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

Qt Reference Documentation

# Adjuster.qml Example File

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

     /****************************************************************************
     **
     ** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
     ** All rights reserved.
     ** Contact: Nokia Corporation (qt-info@nokia.com)
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     ** This file is part of the QtDeclarative module of the Qt Toolkit.
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     ** $QT_BEGIN_LICENSE:BSD$
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     **
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     ** modification, are permitted provided that the following conditions are
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     **     the names of its contributors may be used to endorse or promote
     **     products derived from this software without specific prior written
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     import QtQuick 1.0
     import "adjustbars.js" as AdjustBars

     /* A barchart-like adjuster component. */
     Rectangle {
         id: adjuster

         property real max: 100
         property real value: 0
         property bool created: false

         signal valueChanged(real value)
         signal focusChangedByClick()
         signal arrowPressedWhenValueOverLimits()

         function setValue(pValue) {
             value = pValue;
             AdjustBars.fillBars(value/max*AdjustBars.maxBars);
             valueChanged(value);
         }

         height: 60; width: 300
         color: "transparent"
         Keys.onRightPressed: {
             var val = value+max/AdjustBars.maxBars;
             if (val <= max) {
                 value = val;
                 AdjustBars.fillBars(value/max*AdjustBars.maxBars);
                 valueChanged(value);
             }
             else {
                 arrowPressedWhenValueOverLimits()
             }
         }
         Keys.onLeftPressed: {
             var val = value-max/AdjustBars.maxBars;
             if (0 <= val) {
                 value = val;
                 AdjustBars.fillBars(value/max*AdjustBars.maxBars);
                 valueChanged(value);
             }
             else {
                 arrowPressedWhenValueOverLimits()
             }
         }
         Component.onCompleted: {
             AdjustBars.createBars();
             AdjustBars.fillBars(value/max*AdjustBars.maxBars);
             created = true;
         }
         Component.onDestruction: {
             AdjustBars.destroyBars;
         }
         //Dynamic objects have to be recreated when the window size changes.
         onWidthChanged: {
             if (created) {
                 AdjustBars.destroyBars();
                 AdjustBars.createBars();
                 AdjustBars.fillBars(value/max*AdjustBars.maxBars);
             }
         }
         onHeightChanged: {
             if (created) {
                 AdjustBars.destroyBars();
                 AdjustBars.createBars();
                 AdjustBars.fillBars(value/max*AdjustBars.maxBars);
             }
         }

         MouseArea {
             anchors.fill: parent
             onPositionChanged: {
                 focusChangedByClick();
                 var val = mouse.x/parent.width*parent.max;
                 if (0 < val && val < max) {
                     parent.value = val;
                     AdjustBars.fillBars(parent.value/parent.max*AdjustBars.maxBars);
                     valueChanged(parent.value);
                 }
             }
             onClicked: {
                 focusChangedByClick();
                 var val = mouse.x/parent.width*parent.max;
                 if (0 < val && val < max) {
                     parent.value = val;
                     AdjustBars.fillBars(parent.value/parent.max*AdjustBars.maxBars);
                     valueChanged(parent.value);
                 }
             }
         }
     }