VRS/UserComboBox.qml

import QtQuick 2.12
import QtQuick.Controls 2.12

ComboBox {
    id: control
    property var bgColor
    font.bold: true
    font.pixelSize: 20

    delegate: ItemDelegate {
        width: control.width
        height: control.height
        contentItem: Text {
            text: modelData
            color: "black"
            font: control.font
            elide: Text.ElideRight
            verticalAlignment: Text.AlignVCenter
        }
        highlighted: control.highlightedIndex === index
    }

    indicator: Canvas {
        id: canvas
        x: control.width - width - control.rightPadding
        y: control.topPadding + (control.availableHeight - height) / 2
        width: 12
        height: 8
        contextType: "2d"
        Connections {
            target: control
            function onPressedChanged() { canvas.requestPaint(); }
        }

        onPaint: {
            context.reset();
            context.moveTo(0, 0);
            context.lineTo(width, 0);
            context.lineTo(width / 2, height);
            context.closePath();
            //context.fillStyle = control.pressed ? "red" : "green";
            context.fillStyle ="gray"
            context.fill();
        }
    }

    contentItem: Text {
        leftPadding: 5
        rightPadding: control.indicator.width + control.spacing

        text: control.displayText
        font: control.font
        color: "black"
        //color: control.pressed ? "#17a81a" : "#21be2b"
        verticalAlignment: Text.AlignVCenter
        elide: Text.ElideRight
    }

    background: Rectangle {
        implicitWidth: control.width-2
        implicitHeight: control.height-2
        color: bgColor
        //border.color: control.pressed ? "#17a81a" : "#21be2b"
        //border.width: control.visualFocus ? 2 : 0
        radius: 3
    }

    popup: Popup {
        y: control.height - 1
        width: control.width
        implicitHeight: contentItem.implicitHeight
        padding: 1


        contentItem: ListView {
            clip: true
            implicitHeight: contentHeight+3
            model: control.popup.visible ? control.delegateModel : null
            currentIndex: control.highlightedIndex

            ScrollIndicator.vertical: ScrollIndicator { }
        }

        background: Rectangle {
            border.color: "gray"//"#21be2b"
            radius: 2
            opacity:1.0
        }
    }
}