Qt 4.8: Meter.qml Example File (demos/mobile/guitartuner/src/mycomponents/Meter.qml)

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# Meter.qml Example File

demos/mobile/guitartuner/src/mycomponents/Meter.qml

     /****************************************************************************
     **
     ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
     ** Contact: http://www.qt-project.org/legal
     **
     ** This file is part of the QtDeclarative module 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 Digia Plc and its Subsidiary(-ies) 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,
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     ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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     ****************************************************************************/

     import QtQuick 1.0

     /* A meter component. */
     Rectangle {
         id: meter

         property real value: 0
         property real minValue: -1
         property real maxValue: 1
         property alias imageSize: meterImage.sourceSize

         function valueChanged(pValue) {
             value = pValue;
             scaleValueToAngle();
         }
         function scaleValueToAngle() {
             pointer.angle = (((value-minValue)/(maxValue-minValue))*
                               (pointer.angleMax-pointer.angleMin))+
                                pointer.angleMin;
         }

         color: "transparent"

         Image {
             id: meterImage

             smooth: true
             source: "./images/meterBG.png"
             anchors.fill: parent
         }

         Image {
             id:pointerShadow

             x: pointer.x - 2
             y: pointer.y - 2
             height: pointer.height
             smooth: true
             source: "./images/pointerShadow.png"
             transform: Rotation {
                 origin.x: 2
                 origin.y: height
                 angle: -pointer.angle
             }
         }

         Image {
             id: pointer

             property real angle: 0
             property real angleMax: -45
             property real angleMin: 45

             height: parent.height*0.92
             transformOrigin: "Bottom"
             rotation: -angle
             smooth: true
             source: "./images/pointer.png"
             anchors {
                 bottomMargin: 2
                 bottom: parent.bottom;
                 horizontalCenter: parent.horizontalCenter
             }

             Behavior on angle {
                 SpringAnimation {
                     spring: 1.4
                     damping: 0.15
                 }
             }
         }
     }