How to display QML into a native window

L440

Hi,
Could someone point me to an example on how to load a QML file within a native OS window, maybe using QMacNativeWidget?

However, I do not want to spawn a new window, but rather, given a native window (or view?) handle to load a qml scene into it. Is there some reference code that could show me how to do that?

Thanks!

veryqtperson

Perhaps, that's what you need?

L440

Well, I tried that, but I have two problems with it. One is that it suffers from some mysterious crash if I create the QQuickWidget anywhere else but the stack where the QApplication is instantiated and the other is that it too launches its own window.

What I really need is a way to embed this or some other Qt view into a given native window/view handle. Anything I tried so far, including QMacNativeWidget will result in an 'extra' window. Hence why I ask for some minimal trivial example code.

Thanks for the suggestion though

Wieland

@L440 said:

is that it too launches its own window

I doubt that. Only if you don't give it a parent (applies to all widgets). Can we see some code please?

L440

Yes, sure. Thanks for looking into it. This is how I'm trying to do it. The code below is executed directly in the applicationDidFinishLaunching. Please ignore all the memory leaks.

What I get is a result is two windows - the main one where the QML is indeed loaded and a 'ghost' window which is transparent but still has a frame in the center.

I also don't see the qml view refreshing, it is supposed to change the rectangle's color when you click on it.

@interface AppDelegate ()
-(void)processEvents;

@property(nonatomic) NSTimer* timer;
@property(nonatomic) QApplication* qt;
@end

@implementation AppDelegate

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
    // Insert code here to initialize your application
    NSWindow* window = [[[NSApplication sharedApplication] windows] objectAtIndex:0];
    NSView *view = [window contentView];
    assert(view);
    
    char* test[0];
    int count = 0;
    
    QApplication::instance()->setAttribute(Qt::AA_MacPluginApplication);
    _qt = new QApplication(count, test);

    QMacNativeWidget* native = new QMacNativeWidget(view);
    assert(native);
    
    QQuickWidget* qml = new QQuickWidget(native);
    qml->setSource(QUrl(QStringLiteral("main.qml")));
    
    QVBoxLayout* layout = new QVBoxLayout();
    layout->addWidget(qml);
    
    native->setLayout(layout);
    
    qml->show();
    native->show();
    
    
    NSView* qmlView = (NSView*)native->winId();
    [view addSubview:qmlView];
    
    _timer = [NSTimer scheduledTimerWithTimeInterval:0.03 target:self selector:@selector(processEvents) userInfo:nil repeats:YES];
}

- (void)applicationWillTerminate:(NSNotification *)aNotification
{
    // Insert code here to tear down your application
    [_timer invalidate];
    _qt->quit();

}

-(void)processEvents
{
    _qt->processEvents();
    _qt->sendPostedEvents(0,-1);
}

@end

and here's the QML:

import QtQuick 2.7

Item
{
    visible: true
    x: 0;
    y: 0;
    width: 100
    height: 100
    Rectangle
    {
        anchors.fill: parent
        color: 'blue'
        MouseArea
        {
            anchors.fill: parent
            onClicked:
            {
                console.log(parent.color);
                if(parent.color == '#0000ff')
                    parent.color = 'green';
                else
                    parent.color = 'blue';
            }
        }
    }
}