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SIMPLIFIED REPOST How to access "parent" from "closeEvent" ? SIMPLIFIED REPOST

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  • A Anonymous_Banned275

    UPDATE
    Here is a reason why I posted so many variations on the problem
    At present , the cast returns null pointer, however . I can step thru the objects hierarchy tree and can see that the desired object and its VALID parent pointer is about four steps down the hierarchy tree...or up, depending on point of view ...and that is immaterial.
    So, my next step is to iterate thru the "parent" hierarchy , until correct and valid object pointer is found or until desired "action" is found.

    i am looking for Qt way to perform this iteration...
    I am open to suggestions..

    RTFM

    JonBJ Online
    JonBJ Online
    JonB
    wrote on last edited by JonB
    #9

    @AnneRanch said in SIMPLIFIED REPOST How to access "parent" from "closeEvent" ? SIMPLIFIED REPOST:

    I am open to suggestions..

    As suggested in the past, what you want to achieve can be implemented correctly without any "parenting"/iterating/casting/closeEvent() and in a single line of code in your MainWindow_Bluetooth::MainWindow_Bluetooth():

    connect(m_settings, &QDialog::finished, m_mdiarea, &QMdiArea::tileSubWindows);
    

    Why don't you at least try this, instead of keep pursuing the parentage approach?

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    • A Offline
      A Offline
      Anonymous_Banned275
      wrote on last edited by
      #10

      As I said many times, there always is a different way to "skin a cat".

      Your "connect" suggestions implies that "Dialogue is fished " ...
      Finished doing what ?

      That does not meet my spec - unless "clicking x" generates "finished"...
      Can you elaborate on that?

      Thanks

      JonBJ 1 Reply Last reply
      0
      • Christian EhrlicherC Offline
        Christian EhrlicherC Offline
        Christian Ehrlicher
        Lifetime Qt Champion
        wrote on last edited by Christian Ehrlicher
        #11

        Since clicking x = rejecting the dialog, the documentation tells you that finished is emitted: https://doc.qt.io/qt-6/qdialog.html#finished
        You also have could try it out by yourself.

        Qt Online Installer direct download: https://download.qt.io/official_releases/online_installers/
        Visit the Qt Academy at https://academy.qt.io/catalog

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        • A Anonymous_Banned275

          As I said many times, there always is a different way to "skin a cat".

          Your "connect" suggestions implies that "Dialogue is fished " ...
          Finished doing what ?

          That does not meet my spec - unless "clicking x" generates "finished"...
          Can you elaborate on that?

          Thanks

          JonBJ Online
          JonBJ Online
          JonB
          wrote on last edited by JonB
          #12

          @AnneRanch said in SIMPLIFIED REPOST How to access "parent" from "closeEvent" ? SIMPLIFIED REPOST:

          That does not meet my spec - unless "clicking x" generates "finished"...
          Can you elaborate on that?

          It does. Since it's a QDialog. Did you try it?

          And even if it didn't we would simply make your override of closeEvent() emit a signal like finished or closed or whatever we like (3 lines of code) and the principle would still be to connect() that signal up in MainWindow_Bluetooth to a slot which does your tlleSubWindows() or whatever else you want to do (1 line of code). No parent stuff.

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          • A Offline
            A Offline
            Anonymous_Banned275
            wrote on last edited by
            #13

            OK, I 'll try it , but I have to bypass the current code first... maybe just deleting "closeEvent " will do .

            JonBJ 1 Reply Last reply
            0
            • A Anonymous_Banned275

              OK, I 'll try it , but I have to bypass the current code first... maybe just deleting "closeEvent " will do .

              JonBJ Online
              JonBJ Online
              JonB
              wrote on last edited by
              #14

              @AnneRanch
              Comment out existing closeEvent() override, or the code inside it, while you get this working.

              A 1 Reply Last reply
              1
              • JonBJ JonB

                @AnneRanch
                Comment out existing closeEvent() override, or the code inside it, while you get this working.

