ScrollBar.qml Example File

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 import QtQuick 1.0

 Item {
     id: container

     property variant scrollArea
     property variant orientation: Qt.Vertical

     opacity: 0

     function position()
     {
         var ny = 0;
         if (container.orientation == Qt.Vertical)
             ny = scrollArea.visibleArea.yPosition * container.height;
         else
             ny = scrollArea.visibleArea.xPosition * container.width;
         if (ny > 2) return ny; else return 2;
     }

     function size()
     {
         var nh, ny;

         if (container.orientation == Qt.Vertical)
             nh = scrollArea.visibleArea.heightRatio * container.height;
         else
             nh = scrollArea.visibleArea.widthRatio * container.width;

         if (container.orientation == Qt.Vertical)
             ny = scrollArea.visibleArea.yPosition * container.height;
         else
             ny = scrollArea.visibleArea.xPosition * container.width;

         if (ny > 3) {
             var t;
             if (container.orientation == Qt.Vertical)
                 t = Math.ceil(container.height - 3 - ny);
             else
                 t = Math.ceil(container.width - 3 - ny);
             if (nh > t) return t; else return nh;
         } else return nh + ny;
     }

     Rectangle { anchors.fill: parent; color: "Black"; opacity: 0.3 }

     BorderImage {
         source: "images/scrollbar.png"
         border { left: 1; right: 1; top: 1; bottom: 1 }
         x: container.orientation == Qt.Vertical ? 2 : position()
         width: container.orientation == Qt.Vertical ? container.width - 4 : size()
         y: container.orientation == Qt.Vertical ? position() : 2
         height: container.orientation == Qt.Vertical ? size() : container.height - 4
     }

     states: State {
         name: "visible"
         when: container.orientation == Qt.Vertical ? scrollArea.movingVertically : scrollArea.movingHorizontally
         PropertyChanges { target: container; opacity: 1.0 }
     }

     transitions: Transition {
         from: "visible"; to: ""
         NumberAnimation { properties: "opacity"; duration: 600 }
     }
 }