procedure TForm1.ImageEnView1LayerNotify(Sender: TObject; layer: Integer; event: TIELayerEvent);
var
  iDimensions: string;
begin
  if event = ielSelected then
  begin
    // user selected a layer 
    // layer is the layer index of the selected layer
    // to get layer info look at layer property
    // you can get the layers width, height, position... 
    iDimensions := IntToStr(ImageEnView1.Layers[layer].Width) + '     pixels x ' + IntToStr(ImageEnView1.Layers[layer].Height) + ' pixels';
  end;
end;

procedure TForm1.ImageEnView1MouseDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
var
  iLayer: integer;
begin
  iLayer:= ImageEnView1.FindLayerAt(X, Y, True);
  StatusBar1.Panels[6].Text := 'Current layer: ' + IntToStr(iLayer) + '.'
end;

iLayer:= ImageEnView1.FindLayerAt(X, Y, True);