quadraticCurveTo.qml Example File | Qt Quick 5.12.8

- Qt 5.12
- Qt Quick
- Qt Quick Examples - Canvas
- quadraticCurveTo.qml Example File
- Qt 5.12.8 Reference Documentation

# quadraticCurveTo.qml Example File

canvas/quadraticCurveTo/quadraticCurveTo.qml

     /****************************************************************************
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     ** This file is part of the examples of the Qt Toolkit.
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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: "Quadratic Curve"
                 anchors.horizontalCenter: parent.horizontalCenter
                 color: "#777"
             }

             Canvas {
                 id: canvas
                 width: 320
                 height: 280

                 property color strokeStyle:  Qt.darker(fillStyle, 1.3)
                 property color fillStyle: "#14aaff" // blue
                 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 = 75
                     var originY = 75

                     ctx.save();
                     ctx.clearRect(0, 0, canvas.width, canvas.height);
                     ctx.translate(originX, originX);
                     ctx.strokeStyle = canvas.strokeStyle;
                     ctx.fillStyle = canvas.fillStyle;
                     ctx.lineWidth = canvas.lineWidth;

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

                     // ![0]
                     ctx.beginPath();
                     ctx.moveTo(75,25);
                     ctx.quadraticCurveTo(25,25,25,62.5);
                     ctx.quadraticCurveTo(25,100,50,100);
                     ctx.quadraticCurveTo(50,120,30,125);
                     ctx.quadraticCurveTo(60,120,65,100);
                     ctx.quadraticCurveTo(125,100,125,62.5);
                     ctx.quadraticCurveTo(125,25,75,25);
                     ctx.closePath();
                     // ![0]

                     if (canvas.fill)
                         ctx.fill();
                     if (canvas.stroke)
                         ctx.stroke();

                     // ![1]
                     ctx.fillStyle = "white";
                     ctx.font = "bold 17px sans-serif";
                     ctx.fillText("Qt Quick", 40, 70);
                     // ![1]
                     ctx.restore();
                 }
             }
         }
         Column {
             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"}
         }
     }