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

Qt Reference Documentation

# Meter.qml Example File

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

     /****************************************************************************
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     ** This file is part of the QtDeclarative module of the Qt Toolkit.
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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
                 }
             }
         }
     }