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How to activate keyboard shortcut in QMenu



  • I have QTabWidget that shows some tabs, now I have added a QMenu that works as a right click Context Menu on those tabs (close tab, close other tabs ...). One of the actions in the QMenu has a keyboard shortcut and it's shown in the menu but I can't activate it, no mater if the menu is shown or not. The primary goal is to have the shortcut work when the QMenu is not shown.

    This is my ContextMenu Class (only the relevant stuff):

    AnnotationTabContextMenu::AnnotationTabContextMenu(QWidget *parent)
    	: QMenu(parent),
    	  mCloseTab(new QAction(this))
    {
    	mCloseTab->setText(tr("Close"));
            mCloseTab->setShortcut(QKeySequence(Qt::CTRL + Qt::Key_F4));
    
    	connect(mCloseTab, &QAction::triggered, this, &AnnotationTabContextMenu::closeTabTriggered);
    
    	addAction(mCloseTab);
    }
    
    AnnotationTabContextMenu::~AnnotationTabContextMenu()
    {
    	delete mCloseTab;
    }
    
    void AnnotationTabContextMenu::show(int tabIndex, const QPoint &pos)
    {
    	mTabIndex = tabIndex;
    	exec(pos);
    }
    
    void AnnotationTabContextMenu::closeTabTriggered() const
    {
    	emit closeTab(mTabIndex);
    }
    

    And here is use it (only the relevant stuff):

    AnnotationTabWidget::AnnotationTabWidget() :
    	mTabBar(tabBar()),
    	mTabContextMenu(new AnnotationTabContextMenu(this))
    {
    	setTabsClosable(true);
    	mTabBar->setContextMenuPolicy(Qt::CustomContextMenu);
    
    	connect(mTabBar, &QTabBar::customContextMenuRequested, this, &AnnotationTabWidget::showTabContextMenu);
    	connect(mTabContextMenu, &AnnotationTabContextMenu::closeTab, this, &AnnotationTabWidget::tabCloseRequested);
    }
    
    void AnnotationTabWidget::showTabContextMenu(const QPoint &pos)
    {
    	if (!pos.isNull()) {
    		int tabIndex = mTabBar->tabAt(pos);
    		mTabContextMenu->show(tabIndex, mTabBar->mapToGlobal(pos));
    	}
    }
    

    Any idea what could be preventing the shortcut from being triggered?


  • Lifetime Qt Champion

    Hi,

    IIRC, you should add the action to your main widget using the addAction method.

    If you have centralized actions that can be found in several places, you should also centralize their creation and propagate them as needed. Or provide an accessor like QDockWidget's toggleViewAction.



  • @dporobic said in How to activate keyboard shortcut in QMenu:

    One of the actions in the QMenu has a keyboard shortcut and it's shown in the menu but I can't activate it, no mater if the menu is shown or not

    Triggering the action with your mouse works?!
    Check your ShortcutContext and which widget has focus / is active while pressing the key sequence.



  • Yes, clicking works of course.

    I have tested setting ShortcutContext on the QAction to Qt::WidgetWithChildrenShortcut, Qt::WindowShortcut and Qt::ApplicationShortcut, no change.

    Why is the focus relevant? I was aiming for a Application wide shortcut or at least when the focus is on the QTabWidget should it be possible to trigger it. Sorry if that wasn't clear, I'll update my initial post.



  • @dporobic
    I just wondered whether it's worth trying your code with a simpler shortcut, not involving Ctrl or a function key, just in case? Also, you're not on a Mac, are you? Probably this is not the issue, but while you're awaiting a better response....



  • @dporobic said in How to activate keyboard shortcut in QMenu:

    Why is the focus relevant?

    Because you can have the same shortcuts on multiple widgets (some key sequences get intercepted by OS e.g. Alt +F4, Ctrl + C). So you could use shortcut A while MainWindow or some child window has focus (Window- or App-Shortcut), to do something and use the same key sequence A (as Widget shortcut) to activate another action while a specific widget has focus.

