Using QScrollArea with QQuickWidget

Question

I have a QQuickWidget. I'd like to make it autosizable according to its QML content and to provide both horizontal and vertical scrollbars in case when its content cannot fit the window.

I put the QQuickWidget inside a QScrollArea and added layout to the QScrollArea to make the QQuickWidget to fill it. In the parent window constructor I added a line:

scroll_area->setWidget(quick_widget);

However no scroll bars are available, independently on QML content size. How should QQuickWidget and QScrollArea be configured to work as I need?

UPDATE1: Well, I'm trying to make that via QDesigner. Actual UI XML is:

<widget class="QScrollArea" name="scroll_area">
 <property name="sizePolicy">
  <sizepolicy hsizetype="Expanding" vsizetype="Expanding">
   <horstretch>0</horstretch>
   <verstretch>0</verstretch>
  </sizepolicy>
 </property>
 <property name="widgetResizable">
  <bool>true</bool>
 </property>
 <widget class="QQuickWidget" name="quick_widget">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>502</width>
    <height>269</height>
   </rect>
  </property>
  <property name="sizePolicy">
   <sizepolicy hsizetype="Expanding" vsizetype="Expanding">
    <horstretch>0</horstretch>
    <verstretch>0</verstretch>
   </sizepolicy>
  </property>
  <property name="resizeMode">
   <enum>QQuickWidget::SizeViewToRootObject</enum>
  </property>
  <property name="source">
   <url>
    <string>…</string>
   </url>
  </property>
 </widget>
</widget>

And while debugging I can see that QScrollArea.widget() has been already set to quick_widget (without force call scroll_area.setWidget()), but still there are no scrollbars available, even when the quick_widget content cannot fit its size.

UPDATE2: Well there's possibly a problem that items are added dynamically. And perhaps the root object height and width should be modified manually (or they shouldn't?) For example:

if ( object.x + object.width > root.width )
    root.width = object.x + object.width;
if ( object.y + object.height > root.height )
    root.height = object.y + object.height;

score 1 · Answer 1 · answered Mar 08 '16 at 05:37

I have tried following code, and it works fine.

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

    auto scrollArea = new QScrollArea();
    setCentralWidget(scrollArea);

    auto quickWidget = new QQuickWidget();
    quickWidget->setSource(QUrl("qrc:/main.qml"));
    quickWidget->setResizeMode(QQuickWidget::SizeViewToRootObject);
    scrollArea->setWidget(quickWidget);
}
//main.qml
//a varying Rectangle
import QtQuick 2.0

Rectangle {
    id: root ;color: "red"; width: 400; height: 500
    Timer{
        id: timer
        property real time
        interval: 400
        repeat: true
        onTriggered: {
            root.width = 800 + Math.sin(time*100) *100
            time = time + 1;
            console.log(time)
        }
    }

    Component.onCompleted: {
        timer.time = 0
        timer.start()
    }
}