import QtQuick 2.15
import QtQuick.Window 2.15
import QtQuick.Controls 2.15

Window {
    width: 640
    height: 480
    visible: true
    title: qsTr("ListView Section")

    ListView {
        id: list_view
        anchors.fill: parent
        anchors.margins: 10
        highlightFollowsCurrentItem: true
        highlightMoveDuration: 0
        ScrollBar.vertical: ScrollBar {
            policy: ScrollBar.AlwaysOn
        }

        model: ListModel {
            id: list_model
        }

        section{
            property: "myGroup"
            criteria: ViewSection.FullString
            labelPositioning: ViewSection.InlineLabels
            delegate: Rectangle {
                width: 300
                height: 40
                color: "black"
                Text {
                    anchors.centerIn: parent
                    text: "Group " + section
                    color: "white"
                }
            }
        }

        delegate: Rectangle {
            width: 300
            height: 40
            border.color: "black"
            Text {
                anchors.centerIn: parent
                text: String("%1: %2").arg(model.index).arg(model.msg)
            }
        }
    }

    Row {
        anchors.bottom: parent.bottom
        spacing: 10
        Button {
            text: "Step 0: init model"
            onClicked: {
                for (let i = 0; i < 3; i++)
                {
                    list_model.append({myGroup:"A", msg:"hi"})
                }
                for (let i = 0; i < 20; i++)
                {
                    list_model.append({myGroup:"B", msg:"hi"})
                }
            }
        }
        Button {
            text: "Step 1: scroll to bottom && insert 0"
            onClicked: {
                list_model.insert(0, {myGroup:"A", msg:"2"})
                list_view.currentIndex = 0
                // have no effect
                // list_view.forceLayout()
            }
        }
    }
}