Has anyone worked around iOS safe zone margins, like with iPhone X?

Pradeep P N

These links might help you.

iPhone X - The Screen notch & bottom bar.

Sample code for QML.

ApplicationWindow {
    id: root

    flags: Qt.Window | Qt.WindowTitleHint | Qt.WindowSystemMenuHint
           | (Qt.platform.os === "ios" ? Qt.MaximizeUsingFullscreenGeometryHint : 0)
}

// This function is to support the iPhone X Series notch issue - status bar size is 44pt
    function toolbarMarginSupport() {
        if (isIPad || (Qt.platform.os === "ios" && isPortraitMode)) {
            switch(windowScreen.height * windowScreen.devicePixelRatio) {
            case 1624: // iPhone_XR (Qt Provided Physical Resolution);
            case 1792: // iPhone_XR;
            case 2436: // iPhone_X_XS;
            case 2688: // iPhone_XS_MAX;
                return 44;
            default:
                return 20;
            }
        } else {
            return 0;
        }
    }

    function isIPhoneXSeries() {
        if (isIPad || (Qt.platform.os === "ios" && isPortraitMode)) {
            switch(windowScreen.height * windowScreen.devicePixelRatio) {
            case 1624: // iPhone_XR (Qt Provided Physical Resolution);
            case 1792: // iPhone_XR;
            case 2436: // iPhone_X_XS;
            case 2688: // iPhone_XS_MAX;
                return true;
            default:
                return false;
            }
        } else {
            return false;
        }
    }

Qt World Summit 2018 Conference App.

All the best.

J.Hilk

@patrickkidd

this workaround works

https://bugreports.qt.io/browse/QTBUG-64574

but make sure, to delay the reading after a orientation change

https://bugreports.qt.io/browse/QTBUG-76234

Shrinidhi Upadhyaya

Hi @patrickkidd ,

Here is a sample code,which will return you the notch values:-

QPlatformWindow *platformWindow = static_cast<QPlatformWindow *>(window->handle());
QMargins margins = platformWindow->safeAreaMargins();
int topMargin = 0;
int bottomMorgin = 0;
int leftMargin = 0;
int rightMargin = 0;
topMargin = margins.top();
rightMargin = margins.right();
bottomMorgin = margins.bottom();
leftMargin = margins.left();

You need also need to set this:-

window.setFlag(Qt::MaximizeUsingFullscreenGeometryHint, true);

patrickkidd

All very helpful and interesting responses.

Looks like Qt.MaximizeUsingFullscreenGeometryHint doesn't have an effect. I am using a QMainWindow for my top-level widget with no other flags set.

J.Hilk

@patrickkidd
if you're working with QWidgtes, and your TopMost Widget is a QMainWindow. Then simply set a Layout to the central widget.

By default the layout respects the safe margins

patrickkidd

@J.Hilk Can you paste a code snippet? When you say "set a Layout to the central widget," do you mean 1) layout the central widget as in my .ui file:

        self.centralWidget = QtWidgets.QWidget(MainWindow)
        self.centralWidget.setObjectName("centralWidget")
        self.horizontalLayout = QtWidgets.QHBoxLayout(self.centralWidget)

or 2) lay out the QMainWindow and add the central widget:

        self.ui.centralWidget = QOpenGLWidget(self)
        self.setCentralWidget(self.ui.centralWidget)
        Layout = QVBoxLayout(self)
        Layout.setContentsMargins(0, 0, 0, 0)
        Layout.addWidget(self.ui.centralWidget)

When I run #2 it gives the following warning and the app runs on Mac but only shows a white screen (within the safe zone) on iOS. There is no layout explicitly added so it must be implicit in QMainWindow:

kernel/qlayout.cpp(148): QLayout: Attempting to add QLayout "" to MainWindow "", which already has a layout

J.Hilk

@patrickkidd
Sadly I have next to no experience with the python bindings

but here's a simple c++ example (everything in main)

#include <QApplication>

#include <QVBoxLayout>
#include <QDebug>
#include <QWidget>
#include <QPainter>

class Widget : public QWidget
{
    Q_OBJECT

public:
    Widget(QWidget *parent = nullptr) : QWidget(parent)
    {
        setStyleSheet("background-color:transparent;");
    }
    ~Widget() = default;

    void setGridDistance(int distance)
    {
        m_GridDistance = distance;
        update();
    }

protected:
    void paintEvent(QPaintEvent *event)
    {
        QWidget::paintEvent(event);

        QPainter p(this);
        p.setPen(QPen(Qt::white,3));
        for(int i(0); i < width(); i += m_GridDistance){
            p.drawLine(i,0,i,height());
        }

        for(int i(0); i < height(); i += m_GridDistance){
            p.drawLine(0,i,width(),i);
        }
    }

    int m_GridDistance = 20;
};

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    QWidget *w = new QWidget();
    w->setStyleSheet("background-color:red;");
    w->setWindowFlag(Qt::MaximizeUsingFullscreenGeometryHint,true);
    w->setAttribute(Qt::WA_ContentsMarginsRespectsSafeArea,false);
    w->showFullScreen();

    Widget *wChild = new Widget(w);
    wChild->setStyleSheet("background-color:transparent;");

    //!Does not work
    {
        QVBoxLayout *layout = new QVBoxLayout(w);
        layout->setSizeConstraint(QLayout::SetNoConstraint);
        layout->setMargin(0);
        layout->addWidget(wChild);
    }

    //!Works
    {
//        wChild->resize(w->size());
//        wChild->show();
    }

    return a.exec();
}

the normal QWidget spans the whole screen, the wChild widget only inside the save margins, due to the layout

Ignore the extra part, commended , parts IIRC that is for an other issue x)

patrickkidd

@J.Hilk said in Has anyone worked around iOS safe zone margins, like with iPhone X?:

w->setAttribute(Qt::WA_ContentsMarginsRespectsSafeArea,false);

It looks like this was the line to do it. The Qt::MaximizeUsingFullscreenGeometryHint didn't have any effect. I didn't call showFullScreen().

So now it will just be a matter of getting the margins from QPlatformWindow using the example from the following if I can only figure out the include for QPlatformWindow. <qpa/qplatformwindow.h> doesn't seem to work:

@Shrinidhi-Upadhyaya

QPlatformWindow *platformWindow = static_cast<QPlatformWindow *>(window->handle());
QMargins margins = platformWindow->safeAreaMargins();

Any idea what the include is for QPlatformWindow?

J.Hilk

@patrickkidd said in Has anyone worked around iOS safe zone margins, like with iPhone X?:

Any idea what the include is for QPlatformWindow?

inside your *.pro file you need to include this module: QT += gui-private

then this include is available:
#include <QtGui/qpa/qplatformwindow.h>

Luc4

I didn't like too much the idea of using the private module, so this is how I implemented it: https://github.com/carlonluca/lqtutils/blob/master/lqtutils_ui.h#L55. Uses Objective-C++ on iOS and JNI on Android. More info: https://bugfreeblog.duckdns.org/2023/01/qt-qml-cutouts.html.