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{
  Von TRichEdit abgeleitete Komponente, mit der man das Caret ausblenden
  kann. Der Code stammt im Wesentlichen von toms aus dem Delphi-Forum und
  wurde um die Methode MouseUp (galagher) erweitert.

  Nov. 2010
}


unit RichEditPlus;

interface

uses
  SysUtils, Classes, Controls, StdCtrls, ComCtrls, Messages, RxRichEd;

type
  TRichEditPlus = class(TRichEdit)
  procedure MouseUp(Button: TMouseButton; Shift: TShiftState; X, Y: Integer); override;
  private
    FShowCaret: Boolean;
    procedure SetShowCaret(const Value: boolean);
    procedure WMPaint(var Message: TWMPaint); message WM_PAINT;
    procedure WMLButtonDown(var Message: TWMLButtonDown); message WM_LButtonDown;
    procedure WMKeyDown(var Message: TWMKeyDown); message WM_KeyDown;
    procedure HideTheCaret;
  protected
  public
    constructor Create(AOwner: TComponent); override;
  published
    property ShowCaret: Boolean read FShowCaret write SetShowCaret;
  end;

procedure Register;

implementation

uses Windows;

procedure Register;
begin
  RegisterComponents('Samples', [TRichEditPlus]);
end;

{ TRichEditPlus }

procedure TRichEditPlus.HideTheCaret;
begin
  if not FShowCaret then
    CreateCaret(Handle, 0, 0, 0);
end;

constructor TRichEditPlus.Create(AOwner: TComponent);
begin
  inherited;
  FShowCaret := False;
end;

procedure TRichEditPlus.MouseUp(Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
  inherited;
  if Assigned(Parent) then
    HideTheCaret;
end;

procedure TRichEditPlus.SetShowCaret(const Value: boolean);
begin
  FShowCaret := Value;
end;

procedure TRichEditPlus.WMKeyDown(var Message: TWMKeyDown);
begin
  inherited;
  if Assigned(Parent) then
    HideTheCaret;
end;

procedure TRichEditPlus.WMLButtonDown(var Message: TWMLButtonDown);
begin
  inherited;
  if Assigned(Parent) then
    HideTheCaret;
end;

procedure TRichEditPlus.WMPaint(var Message: TWMPaint);
begin
  inherited;
  if Assigned(Parent) then
    HideTheCaret;
end;

end.