ScrollBar.qml Example File

  /****************************************************************************
  **
  ** Copyright (C) 2016 The Qt Company Ltd.
  ** Contact: https://www.qt.io/licensing/
  **
  ** This file is part of the Qt Virtual Keyboard module of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:GPL$
  ** 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 https://www.qt.io/terms-conditions. For further
  ** information use the contact form at https://www.qt.io/contact-us.
  **
  ** GNU General Public License Usage
  ** Alternatively, this file may be used under the terms of the GNU
  ** General Public License version 3 or (at your option) any later version
  ** approved by the KDE Free Qt Foundation. The licenses are as published by
  ** the Free Software Foundation and appearing in the file LICENSE.GPL3
  ** included in the packaging of this file. Please review the following
  ** information to ensure the GNU General Public License requirements will
  ** be met: https://www.gnu.org/licenses/gpl-3.0.html.
  **
  ** $QT_END_LICENSE$
  **
  ****************************************************************************/

  import QtQuick 2.0

  Item {
      property var scrollArea: parent

      width: 6
      opacity: scrollArea && scrollArea.movingVertically ? 1.0 : 0.0
      visible: scrollArea && scrollArea.contentHeight >= scrollArea.height
      anchors { right: parent.right; top: parent.top; bottom: parent.bottom; margins: 2 }

      Behavior on opacity { NumberAnimation { properties: "opacity"; duration: 600 } }

      function size() {
          var nh = scrollArea.visibleArea.heightRatio * height
          var ny = scrollArea.visibleArea.yPosition * height
          return ny > 3 ? Math.min(nh, Math.ceil(height - 3 - ny)) : nh + ny
      }
      Rectangle {
          x: 1
          y: scrollArea ? Math.max(2, scrollArea.visibleArea.yPosition * parent.height) : 0
          height: scrollArea ? size() : 0
          width: parent.width - 2
          color: Qt.rgba(1.0, 1.0, 1.0, 0.5)
          radius: 1
      }
  }