- Qt 5.5
- Qt Quick
- Qt Quick Demo - RSS News
- ScrollBar.qml Example File
- Qt 5.5.1 Reference Documentation

# ScrollBar.qml Example File

demos/rssnews/content/ScrollBar.qml

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the examples of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:BSD$
    ** You may use this file under the terms of the BSD license as follows:
    **
    ** "Redistribution and use in source and binary forms, with or without
    ** modification, are permitted provided that the following conditions are
    ** met:
    **   * Redistributions of source code must retain the above copyright
    **     notice, this list of conditions and the following disclaimer.
    **   * Redistributions in binary form must reproduce the above copyright
    **     notice, this list of conditions and the following disclaimer in
    **     the documentation and/or other materials provided with the
    **     distribution.
    **   * Neither the name of The Qt Company Ltd nor the names of its
    **     contributors may be used to endorse or promote products derived
    **     from this software without specific prior written permission.
    **
    **
    ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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    ****************************************************************************/

    import QtQuick 2.2

    Item {
        id: container

        property variant scrollArea
        property int 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()
            y: container.orientation == Qt.Vertical ? position() : 2
            width: container.orientation == Qt.Vertical ? container.width - 4 : size()
            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 }
        }
    }