- Qt 5.5
- Qt Quick
- Qt Quick Examples - Canvas
- bezierCurve.qml Example File
- Qt 5.5.1 Reference Documentation

# bezierCurve.qml Example File

canvas/bezierCurve/bezierCurve.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
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    **     contributors may be used to endorse or promote products derived
    **     from this software without specific prior written permission.
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    import QtQuick 2.0
    import "../contents"
    import "../../shared"

    Item {
        id:container
        width: 320
        height: 480

        Column {
            spacing:5
            anchors.fill: parent
            anchors.topMargin: 12

            Text {
                font.pointSize: 24
                font.bold: true
                text: "Bezier Curve"
                anchors.horizontalCenter: parent.horizontalCenter
                color: "#777"
            }

            Canvas {
                id:canvas
                width:320
                height:280
                property color strokeStyle:  Qt.darker(fillStyle, 1.4)
                property color fillStyle: "#b40000" // red
                property int lineWidth: lineWidthCtrl.value
                property bool fill: true
                property bool stroke: true
                property real alpha: 1.0
                property real scale : scaleCtrl.value
                property real rotate : rotateCtrl.value
                antialiasing: true

                onLineWidthChanged:requestPaint();
                onFillChanged:requestPaint();
                onStrokeChanged:requestPaint();
                onScaleChanged:requestPaint();
                onRotateChanged:requestPaint();

                onPaint: {
                    var ctx = canvas.getContext('2d');
                    var originX = 85
                    var originY = 75
                    ctx.save();
                    ctx.clearRect(0, 0, canvas.width, canvas.height);
                    ctx.translate(originX, originX);
                    ctx.globalAlpha = canvas.alpha;
                    ctx.strokeStyle = canvas.strokeStyle;
                    ctx.fillStyle = canvas.fillStyle;
                    ctx.lineWidth = canvas.lineWidth;

                    ctx.translate(originX, originY)
                    ctx.scale(canvas.scale, canvas.scale);
                    ctx.rotate(canvas.rotate);
                    ctx.translate(-originX, -originY)

                    ctx.beginPath();
                    ctx.moveTo(75,40);
                    ctx.bezierCurveTo(75,37,70,25,50,25);
                    ctx.bezierCurveTo(20,25,20,62.5,20,62.5);
                    ctx.bezierCurveTo(20,80,40,102,75,120);
                    ctx.bezierCurveTo(110,102,130,80,130,62.5);
                    ctx.bezierCurveTo(130,62.5,130,25,100,25);
                    ctx.bezierCurveTo(85,25,75,37,75,40);
                    ctx.closePath();
                    if (canvas.fill)
                        ctx.fill();
                    if (canvas.stroke)
                        ctx.stroke();
                    ctx.restore();
                }
            }
        }
        Column {
            id: controls
            anchors.bottom: parent.bottom
            anchors.bottomMargin: 12
            Slider {id: lineWidthCtrl; min: 1; max: 10; init: 2; name: "Outline"}
            Slider {id: scaleCtrl; min: 0.1; max: 10; init: 1; name: "Scale"}
            Slider {id: rotateCtrl; min: 0; max: Math.PI*2; init: 0; name: "Rotate"}
        }
    }