how to get notification of mouse down in menu bar?

davecotter

i want one signal or notify callback the moment the user clicks in the menu bar, before any menus are actually shown, so i can do some quick pre-processing for some menu items. how do i do this?

like menuBar::aboutToShow(), which doesn't exist? note i do not want the signal sent before EACH menu is shown, only once just before the user starts browsing the entire menu bar

do i filter all events looking for a menu bar click? how would i detect that?

note: i KNOW that's "not how it's done", i don't need suggestions for what else i should do, i just want to know if what i want is possible and if so, how?

thanks!

davecotter

@mpergand said in how to get notification of mouse down in menu bar?:

You can retreive the mouse location with [event mouseLocation]

But what i was saying is that the i don't GET an event for a click when the user clicks in the menu bar. Just nothing. So there is no way to ASK for for a mouse location.

You can create an NSObject to receive the notification

OMG that worked! YAY!

Gojir4

@davecotter
You can try this.

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent), ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    ui->menuBar->installEventFilter(this);
}

bool MainWindow::eventFilter(QObject *obj, QEvent *event)
{
    if(obj == ui->menuBar){
        if(event->type() == QEvent::MouseButtonPress){
            qDebug() << "Menu bar pressed";
            //Make post processing for menu
        } else if(event->type() == QEvent::MouseButtonRelease){
            qDebug() << "Menu bar released";
        }

    }
    return QObject::eventFilter(obj, event);
}

mpergand

@Gojir4

I don't think it works on MacOs because the main menu is outside the window frame.
I tryed with native event, I had a "mac_generic_NSEvent" by clicking on the main menu.
Look promising , I didn't go any further anyway :)

[edit]
Got more Here

bool CocoaNativeEventFilter::nativeEventFilter(const QByteArray &eventType, void *message, long *)
{
    if (eventType == "mac_generic_NSEvent") {
        NSEvent *event = static_cast<NSEvent *>(message);
        if ([event type] == NSKeyDown) {
            // Handle key event
            qDebug() << QString::fromNSString([event characters]);
        }
    }
    return false;
}

davecotter

thanks for that.

when i try to install that in my menubar object like this:

ui->menuBar->installNativeEventFilter(s_nativeFilterP);

I get this compile error:

error: no member named 'installNativeEventFilter' in 'QMenuBar'

so i attempt to install it in qApp:

qApp->installNativeEventFilter(s_nativeFilterP);

which compiles and runs, but the nativeFilter only gets called for all clicks NOT in the menu bar.

but even if i get that to work, i still must then determine for myself if the user clicked in a menu bar which is complicated by the fact that each display may have a menu bar, i might miss a case.

what i would like is to do is just hook into the existing OS notifications, something like this:

void	InstallUpdateMenusEvenHandler()
{
	NSNotificationCenter*	notifyRef = [NSNotificationCenter defaultCenter];
	NSApplication*		nsAppRef = [NSApplication sharedApplication];
	
	[notifyRef addObserver:nsAppRef selector: @selector(menuBarClicked:) name: NSMenuDidBeginTrackingNotification object: NULL];
}

but then how do i add menuBarClicked: to NSApplication? AFAIK it's not possible to subclass NSApp in Qt ?

mpergand

@davecotter said in how to get notification of mouse down in menu bar?:

which compiles and runs, but the nativeFilter only gets called for all clicks NOT in the menu bar.

You can retreive the mouse location with [event mouseLocation]

but then how do i add menuBarClicked: to NSApplication? AFAIK it's not possible to subclass NSApp in Qt ?

You can create an NSObject to receive the notif and emit a signal from here (or use a custom event).

davecotter

@mpergand said in how to get notification of mouse down in menu bar?:

You can retreive the mouse location with [event mouseLocation]

But what i was saying is that the i don't GET an event for a click when the user clicks in the menu bar. Just nothing. So there is no way to ASK for for a mouse location.

You can create an NSObject to receive the notification

OMG that worked! YAY!