Sip from the Firehose

RAD Studio XE3 includes new classes for identifying, managing and using any sensors that are available on your target Windows and Mac computers. In this blog post I show you how to list all of the sensors that are available on a computer (you can do this using Delphi and C++Builder). Delphi XE3 and C++Builder XE3 include the new the new System.Sensors unit.

From the unit, the categories of sensors (TSensorCategory) are:

• Location
• Environmental
• Motion
• Orientation
• Mechanical
• Electrical
• Biometric
• Light
• Scanner

For each sensor category the unit defines (currently) the following possible sensor types:

  TLocationSensorType = (GPS, Static, Lookup, Triangulation, Broadcast, DeadReckoning, Other);
  TEnvironmentalSensorType = (Temperature, AtmosphericPressure, Humidity, WindSpeed, WindDirection);
  TMotionSensorType = (Accelerometer1D, Accelerometer2D, Accelerometer3D, MotionDetector, Gyrometer1D, Gyrometer2D, Gyrometer3D, Speedometer);
  TOrientationSensorType = (Compass1D, Compass2D, Compass3D, Inclinometer1D, Inclinometer2D, Inclinometer3D, Distance1D, Distance2D, Distance3D);
  TElectricalSensorType = (Voltage, Current, Capacitance, Resistance, Inductance, ElectricalPower, Potentiometer);
  TMechanicalSensorType = (BooleanSwitch, BooleanSwitchArray, MultiValueSwitch, Force, Scale, Pressure, Strain);
  TBiometricSensorType = (HumanPresence, HumanProximity, Touch);
  TLightSensorType = (AmbientLight);
  TScannerSensorType = (RFID, Barcode);

The following code will get the number of sensors on a computer (you first have to activate the sensors) and displays the names of the sensors and their category:

interface
uses
  System.SysUtils, System.Types, System.UITypes, System.Rtti, System.Classes,
  System.Variants, FMX.Types, FMX.Controls, FMX.Forms, FMX.Dialogs, FMX.Layouts,
  FMX.Memo, FMX.Media, System.Sensors;

type
  TForm3 = class(TForm)
    Button2: TButton;
    Label2: TLabel;
    Memo2: TMemo;
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
    NumberOfSensors : integer;
  public
    { Public declarations }
  end;

var
  Form3: TForm3;

implementation

{$R *.fmx}
uses System.TypInfo;

procedure TForm3.Button2Click(Sender: TObject);
var
  i : integer;
begin
  // get list of found sensors - if any
  TSensorManager.Current.Active := true;
  NumberofSensors := TSensorManager.Current.Count;
  Label2.Text := 'Sensors: '+IntToStr(NumberOfSensors);
  Memo2.Lines.Clear;
  for i := 0 to NumberOfSensors-1 do begin
    Memo2.Lines.Add(
      IntToStr(i)
      + ': '
      + TSensorManager.Current.Sensors[i].Name
      + '", Category: '
      + GetEnumName(System.TypeInfo(TSensorCategory),
            Ord(TSensorManager.Current.Sensors[i].Category))
    );
  end;
  TSensorManager.Current.Active := false;
end;

On my Samsung Slate 7 computer running Windows 8 Professional, the Delphi XE3 code will find several hardware and software based sensors including the following:

FireMonkey 2 also includes two new non-visual components, TLocationSensor and TMotionSensor, that you can drag and drop onto your forms. With these components and sensor-based code you can build FireMonkey 2 applications that take advantage of hardware in currently available notebooks/slates and have your applications ready for future FireMonkey mobile device support  (see the RAD Studio Mobile Roadmap at http://edn.embarcadero.com/article/42544).

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