I am trying to programmatically add QMenuBar , QMenu and QAction to a dynamically created instance of QMainWindow . The configuration is read from an XML file: <menubar id="mnuBar"> <menu id="mnuFile" text="File" tooltip="File tooltip!" shortcut="Ctrl+F"> <action text="New" tooltip="New tooltip!" shortcut="Ctrl+N"/> <action text="Open" tooltip="Open tooltip!" shortcut="Ctrl+O"/> <action text="Save" tooltip="Save tooltip!" shortcut="Ctrl+S"/> </menu> </menubar> The code that processes the XML: } else if ( mstrName.compare(clsXMLnode::mscszNodeMenu) == 0 ) { Q_ASSERT_X( blnIsParentAMenuBar()==true, cpszClassConstr , "Menu's can only be added to a menu bar!"); const QString cstrShortcut(strGetAttribute(clsXMLnode::mscszAttrShortcut)) ,cstrText(strGetAttribute(clsXMLnode::mscszAttrText)) ,cstrTooltip(strGetAttribute(clsXMLnode::mscszAttrTooltip)); QMenuBar* pobjMenuBar(qobject_cast<QMenuBar*>(pobjParWidget)); Q_ASSERT_X(pobjMenuBar!=nullptr, cpszClassConstr, "Menu bar isn't present"); QMenu* pobjMenu(new QMenu(pobjMenuBar)); Q_ASSERT_X(pobjMenu!=nullptr, cpszClassConstr, "Menu cannot be created!"); QAction* pobjAction(pobjMenu->menuAction()); if ( pobjAction != nullptr ) { pobjAction->setShortcut(cstrShortcut); pobjAction->setText(cstrText); pobjAction->setToolTip(cstrTooltip); pobjMenuBar->addAction(pobjAction); pobjWidget = pobjMenu; } } else if ( mstrName.compare(clsXMLnode::mscszNodeMenuBar) == 0 ) { //The parent node must be a window if ( pobjParent != nullptr ) { QMainWindow* pobjWindow(pobjParent->pobjGetMainWindow()); if ( pobjWindow != nullptr ) { QMenuBar* pobjMenuBar(new QMenuBar(pobjWindow)); if ( pobjMenuBar != nullptr ) { int intHeight(pobjMenuBar->fontMetrics().height()); QRect rctWindow(pobjWindow->geometry()) ,rctMenuBar(0, 0, rctWindow.width(), intHeight); pobjMenuBar->setGeometry(rctMenuBar); pobjWindow->setMenuBar(pobjMenuBar); pobjWidget = pobjMenuBar; } } } } I've been through this quite a few times and everything in the debugger looks ok, but I'm not seeing the menu bar or the menu in the window. Everything else looks ok, I've compared the logic with a UI I've created in Qt Creator and cannot see what I've missed.

@JonB said in QMenuBar, QMenu and QAction : @SPlatten said in QMenuBar, QMenu and QAction : @SGaist , how do I do that? Do what? "dump the object tree to see how is your QMainWindow structured"? Every QObject (including widgets) has const QObjectList &QObject::children() const . @SGaist suggests you write a debugging routine which calls that recursively starting from your QMainWindow so as to examine the actual object tree (widgets) hierarchy. I was rather thinking of dumpObjectTree but that's the idea.

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QMenuBar, QMenu and QAction

Unsolved General and Desktop

21 Posts 4 Posters 2.1k Views

S SPlatten

Finally fixed:

