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!