                A Offline
                A Offline
                Anonymous_Banned275
                wrote on last edited by
                #15

                @JonB I have taken a different approach, - just added the suggested connect. That should also work since my current code does not do the "tileSunwindows". Unfortunately neither the connect code, hence more debugging is due.
                I find the "finished" doc because DIALOG was "rejected" misleading.
                As a user I am "working" with GUI commonly called "window". I am using its "feature " to close . As a user I could careless if the class is called "dialogue" - I am not using anything even suggesting I am "rejecting" the GUi.
                As a coder I did the same - used visible GUI feature called "close"...
                In an essence - "standard " (ISO term ?) "close" is being renamed "reject"...
                Not cool... so well...
                Cheers

                1 Reply Last reply
                0
                • JonBJ Online
                  JonBJ Online
                  JonB
                  wrote on last edited by
                  #16

                  QDialog emits finished when it is done() --- no matter accepted, rejected, or press "close" button. It just means finished with the dialog, and only applies to a dialog. There are no "standard ISO terms" for anything. If you don't want to use finished because you don't like the word that's up to you. If you want to define your own signal with a different word:

                  // In settingsdialog.h
                  signals:
                      void closed();
                  
                  // In settingsdialog.cpp
                  void SettingsDialog::closeEvent( QCloseEvent* event)
                  {
                      emit closed();
                  }
                  
                  // In MainWindow_Bluetooth::MainWindow_Bluetooth()
                  // any of the following
                  connect(m_settings, &SettingsDialog::closed, m_mdiarea, &QMdiArea::tileSubWindows);
                  connect(m_settings, &SettingsDialog::closed, this, &MainWindow_Bluetooth::anySlotYouCareToWrite);
                  connect(m_settings, &SettingsDialog::closed, this, [] () { qDebug() << "What to do when SettingsDialog closed"; });
                  

                  Whichever this connection of signal to slot is the correct way to do it rather than attempting to walk up SettingDialog's parent hierarchy.

                  A 1 Reply Last reply
                  2
                  • JonBJ JonB

                    QDialog emits finished when it is done() --- no matter accepted, rejected, or press "close" button. It just means finished with the dialog, and only applies to a dialog. There are no "standard ISO terms" for anything. If you don't want to use finished because you don't like the word that's up to you. If you want to define your own signal with a different word:

                    // In settingsdialog.h
                    signals:
                        void closed();
                    
                    // In settingsdialog.cpp
                    void SettingsDialog::closeEvent( QCloseEvent* event)
                    {
                        emit closed();
                    }
                    
                    // In MainWindow_Bluetooth::MainWindow_Bluetooth()
                    // any of the following
                    connect(m_settings, &SettingsDialog::closed, m_mdiarea, &QMdiArea::tileSubWindows);
                    connect(m_settings, &SettingsDialog::closed, this, &MainWindow_Bluetooth::anySlotYouCareToWrite);
                    connect(m_settings, &SettingsDialog::closed, this, [] () { qDebug() << "What to do when SettingsDialog closed"; });
                    

                    Whichever this connection of signal to slot is the correct way to do it rather than attempting to walk up SettingDialog's parent hierarchy.

                    A Offline
                    A Offline
                    Anonymous_Banned275
                    wrote on last edited by
                    #17

                    @JonB OK, then I will have to ask this - what is "being done" in my case?
                    The dialog is added as QMdiArea subwindow and has few tasks to do.
                    There is no task indicating that the dialogue is "done" and that is irrelevant to task "close" and process such "close" .
                    Dialog tasks and "close" are independent.
                    I am not disputing your connect approach , but it extreme - using "done" is like say "today is Monday" so lets close the window.

                    Besides - I think down the line
                    if the "dialog" is "rejected" how am I doing to apply - "restore previous display of subwindows "?

                    I realize this is mater of semantics - but does "close" means just that and the object is still in memory ?

                    And no , I am not that far in code .....

                    JonBJ 1 Reply Last reply
                    0
                    • A Anonymous_Banned275

                      @JonB OK, then I will have to ask this - what is "being done" in my case?
                      The dialog is added as QMdiArea subwindow and has few tasks to do.
                      There is no task indicating that the dialogue is "done" and that is irrelevant to task "close" and process such "close" .
                      Dialog tasks and "close" are independent.
                      I am not disputing your connect approach , but it extreme - using "done" is like say "today is Monday" so lets close the window.

                      Besides - I think down the line
                      if the "dialog" is "rejected" how am I doing to apply - "restore previous display of subwindows "?

                      I realize this is mater of semantics - but does "close" means just that and the object is still in memory ?

                      And no , I am not that far in code .....

                      JonBJ Online
                      JonBJ Online
                      JonB
                      wrote on last edited by JonB
                      #18

                      @AnneRanch
                      QDialog::finished() is a signal which, so far as I understand, is emitted by a QDialog whenever it gets closed --- be that by pressing a button or closing it with the "X" button. That is what you were trying to capture when you were overriding closeEvent(). I believe this finished signal gets emitted in the same circumstance, which is what you were looking for.

