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QWidget::windowRole() use as storage for small textual data

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  • JonBJ JonB

    @Please_Help_me_D
    I was doing this just today. The focus can be hitting some sub widget on a container. In my case widgets on a QMdiSubWindow. To find that I go up via parentWidget() till I find one or hit the topmost. If you are same thing you will want to go up parents from old/now, not chidren?

    Please_Help_me_DP Offline
    Please_Help_me_DP Offline
    Please_Help_me_D
    wrote on last edited by
    #8

    @JonB nice to hear that
    As I understood I should go up from old/now until I meet ads::CDockWidget* dockWidget != nullptr condition, correct? Like:

    {
    ads::CDockWidget* dockWidget = qobject_cast<ads::CDockWidget*>(old->parent());
    if (CDockWidget != nullptr){}
    }
    

    but in some while or for loop...

    JonBJ 1 Reply Last reply
    0
    • Please_Help_me_DP Please_Help_me_D

      @JonB nice to hear that
      As I understood I should go up from old/now until I meet ads::CDockWidget* dockWidget != nullptr condition, correct? Like:

      {
      ads::CDockWidget* dockWidget = qobject_cast<ads::CDockWidget*>(old->parent());
      if (CDockWidget != nullptr){}
      }
      

      but in some while or for loop...

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

      @Please_Help_me_D

      ads::CDockWidget* dockWidget = nullptr;
      while (old != nullptr && (dockWidget = qobject_cast<ads::CDockWidget*>(old)) == nullptr)
          old = old->parentWidget();
      qDebug() << dockWidget;
      
      Please_Help_me_DP 1 Reply Last reply
      1
      • JonBJ JonB

        @Please_Help_me_D

        ads::CDockWidget* dockWidget = nullptr;
        while (old != nullptr && (dockWidget = qobject_cast<ads::CDockWidget*>(old)) == nullptr)
            old = old->parentWidget();
        qDebug() << dockWidget;
        
        Please_Help_me_DP Offline
        Please_Help_me_DP Offline
        Please_Help_me_D
        wrote on last edited by
        #10

        @JonB thank you
        But the loop ended and dockWidget is always nullptr. It takes about 7 cycles and there is no ads::CDockWidget*

        JonBJ 1 Reply Last reply
        0
        • Please_Help_me_DP Please_Help_me_D

          @JonB thank you
          But the loop ended and dockWidget is always nullptr. It takes about 7 cycles and there is no ads::CDockWidget*

          JonBJ Offline
          JonBJ Offline
          JonB
          wrote on last edited by
          #11

          @Please_Help_me_D
          So in that case the old or now (you have written this loop on both, haven't you?!) in the focus change is not a descendent of your ads::CDockWidget* dockWidget. I never said it was, you did! Or you check children if whatever it is works that way.

          Please_Help_me_DP 2 Replies Last reply
          0
          • JonBJ JonB

            @Please_Help_me_D
            So in that case the old or now (you have written this loop on both, haven't you?!) in the focus change is not a descendent of your ads::CDockWidget* dockWidget. I never said it was, you did! Or you check children if whatever it is works that way.

            Please_Help_me_DP Offline
            Please_Help_me_DP Offline
            Please_Help_me_D
            wrote on last edited by
            #12

            @JonB yes I have written both old and now
            Yes I'm trying to find this widget via old->children();. I need few minuts

            1 Reply Last reply
            0
            • JonBJ JonB

              @Please_Help_me_D
              So in that case the old or now (you have written this loop on both, haven't you?!) in the focus change is not a descendent of your ads::CDockWidget* dockWidget. I never said it was, you did! Or you check children if whatever it is works that way.

              Please_Help_me_DP Offline
              Please_Help_me_DP Offline
              Please_Help_me_D
              wrote on last edited by
              #13

              @JonB this code can't find ads::CDockWidget* neither:

              void MainWindow::onFocusChanged(QWidget* old, QWidget* now){
                  if (old != nullptr){
                      ads::CDockWidget* dockWidget = nullptr;
                      QObjectList objList = old->children();
                      int i = 0;
                      while (i < objList.count() && dockWidget == nullptr){
                          dockWidget = qobject_cast<ads::CDockWidget*>(objList.at(i));
                          i++;
                      }
                  }
              
                  if (now != nullptr){
                      ads::CDockWidget* dockWidget = nullptr;
                      QObjectList objList = now->children();
                      int i = 0;
                      while (i < objList.count() && dockWidget == nullptr){
                          dockWidget = qobject_cast<ads::CDockWidget*>(objList.at(i));
                          i++;
                      }
                  }
              }
              
