how to scale to the items of scrollview for qml

[jimfar]

ApplicationWindow {
id: mainWindow
// title: qsTr("AutoResize")
width: 800
height: 600
visible: true
ScrollView {
id: control

    width:  parent.width
    height: parent.height
    focus: true
    MouseArea{
        id: dragRegion
        drag.target: control
        drag.axis: "XAxis"
        drag.minimumX: -9999999999999
        drag.minimumY: -9999999999999
        drag.maximumX: 9999999999999 //parentw - inputoutput.width
        drag.maximumY: 9999999999999// parenth - inputoutput.height
        anchors.fill: parent
        property point origin:Qt.point(0,0)
        property point clickPos : "0,0"
        property point lastPos : "0,0"
         onPressed: {
           drag.axis = Drag.XAndYAxis
           origin = Qt.point(mouse.x, mouse.y)

          }
          onPositionChanged: {
               switch (drag.axis) {
               case Drag.XAndYAxis:
                   var curpos=Qt.point(mouse.x, mouse.y)
                   var deltapos=curpos-lastPos ;
                    control.contentItem.x  += deltapos.y
                    control.contentItem.y+= deltapos.x
                  
                   break
               }

           }

onWheel : {

                            if (wheel.modifiers & Qt.ControlModifier) {
                                  console.log("inputoutput"  )
                                         if (wheel.angleDelta.y > 0)
                                             control.contentItem.scale += 0.2;
                                         else if (control.contentItem.scale - 0.2 > 0.2)
                                             control.contentItem.scale -= 0.2;
                                         else
                                           {
                                              if(control.contentItem.scale>0.05)
                                                control.contentItem.scale -= 0.01;
                                           }
                                     }

                     }
    }

function loadInputOutput(i) {

                   var component = Qt.createComponent("Button.qml");
                   if (component.status == Component.Ready) {
                       var InputOutput = component.createObject(control);
                       InputOutput.parentw=parent.width
                       InputOutput.parenth=parent.height
                       InputOutput.index=i;
                       InputOutput.x=i*(InputOutput.width+20);
                       return (InputOutput.width+20);
                   }
               }


           Component.onCompleted:
            {
               var i=0;
                 var totallength=0;
               totallength=0;
               for(  i=0;i<2000;i++)
                     totallength+= loadInputOutput(i);


            }

}

i wanna to scale the items within Button.qml but not work

[jimfar]

anyone has some advice