ScrollBar.qml Example File

 /****************************************************************************
 **
 ** Copyright (C) 2015 The Qt Company Ltd.
 ** Contact: http://www.qt.io/licensing/
 **
 ** This file is part of the QtDeclarative module of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:LGPL$
 ** Commercial License Usage
 ** Licensees holding valid commercial Qt licenses may use this file in
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
 ** and conditions see http://www.qt.io/terms-conditions. For further
 ** information use the contact form at http://www.qt.io/contact-us.
 **
 ** GNU Lesser General Public License Usage
 ** Alternatively, this file may be used under the terms of the GNU Lesser
 ** General Public License version 2.1 or version 3 as published by the Free
 ** Software Foundation and appearing in the file LICENSE.LGPLv21 and
 ** LICENSE.LGPLv3 included in the packaging of this file. Please review the
 ** following information to ensure the GNU Lesser General Public License
 ** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
 ** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
 **
 ** As a special exception, The Qt Company gives you certain additional
 ** rights. These rights are described in The Qt Company LGPL Exception
 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
 **
 ** GNU General Public License Usage
 ** Alternatively, this file may be used under the terms of the GNU
 ** General Public License version 3.0 as published by the Free Software
 ** Foundation and appearing in the file LICENSE.GPL included in the
 ** packaging of this file.  Please review the following information to
 ** ensure the GNU General Public License version 3.0 requirements will be
 ** met: http://www.gnu.org/copyleft/gpl.html.
 **
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 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: 0.5 }

     BorderImage {
         source: "pics/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 }
     }
 }