text mode 

[dipeshtech]

Friend is in my original code which is in my first thread. Initially, i thought my problem is due to friend class.

And, Why i want to keep 2 listwidgets is that i wish to maintain 2 different lists containing different items in 2 tabs.

[Rhayader]

And, Why i want to keep 2 listwidgets is that i wish to maintain 2 different lists containing different items in 2 tabs.

Since this is by design then it's ok, but you have to let the two objects(1 and 4 in my previous post) to be known to eachother.

[dipeshtech]

If you have browsed my code, can you please help me in getting it work, the way i want it. If you can point out the changes to made (in my code) for this. I am just a month old to it.

[Rhayader]

See the changes made for the QListWidgetItem to be passed from Inbox object to SpamBox object.
Please note that I don't "agree" with your implementation. You are making things too complicated without reason (but I will not redesign your classes )

NOTE: I had to comment out many headers that were not in my system to compile but they are irrelevant to your problem