ScrollView Binding Loop

krobinson

I am trying to create a zoom control using the ScrollView. Under normal conditions I want the content of the ScrollView to be the same size as the container. Then when you zoom in, I want the contents to be the size * 2. This will give you a bigger size content that you can scroll to see.

Item
{
id: container
anchors.fill: parent

ScrollView
{
    anchors.fill: parent

    Rectangle
    {
        height: surfaceContainer.height
        width: surfaceContainer.width
    }
}

}

The problem is this causes a binding loop.
qrc:/Qml/CustomScrollView.qml:322:9: QML ScrollViewHelper: Binding loop detected for property "horizontalScrollbarOffset"
file:///C:/Qt/5.5/msvc2013/qml/QtQuick/Controls/Private/ScrollViewHelper.qml:124:5: QML ScrollBar: Binding loop detected for property "height"

I tracked it down to this code in the ScrollViewer

property int horizontalScrollbarOffset: horizontalScrollBar.visible && !horizontalScrollBar.isTransient ?
horizontalScrollBar.height + scrollBarSpacing : 0

It seems like it uses the scroll bar height to figure out the offset which causes the loop. If I take this out it works fine, but then it resets the scroll position every time.

Is there any good way to get around this? Is there another control I could use instead of doing it this way.

p3c0

@krobinson Try updating those properties by assignment i.e using = when height or width change signal handler.