                      Why don't you start with no more or less than:

                      connect(m_settings, &SettingsDialog::finished, this, [] () { qDebug() << "What to do when SettingsDialog closed"; });
                      

                      You can add this line (in MainWindow_Bluetooth::MainWindow_Bluetooth()) regardless of what else you have there/without changing anything of your own. Then see when that message appears, e.g. we're hoping it does when you close the settings dialog, since that is what you were looking for. Assuming it does, you can then connect it to whatever you actually want to from the main window do when the dialog gets closed.

                      A 1 Reply Last reply
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                      • JonBJ JonB

                        @AnneRanch
                        QDialog::finished() is a signal which, so far as I understand, is emitted by a QDialog whenever it gets closed --- be that by pressing a button or closing it with the "X" button. That is what you were trying to capture when you were overriding closeEvent(). I believe this finished signal gets emitted in the same circumstance, which is what you were looking for.

                        Why don't you start with no more or less than:

                        connect(m_settings, &SettingsDialog::finished, this, [] () { qDebug() << "What to do when SettingsDialog closed"; });
                        

                        You can add this line (in MainWindow_Bluetooth::MainWindow_Bluetooth()) regardless of what else you have there/without changing anything of your own. Then see when that message appears, e.g. we're hoping it does when you close the settings dialog, since that is what you were looking for. Assuming it does, you can then connect it to whatever you actually want to from the main window do when the dialog gets closed.

                        A Offline
                        A Offline
                        Anonymous_Banned275
                        wrote on last edited by
                        #19

                        @JonB OK, getting somewhere,,, since I got the "cut ans paste " save and ready let me post this and the reply to your last post.

                        This is is all working as "single stage iteration" and what is left is to extend the code "up stream" - up the current hierarchy until CORRECT class is activated.
                        I do not have a clue how to implement that!!!

                        I have bee looking at various QTree and so far no success .

                        The issues are - there are many intermediate classes / objects hence the up- stream object cannot be explicitly named - it has to be machine friendly and probably "all the way " to QObject base class.

                        Now to the use of "finished".
                        I am not saying it is not usable, however , it seem to just duplicate the "closeEvent".
                        Secondly
                        the "close" task HAS to be implemented to ALL subwindows AND according to the doc "closeEvent" can be "reimplemented" up the hierarchy tree. In that case the "parent" class would contain the common code - no need to have each subwindow to process the "closeEvent". If "finished " is used - I would have to have connect all over the place...

                        BUT I am not convinced this "reimplementing " of "closeEvent" actually works - the doc SPECIFICALLY say "it MAY work..."
                        With that - I may have to use your "connect" approach anyway....

                        I do appreciate your assistance .

                        void SettingsDialog::closeEvent( QCloseEvent* event )
                        {
                        #ifdef RETILE
                            text = "\t#ifdef RETILE \n";
                            text += "\t\t\tTRACE START Retile mdiArea subwindows ....  ";
                            text += " ";
                            //text += " TASK  initActionsConnections() ";
                            text += Q_FUNC_INFO;
                            text += QString::number(__LINE__);
                            qDebug().noquote() << text;
                        
                        //    text =" parent ???";
                        //    text += parent()->objectName();
                        //     qDebug().noquote() << text;
                        #endif
                        
                        
                        #ifdef BYPASS
                            //event->accept();   // what does it do ??
                            emit PassMessage(text,0);
                            // setup message passing QString for now
                            connect(SDD,SIGNAL(PassMessage(QString,int)),this,SLOT(PostMessage(QString,int)));
                        #endif
                        
                            // Accept the event to allow the window to close
                            event->accept();  // TOK
                            // looking for action = tileSubwindows
                            QString textMmatch = "tileSubwindow";
                            // access to QMdiArea
                            // who is immedate upstrem in hirerarchy?
                            QObject *object = qobject_cast<QObject*>(parent()); // this->parentWidget());
                            QMdiSubWindow* mdiArea = qobject_cast<QMdiSubWindow*>(this->parentWidget());
                            // doesit have action = textMatch ?
                            QList<QObject*> list = object->children();
                            foreach(auto *action,list)
                            {
                                if( action->objectName().contains(textMmatch))
                                {
                                    text = " /t/t/t found match ";
                                }
                                else
                                {
                                    text = " Match not found continue search... ";
                                }
                                text += action->objectName();
                                qDebug().noquote() << text;
                            }
                            text += Q_FUNC_INFO;
                            text += QString::number(__LINE__);
                            qDebug().noquote() << text;
                        
                        
                            return;
                        
                        
                        
                        A 1 Reply Last reply
                        0
                        • A Anonymous_Banned275

                          @JonB OK, getting somewhere,,, since I got the "cut ans paste " save and ready let me post this and the reply to your last post.