              JonBJ 1 Reply Last reply
              0
              • Please_Help_me_DP Please_Help_me_D

                @JonB this code can't find ads::CDockWidget* neither:

                void MainWindow::onFocusChanged(QWidget* old, QWidget* now){
                    if (old != nullptr){
                        ads::CDockWidget* dockWidget = nullptr;
                        QObjectList objList = old->children();
                        int i = 0;
                        while (i < objList.count() && dockWidget == nullptr){
                            dockWidget = qobject_cast<ads::CDockWidget*>(objList.at(i));
                            i++;
                        }
                    }
                
                    if (now != nullptr){
                        ads::CDockWidget* dockWidget = nullptr;
                        QObjectList objList = now->children();
                        int i = 0;
                        while (i < objList.count() && dockWidget == nullptr){
                            dockWidget = qobject_cast<ads::CDockWidget*>(objList.at(i));
                            i++;
                        }
                    }
                }
                
                JonBJ Offline
                JonBJ Offline
                JonB
                wrote on last edited by JonB
                #14

                @Please_Help_me_D
                So read up on what a ads::CDockWidget is/how it works. Your assumption in that QWidget::focusChanged(old, now) must lead to widgets either ancestors or descendants of this dock widget. I have no idea whether that is the case. Also your code may need to recurse down through children, no? At least start by finding out what old & now actually are in your focus change.

                Please_Help_me_DP 1 Reply Last reply
                0
                • JonBJ JonB

                  @Please_Help_me_D
                  So read up on what a ads::CDockWidget is/how it works. Your assumption in that QWidget::focusChanged(old, now) must lead to widgets either ancestors or descendants of this dock widget. I have no idea whether that is the case. Also your code may need to recurse down through children, no? At least start by finding out what old & now actually are in your focus change.

                  Please_Help_me_DP Offline
                  Please_Help_me_DP Offline
                  Please_Help_me_D
                  wrote on last edited by
                  #15

                  @JonB yes possibly I should have done the recursion down to the other children but it alredy becomes too complicated solution for such kind of a task.
                  Now I'm trying to set property not on CDockWidget but to some parent. I'm trying...

                  1 Reply Last reply
                  0
                  • mrjjM Offline
                    mrjjM Offline
                    mrjj
                    Lifetime Qt Champion
                    wrote on last edited by
                    #16

                    Hi
                    It wont be the DockWidget that has the focus. it will be its widget/children.

                    I would call dumpObjectTree()
                    on old and now to see how they are made up.

                    Please_Help_me_DP 1 Reply Last reply
                    1
                    • mrjjM mrjj

                      Hi
                      It wont be the DockWidget that has the focus. it will be its widget/children.

                      I would call dumpObjectTree()
                      on old and now to see how they are made up.

                      Please_Help_me_DP Offline
                      Please_Help_me_DP Offline
                      Please_Help_me_D
                      wrote on last edited by Please_Help_me_D
                      #17

                      @mrjj thank you for advice. Here is the output:

                      setFocus(Qt::OtherFocusReason);
                      setFocus(Qt::OtherFocusReason);
                      ads::CDockWidget::2D Window 
                          QBoxLayout:: 
                          QAction:: 
                          QScrollArea::dockWidgetScrollArea 
                              QWidget::qt_scrollarea_viewport 
                                  QVTKOpenGLStereoWidget:: 
                                      QVBoxLayout:: 
                                      QWindowContainer:: 
                              QWidget::qt_scrollarea_hcontainer 
                                  QScrollBar:: 
                                  QBoxLayout:: 
                              QWidget::qt_scrollarea_vcontainer 
                                  QScrollBar:: 
                                  QBoxLayout:: 
                      setFocus(Qt::OtherFocusReason);
                      setFocus(Qt::OtherFocusReason);
                      setFocus(Qt::OtherFocusReason);
                      

                      So the focus should be on one of those?
                      By the way this tree is from ads::CDockWidget
                      Just a moment and I find tree for old
                      /
                      and here is tree for now object:

                      ads::CDockWidgetTab:: 
                          QBoxLayout:: 
                          ads::CElidingLabel::dockWidgetTabLabel 
                          QPushButton::tabCloseButton 
                      
                      mrjjM 1 Reply Last reply
                      0
                      • Please_Help_me_DP Please_Help_me_D

                        @mrjj thank you for advice. Here is the output:

