FpsDisplay.qml Example File

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  import QtQuick 2.0

  Item {
      id: fpsDisplayControl
      property bool hidden: true
      property real fps: 0.0

      onHiddenChanged: {
          if (fpsDisplayControl.hidden)
              fpsDisplay.color = "transparent"
          else
              fpsDisplay.color = "#000000FF"
      }

      onFpsChanged: {
          fpsDisplay.updateFps()
      }

      Rectangle {
          anchors.fill: parent
          id: fpsDisplay
          color: "transparent"

          property real maxFps: 60.0
          property color maxFpsColor: "#5500FF00"
          property color minFpsColor: "#55FF0000"

          function updateFps() {
              var scale = (fps > maxFps)?1.0:(fps/maxFps)
              var r = (1 - scale) * minFpsColor.r + scale * maxFpsColor.r
              var g = (1 - scale) * minFpsColor.g + scale * maxFpsColor.g
              var b = (1 - scale) * minFpsColor.b + scale * maxFpsColor.b
              var a = (1 - scale) * minFpsColor.a + scale * maxFpsColor.a
              fpsCauge.height = scale * fpsDisplay.height
              fpsCauge.color = Qt.rgba(r, g, b, a)
          }

          Rectangle {
              id: fpsCauge
              width: parent.width
              anchors.bottom: parent.bottom
              visible: !fpsDisplayControl.hidden
          }

          Text {
              id: fpsText
              text: ""+(fps | 0)
              font.family: "Helvetica"
              font.pixelSize: 16
              font.weight: Font.Light
              color: "white"
              anchors.fill: parent
              verticalAlignment: Text.AlignVCenter
              horizontalAlignment: Text.AlignHCenter
              visible: !fpsDisplayControl.hidden
          }
      }

      MouseArea {
          anchors.fill: parent
          onClicked: {
              fpsDisplayControl.hidden = !fpsDisplayControl.hidden
          }
      }
  }