inter widget communication

[venk2ksubbu]

Hi All,

I have created three classes, of which one is inherited from QMainWindow and other two are inherited from QWidget. I have designed the GUI using QT Designer. The classes are as follows.

MainWindow - inherited from QMainWindow.
wrapperSDKParams - inherieted from QWidget
wrapperLog - inherieted from QWidget

Now inside MainWindow class I have created objects of the rest of the two. Now I want to send a message from object of wrapperSDKparams to wrapperLog. How can I do it ? Please help me.

class MainWindow : public QMainWindow
{
    Q_OBJECT
 
    private:
       QWorkspace *workspace;
       QMenu *initMenu;
       QMenu *viewMenu;
       QAction *initAction;
       QAction *viewAction;
       wrapperLog *log;
 
    public:
       MainWindow();
       void AddActions();
       void AddMenus();
       void initErrors();
       //void addError(QString *error);
 
    public slots:
       void displayForm();
       void displayErrors();
};
 
class wrapperSDKParams : public QWidget, private Ui::sdk_params
{
    Q_OBJECT
 
    private:
        unsigned int debug_flag;
 
    public:
        wrapperSDKParams(QWidget *parent = 0);
        void setDefault();
        void updateDebugFlag();
 
    public slots:
        void setDefaultValues();
        void enableGroupBox();
        void start_SDK();
};
 
class wrapperLog : public QWidget, private Ui::frmLog
{
    Q_OBJECT
 
    public:
        wrapperLog(QWidget *parent = 0);
        void append(QString error);
};

class MainWindow : public QMainWindow
{
    Q_OBJECT

    private:
       QWorkspace *workspace;
       QMenu *initMenu;
       QMenu *viewMenu;
       QAction *initAction;
       QAction *viewAction;
       wrapperLog *log;

    public:
       MainWindow();
       void AddActions();
       void AddMenus();
       void initErrors();
       //void addError(QString *error);

    public slots:
       void displayForm();
       void displayErrors();
};

class wrapperSDKParams : public QWidget, private Ui::sdk_params
{
    Q_OBJECT

    private:
        unsigned int debug_flag;

    public:
        wrapperSDKParams(QWidget *parent = 0);
        void setDefault();
        void updateDebugFlag();

    public slots:
        void setDefaultValues();
        void enableGroupBox();
        void start_SDK();
};

class wrapperLog : public QWidget, private Ui::frmLog
{
    Q_OBJECT

    public:
        wrapperLog(QWidget *parent = 0);
        void append(QString error);
};

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I want to call append from wrapperSDKParams.

[wysota]

Make append() a slot, create a signal carrying a QString in wrapperSDKParams and connect() them from MainWindow constructor.

MainWindow::MainWindow() : QMainWindow(){
  //...
  log = new wrapperLog(this);
  sdk = new wrapperSDKParams(this);
  //...
  connect(sdk, SIGNAL(message(QString)), log, SLOT(append(QString)));
  //...
}

MainWindow::MainWindow() : QMainWindow(){
  //...
  log = new wrapperLog(this);
  sdk = new wrapperSDKParams(this);
  //...
  connect(sdk, SIGNAL(message(QString)), log, SLOT(append(QString)));
  //...
}

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Then emit the signal each time when you want append() called.

[venk2ksubbu]

Thanks a lot Mr. Wysota. It helped me so much. Now the program is working as I expected.

Thanks again,
Venkata Subba Rao A.