Simulate left mouse button unclick (release button)

Andrey Shmelew

Hi all!
i have an applcation on qt 5.7.0 for my beaglebone board.
I need to ... how to say... need to clear mouse button pressed flag, or make mouse button to become unpressed. That happend with me because i use 10 inch lcd with capacitive touch screen, and when i click any combobox with my finger, and then click on any other place on the screen, mouse button state is still stays as pressed and i do not can press any other controls.

mrjj

Hi
Something else is wrong I think.
Maybe the touch controller only sends MouseDown event or the up event get eaten somehow.

Does touch work correctly with buttons?
Click and hold the button. It should stay down. Then release and it go up.

You can construct a Mouse Event yourself and send it but i would look for other reason before trying that.

Andrey Shmelew

@mrjj
Hi! if we are talking about buttons, all works fine, when i hold finger on the button it stays down.
When i click on combobox, it opens and shows all submenus. When i release my finger, combobox becomes normal. After it i touch on any other area, and for somehow this combobox becomes opened again, as if I pressed it again (but i did not). At this moment we have button pressed event and i can not press other buttons.

mrjj

Hi, sounds like the combobox eats the events after.

Is this a std combo box?

When you click outside, it should not stay open.

Andrey Shmelew

@mrjj
i think it is std combobox

the problem exsists if only i use touch screen (connected by USB). if i click outside it stays open for a while, and then when i clicked outside second time - combobox closes (and "finger" click becomes pressed forewer),

If i manipulate by regular USB mouse, comboboxes are working fine!

So, i want to try to generate mous unclick event

mrjj

well
the drop down part of a combo box is using an event filter. I think its related to this but
not sure. If it works with a real mouse, why not with touch ?

Do you use real touch events or did you tell it to act like a mouse? ( the touch controller)

Well, no harm in trying but I guess it will just be eaten too
QMouseEvent *mEvnRelease = new QMouseEvent(QEvent::MouseButtonRelease, pos, Qt::LeftButton, Qt::LeftButton, Qt::NoModifier);
QCoreApplication::sendEvent(QWidget::focusWidget(),mEvnRelease);

Did you try with other applications?
Anything with a combobox should do the same. :)

Andrey Shmelew

@mrjj
hmmm...

i use yours code:

void MainWindow::mousePressEvent(QMouseEvent* event)
{
    if(event->buttons() == Qt::RightButton)
        ui->label_7->setText("Only right button");
    if(event->buttons() == Qt::LeftButton)
        ui->label_7->setText("Only left button");
    QMouseEvent *mEvnRelease = new QMouseEvent(QEvent::MouseButtonRelease, QCursor::pos(), Qt::LeftButton, Qt::LeftButton, Qt::NoModifier);
    QCoreApplication::sendEvent(QWidget::focusWidget(),mEvnRelease);
}

, it works now better, but even if MouseButtonRelease event exsists, buttons somehow becomes untouchable.

"Do you use real touch events or did you tell it to act like a mouse? ( the touch controller)"

it acts like a mouse (touch controller presents)!

I have uploaded example project with combobox to the device, and there is exactly the same problem.

mrjj

@Andrey-Shmelew
Hmm really sounds like the touch controller is not acting as a mouse and only
sends touch events.

You could set a event filter and watch what events you get.
http://www.informit.com/articles/article.aspx?p=1405544&seqNum=2

also note with the code its sends m up to the focused control so if it was not the
same control that got Mouse Press, it will not work.

Ps. to get names and not ints for the events, you can use
https://www.dropbox.com/s/rujoldiax0cql3z/names.txt?dl=0

Andrey Shmelew

@mrjj

thank you for the link, sir!

i have event handler:

void MainWindow::mouseReleaseEvent(QMouseEvent* event)
{
    ui->label_7->setText("button Released");
}

and touch controller sends this event.

maybe, it sends mouseReleaseEvent properly not every time i when i touch

Andrey Shmelew

i found a bug,
in my project i have a dial control...
firstly i touched to control and manipulated a litlle bit,
then i touched free area (without any controls or widgets) and noticed than dial reacts on my touching and rotates in direct of my touch spot (i did not touch dial but it turned).

mrjj

@Andrey-Shmelew
Well you can check with mouseReleaseEvent if it fires every time.
If yes, then something else is still not 100% like a mouse.

I had some issues with some widgets that look for mouse move and mouse leave events ( focusin/out)
which is not (always) send with a touch. But I dont remember a plain combobox being an issue.

Have you tested with some non Qt app ?
Does it accept the touch fully as a mouse?

Andrey Shmelew

@mrjj
i will answer tomorrow! need to go :(
Thank you!

Andrey Shmelew

@mrjj
Hello and Happy New Year!

I installed VLC media player on my beaglebone, and have been playing with controls (combobox, scrollbars etc...), and all was going well, no bugs with comboboxes, touch screen clicks and releases fine.
I noticed that combobox in VLC player and combobox in QT are differented of each other.

VLC acceps the touch fully as a mouse, i suppose.

mrjj

@Andrey-Shmelew
Hi
Happy new year to you too

Ok it does sound like it is working as it should. Maybe VLC is very touch friendly.

Can we test with one app ( nothing as well used with touch as VLC ) to test ?

Still think its just controller that slips a mouse up sometimes but not sure yet.

Andrey Shmelew

@mrjj said in Simulate left mouse button unclick (release button):

Can we test with one app ( nothing as well used with touch as VLC ) to test ?

yes, sure, i will try evrethyng i can

mrjj

@Andrey-Shmelew
Super
Did you also check with main window that
void MainWindow::mouseReleaseEvent(QMouseEvent* event)
{
qDebug() << ("button Released");
}

is always called?
Make sure only to click on the mainwindow.

Andrey Shmelew

@mrjj said in Simulate left mouse button unclick (release button):

is always called

if only i did not press combobox...

As soon as I clicked combobox, no matter how many times I clicked on the mainwindow, label_7 is always "Only left button"

qDebug() << ("button Released"); is not working in linux app, so i use label_7 as debug out

mrjj

@Andrey-Shmelew
Yes combo is special as it drop down a floating window and use event filer for selection so
it is not canceled correctly, it will then eat all events and nothing else can be clicked.

ehh qDebug() not working in linux ? you mean outside Creator or ?
Dont matter. Label is fine :)

Andrey Shmelew

@mrjj
Hello!

So, the problem is not solved,
should i use events filter?

thanks!

mrjj

@Andrey-Shmelew
well, i would dig a bit deeper into what is going on.
I never seen combo not work like that.
Seems something else than missing events.

But yes, you can most likely work around using event filters but there might surface other stuff
like broken drag and drop or something as its not a bug in combobox ( no other reports) as such so
something else is not as expected with the touch.

I tried at work with touch screen and could not reproduce it so Im a bit lost why
its not just closing its dropdown.

I think it will/might be a mess with eventfilter
but if you only have one combobox you
need to fix it should be ok
but if you use combos all over program i would
go for better solution.