DashboardGaugeStyle.qml Example File

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  import QtQuick 2.2
  import QtQuick.Controls.Styles 1.4

  CircularGaugeStyle {
      tickmarkInset: toPixels(0.04)
      minorTickmarkInset: tickmarkInset
      labelStepSize: 20
      labelInset: toPixels(0.23)

      property real xCenter: outerRadius
      property real yCenter: outerRadius
      property real needleLength: outerRadius - tickmarkInset * 1.25
      property real needleTipWidth: toPixels(0.02)
      property real needleBaseWidth: toPixels(0.06)
      property bool halfGauge: false

      function toPixels(percentage) {
          return percentage * outerRadius;
      }

      function degToRad(degrees) {
          return degrees * (Math.PI / 180);
      }

      function radToDeg(radians) {
          return radians * (180 / Math.PI);
      }

      function paintBackground(ctx) {
          if (halfGauge) {
              ctx.beginPath();
              ctx.rect(0, 0, ctx.canvas.width, ctx.canvas.height / 2);
              ctx.clip();
          }

          ctx.beginPath();
          ctx.fillStyle = "black";
          ctx.ellipse(0, 0, ctx.canvas.width, ctx.canvas.height);
          ctx.fill();

          ctx.beginPath();
          ctx.lineWidth = tickmarkInset;
          ctx.strokeStyle = "black";
          ctx.arc(xCenter, yCenter, outerRadius - ctx.lineWidth / 2, outerRadius - ctx.lineWidth / 2, 0, Math.PI * 2);
          ctx.stroke();

          ctx.beginPath();
          ctx.lineWidth = tickmarkInset / 2;
          ctx.strokeStyle = "#222";
          ctx.arc(xCenter, yCenter, outerRadius - ctx.lineWidth / 2, outerRadius - ctx.lineWidth / 2, 0, Math.PI * 2);
          ctx.stroke();

          ctx.beginPath();
          var gradient = ctx.createRadialGradient(xCenter, yCenter, 0, xCenter, yCenter, outerRadius * 1.5);
          gradient.addColorStop(0, Qt.rgba(1, 1, 1, 0));
          gradient.addColorStop(0.7, Qt.rgba(1, 1, 1, 0.13));
          gradient.addColorStop(1, Qt.rgba(1, 1, 1, 1));
          ctx.fillStyle = gradient;
          ctx.arc(xCenter, yCenter, outerRadius - tickmarkInset, outerRadius - tickmarkInset, 0, Math.PI * 2);
          ctx.fill();
      }

      background: Canvas {
          onPaint: {
              var ctx = getContext("2d");
              ctx.reset();
              paintBackground(ctx);
          }

          Text {
              id: speedText
              font.pixelSize: toPixels(0.3)
              text: kphInt
              color: "white"
              horizontalAlignment: Text.AlignRight
              anchors.horizontalCenter: parent.horizontalCenter
              anchors.top: parent.verticalCenter
              anchors.topMargin: toPixels(0.1)

              readonly property int kphInt: control.value
          }
          Text {
              text: "km/h"
              color: "white"
              font.pixelSize: toPixels(0.09)
              anchors.top: speedText.bottom
              anchors.horizontalCenter: parent.horizontalCenter
          }
      }

      needle: Canvas {
          implicitWidth: needleBaseWidth
          implicitHeight: needleLength

          property real xCenter: width / 2
          property real yCenter: height / 2

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

              ctx.beginPath();
              ctx.moveTo(xCenter, height);
              ctx.lineTo(xCenter - needleBaseWidth / 2, height - needleBaseWidth / 2);
              ctx.lineTo(xCenter - needleTipWidth / 2, 0);
              ctx.lineTo(xCenter, yCenter - needleLength);
              ctx.lineTo(xCenter, 0);
              ctx.closePath();
              ctx.fillStyle = Qt.rgba(0.66, 0, 0, 0.66);
              ctx.fill();

              ctx.beginPath();
              ctx.moveTo(xCenter, height)
              ctx.lineTo(width, height - needleBaseWidth / 2);
              ctx.lineTo(xCenter + needleTipWidth / 2, 0);
              ctx.lineTo(xCenter, 0);
              ctx.closePath();
              ctx.fillStyle = Qt.lighter(Qt.rgba(0.66, 0, 0, 0.66));
              ctx.fill();
          }
      }

      foreground: null
  }