Recull Components Delphi

BlinkingLabel

Descendent del TLabel que canvia de color intermitentment

unit BlinkingLabel;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, ExtCtrls;

type
  TBlinkingLabel = class(TCustomLabel)
  private
    { Private declarations }
    Timer: TTimer;
    FBlinkingEnabled: boolean;
    FBlinkingInterval: integer;
    FBlinkingFirstColor: TColor;
    FBlinkingSecondColor: TColor;
    procedure RefreshLabel;
  protected
    { Protected declarations }
    procedure SetBlinkingEnabled(ABlinkingEnabled: boolean);
    procedure SetBlinkingInterval(ABlinkingInterval: integer);
    procedure OnTimer(Sender: TObject); virtual;
  public
    { Public declarations }
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
  published
    { Published declarations }
    property BlinkingEnabled: boolean read FBlinkingEnabled write SetBlinkingEnabled default True;
    property BlinkingInterval: integer read FBlinkingInterval write SetBlinkingInterval default 500;
    property BlinkingFirstColor: TColor read FBlinkingFirstColor write FBlinkingFirstColor;
    property BlinkingSecondColor: TColor read FBlinkingSecondColor write FBlinkingSecondColor;
    property Align;
    property Alignment;
    property Anchors;
    property AutoSize;
    property BiDiMode;
    property Caption;
    property Color;
    property Constraints;
    property DragCursor;
    property DragKind;
    property DragMode;
    property Enabled;
    property FocusControl;
    property Font;
    property ParentBiDiMode;
    property ParentColor;
    property ParentFont;
    property ParentShowHint;
    property PopupMenu;
    property ShowAccelChar;
    property ShowHint;
    property Transparent;
    property Layout;
    property WordWrap;
    property Visible;
    property OnClick;
    property OnDblClick;
    property OnDragOver;
    property OnDragDrop;
    property OnEndDock;
    property OnEndDrag;
    property OnMouseDown;
    property OnMouseUp;
    property OnStartDock;
    property OnStartDrag;
  end;

procedure Register;

implementation

constructor TBlinkingLabel.Create(AOwner: TComponent);
begin
  FBlinkingEnabled := False;
  FBlinkingInterval := 500;
  FBlinkingFirstColor := clBlue;
  FBlinkingSecondColor := clRed;
  Timer := TTimer.Create(Self);
  Timer.Enabled := FBlinkingEnabled;
  Timer.Interval := FBlinkingInterval;
  Timer.OnTimer := OnTimer;
  inherited;
  RefreshLabel;
end;

destructor TBlinkingLabel.Destroy;
begin
  Timer.Free;
  inherited;
end;

procedure TBlinkingLabel.SetBlinkingEnabled(ABlinkingEnabled: boolean);
begin
  FBlinkingEnabled := ABlinkingEnabled;
  Timer.Enabled := ABlinkingEnabled;
end;

procedure TBlinkingLabel.SetBlinkingInterval(ABlinkingInterval: integer);
begin
  FBlinkingInterval := ABlinkingInterval;
  Timer.Interval := ABlinkingInterval;
end;

procedure TBlinkingLabel.OnTimer(Sender: TObject);
begin
  RefreshLabel;
end;

procedure TBlinkingLabel.RefreshLabel;
begin
  if Font.Color=FBlinkingFirstColor then
    Font.Color := FBlinkingSecondColor
  else
    Font.Color := FBlinkingFirstColor;
end;

procedure Register;
begin
  RegisterComponents('Components Delphi', [TBlinkingLabel]);
end;

end.

Les propietats BlinkingFirstColor i BlinkingSecondColor indiquen els dos colors entre els quals s'alterna. La propietat BlinkingInterval indica el període de canvi en milisegons. Amb la propietat BlinkingEnabled activem o desactivem el canvi.