QQuickWidget why different behavior ?

[a-r-t]

when i set the QQuickWidget in the ui design the qml displays the map correctly.
when i initialize the QQuickWidget manual in the code i have nothing.
what am i doing wrong ?

the one working way :

MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    ...
}

the other not working way : ?

    m_view = new QQuickWidget(QUrl::fromLocalFile(":/qml/MapView.qml"), this);
    m_view->setGeometry(0,0,400,500);
    m_view->show();

what is wrong here ?

this is the file MapView.qml

Item
{
    id: window

    Plugin
    {
        id: mapPlugin
        name: "osm"
    }

    Map
    {
        id: map
        anchors.fill: parent
        plugin: mapPlugin
        center: QtPositioning.coordinate(38, 23)
        zoomLevel: 8
    }
}

thanks !

[JKSH]

@a-r-t said in QQuickWidget why different behavior ?:

the other not working way : ?
m_view = new QQuickWidget(QUrl::fromLocalFile(":/qml/MapView.qml"), this);
m_view->setGeometry(0,0,400,500);
m_view->show();

what is wrong here ?

What does QUrl::fromLocalFile(":/qml/MapView.qml") return?

[a-r-t]

thanks !

with:
qDebug() << QUrl::fromLocalFile(":/qml/MapView.qml");
qDebug() << m_view->source();
it returns:
QUrl("file::/qml/MapView.qml")

in mainwindow.ui it is:

<url>
      <string>qrc:/qml/MapView.qml</string>
 </url> 

also from Application Output i get :

QGeoTileProviderOsm: Tileserver disabled at  QUrl("http://maps-redirect.qt.io/osm/5.8/satellite")
QGeoTileFetcherOsm: all providers resolved
QWaitCondition: Destroyed while threads are still waiting

[a-r-t]

@JKSH
i have the same result using this syntax too
QUrl("qrc:/qml/MapView.qml")

thanks for the answer !

[JKSH]

First, try testing with a simplified QML file:

import QtQuick 2.0

Rectangle {
    width: 640
    height: 480
    color: "red"
}

@a-r-t said in QQuickWidget why different behavior ?:

@JKSH
i have the same result using this syntax too
QUrl("qrc:/qml/MapView.qml")

• QUrl::fromLocalFile() is for loading a QML file from disk.
• QUrl("qrc:/qml/MapView.qml") is for loading a QML file from your application Resources section (as specified by the .qrc file).

Open your .qrc file with a text editor and paste its contents here.

[a-r-t]

@JKSH said in QQuickWidget why different behavior ?:

import QtQuick 2.0

Rectangle {
width: 640
height: 480
color: "red"
}

yes, the above example works as expected .
seems something doesn't like in the other qml code
and the question remains, as it works perfect
under the mainwindow.ui

qrc seems to be okay
this is the qml.qrc

<RCC>
    <qresource prefix="/qml">
        <file>MapView.qml</file>
        <file>marker.qml</file>
    </qresource>
    <qresource prefix="/images">
        <file>point.png</file>
    </qresource>
    <qresource prefix="/">
        <file>marker.qml</file>
    </qresource>
</RCC>

thanks for the responce

[JKSH]

@a-r-t Yes, your QRC file looks fine.

Next, try putting a width and height in your top-level Item, and try simplifying your C++ code:

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

	QQuickWidget w(QUrl("qrc:/qml/MapView.qml"));
	w.show();

	return app.exec();
}

QGeoTileProviderOsm: Tileserver disabled at  QUrl("http://maps-redirect.qt.io/osm/5.8/satellite")
QGeoTileFetcherOsm: all providers resolved
QWaitCondition: Destroyed while threads are still waiting

This is weird...

[a-r-t]

@JKSH
try putting a width and height in your top-level Item

you touched the wound with this direction,
now it opens correctly.

looking the why inside the "ui_mainwindow.h"
we see the follow code :

view->setResizeMode(QQuickWidget::SizeRootObjectToView);

that makes the whole difference, using the ui way.

thank you JKSH for the fruitful discussion.
the query resolved !