                        setFocus(Qt::OtherFocusReason);
                        setFocus(Qt::OtherFocusReason);
                        ads::CDockWidget::2D Window 
                            QBoxLayout:: 
                            QAction:: 
                            QScrollArea::dockWidgetScrollArea 
                                QWidget::qt_scrollarea_viewport 
                                    QVTKOpenGLStereoWidget:: 
                                        QVBoxLayout:: 
                                        QWindowContainer:: 
                                QWidget::qt_scrollarea_hcontainer 
                                    QScrollBar:: 
                                    QBoxLayout:: 
                                QWidget::qt_scrollarea_vcontainer 
                                    QScrollBar:: 
                                    QBoxLayout:: 
                        setFocus(Qt::OtherFocusReason);
                        setFocus(Qt::OtherFocusReason);
                        setFocus(Qt::OtherFocusReason);
                        

                        So the focus should be on one of those?
                        By the way this tree is from ads::CDockWidget
                        Just a moment and I find tree for old
                        /
                        and here is tree for now object:

                        ads::CDockWidgetTab:: 
                            QBoxLayout:: 
                            ads::CElidingLabel::dockWidgetTabLabel 
                            QPushButton::tabCloseButton 
                        
                        mrjjM Offline
                        mrjjM Offline
                        mrjj
                        Lifetime Qt Champion
                        wrote on last edited by
                        #18

                        hi
                        yes it should but we don't have to guess.
                        you can do
                        QWidget * fw = qApp->focusWidget();
                        and check out in the debugger (or qDebug its object name) to see what it is.

                        It should be possible to get hold of the Dock again to get your data back.

                        Please_Help_me_DP 2 Replies Last reply
                        1
                        • mrjjM mrjj

                          hi
                          yes it should but we don't have to guess.
                          you can do
                          QWidget * fw = qApp->focusWidget();
                          and check out in the debugger (or qDebug its object name) to see what it is.

                          It should be possible to get hold of the Dock again to get your data back.

                          Please_Help_me_DP Offline
                          Please_Help_me_DP Offline
                          Please_Help_me_D
                          wrote on last edited by
                          #19

                          @mrjj QWidget * fw and now widget is the same. See the picture please
                          1.png

                          1 Reply Last reply
                          0
                          • mrjjM mrjj

                            hi
                            yes it should but we don't have to guess.
                            you can do
                            QWidget * fw = qApp->focusWidget();
                            and check out in the debugger (or qDebug its object name) to see what it is.

                            It should be possible to get hold of the Dock again to get your data back.

                            Please_Help_me_DP Offline
                            Please_Help_me_DP Offline
                            Please_Help_me_D
                            wrote on last edited by Please_Help_me_D
                            #20

                            @mrjj now I'm trying to set property to the tabWidgets to wich CDockWidget belongs to:

                            QVTKOpenGLStereoWidget* MainWindowObjectCreator::createVTK2DWindow(){
                                QVTKOpenGLStereoWidget* qvtkOpenGLStereoWidget = new QVTKOpenGLStereoWidget;
                                ads::CDockWidget* dockWidget = new ads::CDockWidget("2D Window");
                                dockWidget->setWidget(qvtkOpenGLStereoWidget);
                                dockManager->addDockWidget(ads::RightDockWidgetArea, dockWidget);
                                dockWidget->tabWidget()->setProperty("IsVisualization", 4443);
                                //dockWidget->dumpObjectTree();
                                return qvtkOpenGLStereoWidget;
                            }
                            

                            but each time I manually change the focus the MainWindow::onFocusChanged(QWidget* old, QWidget* now) works twice:
                            first time now is the old window
                            second time is the new window
                            and when the second time this method works then I get the correct value of property:

                            void MainWindow::onFocusChanged(QWidget* old, QWidget* now){
                                QWidget * fw = qApp->focusWidget();
                                fw->dumpObjectTree();
                                if (now != nullptr){
                                    now->dumpObjectTree();
                                    QVariant varia = now->property("IsVisualization"); 
                                }
                            }
                            

                            By the way this works only if the focused window is tabbed. Otherwise the focused widget is not a tabWidget(). So idea to set property to the tabWidget() doesn't seem to work

                            mrjjM 1 Reply Last reply
                            0
                            • Please_Help_me_DP Please_Help_me_D

                              @mrjj now I'm trying to set property to the tabWidgets to wich CDockWidget belongs to:

                              QVTKOpenGLStereoWidget* MainWindowObjectCreator::createVTK2DWindow(){
                                  QVTKOpenGLStereoWidget* qvtkOpenGLStereoWidget = new QVTKOpenGLStereoWidget;
                                  ads::CDockWidget* dockWidget = new ads::CDockWidget("2D Window");
                                  dockWidget->setWidget(qvtkOpenGLStereoWidget);
                                  dockManager->addDockWidget(ads::RightDockWidgetArea, dockWidget);
                                  dockWidget->tabWidget()->setProperty("IsVisualization", 4443);
                                  //dockWidget->dumpObjectTree();
                                  return qvtkOpenGLStereoWidget;
                              }
                              

