Hover Event - 2 windows

TomNow99

Hi,

I have 2 windows: main Window and QLabel ( Qt::Tool | Qt::FramelessWindowHint ). The main Window is in green color in pictures and QLabel is in blue color in pictures. QLabel is on the center of main Window.

I would like to have a situation like in a picture:

mouse cursor is outside the main Window - for example in desktop ( label must be hide )
mouse cursor is inside the main Window - I move mouse course from desktop to main Window ( label must be visible )
mouse cursor is inside label - I move mouse cursor from mainWindow to label ( label must be visible )
mouse cursor is inside the main Window - I move mouse cursor from label to main Window ( label must be visible )
mouse cursor is outside the main Window ( label must be hide ) - I move mouse cursor to desktop

I don't know what I should write in hoverEnter and hoverLeave methods in main Window. When I have mouse cursor inside mainWindow and I move it to label I go to hoverLeave() ( because I leave main Window ), but when I move mouse cursor from main Window to desktop I go to hoverLeave() too. I can't find out, if I go to desktop or I go to label.

QCursor::pos is bad solution

SGaist

Hi,

Check what you have under the cursor when the leave event occurs and if it's nothing then hide the label.

TomNow99

@SGaist Thank you for answer. Could you tell me what is "what you have under the cursor"? Any method?

SGaist

QApplication::widgetAt

TomNow99

@SGaist But how? I see here 1 problem:

In this method ( widgetAt ) I need QPoint. I can do something like:

In hoverLeave method:
auto wid = QApplication::widgetAt(QCursor::pos());

I don't see any other method to get QPoint - only from QCursor::pos(). Event->pos() give me QPoint(-1,-1).

So QCursor::pos(). But this is bad solution because when I do very fast move my mouse I get strange position.

SGaist

Which hoverLeave method ?

What about QWidget::leaveEvent ?

TomNow99

@SGaist hoverLeave method is my method which is execute when there is QHoverEvent. I think in this example QWidget::leaveEvent and QHoverEvent are very simillar.

SGaist

Then please show your code.

TomNow99

@SGaist I don't have it on thic pc, so I can only give you some pseudoCode:

bool MainWindow::event(QEvent * e)
{
    switch(e->type())
    {
    case QEvent::HoverEnter:
        hoverEnter(static_cast<QHoverEvent*>(e));
        return true;
        break;
    case QEvent::HoverLeave:
        hoverLeave(static_cast<QHoverEvent*>(e));
        return true;
        break;
    default:
        break;
    }
    return QWidget::event(e);
}

void MainWindow::hoverEnter(QHoverEvent * event) 
{
     if( !label -> isVisible() )
     {
          label->show();
     }
}
void MainWindow::hoverLeave(QHoverEvent * event) 
{
     if( label -> isVisible )
     {
          label->hide();
     }
}

EDIT:
I have while(true) here :) When I have cursor in label I have loop:
hide->show->hide->show->hide->...

SGaist

Why a while ? You will only manage to block the event loop.

TomNow99

@SGaist Could you give me some snippet - I don't do this before

SGaist

A snippet of what ?

TomNow99

@SGaist Blocking event loop

SGaist

You do not want to block the event loop. That will freeze your GUI.

TomNow99

@SGaist Now in functions hoverEnter and hoverLeave I do:

qInfo()<<"enter"; 
or
qInfo()<<"leave";

When my mouse cursor is in place, where label is I see in QT words:
enter, leave, enter, leave, enter, leave, enter, leave, enter, leave, enter, leave, enter, leave, enter, leave, ...

And I see that my label is hidden -> shown ->hidden -> shown ->hidden -> shown ->hidden -> shown ->hidden -> shown ->hidden -> shown ->...

How can I do what I want ( picture ) ?