- Qt 5.5
- Qt Quick Extras
- Qt Quick Extras - Dashboard
- TurnIndicator.qml Example File
- Qt 5.5.1 Reference Documentation

# TurnIndicator.qml Example File

dashboard/qml/TurnIndicator.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
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    import QtQuick 2.2

    Item {
        // This enum is actually keyboard-related, but it serves its purpose
        // as an indication of direction for us.
        property int direction: Qt.LeftArrow
        property bool on: false

        property bool flashing: false

        scale: direction === Qt.LeftArrow ? 1 : -1

        Timer {
            id: flashTimer
            interval: 500
            running: on
            repeat: true
            onTriggered: flashing = !flashing
        }

        function paintOutlinePath(ctx) {
            ctx.beginPath();
            ctx.moveTo(0, height * 0.5);
            ctx.lineTo(0.6 * width, 0);
            ctx.lineTo(0.6 * width, height * 0.28);
            ctx.lineTo(width, height * 0.28);
            ctx.lineTo(width, height * 0.72);
            ctx.lineTo(0.6 * width, height * 0.72);
            ctx.lineTo(0.6 * width, height);
            ctx.lineTo(0, height * 0.5);
        }

        Canvas {
            id: backgroundCanvas
            anchors.fill: parent

            onPaint: {
                var ctx = getContext("2d");
                ctx.reset();

                paintOutlinePath(ctx);

                ctx.lineWidth = 1;
                ctx.strokeStyle = "black";
                ctx.stroke();
            }
        }

        Canvas {
            id: foregroundCanvas
            anchors.fill: parent
            visible: on && flashing

            onPaint: {
                var ctx = getContext("2d");
                ctx.reset();

                paintOutlinePath(ctx);

                ctx.fillStyle = "green";
                ctx.fill();
            }
        }
    }