                              but each time I manually change the focus the MainWindow::onFocusChanged(QWidget* old, QWidget* now) works twice:
                              first time now is the old window
                              second time is the new window
                              and when the second time this method works then I get the correct value of property:

                              void MainWindow::onFocusChanged(QWidget* old, QWidget* now){
                                  QWidget * fw = qApp->focusWidget();
                                  fw->dumpObjectTree();
                                  if (now != nullptr){
                                      now->dumpObjectTree();
                                      QVariant varia = now->property("IsVisualization"); 
                                  }
                              }
                              

                              By the way this works only if the focused window is tabbed. Otherwise the focused widget is not a tabWidget(). So idea to set property to the tabWidget() doesn't seem to work

                              mrjjM Offline
                              mrjjM Offline
                              mrjj
                              Lifetime Qt Champion
                              wrote on last edited by mrjj
                              #21

                              @Please_Help_me_D

                              Ah silly me. of cause now will be the same as qApp->focusWidget(); :)
                              and it does seem to be the actual DockWidget ! which i didn't expect.

                              Is it possible you have 2 connects to the onFocusChanged signal ?
                              Not really sure why it should run twice. I don't recall it normally does that.

                              Its normally not an issue to loop up the chain to find the top parent.
                              So not sure why it dont seem to work for you here.

                              Please_Help_me_DP 1 Reply Last reply
                              1
                              • mrjjM mrjj

                                @Please_Help_me_D

                                Ah silly me. of cause now will be the same as qApp->focusWidget(); :)
                                and it does seem to be the actual DockWidget ! which i didn't expect.

                                Is it possible you have 2 connects to the onFocusChanged signal ?
                                Not really sure why it should run twice. I don't recall it normally does that.

                                Its normally not an issue to loop up the chain to find the top parent.
                                So not sure why it dont seem to work for you here.

                                Please_Help_me_DP Offline
                                Please_Help_me_DP Offline
                                Please_Help_me_D
                                wrote on last edited by
                                #22

                                @mrjj yes, now I also find this looking for parent not working for me strange :)
                                Just a moment I guess that I'm missing something important...

                                mrjjM 1 Reply Last reply
                                0
                                • Please_Help_me_DP Please_Help_me_D

                                  @mrjj yes, now I also find this looking for parent not working for me strange :)
                                  Just a moment I guess that I'm missing something important...

                                  mrjjM Offline
                                  mrjjM Offline
                                  mrjj
                                  Lifetime Qt Champion
                                  wrote on last edited by
                                  #23

                                  @Please_Help_me_D
                                  Yeah as the dumptree clearly shows its the top as we expect
                                  ads::CDockWidget::2D Window
                                  QBoxLayout::
                                  QAction::
                                  QScrollArea::dockWidgetScrollArea
                                  QWidget::qt_scrollarea_viewport
                                  QVTKOpenGLStereoWidget::
                                  QVBoxLayout::
                                  ....

                                  But the test with qApp->focusWidget(); showd now is the Dock so
                                  looking at this code.

                                  f (now != nullptr){
                                  ads::CDockWidget* dockWidget = nullptr;
                                  QObjectList objList = now->children();

                                  Do you only check its children ?
                                  and in that case, the line
                                  dockWidget = qobject_castads::CDockWidget*(objList.at(i));

                                  will always return null as you skip the now ? and only cast children ?

                                  Please_Help_me_DP 1 Reply Last reply
                                  0
                                  • mrjjM mrjj

                                    @Please_Help_me_D
                                    Yeah as the dumptree clearly shows its the top as we expect
                                    ads::CDockWidget::2D Window
                                    QBoxLayout::
                                    QAction::
                                    QScrollArea::dockWidgetScrollArea
                                    QWidget::qt_scrollarea_viewport
                                    QVTKOpenGLStereoWidget::
                                    QVBoxLayout::
                                    ....

                                    But the test with qApp->focusWidget(); showd now is the Dock so
                                    looking at this code.

                                    f (now != nullptr){
                                    ads::CDockWidget* dockWidget = nullptr;
                                    QObjectList objList = now->children();

                                    Do you only check its children ?
                                    and in that case, the line
                                    dockWidget = qobject_castads::CDockWidget*(objList.at(i));

                                    will always return null as you skip the now ? and only cast children ?