        if ( mstrName.compare(clsXMLnode::mscszNodeAction) == 0 ) {
            Q_ASSERT_X(blnIsParentAMenu()==true, cpszClassConstr
                       , "Actions only be used in a menu!");
            Q_ASSERT_X(pobjParWidget!=nullptr, cpszClassConstr, "No menubar!");
            const QString cstrShortcut(strGetAttribute(clsXMLnode::mscszAttrShortcut))
                         ,cstrText(strGetAttribute(clsXMLnode::mscszAttrText))
                         ,cstrTooltip(strGetAttribute(clsXMLnode::mscszAttrTooltip));
            QMenu* pobjParentMenu(qobject_cast<QMenu*>(pobjParWidget));
            Q_ASSERT_X(pobjParentMenu!=nullptr, cpszClassConstr, "Widget is not a menu!");
            QWidget* pobjWindow(pobjParentMenu->window());
            Q_ASSERT_X(pobjWindow!=nullptr, cpszClassConstr, "Cannot get window!");
            QAction* pobjAction(new QAction(pobjWindow));
            Q_ASSERT_X(pobjAction!=nullptr, cpszClassConstr, "Cannot create an action!");
            pobjAction->setShortcut(QCoreApplication::translate("clsMainWnd"
                                                               ,cstrShortcut.toLatin1()
                                   ,nullptr));
            pobjAction->setText(cstrText);
            pobjAction->setToolTip(cstrTooltip);
            pobjParentMenu->addAction(pobjAction);
        } else if ( mstrName.compare(clsXMLnode::mscszNodeMenu) == 0 ) {
            Q_ASSERT_X(blnIsParentAMenuBar()==true, cpszClassConstr
                       , "Menu's can only be added to a menu bar!");
            const QString cstrShortcut(strGetAttribute(clsXMLnode::mscszAttrShortcut))
                         ,cstrText(strGetAttribute(clsXMLnode::mscszAttrText))
                         ,cstrTooltip(strGetAttribute(clsXMLnode::mscszAttrTooltip));
            clsXMLnode* pobjMainWindowNode(nullptr);
            if ( pobjParent != nullptr && pobjParent->mpobjParent != nullptr ) {
                pobjMainWindowNode = pobjParent->mpobjParent;
            }
            Q_ASSERT_X(pobjMainWindowNode!=nullptr
                    && pobjMainWindowNode->mpobjMainWindow!=nullptr, cpszClassConstr
                     ,"Cannot get parent window!");
            QMainWindow* pobjMainWindow(pobjMainWindowNode->mpobjMainWindow);
            QMenuBar* pobjMenuBar(pobjMainWindow->menuBar());
            Q_ASSERT_X(pobjMenuBar!=nullptr, cpszClassConstr, "Cannot get menu bar!");
            QMenu* pobjMenu(new QMenu(pobjMenuBar));
            Q_ASSERT_X(pobjMenu!=nullptr, cpszClassConstr, "Cannot create menu!");
            QAction* pobjAction(pobjMenu->menuAction());
            Q_ASSERT_X(pobjAction!=nullptr, cpszClassConstr, "Cannot get action!");
            pobjAction->setShortcut(cstrShortcut);
            pobjAction->setText(cstrText);
            pobjAction->setToolTip(cstrTooltip);
            pobjMenuBar->addAction(pobjAction);
            pobjMenu->show();
            pobjMenuBar->show();
            pobjWidget = pobjMenu;
        } else if ( mstrName.compare(clsXMLnode::mscszNodeMenuBar) == 0 ) {
    //Nothing required menubar should already be present in an instance of QMainWindow!
      }

Pl45m4

wrote on

#21

@SPlatten said in QMenuBar, QMenu and QAction:

pobjMenu->show();
pobjMenuBar->show();

Still weird that this seems to fix it because usually you dont have to show a QMenuBar explicitly.
Or what fixed it in the end?

QMainWindow::menuBar() says:

Returns the menu bar for the main window. This function creates and returns an empty menu bar if the menu bar does not exist.

And this, either existing QMenuBar or the newly created one, is already a child of QMainWindow.
So I wouldn't expect that you have to show it or apply it to your mainWindow manually again.

Dont know if this is somewhat relevant for you but reading the documentation further, it says:

If you want all windows in a Mac application to share one menu bar, don't use this function to create it, because the menu bar created here will have this QMainWindow as its parent. Instead, you must create a menu bar that does not have a parent, which you can then share among all the Mac windows. Create a parent-less menu bar this way:
QMenuBar *menuBar = new QMenuBar(0);

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