Get screensize

[Natural_Bugger]

hello,

I'm trying to get the screen size for my desktop app.

project file:

QT       += core gui

headers

#include <qrect.h>
#include <qscreen.h>
#include <QMessageBox>

QScreen *screen = QGuiApplication::primaryScreen();
     QRect  screenGeometry = screen->geometry();
     int height = screenGeometry.height();
     int width = screenGeometry.width();

QMessageBox msgBox;
         msgBox.setText((QString)width + " x " + (QString)height);
         msgBox.exec();

or

QSize size = qApp->screens()[0]->size();
QMessageBox msgBox;
         msgBox.setText(((QString)size.width()+ " x " + (QString)size.height() );
         msgBox.exec();

but both methods return "garbage", what am i missing?

regards

[sierdzio]

@Natural_Bugger said in Get screensize:

msgBox.setText((QString)width + " x " + (QString)height);

You should use QString::number() instead:

msgBox.setText(QString::number(width) + " x " + QString::number(height));

[Natural_Bugger]

@sierdzio

thnx,

it works perfect for the first method.
but not for the second.

QSize size = qApp->screens()[0]->size();
QMessageBox msgBox;
         msgBox.setText(QString::number(size.width()) + " x " + QString::number(size.height()));
         msgBox.exec();

it returns:

0801 x 0291

when it should return 1920 x 1080

[JonB]

@Natural_Bugger
Well the code looks right to me now. Just in case, what does qApp->screens().count() return ?

I'm "surprised" at one thing. Your output 0801 & 0291 have leading 0s, and are 4 digits long. That does not look like the default output from QString::number(), what is going on?

EDIT Oh, I see what @sierdzio is saying below. If you read them right-to-left then you do get 1920 x 1080. I think somewhere you have indeed set for Right-to-Left text output! Change your string " x " over to " <<< " and see which direction those chevrons come out --- is it indeed >>>?! EDIT My bad. Corrected in my post below.

[sierdzio]

Woah, that's bizarre!

The only thing that comes to my mind is an RTL language, but even that should not change number direction.

[Natural_Bugger]

thnx @JonB

QMessageBox msgBox;
    msgBox.setText(QString::number(qApp->screens().count()));
    msgBox.exec();

returns 1

but when i change ...

QSize size = qApp->screens()[0]->size();

to

QSize size = qApp->screens()[1]->size();

it doesn't compile

[JonB]

@sierdzio
Excellent spot, as I have edited my response above! But it's not " change number direction", because the numbers have been changed to strings!

[Natural_Bugger]

@sierdzio

indeed!

looking again, you're right!

[JonB]

@Natural_Bugger said in Get screensize:

QSize size = qApp->screens()[1]->size();

Anyway, I now see you do indeed only have one screen. Just forget about this area.

In any case, I have edited my answer. Somewhere I really think you have a text right-to-left issue! Do what I have edited above so that the string has literal <<< in it, which direction do those come out?

[sierdzio]

Yeah I'm right but I shouldn't be :D RTL should not invert numbers, as far as I know, only regular text.

Perhaps this will work better (https://doc.qt.io/qt-5/qlocale.html#toString-6):

QLocale::toString(size.width()) + " x " + QLocale::toStringsize.height())

[Natural_Bugger]

@JonB said in Get screensize:
I think somewhere you have indeed set for Right-to-Left text output! Change your string " x " over to " <<< " and see which direction those chevrons come out --- is it indeed >>>?!

thank you for your answer.

chevrons?

what do i need to do?

[JonB]

@Natural_Bugger said in Get screensize:

what do i need to do?

I told you. Change your string " x " to " <<< ", how much clearer can I be?

msgBox.setText(QString::number(size.width()) + " <<< " + QString::number(size.height()));

EDIT I'm sorry, my bad, I've just realized I was thinking too literally, like a mirror!

Try:

msgBox.setText(QString::number(size.width()) + " abc " + QString::number(size.height()));

I want to know whether that comes out as abc or as cba?

[Natural_Bugger]

@sierdzio said in Get screensize:

Yeah I'm right but I shouldn't be :D RTL should not invert numbers, as far as I know, only regular text.

Perhaps this will work better (https://doc.qt.io/qt-5/qlocale.html#toString-6):

QLocale::toString(size.width()) + " x " + QLocale::toStringsize.height())

#include <QLocale>

returns

error: cannot call member function ‘QString QLocale::toString(int) const’ without object                                                                      ^

[Natural_Bugger]

@JonB

it return: cba

[JonB]

@Natural_Bugger
Yup! So we are all agreed: there is right-to-left going on here, the results of the screen size are correct but are being printed right-to-left! Not my area, but that is what needs sorting out....

[sierdzio]

@Natural_Bugger ok it's not a static method, eh.

Then:

QLocale locale;
msgBox.setText(locale.toString(size.width()) + " x " + locale.toStringsize.height()));

[Natural_Bugger]

@JonB @sierdzio

i found the error.

i used a custom button class, i found online and it contains a method to reverse the text.

void CustomButton::reverseText()
{
    QString buttonText = text();
    std::reverse(buttonText.begin(), buttonText.end());
    setText( buttonText );
}

: )

thank you both

[JonB]

@Natural_Bugger
Using a custom button which calls reverse is not a good place to start from....

But I don't understand, the code you gave us uses QMessageBox::setText(), which is what we looked at, what has that got to do with any custom button, or the reverseText() method?

[sierdzio]

Hah, ok good that you've found it. Happy coding!