Custum signal in QDialog does not launch a slot in another class



  • I have three class:

    1. class A is the main class.
    2. class B inherits from QWidget.
    3. class C inherits from QDialog.

    In the C class there is a QTableWidget ( QTableWidget* tableShape;) and custom slot (void saveTableValue(int r,int c);) and signal (void load();). The saveTableValue slot is called by B class when the user changes a cell (by the signal cellChanged(int,int);). When the saveTableValue slot is executed another signal (void load();) in C class is emitted and calls the custom slot void reloadIfGeometryChanged(); in A class.

    The problem is that that slot void reloadIfGeometryChanged(); (*****) in A class is not executed even though the signal void load(); is emitted (I tested it with a slot in the same class (C) ).

    Here part of my code:

    class A.h

    @class Main_newUI : public QMainWindow
    {
    Q_OBJECT

    public:
    Main_newUI(QString pathPj, QWidget *parent = 0);
    ~Main_newUI();

    // Geometry Docks
    Geometry_UI        *geometryDocks;                                 //!< Create and manage geometry docks
    ShapeDialog        *profileDialog;
    

    public slots:

    void reloadIfGeometryChanged();
    

    };
    }

    #endif // MAIN_NEWUI_H
    @

    class A.cpp

    @Main_newUI::Main_newUI(QString pathPj, QWidget *parent)
    : QMainWindow(parent)
    {

    geometryDocks = new Geometry_UI(...);
    
    profileDialog = geometryDocks->profDialog;
    
    connect(profileDialog, SIGNAL(load()), this, SLOT(reloadIfGeometryChanged())); (******DOES NOT WORK!!!)
    

    }

    void Main_newUI::reloadIfGeometryChanged(){
    .......
    }
    @

    class B.h

    @class Geometry_UI : public QWidget
    {
    Q_OBJECT
    public:
    explicit Geometry_UI(...);
    ~Geometry_UI();

    QMainWindow   *mainWindow;
    
    ShapeDialog* profDialog;
    

    };
    }

    #endif // GEOMETRY_UI_H
    @

    class B.cpp

    @Geometry_UI::Geometry_UI(...)
    {
    profDialog = new ShapeDialog();
    }

    void Geometry_UI::update(){
    QTableWidget* profileTable = new QTableWidget(profDialog);
    profDialog = new ShapeDialog(profBtn, profileTable);
    connect(profileTable, SIGNAL(cellChanged(int,int)), profDialog, SLOT(saveTableValue(int,int)));
    }
    @

    class C.h

    @class ShapeDialog : public QDialog {

    Q_OBJECT
    

    public:
    ShapeDialog(QWidget* parent = 0, QTableWidget* tableSh = NULL);

    ~ShapeDialog();
    
    QTableWidget*   tableShape;
    

    public slots:
    void saveTableValue(int r,int c);

    signals:
    void load();
    };

    #endif // SHAPEDIALOG_H
    @

    class C.cpp

    @ShapeDialog::ShapeDialog(QWidget* parent, QTableWidget* tableSh)
    : QDialog(parent),
    tableShape(tableSh){}

    void ShapeDialog::saveTableValue(int r,int c){

    ....
    
    emit load();
    

    }
    @

    Can someone help me please?


  • Moderators

    check the return value of the connect statement

    check the output on the console

    this gives you a pretty clear reason whats going wrong.



  • Thank you raven-worx, I have checked if the connect statement works and it does (the bool is 1) and I ve printed something in the saveTableValue slot and it works also....


  • Moderators

    when the connect() returns true the connection is fine and everything will work.
    So there must be something else... the posted code looks good.



  • exactely I cant find out what's wrong. I tried to emit the same signal in B class and connected in the A class, and it works! the only difference I see is that the case that doesn't work is a QDialog!! what's wrong with that?!


  • Moderators

    should also work. even if you call QDialog::exec() to show it.
    Did you try a full rebuild of your project?



  • What do you mean with "even if you call QDialog::exec() to show it."?

    yes I tried twice to rebuild...nothing


  • Moderators

    [quote author="valeSimu" date="1422369443"]What do you mean with "even if you call QDialog::exec() to show it."?[/quote]

    because QDialog::exec() opens a new event-loop. Nevermind.

    I don't have any more hints for you sry.



  • Could you show where do you show or exec profDialog.
    Is profHullDialog related to profDialog?



  • Another question.
    How many times do you call Geometry_UI::update()?
    In current implementation you create new table on each update.



    • in class B.cpp show the profDialog in thi way

    @connect(profBtn, SIGNAL(clicked()), profDialog, SLOT(show()));@

    • and yes proHullDialog and profDialog are the same, I corrected it, thx

    • yes the table is created for every element it finds in a list, for this reason update is called many times



  • The connect in MainWindow ctor uses a Geomentry_UI::profDialog pointer allocated in Geometry_UI ctor.
    In Geometry_UI::update() you lose that pointer and allocate another and you use that new pointer to connect with a table widget.
    You need to rethink the connections and allocations.

    @
    Main_newUI::Main_newUI(QString pathPj, QWidget *parent)
    : QMainWindow(parent)
    {
    geometryDocks = new Geometry_UI(...); // Creates a pointer to profDialog
    profileDialog = geometryDocks->profDialog;
    connect(profileDialog, SIGNAL(load()), this, SLOT(reloadIfGeometryChanged())); // Uses that pointer to make a connection.
    }

    void Geometry_UI::update()
    {
    QTableWidget* profileTable = new QTableWidget(profDialog);
    profDialog = new ShapeDialog(profBtn, profileTable); // The pointer previously allocated in ctor is lost here.
    connect(profileTable, SIGNAL(cellChanged(int,int)), profDialog, SLOT(saveTableValue(int,int))); // profileTable is connected to new profDialog that is not connected with MainWindow.
    }

    @


Log in to reply
 

Looks like your connection to Qt Forum was lost, please wait while we try to reconnect.