How to vertical scroll to a specific item - qt

Question

I have a ListView including a lot of radio buttons. The list is bigger than the visible area. One of the radio buttons is checked. Sometimes, if the selected radio button is outside the visible area I want to scroll to it:
ScrollView {
anchors.fill:parent
ListView {
anchors.fill: parent
model: valuesList
delegate: RadioButton {
id: radioBtn
//check of value is index type and do the corresponding checked? test
checked: valueIsIndex ? (parseInt(valueFromParent) == index ? true : false) : (valueFromParent == valueString ? true : false)
onClicked: {
root.selected(valueString, index)
}
Component.onCompleted: {
if(checked)
//Here i want to scroll the list to display this radiobutton
}
}
}
}
Any ideas howto to get the list scrolled? I've played around a lot of with hightlights and contentY but nothing worked.
I've use the ScrollView around the ListView to automatically get the systems scrollbars on the desktop. On mobile devices i have just the flickable ListView.
EDIT
I get it on the way with the help of BaCaRoZzo. Here is my current working example:
ScrollView {
id: scrollView
anchors.fill:parent
property int yOfCheckedRadioButton: 0
ListView {
id:listView
anchors.fill: parent
spacing: Math.round(appWindow.height*0.05)
model: internalValuesList
delegate: RadioButton {
id: radioBtn
//check of value is index type and do the corresponding checked? test
checked: checktest()
style: MyRadioButtonStyle {
myRadioBtn: radioBtn
labelString: value
}
Component.onCompleted: {
//set the position of the checked RadioButton to scroll to it later onContentHeightChange
if(checked) {
var checkedRadioBtnPositionY = Math.round((radioBtn.height + listView.spacing) * index - radioBtn.height * 1.5)
if( checkedRadioBtnPositionY > 0)
scrollView.yOfCheckedRadioButton = checkedRadioBtnPositionY
else
scrollView.yOfCheckedRadioButton = 0
}
}
}
onContentHeightChanged: {
//scroll to the checked RadioButton
contentY = scrollView.yOfCheckedRadioButton
}
}
}

Answer 1

I recall problems with scroll before Qt 5.4 when I found a workaround like:
ScrollView {
anchors.fill: parent // mind how you stretch it
contentItem:
Flow {
id: flow
spacing: 10 // mind gaps
width: parent.parent.width - 20 // select proper width
// Put anything you would like to scroll in here
// Mind that Flow positions items one after another
// left to right, top to bottom
// You can also try containers other than Flow
// but whether it works or not may depend on Qt version
ExclusiveGroup { id: tabPositionGroup }
RadioButton {
text: "RB1"
checked: true
exclusiveGroup: tabPositionGroup
}
RadioButton {
text: "RB2"
exclusiveGroup: tabPositionGroup
}
}
}
Whether ScrollView needs an explicit contentItem or not is another matter and it certainly may not need it but that does not hurt if the SrollView needs to resolve what it actually scrolls.