Qt Reference Documentation

# Adjuster.qml Example File

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

     /****************************************************************************
     **
     ** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
     ** All rights reserved.
     ** Contact: Nokia Corporation (qt-info@nokia.com)
     **
     ** 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 Nokia Corporation 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,
     ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
     ** $QT_END_LICENSE$
     **
     ****************************************************************************/

     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);
                 }
             }
         }
     }