                          This is is all working as "single stage iteration" and what is left is to extend the code "up stream" - up the current hierarchy until CORRECT class is activated.
                          I do not have a clue how to implement that!!!

                          I have bee looking at various QTree and so far no success .

                          The issues are - there are many intermediate classes / objects hence the up- stream object cannot be explicitly named - it has to be machine friendly and probably "all the way " to QObject base class.

                          Now to the use of "finished".
                          I am not saying it is not usable, however , it seem to just duplicate the "closeEvent".
                          Secondly
                          the "close" task HAS to be implemented to ALL subwindows AND according to the doc "closeEvent" can be "reimplemented" up the hierarchy tree. In that case the "parent" class would contain the common code - no need to have each subwindow to process the "closeEvent". If "finished " is used - I would have to have connect all over the place...

                          BUT I am not convinced this "reimplementing " of "closeEvent" actually works - the doc SPECIFICALLY say "it MAY work..."
                          With that - I may have to use your "connect" approach anyway....

                          I do appreciate your assistance .

                          void SettingsDialog::closeEvent( QCloseEvent* event )
                          {
                          #ifdef RETILE
                              text = "\t#ifdef RETILE \n";
                              text += "\t\t\tTRACE START Retile mdiArea subwindows ....  ";
                              text += " ";
                              //text += " TASK  initActionsConnections() ";
                              text += Q_FUNC_INFO;
                              text += QString::number(__LINE__);
                              qDebug().noquote() << text;
                          
                          //    text =" parent ???";
                          //    text += parent()->objectName();
                          //     qDebug().noquote() << text;
                          #endif
                          
                          
                          #ifdef BYPASS
                              //event->accept();   // what does it do ??
                              emit PassMessage(text,0);
                              // setup message passing QString for now
                              connect(SDD,SIGNAL(PassMessage(QString,int)),this,SLOT(PostMessage(QString,int)));
                          #endif
                          
                              // Accept the event to allow the window to close
                              event->accept();  // TOK
                              // looking for action = tileSubwindows
                              QString textMmatch = "tileSubwindow";
                              // access to QMdiArea
                              // who is immedate upstrem in hirerarchy?
                              QObject *object = qobject_cast<QObject*>(parent()); // this->parentWidget());
                              QMdiSubWindow* mdiArea = qobject_cast<QMdiSubWindow*>(this->parentWidget());
                              // doesit have action = textMatch ?
                              QList<QObject*> list = object->children();
                              foreach(auto *action,list)
                              {
                                  if( action->objectName().contains(textMmatch))
                                  {
                                      text = " /t/t/t found match ";
                                  }
                                  else
                                  {
                                      text = " Match not found continue search... ";
                                  }
                                  text += action->objectName();
                                  qDebug().noquote() << text;
                              }
                              text += Q_FUNC_INFO;
                              text += QString::number(__LINE__);
                              qDebug().noquote() << text;
                          
                          
                              return;
                          
                          
                          
                          A Offline
                          A Offline
                          Anonymous_Banned275
                          wrote on last edited by
                          #20

                          @AnneRanch Here is my current "solution" , and it is a embarrassing hack.

                          Can anybody smarter than me put this into nice loop ?
                          ANY loop...

                              QString textMmatch = "actionTile_subwindows";
                          
                              // test code here
                          
                          HACK 
                              **QList<QObject*>  ppList = this->parent()->parent()->parent()->parent()->children();**
                          
                          
                              foreach(auto *action,ppList)
                              {
                                  if( action->objectName().contains(textMmatch))
                                  {
                                      text = " \t\t\t found match ";
                                      text += action->objectName();
                                      qDebug().noquote() << text;
                                      break; //continue;
                                  }
                                  else
                                  {
                                      text = " Match not found continue search... ";
                                  }
                                  text += action->objectName();
                                  qDebug().noquote() << text;
                              }
                              text += Q_FUNC_INFO;
                              text += QString::number(__LINE__);
                              qDebug().noquote() << text;
                          
                          M 1 Reply Last reply
                          0
                          • A Anonymous_Banned275

                            @AnneRanch Here is my current "solution" , and it is a embarrassing hack.

                            Can anybody smarter than me put this into nice loop ?
                            ANY loop...