    @dporobic said in How to activate keyboard shortcut in QMenu:

    I was aiming for a Application wide shortcut or at least when the focus is on the QTabWidget should it be possible to trigger it.

    Then use Qt::ApplicationShortcut at least. But make sure that your key sequence is not used for something else (OS or some other widgets). Try another, simple key (e.g. QKeySequence(Qt::Key_F)), like @JonB wrote.
    If the widget / window where your QTabWidget is in, is active, the Window shortcut should work too.



  • I did try Qt:ALT + Qt::Key_H before, will try with a single letter then. No, not a Mac, Windows and Linux, tested on both, not working.



  • Tested now with all for ShortcutContext and setting the shortcut to a simple Letter, tried H and F, nothing. What I really find strange is even with the menu open, nothing happens:

    mCloseTab->setText(tr("Close"));
    mCloseTab->setShortcut(QKeySequence(Qt::Key_F));
    mCloseTab->setShortcutContext(Qt::ApplicationShortcut);
    

    ee05c08d-3136-4485-93af-18f66e4a6d29-image.png



  • Interesting, I've created a QToolButton in the ContextMenu, just created it and gave it the same QAction as the defaultAction and now it's triggered when the ContextMenu is open:

    mCloseTab->setText(tr("Close"));
    mCloseTab->setShortcut(QKeySequence(Qt::Key_F));
    mCloseTab->setShortcutContext(Qt::ApplicationShortcut);
    
    auto button = new QToolButton(this);
    button->setDefaultAction(mCloseTab);
    

    94658b3d-86fb-4ade-8877-1c69f06762dc-image.png

    Still not working when the menu is closed.



  • Giving the QToolButton the QTabWidget as parent seems to be working even with the menu not shown. Just giving the QAction the QTabWidget as parent doesn't work without the QToolButton.

    mCloseTab->setText(tr("Close"));
    mCloseTab->setShortcut(QKeySequence(Qt::Key_F));
    mCloseTab->setShortcutContext(Qt::ApplicationShortcut);
    
    auto button = new QToolButton(parent);
    button->setDefaultAction(mCloseTab);
    button->setFixedSize(0,0);
    

    It's a workaround, but one of the ugly kind. Any idea how to fix this? Is this a bug?



  • @dporobic

    Looks like there is something wrong with shortcuts and contextMenus in general (I dont know if bug or if we dont use it correctly).
    Your hierarchy is somewhat like this:

    • Top level window / MainWindow
      • TabWidget
        • TabWidgets TabBar
        • ContextMenu
          • Action with shortcut

    And here is the problem... You can't say if the action actually receives the key event / shortcut, due to multiple parents and children.

    At least on Window Ctrl + F4 is used (Shortcut List).


  • Lifetime Qt Champion

    Hi,

    IIRC, you should add the action to your main widget using the addAction method.

    If you have centralized actions that can be found in several places, you should also centralize their creation and propagate them as needed. Or provide an accessor like QDockWidget's toggleViewAction.



  • @SGaist

    But why are these actions and shortcuts in contextMenus possible, if you can not trigger them, even when parent widget has focus or is the only widget? What is the use case for this?


  • Lifetime Qt Champion

    Because it would not make sense to have that restriction because you can build these menus and actions in several different ways and that Qt cannot know that you are actually on purpose adding a shortcut to an action that will only be available in a popup menu.



  • @SGaist said in How to activate keyboard shortcut in QMenu:

    IIRC, you should add the action to your main widget using the addAction method.

    The addAction method on the parent seems to be working indeed, need to think about if I should distribute them differently:

    mCloseTab->setText(tr("Close"));
    mCloseTab->setShortcut(QKeySequence(Qt::Key_F));
    mCloseTab->setShortcutContext(Qt::ApplicationShortcut);
    
    parent->addAction(mCloseTab);
    

    @Pl45m4 it is indeed a close action though it looks like I should be using Ctrl+W which is more cross platform.


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