                                    Please_Help_me_DP Offline
                                    Please_Help_me_DP Offline
                                    Please_Help_me_D
                                    wrote on last edited by Please_Help_me_D
                                    #24

                                    @mrjj let me clarify one moment.
                                    Earlier wrote an unclear post about what widget which dumptree has.
                                    Also there are two possible ways how ads::CDockWidget is attached to the application:

                                    1. CDockWidget is tabbed
                                    2. CDockWidget is float (we can pick and drag it as it is like a new window)

                                    So we have different dumptrees for QWidget* now object on onFocusChanged(QWidget* old, QWidget* now)

                                    Here is dumptree for tabbed CDOckWidget:

                                    ads::CDockWidgetTab:: 
                                        QBoxLayout:: 
                                        ads::CElidingLabel::dockWidgetTabLabel 
                                        QPushButton::tabCloseButton 
                                    

                                    And here is for float CDockWidget:

                                    QScrollArea::dockWidgetScrollArea 
                                        QWidget::qt_scrollarea_viewport 
                                            QVTKOpenGLStereoWidget:: 
                                                QVBoxLayout:: 
                                                QWindowContainer:: 
                                        QWidget::qt_scrollarea_hcontainer 
                                            QScrollBar:: 
                                            QBoxLayout:: 
                                        QWidget::qt_scrollarea_vcontainer 
                                            QScrollBar:: 
                                            QBoxLayout:: 
                                    

                                    So we have a deal with two types of top level widgets :)
                                    But I would like to set the property only to a single type widget and if onFocusChanged() look for that object in now widget

                                    mrjjM 1 Reply Last reply
                                    0
                                    • Please_Help_me_DP Please_Help_me_D

                                      @mrjj let me clarify one moment.
                                      Earlier wrote an unclear post about what widget which dumptree has.
                                      Also there are two possible ways how ads::CDockWidget is attached to the application:

                                      1. CDockWidget is tabbed
                                      2. CDockWidget is float (we can pick and drag it as it is like a new window)

                                      So we have different dumptrees for QWidget* now object on onFocusChanged(QWidget* old, QWidget* now)

                                      Here is dumptree for tabbed CDOckWidget:

                                      ads::CDockWidgetTab:: 
                                          QBoxLayout:: 
                                          ads::CElidingLabel::dockWidgetTabLabel 
                                          QPushButton::tabCloseButton 
                                      

                                      And here is for float CDockWidget:

                                      QScrollArea::dockWidgetScrollArea 
                                          QWidget::qt_scrollarea_viewport 
                                              QVTKOpenGLStereoWidget:: 
                                                  QVBoxLayout:: 
                                                  QWindowContainer:: 
                                          QWidget::qt_scrollarea_hcontainer 
                                              QScrollBar:: 
                                              QBoxLayout:: 
                                          QWidget::qt_scrollarea_vcontainer 
                                              QScrollBar:: 
                                              QBoxLayout:: 
                                      

                                      So we have a deal with two types of top level widgets :)
                                      But I would like to set the property only to a single type widget and if onFocusChanged() look for that object in now widget

                                      mrjjM Offline
                                      mrjjM Offline
                                      mrjj
                                      Lifetime Qt Champion
                                      wrote on last edited by
                                      #25

                                      @Please_Help_me_D
                                      aha. I missed the being tabbed part.
                                      So when tabbed, the Dock becomes a CDockWidgetTab and the Dock is not around any more?

                                      Please_Help_me_DP 1 Reply Last reply
                                      0
                                      • mrjjM mrjj

                                        @Please_Help_me_D
                                        aha. I missed the being tabbed part.
                                        So when tabbed, the Dock becomes a CDockWidgetTab and the Dock is not around any more?

                                        Please_Help_me_DP Offline
                                        Please_Help_me_DP Offline
                                        Please_Help_me_D
                                        wrote on last edited by
                                        #26

                                        @mrjj when tabbed the focused widget is CDockWidgetTab (because I do this dumptree on the now widget when certain widget is focused). And I don't know exactly where CDockWidget disappears :)

                                        mrjjM 1 Reply Last reply
                                        0
                                        • Please_Help_me_DP Please_Help_me_D

                                          @mrjj when tabbed the focused widget is CDockWidgetTab (because I do this dumptree on the now widget when certain widget is focused). And I don't know exactly where CDockWidget disappears :)

                                          mrjjM Offline
                                          mrjjM Offline
                                          mrjj
                                          Lifetime Qt Champion
                                          wrote on last edited by
                                          #27

                                          @Please_Help_me_D
                                          Is CDockWidget just a normal QDockWidget ?

                                          alt text

                                          Please_Help_me_DP 1 Reply Last reply
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