unit CsPanels;

interface

uses
  SysUtils, Classes, Controls, ExtCtrls, Graphics, Forms, Types;

type
  TCsBorderPosition = (cbpTop, cbpBottom, cbpLeft, cbpRight);

  { Forward-Deklarationen }
  TCsCustomPanel = class;

  TCsPanel = class;

  TCsBorderStyle = class;

  TCsCustomPanel = class(TCustomPanel)
  private
    FBorderLeft: TCsBorderStyle;
    FBorderRight: TCsBorderStyle;
    FBorderTop: TCsBorderStyle;
    FBorderBottom: TCsBorderStyle;
  protected
    procedure SetBorderLeft(Value: TCsBorderStyle);
    procedure SetBorderRight(Value: TCsBorderStyle);
    procedure SetBorderBottom(Value: TCsBorderStyle);
    procedure SetBorderTop(Value: TCsBorderStyle);

    procedure DrawBorder(Style: TCsBorderStyle; Position: TCsBorderPosition);
    function GetBorderStartPosition(Position: TCsBorderPosition): TPoint;
    function GetBorderEndPosition(Position: TCsBorderPosition): TPoint;

    property BorderLeft: TCsBorderStyle read FBorderLeft write SetBorderLeft;
    property BorderRight: TCsBorderStyle read FBorderRight write SetBorderRight;
    property BorderTop: TCsBorderStyle read FBorderTop write SetBorderTop;
    property BorderBottom: TCsBorderStyle read FBorderBottom write SetBorderBottom;
  public
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
    procedure Loaded; override;
    procedure Paint; override;
  published
    { Published-Deklarationen }
  end;

  TCsPanel = class(TCsCustomPanel)
  published
    property BorderLeft;
    property BorderRight;
    property BorderTop;
    property BorderBottom;
    property Color;
    property Align;
    property ParentBackground;
    property Font;
  end;

  TCsBorderStyle = class(TPersistent)
  private
    FColor: TColor;
    FWidth: Byte;
    FVisible: Boolean;
  public
    procedure Assign(Source: TPersistent); override;
    procedure AssignTo(Dest: TPersistent); override;
  published
    property Color: TColor read FColor write FColor;
    property Width: Byte read FWidth write FWidth;
    property Visible: Boolean read FVisible write FVisible;
  end;

implementation

{ TCsCustomPanel ------------------------------------------------------------- }
constructor TCsCustomPanel.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);

  BevelInner := bvNone;
  BevelOuter := bvNone;
  BorderStyle := bsNone;
  ShowCaption := False;

  FBorderLeft := TCsBorderStyle.Create;
  FBorderRight := TCsBorderStyle.Create;
  FBorderTop := TCsBorderStyle.Create;
  FBorderBottom := TCsBorderStyle.Create;

  Repaint;
end;

destructor TCsCustomPanel.Destroy;
begin
  FreeAndNil(FBorderLeft);
  FreeAndNil(FBorderRight);
  FreeAndNil(FBorderTop);
  FreeAndNil(FBorderBottom);

  inherited Destroy;
end;

procedure TCsCustomPanel.SetBorderLeft(Value: TCsBorderStyle);
begin
  FBorderLeft.Assign(Value);
  Invalidate;
end;

procedure TCsCustomPanel.SetBorderRight(Value: TCsBorderStyle);
begin
  FBorderRight.Assign(Value);
  Invalidate;
end;

procedure TCsCustomPanel.SetBorderBottom(Value: TCsBorderStyle);
begin
  FBorderBottom.Assign(Value);
  Invalidate;
end;

procedure TCsCustomPanel.SetBorderTop(Value: TCsBorderStyle);
begin
  FBorderTop.Assign(Value);
  Invalidate;
end;

procedure TCsCustomPanel.Loaded;
begin
  inherited Loaded;
  //Repaint;
end;

procedure TCsCustomPanel.DrawBorder(Style: TCsBorderStyle;
  Position: TCsBorderPosition);
var
  Coord: TPoint;
begin
  if Style.Visible then
  begin
    Canvas.Pen.Color := Style.Color;
    Canvas.Pen.Width := Style.Width;
    Canvas.PenPos := GetBorderStartPosition(Position);

    Coord := GetBorderEndPosition(Position);

    Canvas.LineTo(Coord.X, Coord.Y);
  end;
end;

function TCsCustomPanel.GetBorderStartPosition(Position: TCsBorderPosition): TPoint;
begin
  case Position of
    cbpTop:
    begin
      Result.X := 0;
      Result.Y := 0;
    end;
    cbpBottom:
    begin
      Result.X := 0;
      Result.Y := Height;
    end;
    cbpLeft:
    begin
      Result.X := 0;
      Result.Y := 0;
    end;
    cbpRight:
    begin
      Result.X := Width;
      Result.Y := 0;
    end;
  end;
end;

function TCsCustomPanel.GetBorderEndPosition(Position: TCsBorderPosition): TPoint;
begin
  case Position of
    cbpTop:
    begin
      Result.X := Width;
      Result.Y := 0;
    end;
    cbpBottom:
    begin
      Result.X := Width;
      Result.Y := Height;
    end;
    cbpLeft:
    begin
      Result.X := 0;
      Result.Y := Height;
    end;
    cbpRight:
    begin
      Result.X := Width;
      Result.Y := Height;
    end;
  end;
end;

procedure TCsCustomPanel.Paint;
begin
  inherited Paint;

  DrawBorder(FBorderLeft, cbpLeft);
  DrawBorder(FBorderRight, cbpRight);
  DrawBorder(FBorderTop, cbpTop);
  DrawBorder(FBorderBottom, cbpBottom);
end;

{ TCsBorderStyle ------------------------------------------------------------- }
procedure TCsBorderStyle.Assign(Source: TPersistent);
begin
  if Source is TCsBorderStyle then
  begin
    FColor := TCsBorderStyle(Source).Color;
    FWidth := TCsBorderStyle(Source).Width;
    FVisible := TCsBorderStyle(Source).Visible;
  end
  else
    inherited Assign(Source);
end;

procedure TCsBorderStyle.AssignTo(Dest: TPersistent);
begin
  if Dest is TCsBorderStyle then
  begin
    TCsBorderStyle(Dest).Color := FColor;
    TCsBorderStyle(Dest).Width := FWidth;
    TCsBorderStyle(Dest).Visible := FVisible;
  end
  else
    inherited AssignTo(Dest);
end;

end.