5 property int xv:(knob.x-(width-knob.width)/2)*(200/(width-knob.width))
6 property int yv:(knob.y-(height-knob.height)/2)*(200/(height-knob.height))
7 property bool pressed:mouse_area.pressed
13 x:parent.width/2-width/2
14 y:parent.width/2-height/2
18 anchors.centerIn:parent
30 drag.maximumX:parent.width-knob.width
31 drag.maximumY:parent.height-knob.height
34 knob.x=parent.width/2-knob.width/2;
35 knob.y=parent.height/2-knob.height/2;