                                QString textMmatch = "actionTile_subwindows";
                            
                                // test code here
                            
                            HACK 
                                **QList<QObject*>  ppList = this->parent()->parent()->parent()->parent()->children();**
                            
                            
                                foreach(auto *action,ppList)
                                {
                                    if( action->objectName().contains(textMmatch))
                                    {
                                        text = " \t\t\t found match ";
                                        text += action->objectName();
                                        qDebug().noquote() << text;
                                        break; //continue;
                                    }
                                    else
                                    {
                                        text = " Match not found continue search... ";
                                    }
                                    text += action->objectName();
                                    qDebug().noquote() << text;
                                }
                                text += Q_FUNC_INFO;
                                text += QString::number(__LINE__);
                                qDebug().noquote() << text;
                            
                            M Offline
                            M Offline
                            mpergand
                            wrote on last edited by mpergand
                            #21

                            @AnneRanch said in SIMPLIFIED REPOST How to access "parent" from "closeEvent" ? SIMPLIFIED REPOST:

                            QList<QObject*>  ppList = this->parent()->parent()->parent()->parent()->children();
                            
                            QObject* p=this;
                            
                            while(p->parent()) p = p->parent();
                            QObjectList  ppList = p->children();
                            
                            Pl45m4P A 2 Replies Last reply
                            2
                            • M mpergand

                              @AnneRanch said in SIMPLIFIED REPOST How to access "parent" from "closeEvent" ? SIMPLIFIED REPOST:

                              QList<QObject*>  ppList = this->parent()->parent()->parent()->parent()->children();
                              
                              QObject* p=this;
                              
                              while(p->parent()) p = p->parent();
                              QObjectList  ppList = p->children();
                              
                              Pl45m4P Offline
                              Pl45m4P Offline
                              Pl45m4
                              wrote on last edited by
                              #22

                              @mpergand said in SIMPLIFIED REPOST How to access "parent" from "closeEvent" ? SIMPLIFIED REPOST:

                              QObject* p=this;
                              
                              while(p->parent()) p = p->parent();
                              QObjectList  ppList = p->children();
                              

                              @mpergand A piece of art lmao :D


                              If debugging is the process of removing software bugs, then programming must be the process of putting them in.

                              ~E. W. Dijkstra

                              A 1 Reply Last reply
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                              • Pl45m4P Pl45m4

                                @mpergand said in SIMPLIFIED REPOST How to access "parent" from "closeEvent" ? SIMPLIFIED REPOST:

                                QObject* p=this;
                                
                                while(p->parent()) p = p->parent();
                                QObjectList  ppList = p->children();
                                

                                @mpergand A piece of art lmao :D

                                A Offline
                                A Offline
                                Anonymous_Banned275
                                wrote on last edited by
                                #23

                                Thanks a million .. true piece of art code = KISS !
                                I am not just saying this , but this morning I came up with identical idea... but I was not sure how to implement the while loop.
                                Woks great, skips over all of the intermediate classes...
                                And most of all - no RTFM,
                                I do appreciate your help.

                                1 Reply Last reply
                                0
                                • A Anonymous_Banned275 has marked this topic as solved on
                                • M mpergand

                                  @AnneRanch said in SIMPLIFIED REPOST How to access "parent" from "closeEvent" ? SIMPLIFIED REPOST:

                                  QList<QObject*>  ppList = this->parent()->parent()->parent()->parent()->children();
                                  
                                  QObject* p=this;
                                  
                                  while(p->parent()) p = p->parent();
                                  QObjectList  ppList = p->children();
                                  
                                  A Offline
                                  A Offline
                                  Anonymous_Banned275
                                  wrote on last edited by Anonymous_Banned275
                                  #24

                                  @mpergand Hello,
                                  I have posted more stuff related to my task and it may look as negative toward you.
                                  I am posting this to make sure it is not interpreted that way and woudl like to let you know that I do appreciate all the help you have given me.
                                  The whole idea of automatic re-tillling of QMdiArea subwindows after one is deleted , was really just "bells and whistles ",
                                  nice to have and not essential for my project.
                                  This is / was an extremely (sic?) positive , hence beneficial experience for me, with an exception of uncalled for "contributions" AI / RTFM style.
                                  I realized that big part of the mess was my silly way to keep the Qt example and add QMdiArea to it. Then I ended up with two instances of same class and it was not easy to keep track of which is which.

                                  It really does not matter I did not end up with working code, but I sure can reuse it in my next "GUI class hierarchy " - another B&W project.

                                  Yours truly
                                  MFTR

                                  1 Reply Last reply
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