TurnIndicator.qml Example File

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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();
          }
      }
  }