Button {
    id: btn
    width: 250
    height: 100
    anchors.centerIn: parent
    text: "A button"
    style: ButtonStyle {
        background: Image {
            fillMode: Image.PreserveAspectFit
            source: "btn_state.png"
        }
      }
    }

style: ButtonStyle {
        background: Image {
            fillMode: Image.PreserveAspectFit
            source: control.pressed ? "btn_pressed.png" :
                 (control.hovered ? "btn_hovered.png" : "btn_state.png")
        }
      }